ANNUAL REPORT 2011
MESA+ Annual Report 2011
General
Highlights
Preface.................................................................................................. 5
BES
About MESA+, in a nutshell.................................................................... 6 MESA+ Strategic Research Orientations........................................... 8 Commercialization.................................................................................. 16
The Dutch Nano-landscape................................................................. 18 National NanoLab facilities................................................................. 20 International Networks......................................................................... 22
Education.................................................................................................... 24 Awards, honours and appointments................................................ 26
BIOS BNT CBP CMS COPS CPM ICE IM IMS IOMS LPNO MCS MnF MSM MST MTP MaCS
Biomolecular Electronic Structure..................................32 BIOS Lab-on-a-Chip............................................................... 33
BioMolecular Nanotechnology.......................................... 34
About MESA+
Complex Photonic Systems................................................. 37
MESA+ Governance Structure...................................................... 76
Computational Materials Science..................................... 36
Catalytic Processes and Materials.................................. 38 Interfaces and Correlated Electron systems............... 39
Inorganic Membranes.......................................................... 40 Inorganic Materials Science................................................ 41
Integrated Optical MicroSystems..................................... 42 Laser Physics and Nonlinear Optics.............................. 43 Mesoscale Chemical Systems........................................... 44
Molecular nanoFabrication................................................. 45
Multi Scale Mechanics......................................................... 46
Membrane Science and Technology............................... 47
Materials Science and Technology of Polymers............. 48
Mathematics of Computational Science............................. 49
NE NanoElectronics..................................................................... 51
NanoElectronic Materials.................................................... 52
NI NanoIonics................................................................................ 53 NLCA OS PCF PCS PIN PNS PoF PGMF QTM SC SFI ST PS TST
MESA+ Scientific Publications 2011............................................ 70
Computational BioPhysics................................................... 35
NBP Nanobiophysics...................................................................... 50 NEM
Publications
Nanofluidics for Lab on a Chip Applications................... 54
Optical Sciences..................................................................... 55
Physics of Complex Fluids.................................................. 56 Photocatalytic Synthesis..................................................... 57
Physics of Interfaces and Nanomaterials..................... 58
Programmable NanoSystems............................................ 59 Physics of Fluids.................................................................... 60
Physics of Granular Matter and Interstitial Fluids..... 61
Quantum Transport in Matter............................................ 62
Semiconductor Components.............................................. 63 Soft Matter, Fluidics and Interfaces................................ 64 Science, Technology and Policy Studies....................... 65
Transducer Science and Technology............................. 66
Contact details.................................................................................. 76
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[PREFACE]
2011 - The Year Between 2011 was a year between two major Nanotechnology programmes: NanoNed had come to an end and NanoNextNL had just started. With the launch of NanoNextNL a new period was heralded in, in which innovation research grants became available to the Dutch nanotechnology community. The main difference between these two national programmes is the focus on valorisation and collaboration with industry. This is completely in line with another topic that marked 2011: a new Dutch Government programme on innovation called 'topsectors', i.e. strong industrial areas reinforced by the joint research and development of Dutch industry, research institutes and universities, and science foundations. MESA+ was fervently involved in both these initiatives. First, through the roll out of NanoNextNL with significant contributions from several MESA+ research groups. Second, by actively participating in the updated research agenda of the national nanotechnology roadmap. Over the coming years it will become clear whether and how this new strategy of the Dutch Government to stimulate innovation through active interaction between industry and institutes such as MESA+ will prove to be a sound alternative to the successful programmes NanoNed and NanoNextNL. 2011 was also the first year of actually running the new NanoLab at MESA+. Obviously, starting up such a complex new lab is no trivial matter; in fact you could say it is quite a challenge. But apart from a few minor setbacks, when the time came the inauguration went very smoothly, thanks to the users and technicians. The number of visitors who are motivated to learn more about nanotechnology and wish to see the new NanoLab is significant and still on the increase. Furthermore, the organisation of this Dutch national facility, NanoLabNL, has been formalised and is certainly prepared for the future. 2011 was also a year in which MESA+ realised a significant increase in the number of research groups. A rearrangement of research at the University of Twente resulted in an expansion of MESA+, which increased to 34 research chairs and over 525 researchers, including more than 300 PhD-students. 2011, a year between a very successfully period of developing into a mature institute and a period marked by a challenging future with new opportunities.
Ir. Miriam Luizink, Technical Commercial Director,
Prof. dr. ing. Dave H.A. Blank, Scientific Director,
MESA+ Institute for Nanotechnology
MESA+ Institute for Nanotechnology
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[RESEARCH] “MESA+ Institute for
Nanotechnology is one of the largest nanotechnology research institutes in the world”
About MESA+, in a nut shell MESA+ Institute for Nanotechnology is one of the largest nanotechnology research institutes in the world, delivering competitive and successful high quality research. MESA+ is part of the University of Twente, and cooperates closely with various research groups within the university. The institute employs 525 people of whom 300 are PhD candidates or postdocs. With its NanoLab facilities the institute holds 1250 m2 of cleanroom space and state of the art research equipment. MESA+ has an integral turnover of approximately 50 million euros per year of which 60% is acquired in competition from external sources (National Science Foundation, European Union, industry, etc.). MESA+ supports and facilitates researchers and actively stimulates cooperation. MESA+ combines the disciplines of physics, electrical engineering, chemistry and mathematics. Currently 34 research groups participate in MESA+. MESA+ introduced Strategic Research Orientations, headed by a scientific researcher, that bridge the research topics of a number of research groups working in common interest fields. The SROs’ research topics are an addition to the research topics of the chairs. Their task is to develop these interdisciplinary research areas which could result in new independent chairs. Internationally attractive research is achieved through this multidisciplinary approach. MESA+ uses a unique structure, which unites scientific disciplines, and builds fruitful international cooperation to excel in science and education. MESA+ has been the breeding ground for more than 45 MESA+ high-tech start-ups to date. A targeted program for cooperation with small and medium-sized enterprises has been specially created for start-ups. MESA+ offers the use of its extensive NanoLab facilities and cleanroom space under hospitable conditions. Start-ups and MESA+ work together intensively to promote the transfer of knowledge. MESA+ has created a perfect habitat for start-ups in the micro and nano-industry to establish and to mature. MESA+ is a Research School, designated by the Royal Dutch Academy of Science. All MESA+ PhD’s are member of the MESA+ School for Nanotechnology, part of the Twente Graduate School.
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[RESEARCH] Mission and strategy MESA+ conducts research in the strongly multidisciplinary field of nanotechnology and nanoscience. The mission of MESA+ is: n to excel in its research field; n to explore (new) research themes; n to educate researchers and engineers in its field; n to commercialize and valorize research results; n to initiate and participate in fruitful (inter)national cooperation. MESA+ has defined the following key performance indicators for achieving its mission: n scientific papers in high ranked jounals like Science or Nature; n 1:1 balance between university funding and externally acquired funds; n sizable spin-off activities. MESA+ focuses on three issues to pursue its mission: n to create a top environment for international scientific talent; n to create strong multidisciplinary cohesion within the institute; n to become a national leader and international key player in nanotechnology.
Organizational structure University Board
Scientific Advisory Board
Governing Board
Scientific Director/ Technical Commercial Director Management Support
NanoLab
Advisory Board: • Strategic Research Orientations • Research Groups
MESA+ is an institute of the University of Twente and falls under the responsibility of the board of the university. The scientific advisory board assists the MESA+ management in matters concerning the research conducted at the institute and gives feedback on the scientific results of MESA+. The governing board advises the MESA+ management in organizational matters. The scientific director accepts responsibility for the institute and the scientific output. The managing director is responsible for commercialization, central laboratories, finance, communications and the internal organization. The participating research groups and SRO program directors form the MESA+ advisory board.
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[strategic RESEARCH orientations] Dr. Pepijn W.H. Pinkse:
NanoPhotonics: there's more to light than meets the eye" "Applied
Applied NanoPhotonics Optics has revolutionized fields as various as data storage and long-distance communication. Optical systems have a chance to become even more ubiquitous in other areas, like today’s smart devices, but this step requires further miniaturization. The example of electronics shows us that miniaturization will sooner or later hit physical limitations. In the case of optics this will be in the nanodomain. Working with optics on this scale requires new concepts to be developed and many questions to be answered: How can we shrink the dimensions of optical structures to or even below the wavelength limit? To what extend can we build so called ‘’meta-materials” that have specially engineered optical properties by nanostructuring? How can we miniaturize lasers, reduce their threshold and increase their yield? How can one make high-sensitivity optical detectors, e.g. for medical applications, and integrate them in low-cost labs on a chip? And on the more fundamental side: Can single emitters be controlled efficiently and embedded into nanophotonic structures? Can we use nanophotonics to study complex (molecular) systems and can we tailor light to efficiently steer their behavior? Are there opportunities to exploit the quantum character of light for new functionality? The goal of our SRO is to address these questions exploiting the expertise in MESA+ groups. Building adaptivity into nanophotonic systems will be a common paradigm in answering these questions. Adaptivity allows optimizing properties or processes with clever learning algorithms. Adaptive systems can react on external stimulus, can compensate for fluctuations and inevitable randomness in nanophotonic structures.
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[strategic RESEARCH orientations]
Applied Nanophotonics (ANP) started in October 2009 with the arrival of Pepijn Pinkse from the Max Planck Institute for Quantum Optics in Garching to become ANP program director at MESA+. ANP fosters new research and develops new expertise on a few key areas. For instance by means of ANP group meetings, colloquia and workshops, ANP stimulates cooperation between the research groups at MESA+ that have a strong optics focus including COPS, IOMS, LPNO, NBP, and OS. Program director: Dr. P.W.H. Pinkse, phone +31 53 489 2537, p.w.h.pinkse@utwente.nl, www.utwente.nl/mesaplus/anp
Data taken in an ANP collaboration with the groups COPS and OS. Visible are Near-field Scanning Optical Microscopy images of propagating light in a photonic-crystal waveguide. For specific ANP in action at the open air Museum in Ootmarsum. In 2011 we organized our second
wavelengths and locations, Anderson-localized light is observed
yearly workshop with over 70 participants from the MESA+ groups COPS, IOMS, LPNO,
(purple highlights) [S.R. Huisman et al., arXiv:1201.0624v1.]
NBP & OS.
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[strategic RESEARCH orientations] Dr. Peter M. Schön:
"What makes Nanotechnology possible? There are many important driving
forces to mention, but for sure one of the most influential was the development of scanning probe microscopies.”
Enabling Technologies The Strategic Research Orientation (SRO) Enabling Technologies has started its activity in January 2011. It is a multidisciplinary program aiming at bundling the research activities of MESA+ in a very important enabling area in nanotechnology, that is Scanning Probe Microscopy. Of key interest for the SRO are scanning probe microscopies for nanoscale electrochemistry and novel combinations with optics/ spectroscopies. Enabling Technologies aims to foster research and expertise in the field of nanoscale electrochemistry and electrical probing. For instance by means of ET group meetings and workshops, the strategic research orientation Enabling Technologies aims to stimulate cooperation between the research groups at MESA + that have a strong interest in nanoscale electrochemistry and electrical probing. With respect to novel combinations of scanning probes with optical techniques the collaboration with the SRO ANP provides an excellent base. Towards an ultra-high speed AFM with chemical sensitivity The research groups Materials Science and Technology of Polymers (MTP) and Physics of Interfaces and Nanomaterials (PIN) work in collaboration aiming to integrate STM and electrochemistry into AFM. The approach will encompass the combination of tunnel current sensing AFM and SECM (scanning electrochemical microscope). Novel spectroscopic modes are in development for these hybrid atomic force microscopies with the key objectives of chemical imaging and reactivity studies at the molecular level under various conditions, for instance in a liquid environment. As model systems molecular layers on conducting substrates will be investigated, such as self-assembled monolayers (SAMs) on gold and phthalocyanine layers comprising different central ions.
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[strategic RESEARCH orientations]
These systems shall be used for initial fundamental chemical identification and reactivity studies. Program director: Dr. Peter M. Schön, phone +31 53 489 3170, p.m.schon@utwente.nl, www.utwente.nl/mesaplus/enablingtechnologies
Poster price for Hairong Wu Hairong Wu (second person on the right side)- PhD student bridging between the groups MTP and PIN and funded from the SRO ‘Enabling Technologies’ won two times a poster price. The first time was at the Dutch Polymer Days 2012 in Lunteren, the second time at the ISPAC 25th 2012 conference. This picture is taken on the ISPAC conference. Left: Prof. dr. Pavel Kratochvíl (Institute of Macromolecular Chemistry, Czech Republic (ISPAC)). Right: Prof. dr. ir. Peter J. Schoenmakers (University of Amsterdam).
HIGHLIGHTED PUBLICATION: R. Heimbuch, H. Wu, A. Kumar, B. Poelsema, P. Schön, G.J. Vancso, H.J.W. Zandvliet, Temperature dependent transport study of a single octanethiol molecule, submitted
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[strategic RESEARCH orientations] Dr. Séverine Le Gac:
"Nanotechnology offers new approaches to medicine for early disease detection, for targeted, localized, personalized treatment, and for better understanding of molecular processes involved in diseases.”
Nanomedicine Healthcare faces new challenges in the 21st century. Populations are evolving, and life expectancy continues to increase in developed countries. Consequently, new classes of diseases which are related to ageing must be handled, and a new paradigm of “healthy ageing” has been identified by the EU as a priority. Furthermore, the healthcare system must become more competitive, and drastically reduce its overall expenses. To address these issues, novel and more appropriate approaches must be developed for disease detection and treatment. Cancer -which is the first cause of death in developed countries- is a good example where traditional medical approaches fail for: (i) early disease detection, (ii) efficient, localized and personalized treatment, and (iii) non-invasive tissue analysis for diagnosis and prognosis. A reason for this failure lies in the difference in scales between traditional medical techniques and molecular processes involved in disease development. Diseases are primarily correlated with molecular and nm-scale phenomena such as DNA mutations, dysregulation in protein functioning, while medical approaches mostly work at the scale of a whole organism or tissue. In that context, the advent of nanotechnology that deals with the manipulation of matter at the sub-100 nm scale is expected to have a tremendous impact in medicine. Using nm-size tools offers exciting new possibilities such as probing and acting at the subcellular or molecular scale; which enables to bridge the gap between traditional medicine and molecular processes. Nanomedicine is the particular sub-field of medicine where structures originating from the parent field of nanotechnology are employed to derive new approaches for diagnosis, imaging, treatment, and to get better insight into molecular events involved in disease
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[strategic RESEARCH orientations]
processes. Nanotechnology-based protocols bring new capabilities in terms of localized, specific and targeted in vivo protocols, for both imaging and treatment. For diagnosis and fundamental analysis, nm-size structures and miniaturized sensors present the required detection sensitivity to determine the molecular signature of a disease, for instance using a single cell analysis approach, which is essential for patient-specific treatment. Nanomedicine is an interdisciplinary field, requiring expertise from various disciplines such as medicine, engineering, chemistry, biophysics, and biology. The MESA+ Institute for Nanotechnology covers all these disciplines with the development of nanosensors, miniaturized point-of-care devices, inorganic and organic nanoparticles, nanostructures, new nanomaterials, and biomolecule analysis. In 2012, the SRO will first make an inventory of existing research at MESA+ related to nanomedicine. Thereafter, promising research lines will be identified on which MESA+ can profile worldwide in the field of nanomedicine, and around which the activities of the SRO nanomedicine -or nanotechnology for innovative medicine- will be organized. Program director: Dr. ir. SĂŠverine Le Gac, phone +31 53 489 2722, s.legac@utwente.nl, www.utwente.nl/mesaplus/nanomedicine
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[strategic RESEARCH orientations] Dr. ir. Mark Huijben:
Breakthroughs in energy
applications can only be accomplished by manipulation of novel materials on the nano scale.�
NanoMaterials for Energy The worldwide energy demand is continuously growing and it becomes clear that future energy supply can only be guaranteed through increased use of renewable energy sources. With energy recovery through renewable sources like sun, wind, water, tides, geothermal or biomass the global energy demand could be met many times over; currently however it is still inefficient and too expensive in many cases to take over significant parts of the energy supply. Innovation and increases in efficiency in conjunction with a general reduction of energy consumption are urgently needed. Nanotechnology exhibits the unique potential for decisive technological breakthroughs in the energy sector, thus making substantial contributions to sustainable energy supply. The goal of the Strategic Research Orientation (SRO) NanoMaterials for Energy is to exploit and expand the present expertise of the MESA+ groups in the field of nano-related energy research. Through multidisciplinary collaboration between various research groups new materials with novel advanced properties will be developed in which the functionality is controlled by the nanoscale structures leading to improved energy applications. The range of new research projects for nano-applications in the energy sector comprises gradual short and medium-term improvements for a more efficient use of conventional and renewable energy sources as well as completely new long-term approaches for energy recovery and utilization.
Ultra-thin piezoelectrics for energy harvesting Piezoelectric materials can transform mechanical energy into electrical energy and vice versa. Because of that they are used in a multitude of everyday applications from gas lighters to inkjet printers and from ultrasound generators in medical applications (echography devices, blood sensors, lithotripters) to vibration dampers (in cars, skis, helicopter blade). However, piezoelectric materials have the potential to play an even greater role in society by harvesting the energy that is wasted ubiquitously as vibrations (from cars, house appliances, industrial machine) and transforming it into electricity. But in order to fulfill our dream of paving roads,
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[strategic RESEARCH orientations]
railways and homes with piezoelectrics, these materials have to be made lighter, thinner and less toxic than the ones available today (which contain heavy chemical elements). An important step into this direction has been achieved by collaboration between Guus Rijnders and co-workers (IMS, MESA+ Institute for Nanotechnology, University of Twente), Beatriz Noheda (RUG, Zernike Institute for Advanced Materials), the CIN2-Barcelona and the CEMES-CNRS Institutes in Toulouse and Zaragoza. The results have been published in Nature Materials. The researchers have shown that ultra-thin films (with thickness of about 100 atomic layers) of piezoelectric materials deposited under carefully designed conditions, self-organize and flex at the nanometer scale in periodic fashion. This produces huge strain gradients (large differences in the distances between atoms) in such a way that a new mechanism to produce piezoelectricity can take place (so-called flexoelectricity). This greatly increases the materials response at these small thicknesses. Moreover, this novel way of producing piezoelectricity is less dependent on the chemical composition and will allow non-toxic and more readily available materials to be investigated for piezoelectric energy harvesting application. Program director: Dr. ir. Mark Huijben, phone +31 53 489 4710, m.huijben@utwente.nl, www.utwente.nl/mesaplus/nme
HIGHLIGHTED PUBLICATIONS: [1] G. Catalan, A. Lubk, A. H. G. Vlooswijk, E. Snoeck, C. Magen, A. Janssens, G. Rispens, G. Rijnders, D. H. A. Blank, B. Noheda, Flexoelectric rotation of polarization in ferroelectric thin films, Nature Materials 10 (2011) 963-967. [2] H.J. Chang, S.V. Kalinin, A.N. Morozovska, M. Huijben, Y.H. Chu, P. Yu, R. Ramesh, E.A. Eliseev, G.S. Svechnikov, S.J. Pennycook, A. Borisevich, Atomically-resolved mapping of polarization and electric fields across ferroelectric-oxide interfaces by Z-contrast imaging, Advanced Materials 23 (2011) 2474.
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[commercialization]
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[commercialization]
Commercialization Nanotechnology offers chances for new business. Around knowledge institutions, stimulated by a dynamic entrepreneurial environment, nuclei of spin-off companies arise. The number of new businesses based on nanotechnology is growing rapidly. MESA+ plays an important role nationwide, being at the start of more than 45 spin-offs. Access to state-of-the-art nanotech infrastructure, shared facilities functioning in an open innovation model, is of crucial importance for both creation and further development of spin-off companies. These spin-off companies are important for the national and regional economy; SMEs will become increasingly important for employment and turnover. MESA+ intensifies and strengthens its commercialization activities to further increase the number of patents, the number and size of spin-offs and, consequently, its national and international reputation.
High Tech Factory MESA+ is establishing the High Tech Factory, a shared production facility for products based on micro- and nanotechnology. High Tech Factory is designed to ensure that the companies involved can concentrate on business operations and focus their energies on growth rather than on realizing the basic production infrastructure required for achieving that growth. In 2011 the first 500 m2 of High Tech Factory labs have become available as production environment. Development of cleanrooms, labs and offices will continue and is expected to be finalized by the end of 2012.
High Tech Fund The technical infrastructure fund High Tech Fund offers an operational lease facility for companies in micro- and nanotechnology. Equipment is located in the production facility High Tech Factory. The 9 Mâ‚Ź fund, supported by the ministry of Economic Affairs, the province of Overijssel and the region of Twente, was launched successfully in June 2010. In 2011 investments have been realized for the companies SolMateS and Medspray.
MESA+ Technology Accelerator With the MESA+ Technology Accelerator, organized in UT international ventures (UTIV), MESA+ invests in early stage scouting of knowledge and expertise with a potential interest from the market. The first phase of technology and market development is organized in so-called stealth projects. A successful stealth project is continued as a spin-off or license. Through the initiative Kennispark, the UT is applying the UTIV model more widely at the University.
Kennispark Twente Commercialization of nanotechnology research is one of the very strong drivers of MESA+. As illustrated in the topics above, key aspects of the MESA+ agenda encompass business development, facility sharing, area development, and growth towards a production facility. With these key commercialization projects MESA+ contributes strongly to the Kennispark agenda and the provincial and regional innovation systems.
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The Dutch Nano-landscape The Dutch Nano-landscape The Dutch Nano-landscape The Dutch Nano-landscape
The Dutch Nano-landscape
The Dutch Nano-landscape
The Dutch Nano-landscape The
The Dutch Nano-landscape
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Dutch Nano-landscape
The Dutch Nano-landscape
[the dutch nano-landscape]
The Dutch Nano-landscape Netherlands Nano Initiative The nanotechnology research area is comprehensive and still extending. The Netherlands continually makes choices based on existing strengths supplemented with arising opportunities, as is described in the NNI business plan ‘Towards a Sustainable Open InnovationEcosystem’ (2009) in micro and nanotechnology. Generic themes in which the Netherlands excel are beyond Moore and nanoelectronics, nanomaterials, bionanotechnology and instrumentation, while application lies within the areas of water, energy, food, and health and nanomedicine. These generic and application areas are, when applicable, covered by risk analyses and technology assessment of nanotechnology. NanoLabNL provides the infrastructure for the implementation of the NNI strategic research agenda. In 2011 an update of the nanotechnology roadmap has been established, and forms part of the ‘topsector’ innovation policy of the Dutch government.
NanoNextNL NanoNextNL, the 250 M€ innovation program has started in 2011. NanoNextNL, a collaboration of 120 partners, proposes to apply micro- and nanotechnologies to strengthen both the technology base and competitiveness of the high tech and materials industry and to apply them in support of a variety of societal needs in food, energy, healthcare, clean water and the societal risk of certain nanotechnologies. The main economic and societal issues addressed in this initiative are: n the societal need for risk analysis of nanotechnology; n the need for new materials; n ageing society and healthcare cost; n more healthy foods; n need for clean tech to reduce energy consumption, waste production and provide clean water; n advanced equipment to process and manufacture products that address these issues. NanoNextNL covers all relevant generic, application and social themes.
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National NanoLab facilities National NanoLab facilities National NanoLab facilities National NanoLab facilities National NanoLab facilities
National NanoLab facilities
National NanoLab facilities National
National NanoLab facilities
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NanoLab facilities
National NanoLab facilities
[national nanolab facilities]
National NanoLab facilities NanoLabNL NanoLabNL is listed on the ’The Netherlands’ Roadmap for Large-Scale Research Facilities’ as one of 28 large-scale research facilities whose construction or operation is important for the robustness and innovativeness of the Dutch science system. NanoLabNL provides access to a coherent, high-level, state-of-the-art infrastructure for nanotechnology research and innovation in the Netherlands. The NanoLab facilities are open to researchers from universities as well as employees from companies. NanoLabNL seeks to bring about coherence in national infrastructure, access, and tariff structure. Since its establishment in 2004 the NanoLabNL partners invested about 110 M€ in nanotech facilities through their own funding and additional public funding. The partners in NanoLabNL are: n Twente: MESA+ Institute of Nanotechnology at University of Twente; n Delft: Kavli Institute of Nanoscience at Delft University of Technology and TNO Science & Industry; n Groningen: Zernike Institute for Advanced Materials at Groningen University; n Eindhoven, Technical University Eindhoven and Philips Research Laboratories (associate partner). Together, these four locations cover most of the country and offer the widest possible spectrum of nanotechnology facilities for researchers in the Netherlands to use.
MESA+ NanoLab MESA+ NanoLab has extensive laboratory facilities at its disposal, offering a wide spectrum of opportunities for researchers in the Netherlands and abroad: n a 1250 m2 fully equipped cleanroom, with a focus on microsystems technology, nanotechnology, CMOS and materials and process engineering; n a fully equipped central materials analysis laboratory; n a number of specialized laboratories for chemical synthesis and analysis, materials research and analysis, and device characterization. In 2011 MESA+ has invested largely in realizing its new BioNanoLab, part of the MESA+ NanoLab, for research in bionanotechnology, nanomedicine and risk analysis. The MESA+ NanoLab facilities play a crucial role in the research programs and in collaborations with industry. MESA+ has a strong relationship with industry, both through joint research projects with the larger multinational companies, and through a commercialization policy focused on small and medium sized enterprises.
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[international networks]
International Networks (Inter)national position and collaborations MESA+ has a strong international position, several strategic collaborations and is active in international networks and platforms. MESA+ has strategic collaborations with: NINT (Canada), Ohio State, Materials Science Nano Lab (US), Stanford, Geballe Lab of Advanced Materials (US), Berkeley, nanoscience lab Ramesh group (US), California NanoSystems Institute at UCLA (US), JNCASR (India), NIMS (Japan), University of Singapore, and the Chinese Academy of Science CAS, and in Europe with: Cambridge, IMEC, Karlsruhe, Munster, Aarhus and Chalmers University.
EICOON EICOON is the FP7 Euro-Indo forum for nano-materials research coordination & cooperation of researchers in sustainable energy technologies. The consortium addresses the strategic assessment including synergy analysis of nano-materials research needs in the EU and India. It establishes and communicates the mutual interests and topics for future coordinated calls to enable decision and policy makers to make better informed decisions. Besides the assessment, the project also addresses the dissemination of the "nano-materials research acquis" in the field by organization of events. Finally, it brings together researchers to exchange ideas for joint projects for future research collaboration. Visit the EICOON website for more information: www.eicoon.eu.
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International Networks International Networks International Networks International Networks International Networks
International Networks
International Networks International
International Networks
Networks
International Networks
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Impressions of MESA+ meeting
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[education]
Education Twente Graduate School MESA+ School for Nanotechnology MESA+ is a Research School, designated by the Royal Dutch Academy of Science. All PhD students are member of the MESA+ School for Nanotechnology which is part of the University of Twente’s Twente Graduate School. The Graduate School is aiming to strengthen education and improve the skills of PhD students.
Master of Science Nanotechnology Access to the best research students worldwide is critical to the success of MESA+. In the academic year 2005-2006 a master track nanotechnology was started as the first accredited master’s training at the University of Twente. MESA+ invests in information to students of appropriate bachelor’s courses, and brings the master’s nanotechnology to the attention of its international cooperation partners. The master Nanotechnology will be incorporated into the MESA+ School for Nanotechnology.
Fundamentals of Nanotechnology Nanotechnology is a multidisciplinary research field, and requires expertise from the field of electrical engineering, applied physics, chemical technology and life sciences. The course ‘Fundamentals of Nanotechnology’ is annually organized by MESA+ and provides an initial introduction to the complete scope of what nanotechnology is about. The course is set up for graduate students and postdoctoral fellows that are starting to work or are currently working in the field of nanotechnology. The workshop is given in an intensive oneweek format; participants attend about 20 lectures and labtours on different subfields of nanotechnology. Each year about 25 students participate.
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Awards, honours and appointments Simon Stevin Meester 2011 The STW Technology Foundation has awarded Prof. dr. ing. Dave Blank the title of Simon Stevin Meester 2011. The prize was presented on 6 October during a conference organized in honour of STW's 30th anniversary. The Simon Stevin Meester prize is the largest award given for technological-scientific research in the Netherlands. The prize is intended for top researchers who are successful in linking excellent fundamental scientific research to socially-relevant issues and applications. Blank is the sixth scientist from the University of Twente/MESA+ Institute for Nanotechnology to have been awarded the Simon Stevin Meester title. Previous winners include Detlef Lohse (2009), Albert van den Berg (2002), Cock Lodder (2002), Miko Elwenspoek Dr. Regina Luttge
(1998) and David Reinhoudt (1998).
ERC Proof of Concept Prof. dr. Detlef Lohse (Physics of Fluids group) and Prof. dr. ir. Albert van den Berg (BIOS Lab-on-a-chip group) are among the first European researchers who are granted the new European Research Council (ERC) Proof-of-Concept grant. These 'top up' grants, worth up to €150,000 each, are designed to help in the valorisation of ERC-funded research. In total, 30 top researchers, already holding ERC grants, will be given this additional support to bridge the gap between their research and the earliest stage of a marketable innovation. The funding can cover activities related to for instance intellectual property rights, technical validation, market research or investigation of commercial and business opportunities. Dr. Allard Mosk
ERC Starting Grant In 2011 four young MESA+ researchers have been awarded the ERC Starting Grant of 1,5 million euros each. Dr. Regina Luttge of the Mesoscale Chemical Systems group, Dr. Allard Mosk of the Complex Photonic Systems group, Prof. dr. Serge Lemay of the NanoIonics group and Dr. ir. Michel de Jong of the NanoElectronics group. ERC Starting Grants aim to support up-and-coming research leaders who are about to establish or consolidate a proper research team and to start conducting independent research in Europe.
VIDI grant Dr. Nathalie Katsonis of the Biomolecular NanoTechnology group is the recipient of a Netherlands Organisation for Scientific Research NWO Vernieuwingsimpuls VIDI grant (2011) on a project called “Nanostructured super-reflectors: learning lessons from scarab beetles”. This grant of maximum 800,000 euros enables her to develop her own research topic and start a research group Prof. dr. Serge Lemay
of her own.
VENI grant The Netherlands Organisation for Scientific Research (NWO) has awarded a VENI-STW grant to Transducers Science and Technology researcher Dr. ing. Léon Woldering and Dr. ir. Floris Zwanenburg of the NanoElectronics group. With this prestigious grant of 250,000 euro, both can develop their research ideas for a further three years. The topic of research of Léon Woldering is ‘controlled three-dimensional self-assembly of silicon nanoparticles using hydrogen-bonds’. Floris Zwanenburg’s research is focused on spin quantum bits in silicon quantum dots.
Marie Curie Career Integration Grant Dr. Sonia Garcia-Blanco of the Integrated Optical Microsystems group and Dr. ir. Floris Zwanenburg of the NanoElectronics group Dr. ir. Michel de Jong
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both won the Marie Curie Career Integration Grant of 100,000 euros. Marie Curie Career Integration Grants are intended to improve
considerably the prospects for the permanent integration of researchers who are offered a stable research post in Europe after a mobility period in a country different from the country where the researcher has been active during the past years.
KNCV Gold Medal Prof. dr. Jeroen Cornelissen of the MESA+ group Biomolecular Nanotechnology won the KNCV (Royal Netherlands Chemical Society) Gold Medal. During the official opening of the international Year of Chemistry 2011 he received the Gold Medal, which is regarded as the most important Dutch prize for young researchers who have excelled in the area of chemical research.
Valorization Grants phase 1 Dr. Burak Eral and Dr. Dileep Mampallil of the Physics of Complex Fluids Group are awarded an STW Valorisation Grant phase 1 of 25,000 euros for exploring the commercialization of a substantial improvement of a workhorse method in analytical chemistry: Matrix assisted laser adsorption Ionization mass spectroscopy for short MALDI-MS. Dr. ir. Wim van Hoeve, former PhD of the Physics of Fluids group, received the 25,000 euros STW Valorisation Grant for the validation of a monodisperse microbubble generator. His grant is financed by FOM (Foundation for Fundamental Research on Matter). Van Hoeve started the spin off company Tide Microfluidics. Dr. Loes Segerink, PhD at the BIOS, Lab- on- a-Chip group received a valorization grant for the project “fertility chip, on-chip semen
Dr. Nathalie Katsonis
analysis system”. The grant will be used to conduct a study into the technical and commercial feasibility of the fertility, in close cooperation with the MESA+ spin-off company Blue4Green.
YES! Fellow FOM The Foundation for Fundamental Research on Matter has awarded a Young Energy Scientist (YES!) Fellowship to Dr. Süleyman Er of the Computational Materials Science group. The former FOM PhD student will spend the next four years looking for a new class of solar cell components that can convert sunlight into electricity more efficiently and at a low cost. With a YES! Fellowship, FOM gives young researchers the chance to develop themselves at a top foreign institute in fundamental energy research.
Grant for Fertility Innovation Dr. ir. Séverine Le Gac is one of the winners of the Grant for Fertility Innovation (GFI) of 200,000 euros at the 27th Annual meeting of the European Society of Human Reproduction and Embryology (ESHRE) in Stockholm, Sweden on July 4th 2011. The grant will focus on the application of microfluidic devices for the culture of human embryos.
Simon Stevin gezel Dr. Loes Segerink, PhD at the BIOS Lab-on-a-chip group has won both the jury and the public prize (1,000 euros each) of the STW ‘Simon Stevin leerling’ for her research on the "fertility chip" that can count sperm and measure their motility (ability of sperm to move properly towards an egg).
Ercoftac Da Vinci award On 10 October, Dr. Richard Stevens received the Da Vinci Award 2011, which is awarded by the 'European Research Community on Flow, Turbulence and Combustion'. Stevens gained his doctorate on 30 June 2011 in the MESA+ Physics of Fluids group of prof. dr. Detlef Lohse for his thesis entitled 'Rayleigh-Bénard turbulence'. The Da Vinci Award is a recognition of his scientific work and his talent for presenting data clearly. The prize consists of 1,000 euros, a certificate and a medal. Dr. ing. Léon Woldering
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Overijssel PhD award At the 50th Dies Natalis, Dr. ir. Martin Jurna, former PhD of MESA+ Optical Sciences group, received the 2011 Overijssel PhD award for the best University of Twente thesis from last year. The award, 5,000 euros, was presented by the Queen’s Commissioner, Drs. Ank Bijleveld. Martin Jurna received this award for his thesis ‘Vibrational phase contrast cars microscopy’.
Cum laude distinction In 2011 two MESA+ PhD candidates received cum laude distinctions for their work: Dr. ir. Hans Boschker of the Inorganic Materials Science group for his thesis: ‘Perovskite oxide heteroepitaxy strain and interface engineering’ and Dr. Tian Gang of the Dr. Sonia Garcia-Blanco and Dr. ir. Floris Zwanenburg
NanoElectronics group for his thesis on Inorganic-organic hybrid electronics.
Graduate programme MESA+ MESA+ School for Nanotechnology received 800,000 euros from the Netherlands Organisation for Scientific Research (NWO) for the training of four young researchers. The funding is part of NWO’s Graduate Programme and is aimed at encouraging the development of Dutch PhD courses.
MESA+ meeting 2011 During the MESA+ meeting 2011 in the Grolsch Veste on September 27, Ir. René Heimbuch, Physics of Interfaces and Nanomaterials group, won the 1st prize for the best poster. The 2 nd prize was won by Ir. Shuo Kang, NanoIonics group, and the 3rd prize by Ir. Carmen Stoffelen, Molecular NanoFabrication group. The MESA+ meeting is to illustrate the various projects and programs of the MESA+ institute by means of lectures and scientific poster presentations.
Appointments n F rom February 1, 2011 Prof. dr. ir. Alexander Brinkman is appointed as head of the new chair on Quantum Transport in Matter. The research addresses quantum aspects of electronic transport in novel materials and devices. Examples of quantum phenomena of interest are entanglement and teleportation. Materials under study are correlated electron systems such as superconductors, oxides and their interfaces, and topological insulators. n P rof. dr. ir. Leon Lefferts of the Catalytic Processes and Materials group has been appointed part-time professor at Aalto Dr. Loes Segerink
University in Helsinki. At the Finnish university, he will carry out research into the production of hydrogen gas from biomass. n P rof. dr. Vinod Subramaniam of the Nanobiophysics group received visiting professorship at University of Konstanz. He is also appointed as extraordinary professor Nanoscale Imaging at the Radboud University Nijmegen, Faculty of Medical Sciences, from December 1, 2011. n P rof. dr. ir. Albert van den Berg has joined the board of the KNAW, the Royal Netherlands Academy of Arts and Sciences, in June 2011. n Prof. dr. ing. Dave Blank has become captain of science of the topsector board High Tech Systems and Materials. n Ir. Miriam Luizink has been elected chairman of the board of the NanoLabNL association. n NanoElectronics prof. dr. ir. Wilfred van der Wiel has become a member of the Global Young Academy. This Academy aims to empower and mobilize young scientists to address issues of particular importance to early career scientists. Current working groups focus on improving Early Scientific Careers, Science-Society Dialogue, Science-Education, and Interdisciplinary Research.
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MESA+ ANNUAL REPORT 2011
[highlights] The Biomolecular Electronic Structure (BES) group is a computational group in the field of electronic structure theory and focuses on the methodological
Prof. dr. Claudia Filippi
development of novel and more effective approaches for investigating the
“Electronic-structure theory has dramatically
electronic properties of materials. Our current research centers on the
expanded the role of computational modeling,
problem of describing light-induced phenomena in biological systems, where
enabling a detailed atomistic understanding of
available computational techniques have limited applicability. Deepening
real materials. Our research focuses on the
our physical understanding of the primary excitation processes in
challenge to further enhance the predictive
photobiological systems is important both from a fundamental point of view
power of these approaches while bridging to
and because of existing and potential applications in biology, biotechnology,
the length-scales of complex (bio)systems.�
and artificial photosynthetic devices.
Biomolecular Electronic Structure Why is Green Fluorescent Protein not green? A challenge for multi-scale modeling We are currently interested in rationalizing the structural mechanisms underlying the optical properties of autofluorescent proteins, in particular the homologues of Green Fluorescent Protein (GFP), a family of proteins widely used for noninvasive in-vivo imaging of cells and tissues. Given the complexity of these photo-biological systems, theoretical approaches rely on multi-scale embedding schemes to couple a quantum description of the photosensitive chromophore with a classical treatment of the rest of the protein. Contrary to what is generally portrayed in the literature, we demonstrate that the use of a standard classical description of the protein does not allow us to correctly predict the position of the absorption maxima of wild-type GFP and to reproduce the bathochromic shift in the protein, which should be particularly significant for the neutral form. Because of these distressing findings, we are currently working on the developments of novel approaches to treat chromophore-protein interactions beyond standard hybrid models.
Figure: The Green Fluorescent Protein chromophore in its protein environment.
HIGHLIGHTED PUBLICATION: C. Filippi, F. Buda, L. Guidoni, A. Sinicropi, Bathochromic Shift in Green Fluorescent Protein: A Puzzle for QM/MM Approaches, J. Chem.
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Theory Comput., publication date (Web) November 21, 2011.
[HIGHLIGHTS] In the BIOS Lab-on-a-Chip group fundamental and applied aspects of miniaturized bioanalytical laboratories are studied. With the use of
Prof. dr. ir. Albert van den Berg
advanced and newly developed micro- and nanotechnologies, enabled
“We try to do top-level research
medical and sustainable applications are realized, ranging from chips
on micro- and nanofluidics and
for monitoring medication to counting sperm cells, and from discovery
new nanosensing principles, and
of new biomarkers and ultrasensitive detection thereof to harvesting
to integrate that into real-life Lab-
electrical energy from water.
by the MESA+ Nanolab facilities, microdevices with nanostructures for
on-Chip systems for biomedical and sustainable applications.”
BIOS Lab-on-a-Chip
Figure 1: (a) High-resolution scanning electron microscopy images of fabricated silicon nanowires. (b) Schematic of
Al2O3/Silicon NanoISFET with Near Ideal Nernstian Response
electrical measurement, Inset: microscope image of polyimide encapsulated device prior to testing. (SiN: low-stress silicon nitride; Al: Aluminum; PI: polyimide).
The multidisciplinary work presented here concerns Nanoscale ISFET (ion sensitive field-effect transistor) pH sensors that produce the well-known sub-Nernstian pH-response for silicon dioxide (SiO2) surfaces and near ideal Nernstian sensitivity for alumina (Al2O3) surfaces. Measured pH responses from titrations of thin atomic layer deposited (ALD) alumina (Al2O3) surfaces on the nanoISFETs results in near ideal Nernstian pH sensitivity of 57.8 ± 1.2 mV/pH (pH range: 2 - 10; T = 22 °C) and temperature sensitivity of 0.19 mV/ pH °C (22 °C ≤ T ≤ 40 °C). A comprehensive analytical model of the nanoISFET sensor based on the combined Gouy-Chapman-Stern and Site-Binding (GCS-SB) models supports the experimental results and an extracted ∆pK ≈ 1.5 from the measured responses further supports the near ideal Nernstian pH sensitivity.
Figure 2: (a) and (b) pH behavior of SiO2 surfaces. (a) Bare SiO2 with non-linear ∆Ids with increasing pHB. (b) Measured pHB-Δo of bare SiO2 with measured and fitted response. (c) and (d) pHB-Δo response of ALD Al2O3 surfaces. (c) pH titration direction showing the response hysteresis. (d) Measured and fitted response for four different silicon nanowire devices at T = 22 °C, Δo / ΔpHB = 57.8±1.2 mV/pH; at T = 30 °C, Δo / ΔpHB = 59.4±0.3 mV/pH; and at T = 40 °C, Δo / ΔpHB = 61.3±0.8 mV/pH.
HIGHLIGHTED PUBLICATION: S. Chen, J.G. Bomer, E.T. Carlen, A. van den Berg, Al2O3/Silicon NanoISFET with Near Ideal Nernstian Response, Nano Lett. 11 (2011) 2334.
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[highlights] The BioMolecular Nanotechnology (BNT) group is founded in 2009 by the appointment of it’s chair prof. Jeroen Cornelissen and acts on the interface of biology, physics and materials science coming from a strong chemical back ground. The research of the group centers around the use of biomolecules as building blocks for (functional) nanostructures, relying on principles from Supramolecular and Macromolecular
Prof. dr. Jeroen J.L.M. Cornelissen
Chemistry. Current research lines involve the use of well-defined nanometer-sized
“Using the building blocks from
the field of liquid crystalline materials are explored. The success of the multidisciplinary
Nature to make and understand
work of the group partly relies on intense interactions within MESA+ and with other
new technologies.”
(inter)national collaborators.
protein cages as reactors and as scaffolds for new materials, while new directions in
BioMolecular Nanotechnology Encapsulation of Phthalocyanine Supramolecular Stacks into Virus-like Particles Naturally occurring nanoparticles such as protein cages can be used as well-defined and monodisperse platforms for the organization of chemical entities both in their inner cavities and on their exterior surfaces. We developed a method to stack phthalocyanine dyes inside virus based protein cages. The advantage of using protein cages for the formation of phthalocyanine stacks is i) the low concentration of phthalocyanine in bulk solutions second, ii) it is possible to control the size and structures of such stacks, which allow an efficient way to determine the properties of these macrocycles and iii) the enclosure of phthalocyanine inside protein cages make them suitable for medical applications such as photodynamic therapy. To enclose phthalocyanine inside protein cages a water-soluble zinc phthalocyanine (ZnPc) and the native virus protein were simply co-incubated in solution (Figure 1). Interestingly, capsids of two different sizes can be obtained, depending on the pH. At neutral pH the formation of stacks inside the protein shell is favored, whereas the formation of dimers is favored at lower pH. In both cases the stacking behavior and the optical properties can be followed by spectroscopy. The superior optical and electronic properties of phthalocyanines together with the biocompatible nature of the protein cages makes the system applicable for biomedical applications such as photodynamic therapy.
Figure: Schematic representation of the encapsulation of Pc stacks into CCMV VLPs. The length and arrangement of the stacks within the capsids in the cartoon are tentative.
HIGHLIGHTED PUBLICATION: M. Brasch, A. de La Escosura, Y. Ma, C. Uetrecht, A.J.R. Heck, T. Torres, J.J.L.M. Cornelissen, Encapsulation of phthalocyanine supramolecular stacks
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into virus-like particles, Journal of the American Chemical Society 133 (18) (2011) 6878-6881.
[HIGHLIGHTS] The Computational BioPhysics (CBP) group investigates how the thermo dynamic and rheological properties of a complex fluid emerge from its molecular constitution. Our computational studies focus on the mesoscopic level, i.e. the time and length scales of the macro-molecules determining the macroscopic behaviour, while the atomic details of these molecules are reduced to their bare essentials. By developing equations of motions and force fields that capture only the crucial molecular features, a complex molecule like a polymer or a protein can be modeled as a single particle.
Prof. dr. Wim J. Briels
This approach proves very successful in studying the emerging macroscopic
“There's plenty of room in the middle.”
properties of biological and non-biological soft condensed matter.
Computational BioPhysics Is it possible for flat clathrin lattices to transform into cages?
Figure 1: Simulations have uncovered the prerequisites that allow clathrin proteins to self-assemble into a wide variety of polyhedral cages.
Clathrin is a three-legged protein with the ability to self-assemble into a large variety of polyhedral cages. The nucleation and growth of a curved lattice against the inside of a cell membrane wraps the membrane around a cargo at the opposite side of the membrane, thereby creating a cargo-laden vesicle inside the cell (endocytosis). Completed cages contain exactly twelve pentagons and a variable number of hexagons. We have developed a highly coarse-grained simulation model of this protein, see Figure 1, and thereby determined the crucial features enabling self-assembly. Cryo-electron microscopy images (cryo-EM) show that clathrin also self-assembles into flat hexagonal lattices adjacent to a membrane. A long-standing conundrum in the field is whether and how a flat ‘plaque’ transforms into a cage, the main problem being that the introduction of twelve pentagons requires a daunting amount of reshuffling of the lattice. Our simulations reveal a much simpler mechanism: when the flat triskelia in a plaque acquire a small pucker, e.g. in response to the presence of cargo, the resulting build-up of stresses causes the lattice to fracture and release a dome-like fragment. This nucleus subsequently grows into a cage by binding free clathrin from the cytosol, with the obligatory twelve pentagons easily being created at the lattice edge. Numerous cryo-EM images show hemi-spherical clathrin domes partially surrounded by semi-circular frayed lattice edges, remarkably similar to our simulation snapshots, which hitherto were overlooked as transition intermediates. The novel mechanism also explains why multiple coats often appear to originate from the same ‘hot spot’.
Figure 2: Snapshot of colloidal particles in a sheared nonNewtonian fluid, made possible by the in-house development of Responsive Particle Dynamics. The simulations are producing new insights into the unexplained phenomenon that some viscoelastic fluids induce alignment of colloids under shear, with the arrows indicating the flow direction, while other fluids with superficially similar flow properties leave the colloids randomly distributed.
HIGHLIGHTED PUBLICATION: W.K. den Otter, W.J. Briels, The generation of curved clathrin coats from flat plaques, Traffic 12 (2011) 1407-1416.
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[highlights] Understanding the magnetic, optical, electrical and structural properties of solids in terms of their chemical composition and atomic structure by numerically solving the quantum mechanical equations describing the motion of the electrons is the central research activity of the group Computational Materials Science (CMS). These equations contain no input from experiment other than the fundamental physical constants, making it possible to analyze
Prof. dr. Paul J. Kelly
the properties of systems which are difficult to characterize experimentally or
�Computational Materials Science:
to predict the physical properties of materials which have not yet been made.
taking the guesswork out of
This is especially important when experimentalists attempt to make hybrid
NanoScience and Technology.�
structures approaching the nanoscale.
Computational Materials Science Ultrathin gate dielectric for graphene The performance of silicon-based technology could be improved for almost half a century by making devices smaller and smaller. Because this approach will eventually come up against the intrinsic limitations of silicon, there is a constant search for alternatives. A material that has received much attention recently is graphene, a monolayer of graphite. Graphene is a two dimensional half metal comprising sp2-bonded carbon atoms arranged in a honeycomb structure. The high mobility of both electrons and holes in graphene makes it a promising starting material for high frequency transistors. For practical applications of such a material only one atom thick, the choice of a suitable substrate is non-trivial. Hexagonal boron nitride (h-BN) is a completely flat layered material with the same honeycomb structure as graphene with strong in-plane and weak out-of-plane interactions. Unlike graphene, it has a very large band gap so it is an ideal substrate and gate dielectric with which to build metal|h-BN|graphene field-effect devices. We used first-principles density functional theory (DFT) calculations for Cu|h-BN|graphene stacks to study how the position of the Fermi level in graphene depends on the thickness of the h-BN layer and on a potential difference applied between Cu and graphene. We developed an analytical model that describes this doping very well, allowing us to identify the key parameters that govern the device behaviour. For ultrathin layers of h-BN, we predict an intrinsic doping of graphene that should be observable in experiment. It is dominated by novel interface terms that were evaluated from DFT calculations for the individual materials and for interfaces between h-BN and Cu or graphene. Figure: A single layer of graphene (Gr) separated from a copper electrode (Cu) by three layers of hexagonal boron nitride (BN). The dipole layers are visible as negative (blue) and positive (red) charge contours.
HIGHLIGHTED PUBLICATION: M. Bokdam, P.A. Khomyakov, G. Brocks, Z.C. Zhong, P.J. Kelly, Electrostatic Doping of Graphene through Ultrathin Hexagonal Boron Nitride
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Films, Nano Letters 11 (2011) 4631-4635.
[HIGHLIGHTS] The Complex Photonic Systems (COPS) group studies light propagation in ordered and disordered nanophotonic materials. We investigate photonic bandgap materials, random lasers, diffusion and Anderson localization of light. We have recently
Prof. dr. Willem L. Vos
pioneered the control of spontaneous emission in photonic bandgaps and the active
“COPS strives to catch light with
control of the propagation of light in disordered photonic materials. Novel photonic
nanostructures. But beware dear
nanostructures are fabricated and characterized in the MESA+ cleanroom. Optical
colleagues, since Shakespeare once
experiments are an essential aspect of our research, which COPS combines with a
said: ‘Light, seeking light, doth light of
theoretical understanding of the properties of light. Our curiosity driven research
light beguile’. In other words: the eye in
is of interest to various industrial partners, and to applications in medical and
seeking truth deprives itself of vision.”
biophysical imaging.
Figure 1: Electron microscope image of a three-dimensional diamond structure in silicon (encircled), consisting of identical pores in an orthogonal pattern that cross each other at an angle
Complex Photonic Systems
of 90º. The upper part of the figure shows the upper surface of the chip, in which many pores have been etched. Top left a dust particle can be seen that ended up on the crystal after the process. In the side of the chip an orthogonal pattern of pores has
No permission for emission
been etched in a single go, perpendicular to the other pores. The scale at the top right is two micrometres, about 50 times as thin as a human hair.
COPS scientists have experimentally demonstrated a prediction made nearly a quarter-century ago: that spontaneous emission of light can be inhibited within a 3-D photonic bandgap. By learning how to control such emission and suppression, researchers could someday build better solid-state lasers or reduce the inevitable noise in quantum computers. To this end, the group developed “inverse woodpile” photonic band gap crystals with a 3-D diamond structure, in collaboration with ASML, Philips, TNO. The crystals were etched out of silicon with nanometre precision utilizing a fully CMOS-compatible process - in itself a remarkable, pioneering achievement. They calculated the theoretical band gap where all modes of light waves are forbidden in all 3 dimensions - the photonic band gap. Next, the researchers immersed the crystal into a suspension of colloidal quantum dots made of lead sulfide, which emit at photon energies of 0.8 to 0.9 eV at room temperature, corresponding to telecommunications wavelengths (1,500 to 1,390 nm). The team excited the quantum dots with short pulses from a 532-nm-wavelength laser. The excited dots act as single-photon sources. Because the quantum-dot emission was relatively low, the scientists had to collect the light for hours and carefully subtract background noise. As predicted, the decay rates of the quantum dot emissions within the photonic bandgap were reduced by a factor of 10, while they
Figure 2: The graph shows when quantum dot light sources in
were enhanced by as much as a factor of two outside the bandgap. In other words, it took the dots 10 times longer to emit a photon
a photonic crystal emit light after being excited by a short laser
within the crystal. In an actual finite-sized photonic band gap crystal, the strength of the effect depends on the distance of the dots
pulse at time 0 (blue triangles). The slope of the curves is inversely
from the surface of the crystal.
proportional to the lifetime: the shallower the curve, the longer
The results build on theoretical studies of cavity quantum electrodynamics begun by American and Canadian scientists in the 1980s.
the lifetime of the quantum dots. For comparison, dots outside
In parallel to the spontaneous emission work, COPS has also obtained a great success in realizing a record-high resolution optical focus
a crystal reveal a much shorter lifetime. The 10x longer lifetime
by using a so-called high-index resolution enhancement by scattering (HIRES).
in the crystal is a measure for the strong inhibition of vacuum fluctuations by the photonic band gap crystal.
HIGHLIGHTED PUBLICATIONS: [1] M.D. Leistikow, A.P. Mosk, E. Yeganegi, S.R. Huisman, A. Lagendijk, W.L. Vos, Inhibited spontaneous emission of quantum dots observed in a 3D photonic band gap, Phys. Rev. Lett. 107 (2011) 193903: 1-5. [2] E.G. van Putten, D. Akbulut, J. Bertolotti, W.L. Vos, A. Lagendijk, A.P. Mosk, Scattering Lens Resolves sub-100 nm Structures with Visible Light, Phys. Rev. Lett. 106 (2011) 193905: 1-4.
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[highlights] Prof. dr. ir. Leon Lefferts
The aim of the Catalytic Processes and Materials (CPM) group is to understand heterogeneous
“One of the most valuable
catalysis by investigation of catalytic reactions and materials on a fundamental level in
applications of nanotechnology
combination with their application in practical processes. Our research focuses on three themes:
is in the area of heterogeneous
1. Sustainable processes for fuels and chemicals, like catalytic conversion of biomass to fuels.
catalysis. The challenges are to
2. Heterogeneous catalysis in liquid phase.
improve the level of control over the
3. High yield selective oxidation.
active nanoparticles as well as the
The fundamental study of surface reactions in liquid phase requires the development of new
local conditions at those particles,
analysis techniques for which CPM is in the forefront of leading catalysis groups in the world.
and to understand the molecular
Moreover, we explore preparation and application of new highly porous, micro-structured
mechanism at the surface.”
support materials as well as micro-reactors and micro-fluidic devices, using the information obtained from in-situ spectroscopy studies.
Catalytic Processes and Materials Figure 1: A schematic representation of reactant flow inside
Carbon-nano-fibers in microchannels: an advanced catalyst support for operation in liquid phase
micro-channel coated with a classical washcoat layer (left) versus carbon nanofiber layer (right).
Interdisciplinary work performed by Vijay Thakur in cooperation with the MCS group resulted in two publications in one issue of Applied Catal. B, Environmental, the leading journal in environmental catalysis. It was nicely demonstrated that manipulation of the microstructure (Figure 1) of the catalysts support layer based on carbon-nano-fibers (Figure 2), inside the channel in a microreactor, induced am important improvement in the transport of traces of bromate to the catalytic active site. This improvement results in enhanced removal of bromate (BrO3-) in the sub ppm range in drinking water. Bromate is a safety problem in drinking water produced in regions close to salty water, thus always containing traces of Br-, in combination with ozone treatment.
Figure 2: SEM images in top view (left) and cross-section of a micro-channel filled with CNFs. The micro-channels contain Si pillars to improve the attachment of the fibers to the wall.
HIGHLIGHTED PUBLICATIONS: [1] D.B. Thakur, R.M. Tiggelaar, T.M.C. Hoang, J.G.E. Gardeniers, L. Lefferts, K. Seshan, Ruthenium catalyst on carbon nanofiber support layers for use in silicon-based structured microreactors, Part I: Preparation and characterization, Applied catalysis B: environmental 102(1-2) (2011) 232-242. [2] D.B. Thakur, Y. Weber, R.M. Tiggelaar, J.G.E. Gardeniers, L. Lefferts, K. Seshan, Ruthenium catalysts on Carbon Nano Fiber support layers for S-based structured microreactors I - Catalytic reduction of
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bromate in aqueous phase, Applied catalysis B: environmental 102(1-2) (2011) 243-250.
[HIGHLIGHTS] Materials with exceptional, well-tailored properties are at the heart of many new applications. In the electronic/magnetic domains, powerful means to create such
Prof. dr. ir. Hans Hilgenkamp
properties are nanostructuring as well as the use of compounds in which the intrinsic
"The Interfaces and Correlated Electron
mobile charge carriers mutually and/or with the crystal lattice. In the Interfaces and
systems group (ICE) focuses on materials
Correlated Electron systems group (ICE), the fabrication and basic properties of such
and interfaces with unconventional
(nano-structured) novel materials are studied, and their potential for applications is
electronic properties, especially related
explored. Current research involves superconductors, p- and n-doped Mott compounds,
to interactions between the mobile
topological insulators, electronically active interfaces between oxide insulators and
charge carriers".
novel electronic materials for energy harvesting applications.
physics involves ‘special effects’. These can arise from intricate interactions of the
Interfaces and Correlated Electron systems Opposites attract; can excitons lead to a dissipation-less energy transport? In physics a crucial difference exists between fermions and bosons. The former are spin-½ particles such as electrons, and the latter are particles with zero or integer spin, such as photons and ‘Cooper-pairs’ of two electrons. The most spectacular manifestation of the difference between the two classes of particles is the fact that at a sufficiently low temperature a system of bosons can
Figure 1: Prediction of a novel quantum effect; the magnetic flux
become completely entangled into a macroscopic phase-coherent quantum state; a Bose-Einstein condensate. Superconductivity is a
in a concentric ring structure composed of an electron-doped
consequence of this condensation of the bosonic Cooper-pairs.
and hole-doped layers becomes quantized in the case of a Bose-
In the still enigmatic high-Tc superconductors an additional aspect comes into play, namely the fact that also in the ‘normal state’
Einstein condensation of the indirect excitons formed between
the charge transport is highly anomalous, and strongly influenced by mutual interactions between the charge carriers (‘electronic
these layers (Rademaker et al., PRB 2011).
correlations’). In the MESA+ ICE group, and in the frame of an NWO VICI grant, a study is carried out on the creation and possible Bose-Einstein condensation of another type of bosonic particles in such correlated electron compounds, namely bound states of electrons and holes (excitons). Experimental studies are performed on thin-film sandwiches comprised of p-doped and n-doped cuprate perovskites, and in a collaboration with the Institute Lorentz in Leiden the consequences of a Bose-Einstein condensation of excitons is studied theoretically. A particulary interesting question is whether such exciton condensation could provide an alternative pathway to high(er) temperature superfluidity and perhaps even superconductivity, which both are of great interest for a dissipationless transportation of energy. The research has led to the prediction of a novel quantum effect, namely the quantization of magnetic flux enclosed in a ring-shaped bilayer system (Fig. 1) as a crucial test to verify the occurrence of exciton Bose-Einstein condensation. Experimental research is underway to test these predictions (Fig. 2).
Figure 2: Schematic of a concentric p-n ring structure to study exciton formation in correlated electron systems and their possible Bose-Einstein condensation, as fabricated using thin film technologies in the MESA+ Institute.
HIGHLIGHTED PUBLICATION: L. Rademaker, J. Zaanen, H. Hilgenkamp, Prediction of quantization of magnetic flux in double-layer exciton superfluids, Phys. Rev. B. 83 (2011) 012504.
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[highlights] Activities of the group Inorganic Membranes (IM) revolve around energy efficient molecular separation under extreme conditions, for instance high temperature, elevated pressures, and chemically demanding environments, using
Prof. dr. ir. Arian Nijmeijer
inorganic membranes. The group combines Materials
“Material science on the Ă…ngstrom
Technology on macroscopic scale. Particular topics include
scale to make ceramic membranes
sol-gel derived nano-porous membranes, ultra-thin hybrid
that can be applied in large scale
membranes, dense ion conducting membranes, and
separation processes�.
inorganic porous scaffolds.
Science in the nanometer range length scale with Process
Inorganic Membranes Porous inorganic hollow fibers with shrinkage-controlled small radial dimensions The Inorganic Membranes group has developed a facile method for inexpensive production of thin inorganic hollow fiber membranes, with unprecedented small radial dimensions, superior thermal and chemical stability, and high mechanical strength. The method is based on dry-wet spinning of a particle loaded polymer solution, followed by thermal treatment to burn out the polymer and sinter the inorganic particles together. The extremely small radii (down to ~200 mm) are achieved by surface energy driven viscous deformation of the fibers above the glass transition (Tg) of the polymer, prior to burn out of the polymer and sintering. During viscous deformation, so-called macro-voids are removed from the fiber, causing extensive shrinkage and enhanced mechanical properties. Figure 1 depicts schematically the change in morphology and dimensions of a stainless steel loaded fiber during heat treatment. The method is applicable for a broad range of inorganic materials (see Figure 2), on the condition that the particle concentration is kept within a powder specific limited concentration range. Above a certain maximum concentration the timescale of viscous deformation becomes too large and removal of macro-voids is minor. Below a minimum particle concentration, particle cohesion during burn-out Figure 1: Schematic depiction of the fabrication of a thin stainless
of the polymer is insufficient to obtain strong and well-defined fibers. The results allow fabrication of inorganic membranes with
steel hollow fiber.
extremely large surface area to volume ratio that can be used in applications that involve high temperatures, high pressure, and aggressive chemicals, i.e., where organic membranes fail due to limited stability.
Figure 2: Selection of thin inorganic hollow fibers, on the right a commercial alumina capillary for comparison.
HIGHLIGHTED PUBLICATIONS: [1] Luiten-Olieman et al., Porous stainless steel hollow fibers with shrinkage-controlled small radial dimensions, Scripta Materialia 65 (2011) 25-28. [2] Luiten-Olieman et al., Porous stainless steel hollow fiber membranes via dry-wet spinning, J Membrane Sci 370 (2011) 124-130. [3] Luiten-Olieman et al., Towards a generic
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fabrication method of thin organic hollow fibers, submitted.
[HIGHLIGHTS] Prof. dr. ing. Dave H.A. Blank
The Inorganic Materials Science (IMS) group works at the international forefront
“The recent developments in controlled
of materials science research on complex metal oxides and hybrids, and
synthesis and characterization tools has
provides an environment where young researchers and students are stimulated
increased the applicability of inorganic
to excel. The research is focused on establishing a fundamental understanding
nanoscale materials enormously.
of the relationship between composition, structure and solid-state physical and
This holds especially for complex and
chemical properties of inorganic materials, especially oxides. Insights into these
functional oxide materials, enabling the
relationships enable us to design new materials with improved and yet unknown
development of new materials and devices
properties that are of interest for fundamental studies as well as for industrial
with novel functionalities. Our aim is to
applications. With the possibility to design and construct artificial materials on
consolidate our leading role in this field.�
demand, new opportunities become available for novel device concepts.
Inorganic Materials Science Hydrogen Generation from Photocatalytically Active Nanowires: Towards Multifunctional Nanowire Devices Nanorods and nanowires have a high potential for utilization in a wide range of novel nanotechnological and biomedical applications.
Figure 1: Working principle of photoactive segmented Ag|ZnO
For solar fuel applications, we developed a novel type of segmented nanowire with emergent photocatalytic property. The nanowire
nanowire. UV radiation is absorbed by the ZnO segment, creating
is essentially a photo-electrochemical nanowire diode. When dispersed in methanol/water and exposed to UV light, it autonomously
an electron-hole pair. The electrons flow into the Ag phase and
catalyzes the conversion of methanol to hydrogen. The functionality of the nanowire is based on its axially segmented architecture,
are consumed in an electrochemical reduction process, forming
which consists of a photoactive zinc oxide (ZnO) segment, and a metallic segment that are connected via a Schottky barrier. When
hydrogen gas. The hole in the ZnO segment is consumed in an
excitons are formed in the ZnO photoanode upon illumination, the formed electrons are transported to the Ag cathode, where they
oxidative half-reaction, in this case the oxidation of methanol.
participate in the reduction of aqueous protons to hydrogen gas. The electron holes remain behind in the ZnO phase and is eventually consumed at the anode surface in the oxidation of methanol. The modular approach to constructing multiply segmented nanowires is a versatile and flexible way to fabricate autonomously functioning nanosystems that are able to carry out multiple complex tasks, e.g. autonomous movement, magnetic control over the direction of movement, and photocatalytic activity.
Figure 2: Scanning electron microscope image of a axially segmented silver-zinc oxide nanowire. Nanowire length 4 Îźm; diameter 150-200 nm.
Highlighted publication: A.W. Maijenburg, E.J.B. Rodijk, M.G. Maas, M. Enculescu, D.H.A. Blank, J.E. ten Elshof, Hydrogen Generation from Photocatalytic Silver|Zinc Oxide Nanowires: Towards Multifunctional Multisegmented Nanowire Devices, Small 7 (2011) 2709-2713.
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[highlights] The Integrated Optical MicroSystems (IOMS) group performs research on highly compact, potentially low-cost and mass-producible optical waveguide devices with novel functionalities. After careful design using dedicated computational tools, optical chips are realized in the MESA+ clean-room facilities by standard lithographic tools as well as high-resolution techniques for nano-structuring, such as focused ion beam milling and laser interference lithography. Integrated optical devices, including on-chip integrated light sources and
Prof. dr. Markus Pollnau
amplifiers, optically resonant structures, micro-mechanically or thermo-optically actuated
“Guiding light into the
based on these devices are developed for a variety of applications in the fields of optical
future!"
sensing, bio-medical diagnostics, and optical communication.
switches, spectrometers, and novel light generation, manipulation, and detection schemes
Integrated Optical MicroSystems Figure 1a: Optical measurement set-up of the spectral-domain
Integrated optical spectrometers for biomedical sensing applications
OCT system with a free-space Michelson interferometer and an integrated optical AWG spectrometer.
Arrayed waveguide gratings (AWGs) are known as elegant and effective devices for optical wavelength separation. Significant
Figure 1b:OCT image of a three-layered scattering phantom.
improvements in robustness, size, and cost of some biomedical instrumentation may be achieved by replacing the currently used bulky spectrometers by AWGs. To employ these in such sensing applications, design trade-offs need to be made, involving wavelength range, cross-talk, polarization sensitivity, and efficiency of signal collection. We developed AWGs for two biomedical applications: optical coherence tomography (OCT) for cross-sectional imaging of, e.g., the eye or the skin [1], and Raman spectrometry, in this case for quality assessment of tooth enamel [2]. Figure 1a schematically shows a so-called spectral-domain OCT set-up. Back-reflected light from (sub-surface) structures in an object interferes with light directly from a broad-band light source. The resulting interference pattern depends on both the depth of the reflective structure and the wavelength. By spectrally analysing this pattern, the depth structure can be reconstructed, as shown for a layered “phantom” object in Figure 1b. Raman spectroscopy can provide information on the chemical composition of an object, by measuring the wavelength shift of light due to the vibrational energy of specific chemical bonds. Early-stage dental caries is inconspicuous to the naked eye, but the chemical and structural change is readily visible in the Raman spectrum. Two polarization components of a dental Raman spectrum are measured with an AWG. The quality of enamel affects the ratio between these components, as shown in the measured spectra of Figure 2. As the intensity of a Raman spectrum is typically a billion times smaller than that of the light source, efficient collection of the scattered light is of utmost importance. To this end, we have exploited the imaging properties of AWGs to provide an integrated
Figure 2: Raman spectra, measured on human teeth in two
confocal light delivery and signal collection system [3], that can be readily integrated with the spectrometer.
orthogonal polarizations with an integrated optical spectrometer, on (a) sound enamel, (b) early-stage caries.
HIGHLIGHTED PUBLICATIONS: [1] B.I. Akca, V.D. Nguyen, J. Kalkman, N. Ismail, G. Sengo, F. Sun, A. Driessen, T.G. van Leeuwen, M. Pollnau, K. Wörhoff, R.M. de Ridder, Towards spectral-domain optical coherence tomography on a chip, IEEE J. Select. Top. Quantum Electron. 18 (2012) 1223-1233. [2] N. Ismail, L.-P. Choo-Smith, K. Wörhoff, A. Driessen, A. C. Baclig, P. J. Caspers, G. J. Puppels, R. M. de Ridder, M. Pollnau, Raman spectroscopy with an integrated arrayed-waveguide grating, Opt. Lett. 36 (2011) 4629-4631. [3] N. Ismail, B. I. Akca, F. Sun, K. Wörhoff, R. M. de Ridder, M.
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Pollnau, A. Driessen, Integrated approach to laser delivery and confocal signal detection, Opt. Lett. 35 (2010) 2741-2743.
[HIGHLIGHTS] The Laser Physics and Nonlinear Optics (LPNO) group explores the generation and manipulation of coherent light in improved and novel ways. This included new concepts for lasers and nonlinear optical interactions. Research comprises wide ranges of intensities, time scales and light
Prof. dr. Klaus J. Boller
frequencies. Regarding laser concepts we investigate a novel types of laser such as based on slow
"Light displays the
with large spectral bandwidth is investigated [1], such as for sensitive and specific detection of
beauty of nature.
molecules. We devise methods to implement such nonlinear generation in waveguides for use in
We put light to work,
integrated photonics. Nonlinear generation at extreme intensities is investigated, such as to generate
for knowledge and
ultra-short pulses in the XUV wavelength range. Such radiation in combination with nano-structured
applications."
optics can enable improved spectral control [2], microscopy and XUV lithography on the nano-scale.
light in photonic structures or based on phase-locked diode arrays. Nonlinear generation of light
Laser Physics and Nonlinear Optics Ellipsometry with an undetermined polarization state Polarization-based measurements become increasingly important, both as a fundamental tool for scientific research, and as a vital
Figure 1: Schematic of the ellipsometer setup.
tool for applications in the chemical, food, and pharmaceutical industries. In surface science, it is well known that polarization based measurements are extremely sensitive when the polarization of light incident to the sample can be set and detected with high accuracy. An example of this is ellipsometry which can measure sub-monolayer changes in surface coverage. However, it was believed that ellipsometry with such precision was not possible in a remote mode using fiber-transmitted light, because fibers suffer from environmentally induced, unpredictable instabilities of their birefringence that results in a randomly varying output polarization state. We show that, in spite of this randomness, ellipsometry can be performed in a fiber based setup (see Figure 1 [3]), by actually exploiting the randomness. We demonstrate, using a polarization maintaining fiber, that the polarization output state, though undergoing random changes, still remains restricted to a sharply defined orbit on the Poincaré polarization sphere (see Figure 2 left). Once this orbit is mapped out through random walk of the polarization, the effect of the sample on the reflected light shows up as a tilt or deformation of the orbit (see Figure 2). These changes allow retrieval of the ellipsometric parameters and . Using this novel approach, we
Figure 2: Environmentally induced polarization variation of light
demonstrated that the sensitivity is again as high as required for the detection of monolayer films on surfaces.
from an optical fiber shows as a random walk of the Stokes polarization vector on the Poincare sphere, but remains bound to a well-defined orbit (left). An ellipsometric characterization of thin films is then obtained with sub-nanometer precision by measuring the tilt or deformation of such orbits, see e.g. projection on S(3)-S(4) plane (right). Measured orbits are shown for light exiting the fiber (green), for reflection on a multilayer mirror [black] and on carbon films of 0.3 nm [red] and 0.8 nm [blue] on top of the multilayer mirror.
HIGHLIGHTED PUBLICATIONS: [1] J. Storteboom, C.J. Lee, A.F. Nieuwenhuis, I.D. Lindsay, K.-J. Boller, Incoherently pumped continuous wave optical parametric oscillator broadened by non-collinear phasematching, Opt. Express 19 (2011) 21786. [2] I.V. Kozhevnikov, R. van der Meer, H.M.J. Bastiaens, K.-J. Boller, F. Bijkerk, Analytic theory of soft x-ray diffraction by lamellar multilayer gratings, Opt. Express 19 (2011) 9172. [3] F. Liu, C.J. Lee, J. Chen, E. Louis, P. J. M. van der Slot, K.-J. Boller, F. Bijkerk, Ellipsometry with randomly varying polarization states, Opt. Express 20 (2012) 870.
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[highlights] Prof. dr. Han J.G.E. Gardeniers
The research focus of the Mesoscale Chemical Systems (MCS) group is on the themes:
"Downscaling and integration of unit
n Alternative activation mechanisms for chemical process control and process
operations in chemistry is exploited to
intensification: Examples are: electrostatic control of surface processes and reactions
enhance yield and selectivity of chemical
in liquids, photochemical mciroreactors for solar-to-fuel conversion, sonochemical
reactions and product purification, and to
microreactors and microreactors with integrated work-up functionality;
improve the analysis of mass-limited (bio)
n Miniaturization of chemical analysis systems: Examples are: liquid chromatography
chemical samples. Furthermore, micro and
on a chip, microscale NMR, nanostructured gas sensors, micro optical absorption
nanostructured surfaces with integrated
cells (UV, IR); n Micro and nanostructured surfaces for biological studies: Chip-
fluidic and electronic functionality are used in
based array of bioreactors with integrated electronic and microfluidic functionality
the study of living cell and tissue behavior."
are developed for the study of neurophysiologic responses of neuronal tissue.
Mesoscale Chemical Systems LC chips with 1 million theoretical plates Figure 1: Column sections with circular pillars with a diameter of 5 µm, connected via flow distributors and a low dispersion
To cope with the ever increasing sample complexity, in particular in the Life Sciences (metabolomics, proteomics, etc.), analytical
microchannel bend. The arrows indicate the direction of liquid
instruments, like liquid chromatography (LC) systems, have continuously been improved in order to achieve higher separation
flow.
efficiencies. One relatively simple way to create a high efficiency in regular (one dimensional) LC is to fabricate very long separation columns. This has indeed been done by several research teams, using columns of tens of meters long packed with particles of 5 µm diameter or larger, which can result in efficiencies of hundreds of thousands of plates but with the obvious drawbacks of very long separation times and the need for very high pressures. The best results were obtained for a set of coupled monolithic columns (which have higher permeability than packed columns) with a total length of 12 m, giving 1.2 million plates in 2.5 hours, at quite common pressures of 400-500 bars. In collaboration with the Vrije Universiteit of Brussels, chromatographic column chips with micromachined pillar arrays columns have been continuously improved over the last decade. Pillar array columns are a powerful alternative for classical packed bed columns and monoliths, because the perfect order of pillar arrays improves (i.e. decreases) the plate height, which is the characteristic parameter describing the performance of an LC column, by a factor of 2 or more compared to a column packed with particles of similar size as the pillars, as we have demonstrated in previous work (PhD thesis of Wim De Malsche, 2008). An essential additional contribution to the improvement of LC chips was the design and microfabrication of flow distributors at the inlet and outlet of pillar array columns. The optimized flow distributor allows the connection of a pillar array column to conventional commercial chromatographic instrumentation (injectors and detectors) with a minimal effect of separation efficiency. Combining sections of pillar array columns (pillar diameter: 5 µm) connected via optimized flow distributors to low-dispersion bends (Figure 1), it was possible to fold a 3 m LC column on a fraction of a 10 cm diameter silicon wafer (Figure 2). With this chip, 1 million
Figure 2: Photograph of 3 m long pillar array column on a
theoretical plates were achieved for an unretained marker, for a column pressure of 350 bar, within only 20 minutes, which is much
silicon chip, with connecting capillaries and fittings.
faster than what had been previously been achieved.
HIGHLIGHTED PUBLICATIONS: [1] J. Vangelooven, S. Schlautmann, F. Detobel, H. Gardeniers, G. Desmet, Experimental optimization of flow distributors for pressure-driven separations and reactions in flat-rectangular microchannels, Anal. Chem. 83 (2011) 467-477. [2] W. De Malsche, J. Op De Beeck, S. De Bruyne, H. Gardeniers, G. Desmet, The
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realization of 1,000,000 theoretical plates in liquid chromatography using very long pillar array columns, Anal. Chem. 84 (2012) 1214-1219.
[HIGHLIGHTS] The Molecular nanoFabrication (MnF) group, headed by Prof. Jurriaan Huskens, focuses on nano chemistry and self-assembly. Key research elements are: supramolecular and monolayer chemistry at interfaces, multivalency, supramolecular materials, biomolecule assembly and cell patterning, nanoparticle assembly, soft and imprint lithography, chemistry in microfluidic devices, and multistep
Prof. dr. ir. Jurriaan Huskens
integrated nanofabrication schemes. Application areas are: chemical and biosensing, tissue engineering,
"Molecular
electronic devices. The group has several collaborations within MESA+, e.g. on the assembly of proteins
nanoFabrication:
and cells on patterned surfaces (with the TR group) and on nanoelectronic and spintronic devices (with
assembling the future of
the NE group). Furthermore, the group actively participates in the Twente Graduate School program
molecular matter!"
Novel NanoMaterials, and in the national programs NanoNext and Towards BioSolar Cells.
heavy metal waste handling, catalysis and synthesis, solar-2-fuel devices, and nano-, spin- and flexible
Molecular nanoFabrication A hop, skip and jump
Figure 1: Spreading of multivalent molecules on receptor interfaces: cartoon of the elementary mechanisms involved in multivalent surface diffusion.
The kinetics of multivalent (multi-site) interactions at interfaces is poorly understood despite its fundamental importance for molecular or biomolecular motion and molecular recognition events at biological interfaces (membranes). In a recent study published in Nature Chemistry, we have used fluorescence microscopy to monitor the spreading of mono-, di- and trivalent ligand molecules on a receptor-functionalized surface, and performed multi-scale computer simulations, in collaboration with Dr. Damien Thompson from Tyndall, Cork, in order to understand the surface diffusion mechanisms. Three mechanisms for multivalent surface diffusion were identified, which we dubbed walking, hopping and flying (Figure 1). Fluorescent guest molecules were printed in stripe patterns on receptor surfaces, and incubated in solutions containing varying concentrations of the same receptor, in order to induce competition and thus promote spreading (Figure 2). To our surprise, the spreading rate as a function of receptor concentration showed a complex behavior, initially increasing in speed, then decreasing, and increasing again. This could only be explained by assuming the coexistence of several spreading mechanisms (Figure 1). Analogous to chemotaxis, we found that the spreading is directional – along a developing gradient of vacant receptor sites – and is strongly dependent on ligand valency and on the concentration of a competing monovalent receptor in solution. The study shows
Figure 2:
that the interfacial behavior of multivalent systems is much more complex than that of monovalent ones.
Left: Fluorescence microscopy images (top) and integrated line profiles (bottom) of printed patterns of a divalent guest on a receptor surface after incubation in a receptor-containing solution for given amounts of time. Right: Spreading rates as a function of the receptor concentration in solution used for incubating the printed guest samples showing the unexpected decrease in spreading rate for the multivalent guests GII and GIII at intermediate receptor concentrations.
HIGHLIGHTED PUBLICATION: A. Perl, A. Gomez-Casado, D. Thompson, H.H. Dam, P. Jonkheijm, D.N. Reinhoudt, J. Huskens, Gradient-driven motion of multivalent ligand molecules along a surface functionalized with multiple receptors, Nature Chemistry 3 (2011) 317-322.
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[highlights] The group Multi Scale Mechanics (MSM) studies fluids and solids, as well as granular systems where various physical phenomena with different characteristic time- and length-scales are taking place simultaneously. At each length scale, the question arises how the mechanics at that level is determined by the properties of the underlying level, and how, in turn, the current level affects the next level. Micro-Macro theory is one way to predict and describe this
Prof. dr. Stefan Luding
hierarchy, and advanced numerical simulations help us understand the various
“How does contact mechanics at the particle
levels and their couplings. By combining numerical simulations with theory
level determine the macroscopic flow
and experiments, the Multi Scale Mechanics group aims at understanding the
properties of granular matter?”
properties of granular and related advanced materials.
Multi Scale Mechanics Figure 1: Uni-axial compression induces a pattern
Deformation induced pattern transformations in soft granular crystals
transformation in a two-dimensional regular array of particles with contrasting dimensions and softness. Here, the original
Ordered arrays of particles are excellent candidates for components of future acoustic, optical and electronic devices. The MSM
state is recovered upon unloading.
group studied, by experiments and numerical simulations, the compression of a two-dimensional regular array of millimeter scale cylindrical particles with contrasting dimensions. Under uni-axial compression the system undergoes an intriguing transformation to a new periodic pattern, as illustrated in figure 1. The transformation is smooth and homogeneous for particles with a size ratio of 0.53, and the original pattern is recovered after unloading. At a slightly larger size ratio of 0.61, compressions beyond a critical strain induce a sudden transition, reminiscent of a shear band, to a pattern that no longer returns to the initial state upon unloading. The simulations indicate that this qualitative difference is mainly determined by the size ratio of the particles, whereas their mechanical properties are of lesser importance. Future research could be done towards nano-scale mechanical systems where also e.g. light will be affected by the pattern transformation when the structures are of size of the wave-length of electromagnetic waves.
Figure 2: Snapshot of a simulation box containing 125,000 particles with a very wide distribution of radii. By developing an efficient algorithm to detect contacts in extremely polydisperse systems, we are now able to calculate the equations of state, jamming transition densities, and structural slow changes like nucleation for these systems.
HIGHLIGHTED PUBLICATIONS: [1] F. Göncü, S. Willshaw, J. Shim, J. Cusack, S. Luding, T. Mullin, K. Bertoldi, Deformation induced pattern transformation in a soft granular crystal, Soft Matter 7 (2011) 2321. [2] F. Göncü, S. Luding, K. Bertoldi, Exploiting pattern transformation to tune phononic band gaps in a two-dimensional granular crystal,
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J. Acoust. Soc. Am. 6 (2012) EL475-EL480.
[HIGHLIGHTS] The research group Membrane Science & Technology (MST) focuses on the multi-disciplinary topic of membrane science and technology for the separation of molecular mixtures. We aim at designing polymer membrane chemistry, morphology and structure on a molecular level to control mass transport phenomena. We consider our expertise to be a multidisciplinary knowledge chain
Dr. ir. Kitty Nijmeijer
ranging from molecule to process. The research program
“Molecular design of membranes
is divided into three application clusters: Energy, Water
to control mass transport.”
and Life Sciences.
Membrane Science and Technology
CH3 CH2 CH2
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Pushing the limits of block copolymer membranes for CO2 separation
O
CH3 H3C Si O CH3
y
O
O
C
C
N
CH3 O
O
O
C
C
H
Si O
CH3 m
Si O
(CH2)6
N
O
x
CH2 CH
O
(a)
y
O
O
C
C
(b)
O
H
CH3 n
Si CH3
(c)
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This paper presents an integrated concept for the design of PEO based block copolymer membranes as a method to increase the
N
CH2 CH2
H
CH3 CH3
n
O
p
CH3
CO2 permeability while maintaining the CO2/N2 selectivity. It combines the enhancing effect on the permeability of tailoring the
Figure 1: Chemical structure of (a) the PEO-ran-PPO5000 soft
molecular design of the block copolymers with that of molecular blending. The current work describes the synthesis and mass
segment, (b) the T6T6T hard segment and (c) the PDMS-PEG
transport properties of a series of such molecularly tailored PEO based membranes and a poly(ethylene glycol) based additive. PEO-
additive (80 wt.% PEG).
ran-PPO5000-T6T6T/PDMS-PEG blend membranes (Figure 1) have been synthesized and their pure gas permeation characteristics have been analyzed. The addition of the PDMS-PEG additive results in exceptionally high CO2 permeable block copolymer membranes. At 50 wt.% additive content, a CO2 permeability as high as 896 Barrer has been obtained, at sufficiently high CO2/light gas selectivities. The performance of this system (and potential other systems) exceeds the boundaries (described by Robeson) that existed until recently (Figure 2). This shows that by smart design and selection of the molecular structure of the membrane, the performance of membranes can be increased to a level formerly unknown for this type of block copolymers. The concept presented is not limited to this specific case and hence opens a window of opportunity for further development of highly permeable block copolymer systems for CO2 separation and in particular for use in post-combustion CO2 capture.
Figure 2: Robeson CO2/N2 upper bound relationship at 35°C. The data obtained in the current work for blends of the PEO-ranPPO5000-T6T6T block copolymer and the PDMS-PEG additive (n) are compared to work in literature.
HIGHLIGHTED PUBLICATION: S.R. Reijerkerk, M. Wessling, K. Nijmeijer, Pushing the limits of block copolymer membranes for CO2 separation, Journal of Membrane Science 378 (1-2) (2011) 479-484.
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[highlights] Prof. dr. G. Julius Vancso
The current research in the Materials Science and Technology of Polymers (MTP) group
"The general focus of research in the MTP
focuses on platform level research in macromolecular nanotechnology and polymer materials
group revolves around devising and building
chemistry. The applications are utilized in collaborations with specialized groups. The
tools and synthesizing molecular platforms
projects target problems aiming at controlled synthesis of stimulus responsive “intelligent�
that enable studies of macromolecular
polymers, and manipulation as well as fabrication of complex polymeric architectures in
structure and behavior from the nanometer
combination with nanoparticles, and metallic or semiconductor nanocrystals. Controlled
length scale, bottom up. This knowledge is
assembly of systems from the nanoscale to macroscopic dimensions, and their applications
then used in macromolecular materials and
in surface engineering, responsive molecular architectures, devices such as molecular
devices with enhanced or novel properties
motors, sensors and actuators, nanostructured composites, and molecular delivery are
and functions for targeted applications."
considered. The development of enabling tools such as scanning probe microscopes, and optical approaches, including single molecule imaging, complements this effort.
Materials Science and Technology of Polymers Polymeric Coatings for Luminscent Nanocrystals Quantum Dots (QD) are semiconducting nanocrystals that show strong, nearly monochromatic optical fluorescence emission. The color of this emission can be tuned by changing the size of the nanocrystal. The stable and strong fluorescence, and the tunability of the color make these QDs interesting candidates as optical markers in biological and biomedical research. A protocol describing a new class of polymeric coating (Figure 1) for QDs was developed by the Materials Science and Technology group in collaboration with researchers from Singapore. The method described in the protocol is based on functionalization of an anhydride polymer Figure 1: Generic structure of the coating polymer. (R is a
backbone with nucleophilic agents. Small functional groups, bulky cyclic compounds and polymeric chains can be integrated with
functional group, which can show chemical reactivity)
the coating prior to solubilization. The polymer-coated QDs display good colloidal stability in water, which is sufficient for many proposed applications, such as in cell imaging. They furthermore can be covalently coupled to other structures thus allowing one to integrate them in hierarchical, functional materials. To demonstrate bio-labelling applications, the team carried out cell imaging of the mammalian cancer cells C-6 (see image).
Figure 2: Image of mammalian cancer cells marked with red light-emitting QDs. The blue color is emitted by the stained cell nuclei.
´ HIGHLIGHTED PUBLICATION: D. Janczewski, N. Tomczak, M.-Y. Han, G.J. Vancso, Synthesis of functionalized amphiphilic polymers for coating quantum dots, Nature
Protocols 6 (2011) 1546-1553.
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[HIGHLIGHTS] The Mathematics of Computational Science (MaCS) group focuses on the mathematical aspects of advanced scientific computing. The two main research areas are the development, analysis and application of numerical algorithms for the (adaptive) solution of partial differential equations and the mathematical modeling of multi-scale problems making these accessible for computation. Special emphasis is put on the development
Prof. dr. ir. Jaap J.W. van der Vegt
of discontinuous Galerkin finite element methods, efficient (parallel) solution algorithms,
“Without Mathematics there
applications are in the fields of (dispersed) two-phase and granular flows, turbulent flows
will be no significant advances in
(including particles, combustion, rotation and buoyancy), free surface flows, energy
Computational Science.”
systems, bio-fluid mechanics and computational electromagnetics.
and the modeling of complex turbulent flows using Large Eddy Simulation. Important
Mathematics of Computational Science A novel numerical method for multi-fluid flow computations Multi-fluid problems, such as droplets in inkjet printing and gas bubbles in small micro devices require the accurate capturing of the liquid-gas interface. Many numerical algorithms tend to diffuse the interface and do not capture the details of the complex dynamics at the interface, such as instabilities and the break-up and coalescence of the interface. We developed a novel numerical method for multi-fluid computations by combining a space–time discontinuous Galerkin finite element discretization of the multi-fluid equations with a level set method and cut-cell based interface tracking. The space–time discontinuous Galerkin method offers high accuracy, an inherent ability to handle discontinuities and a very local stencil, making it relatively easy to combine with local mesh refinement to capture flow details near the interface. The front tracking is incorporated via cut-cell mesh refinement to ensure a sharp interface between the fluids. To compute the interface dynamics the level set method is used because of its ability to deal with merging and breakup. Also, the level set method is easy to apply in higher dimensions. Small cells arising from the cut-cell refinement are merged to improve the stability and performance. The interface conditions are incorporated in the numerical discretization for the interface and the space-time discontinuous Galerkin discretization ensures that the scheme is conservative as long as the numerical fluxes are conservative. The numerical method is demonstrated on a helium bubble in a tube filled with air modeled with the compressible Euler equations. A shock wave causes a Rayleigh-Taylor instability at the helium-air interface which is accurately modeled by the numerical algorithm.
Figure: Density contours of helium bubble-air shock interaction test using a space-time discontinuous Galerkin finite element method with a combined cut-cell level set approach.
HIGHLIGHTED PUBLICATION: W.E.H. Sollie, O. Bokhove, J.J.W. van der Vegt, Space-time discontinuous Galerkin finite element method for two-fluid flows, Journal of Computational Physics, 230 (2011) 789-817.
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[highlights]
Figure 1: Upon membrane binding -synuclein oligomers
Prof. dr. Vinod Subramaniam
The Nanobiophysics (NBP) group is focusing on research in molecular and cellular biophysics at the
“Our goal is to perform
related protein aggregation, in protein-ligand interactions on cell surfaces, and in the emerging field
world-class research in
of nanobiophotonics, where we use the toolbox of nanophotonics to manipulate biological fluorophores.
molecular and cellular
Nanoscale functional imaging, involving quantitative measurements of dynamic molecular and cellular
biophysics at the nanometer
biophysical processes at high spatial, temporal, and chemical resolutions, is an integral element of
scale, to gain new
our research. We are also fascinated with developing cutting-edge technologies to address these
insights into fundamental
challenging research questions. Strong collaborations with other MESA+ groups and national and
mechanisms related to
international collaborators are essential elements of our work. We are closely involved in NanoNextNL,
disease.”
as project leaders, and as programme director within the theme Nanomedicine.
nanometer scale. We have intellectual interests in the mechanisms of neurodegenerative disease
Nanobiophysics
integrate into the lipid bilayer of large unilamellar vesicles (LUVs) where they form pore like structures or cause membrane thinning. Using chemical bleaching of C6-NBD-PC by dithionite
Unraveling the mechanisms of -Synuclein oligomer-membrane interactions
we could not only observe a fast influx of dithionite but also an additional slow loss of fluorescence presumably due to an
-Synuclein is a small intrinsically disordered protein that is abundantly expressed throughout the human brain. Aggregation of
enhanced lipid flip-flop.
this protein is implicated in the onset and progression of Parkinson’s disease, and there is compelling evidence that the interaction of small oligomeric aggregates of the proteins with lipid membranes contributes to neurotoxicity. Using an assay based on the
(a)
bleaching of fluorescent lipids, postdoctoral fellow Dr. Martin Stöckl has recently shown that -synuclein oligomer-induced impairment of membrane integrity is not limited to the formation of permanent membrane spanning pores. Using lipid mixtures with a varying fraction of negatively charged lipids, a sharp cutoff where the impairment of membrane integrity sets in was observed, suggesting that only membranes with an initial destabilization are susceptible. Detailed studies reveal an additional mechanism attributed to an enhanced lipid flip-flop which has been observed for the first time. These findings indicate that an important mechanism for amyloid
(b)
oligomer toxicity lies in the disruption of lipid packing in the membrane.
Atomic force microscopy: probing frequency-dependent elasticity properties at the nanoscale We have also studied amyloid fibrils of -Synuclein, which are typically several micrometers in length and 3 to 8 nm in diameter. Using newly developed nanomechanical property mapping methods, such as Pulsed Force Microscopy (PFM), Harmonic Force Microscopy Figure 2: (a) Height and stiffness of low-density polyethylene
(HarmoniX) and PeakForce QNM, it is possible with AFM to determine the elastic properties of these protein fibrils on the nanoscale.
(LDPE) islands in a polystyrene (PS) surrounding, obtained with
Interestingly, all the modes mentioned above operate at a different frequency, and one of the outstanding questions is whether the
Pulsed Force Microscopy. (b) Stiffness of LDPE as a function of
operating frequency influences the measured elastic modulus of the material. Kim Sweers, a PhD student who graduated in May
the probing frequency obtained with PFM (closed diamonds) and
2012, used Pulsed Force Microscopy (PFM) and nano-indentation to mechanically characterize a sample consisting of low-density
nano-indentation (open circles).
polyethylene (LDPE, E=0.2 GPa) islands in polystyrene (PS, E=2 GPa). The material’s stiffness did indeed increase significantly with an increasing frequency, and as a result of this also the apparent height of the PS phase.
HIGHLIGHTED PUBLICATIONS: [1] M.T. Stöckl, M.M.A.E. Claessens, V. Subramaniam, Kinetic measurements give new insights into lipid membrane permeabilization by
-synuclein oligomers, Mol. BioSyst. 8 (2012) 338-345. [2] K.K.M. Sweers, K.O. van der Werf, M.L. Bennink, V. Subramaniam, Spatially resolved frequency-dependent
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elasticity measured with pulsed force microscopy and nanoindentation, Nanoscale (2012) 2072-2077.
[HIGHLIGHTS] Prof. dr. ir. Wilfred G. van der Wiel
The Chair NanoElectronics (NE) performs research and provides education in the field of nano
“Nanoelectronics
synergetically combining aspects of Electrical Engineering, Physics, Chemistry, Materials Science,
is where electrical
and Nanotechnology. NE consists of more than 25 group members is actively looking for people to join.
engineering,
The field of nanoelectronics comprises a mix of intriguing physical phenomena and revolutionary novel
physics, chemistry,
concepts for devices and systems with improved performance and/or entirely new functionality.
materials science
NE has some dedicated infrastructure including MBE deposition, scanning tunneling microscopy,
and nanotechnology
cryogenic measurement systems down to temperatures of 10 mK in combination with magnetic fields
inevitably meet.”
up to 10 tesla.
electronics. Our research involves hybrid inorganic-organic electronics, spin electronics and quantum electronics. The research goes above and beyond the boundaries of traditional disciplines,
NanoElectronics
Figure 1: Kondo effect. a] Temperature dependence of the (T)-min
normalized resistivity, norm(T)= p(15OK)-Pmin x Au(150 K) of a (99.99%) pure Au film (green hexagons), and the same Au film with inserted molecular monolayers made from mixed Co
Tunable doping of a metal with molecular spins
complex[x%]/Zn complex[(100-x)%] solutions with x = 0 (orange diamonds), 25 (blue down triangles), 50 (green up triangles), 67 (red dots), and 100 (black squares). Inset: structure of metal
The mutual interaction of localized magnetic moments and their interplay with itinerant conduction electrons in a solid are
terpyridine complex, with “M” being either Co or Zn. b] Data of
central to many phenomena in condensed-matter physics, including magnetic ordering and related many-body phenomena such
(a) with the bare Au film curve subtracted. The solid curves are
as the Kondo effect, the Ruderman–Kittel–Kasuya–Yoshida interaction and carrier-induced ferromagnetism in diluted magnetic
fits to NRG theory for a S = ½ Kondo system. c] The experimental
semiconductors. The strength and relative importance of these spin phenomena are determined by the magnitude and sign of the
data with both normalized temperature and resistivity values are
exchange interaction between the localized magnetic moments and also by the mean distance between them. Detailed studies of
compared with numerical renormalization group (NRG) theory
such systems require the ability to tune the mean distance between the localized magnetic moments, which is equivalent to being
for S =1/2, showing very good agreement.
able to control the concentration of magnetic impurities in the host material. We have developed a conceptually novel approach for doping a non-magnetic metal film with localized magnetic moments that involves depositing a monolayer of metal ligand complexes onto the film [1]. The metal ions in the complexes used are cobalt and zinc, and the concentration of magnetic impurities in the gold film can be controlled by varying the relative amounts of cobalt complexes (which carry a spin) and zinc complexes (which have zero spin). Kondo and weak localization measurements demonstrate that the magnetic impurity concentration can be systematically varied up to ~800 ppm without any sign of interimpurity interaction (see Figure 1). The impurity concentration in the metal is directly proportional to the molecular spin dopant concentration in solution (see Figure 2). Moreover, we find no evidence for the unwanted clustering that is often produced when using alternative methods. This work should pave the way for the further study of the spin phenomena that lie at the very
Figure 2: Tunable molecular spin doping. Two different quantities
heart of solid-state physics. The work was performed at MESA+ in a collaboration of the NanoElectronics (NE) and Molecular
plotted as a function of Co complex fraction in the donor solution:
nanoFabrication (MnF) groups.
Magnetic impurity concentration, c, derived from Kondo measurements (black squares); phase coherence length, l(2 K) (blue dots), derived from weak localization measurements.
HIGHLIGHTED PUBLICATION: T. Gang, M. Deniz Yilmaz, D. Ataç, S.K. Bose, E. Strambini, A.H. Velders, M.P. de Jong, J. Huskens, W.G. van der Wiel, Tunable Doping of a Metal with Molecular Spins, Nature Nanotechnology 7 (2012) 232.
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[highlights] The aim of the NanoElectronic Materials (NEM) group is to advance the field of materials science, with a focus on nanomaterials for applications in electronic devices. The research is based on current trends in nanomaterials science and developments within MESA+, such as the controlled growth of materials, control of their structure, and understanding of the structure-property relations. The research is focused on three areas: Artificial Materials, Functional and Smart
Prof. dr. ing. Guus Rijnders
Materials for Devices, as well as In-situ Characterization of Film Growth and
"Recent advances in materials engineering at the
Interface Processes. These areas have in common that they find their basis in
atomic scale facilitated a significant revival in the
materials science, bridging major disciplines within MESA+, i.e., Chemical
field of functional complex oxide materials."
Engineering, Applied Physics, and Nanotechnology.
NanoElectronic Materials Metallic and Insulating Interfaces of Amorphous SrTiO3-Based Oxide Heterostructures A new type of conducting interfaces in complex oxide heterostructures based on strontium titanate has been created in collaboration with researchers from the Technical University of Denmark. The conductance confined at the interface of complex oxide heterostructures have been shown to provide new opportunities to explore nanoelectronic as well as nanoionic devices. We have realized metallic interfaces in SrTiO 3 -based heterostructures with various insulating overlayers of amorphous LaAlO 3, SrTiO 3, and yttria-stabilized zirconia films. The interfacial conductivity results from the formation of oxygen vacancies near the interface, suggesting that the redox reactions on the surface of SrTiO 3 substrates play an important role. The result is important for understanding the origin of the metallic interface in epitaxial heterostructures, which is essentially a quasi-2D electron gas between two insulating oxides, one of which is SrTiO 3.
Figure 1: Top panel: High-resolution scanning transmission electron microscopy image (cross section) of an atomically sharp interface between amorphous LaAlO 3 and crystalline SrTiO 3. Bottom panel: Electron energy loss spectroscopy image, green=La, purple=Ti. (EMAT, Antwerp)
Highlighted publication: Y. Chen, N. Pryds, J.E. Kleibeuker, G. Koster, J. Sun, E. Stamate, B. Shen, G. Rijnders, S. Linderoth, Metallic and Insulating Interfaces of
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Amorphous SrTiO3-Based Oxide Heterostructures, Nanoletters 11 (9) (2011) 3774-3778, doi: 10.1021/nl201821j.
[HIGHLIGHTS] Prof. dr. Serge J.G. Lemay
The goals of the group NanoIonics (NI) are to add to fundamental
“The physics of ions in liquid are directly
understanding of electrostatics and electron transfer in liquid,
relevant to a surprisingly wide array of
and to explore new concepts for fluidic devices based on this new
research areas of current scientific and
understanding. Our experimental tools, which are largely dictated
societal interest. These include nanoscience
by the intrinsic nanometer scale of the systems that we study,
(the ‘natural’ length scale for ions), energy
include single-molecule techniques borrowed from biophysics,
(fuel cells, supercapacitors), neuroscience
sensitive electronics, and lithography-based microfabrication.
(signal transduction, new experimental
Through its focus on nanoscience and its multidisciplinary
tools), and health and environment
nature, this research is a natural fit for MESA+.
monitoring (new and better sensors)."
NanoIonics A new single-molecule technique based on the ping-pong effect Electrochemical detection is ideally suited for miniaturized sensors, as it directly translates chemical information into electrical signals that can be manipulated on the same chip. Because a typical electrochemical reaction involves the transfer of only one or a few electrons between a molecule and an electrode, however, detecting a single molecule in this way represents an enormous challenge (at least at room temperature, where most real-world sensors need to operate!). To solve this problem, we have developed a new fluidic device, the nanogap. This consists of two electrodes separated by a thin (<100 nm) layer of liquid, as shown in figure 1(a). Different voltages are applied to the two electrodes such that one electrode donates electrons to electrochemically active molecules while the other electrode withdraws electrons. Any electrochemically active molecule trapped between the electrodes thus acts as a ping-pong ball, shuttling electrons from the first to the second electrode and giving rise to a small (but measurable) current. Because our device is open to an outside reservoir, the number of molecules in the nanogap fluctuates with time, giving rise to corresponding steps in the current measured at the electrodes (figure 1(b)). Our goal in the coming years will be to exploit this new capability for fundamental experiments on stochastic detection and as a platform for more selective electrochemical sensors.
Figure: (a) Cross-section image of an electrochemical nanogap device. The spacing between the top and bottom electrode in this device is 31 nm, allowing very fast shuttling of electrons between the electrodes. (b) Measured current versus time for the top (red) and bottom (black) electrodes. The plateaus in the current correspond to 0, 1 or 2 molecule being present in the device at any given time. The currents are equal but opposite because each electron delivered to the top electrode is ejected from the bottom electrode.
HIGHLIGHTED PUBLICATION: M.A.G. Zevenbergen, P.S. Singh, E.D. Goluch, B.L. Wolfrum, S.G. Lemay, Stochastic sensing of single molecules in a nanofluidic electrochemical device, Nano Letters 11 (2011) 2881-2886.
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[highlights] Fluid flow on the nanoscale is fundamentally different from fluid flow on the microscale, since another set of forces becomes dominant. In the Nanofluidics for Lab on a Chip Applications group (NLCA) we explore fundamental
Figure 1: The principle of energy harvesting by the streaming
Prof. dr. Jan Eijkel
phenomena of nanoscale fluidics and apply them to subjects
"The Nanofluidics for Lab on a Chip Applications
ranging from green energy generation to single-molecule
group aims to perform innovative fluidic research for
research and from innovative separation methods to point of
biomedical and energy applications."
care diagnostics.
potential. The useful output power obtained in the lamp equals ILOAD*VS. Due to the low electrical resistance of the aqueous solution, VS must be small to prevent all current from leaking back as IC through the channel. This limits the conversion efficiency and the lamp burns only weakly.
Nanofluidics for Lab on a Chip Applications Green energy from flowing water with bubbles Green energy has become an important topic in scientific research, mainly because society is in dire need for novel environmentallyfriendly energy conversion systems. Lab on a Chip technology provides new opportunities to convert fluidic mechanical energy to electrical energy. We use a fluidic approach to convert mechanical to electrical energy. When a microfluidic channel with glass walls is filled with an aqueous solution, the glass walls become electrically charged due to the dissociation of surface groups. This leads to the formation of an diffuse cloud of mobile counter-ions in the solution directly adjacent to the wall. When we pump the solution through the
Figure 2: Injection of gas bubbles into the channel increases the
channel, these mobile ions move with the flowing liquid thereby creating an electrical current (the â&#x20AC;&#x2DC;streaming currentâ&#x20AC;&#x2122;, I S in figure
electrical resistance of the channel. As a result a much larger VS
1). By placing electrodes at the two ends of the channel, we can capture this current and when we lead it though an external load
can be obtained, and hence a higher output power ILOAD*VS. The lamp
we can harvest electrical energy. This is a straightforward and simple way to convert mechanical energy into electrical energy.
burns much more brightly.
The Achilles heel of the above classical mechanism is, that the current not only flows through the load doing useful work (I LOAD) , but also, uselessly, back through the channel (IC) because the filling solution is electrically conductive. The conversion efficiency as a result remains low. We now have mended this Achilles heel by injecting air bubbles into the channel via a fluidic T-split (figure 2). The air bubbles block the backflow of current and thus increase the current flow through the external load. For the same amount of input energy we now will harvest more output energy. Figure 3 shows how the conversion efficiency increases with increasing gas pressure, generating more and more bubbles in the channel. A more than 100-fold increase in efficiency was observed due to bubble injection.
Figure 3: The conversion efficiency (relative to the efficiency without gas bubbles), as a function of the gas pressure. The efficiency can be increased more than 100-fold using bubble injection. Inset: The
Though the efficiency improvement is remarkable, the total efficiency is still low (inset figure 3). Our research in this NWO-funded
total process efficiency however is still low (inset) and efforts are
TOP program is now aiming at employing gas-liquid flow to further increase the conversion efficiency.
focussed on further improvement.
Highlighted publication: Y. Xie, D. Sherwood, L. Shui, A. van den Berg, J.C.T. Eijkel, Strong enhancement of streaming current power by application of two phase Flow,
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Lab Chip 11 (2011) 4006.
[HIGHLIGHTS] Optical Sciences (OS) is a dynamic and multidisciplinary research group, whose infrastructure and expertise ranges from near-field probing of (single) molecules and materials through nonlinear spectroscopy and imaging to nanostructure fabrication and ultrafast laser spectroscopy. The integration of phase-shaped
Prof. dr. Jennifer L. Herek
femtosecond laser pulses and adaptive learning algorithms within these themes
“Fundamental research in
nanomaterials science. Applications include improving the efficiency of solar-
spectroscopy and imaging
driven photovoltaic and photoc atalytic devices, chemically-selective imaging
shines light on innovation and
in biology and pharmacology, and studying wave propagation and nonlinear
technology.”
phenomena in nanostructured materials.
is leading to exciting new research at the interface of chemistry, physics and
Optical Sciences Exploiting optical and molecular phase relations to improve imaging Our research on nonlinear microspectroscopy has led to a revolutionary new approach that provides an intuitive and unified description of the various signal contributions, allowing for direct extraction of the vibrational response [Figure 1]. Three optical fields create a pair of interfering Stokes-Raman pathways to the same vibrational state. Frequency modulating one of the fields leads to amplitude modulations on all of the fields. This vibrational molecular interferometry technique allows imaging at high speed free of nonresonant
Figure 1: Comparing the new vibrational molecular
background, and is able to distinguish between electronic and vibrational contributions to the total signal.
interferometry (VMI) technique to conventional CARS
Identifying complex molecules often entails detection of multiple vibrational resonances, especially in the case of mixtures. Phase
imaging shows a marked improvement in signal clarity due to
shaping of broadband pump and probe pulses allows for the coherent superposition of several resonances, such that specific molecules
background suppression.
can be detected directly and with high selectivity. We have developed an approach for combining spectral phase shaping and closedloop optimization strategies to perform chemically-selective nonlinear microscopy [Figure 2]. To predict the optimal excitation profile we employ evolutionary algorithms that use the vibrational phase responses of five distinct molecules with overlapping resonances and investigate the effect of phase instability on the optimization.
Figure 2: The coherent control learning loop aims to find optimal pulse shapes to enhance specific chemical signals in nonlinear imaging.
HIGHLIGHTED PUBLICATIONS: [1] A.C.W. van Rhijn, A. Jafarpour, M. Jurna, H.L. Offerhaus, J.L. Herek, Coherent control of vibrational transitions: Discriminating molecules in mixtures, Faraday Discussions 153 (2011) 227-235, [2] E.T. Garbacik, J.P. Korterik, C. Otto, S. Mukamel, J.L. Herek, H.L. Offerhaus, Background-free nonlinear microspectroscopy with vibrational molecular interferometry, Physical Review Letters 107 (2011) 253902.
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[highlights] The goal of the Physics of Complex Fluids (PCF) group is to understand and
a) without EW
b) with EW
Prof. dr. Frieder Mugele
control the physical properties of liquids and solid-liquid interfaces from
â&#x20AC;&#x153;Nanoscience and -technology are
molecular scales up to the micrometer meter range. We are particularly
characterized by large surface-to-volume
interested in i) nanofluidics, ii) (electro)wetting & microfluidics, iii) soft matter
ratios. At PCF, we develop strategies to
mechanics. Our research connects fundamental physical and physico-
understand and manipulate complex fluid
chemical phenomena in nanotribology and -lubrication, microfluidic two-
flows on the micro- and nanometer scale
phase flow, static and dynamic wetting, superhydrophobicity, drop impact,
using various controls of wetting behavior
drop evaporation to practically relevant applications such as enhanced oil
and interfacial properties including in
recovery, inkjet printing, immersion lithography, lab-on-a-chip systems, and
particular electrowetting.â&#x20AC;?
optofluidics.
Physics of Complex Fluids Say goodbye to coffee stains: how electrowetting-driven microfluidics controls pattern formation in evaporating colloidal suspensions Figure 1: Coffee stain formation (a) and its suppression (b) with electrowetting (EW). EW excitation during the evaporation is
Drying drops of complex fluids such as coffee, paint, and blood typically leave behind ring-shaped solid residues on solid surfaces
achieved by applying an AC voltage to interdigitated electrodes
commonly known as coffee stains. This ubiquitous phenomenon is caused by an evaporation-driven flow from the center of the drop
in the substrates (red and blue dashes in the top of (b). Images in
towards the edge that carries along the solute. The resulting heterogeneous deposition of material is undesired in various coating
the bottom are for micrometer-sized colloidal particles.
processes involving drop deposition, such as including inkjet printing of complex fluids, micro-array technology, and MALDI sample preparation. We show that electrowetting can be used to generate flows inside evaporating drops that compensate the evaporationdrive flux and prevent solute accumulation at the drop edge. Rather than being distributed in a wide ring, the entire solute remains concentrated in a single spot (see figures). This complex microfluidic effect allows to improve the signal-to-noise ratio of MALDI mass spectrometry by more than an order of magnitude.
Figure 2: Numerically calculated trajectories of tracer particles in an oscillating drop water drop in ambient oil with timedependent contact angle as in electrowetting experiments. The spiraled trajectories (left) can be decomposed into a timeperiodic oscillatory motion and a net time averaged flow (right), which leads to a vortex within the drop. The latter is responsible for suppressing the coffee stain formation in Fig. 1.
Highlighted publications: [1] H.B. Eral, D. Mampallil, M.H.G. Duits, F. Mugele, Suppressing the coffee stain effect: how to control colloidal self-assembly in evaporating drops using electrowetting, Soft Matter 7 (2011) 4954. [2] J.M. Oh, D. Legendre, F. Mugele, Shaken not stirred - on internal flow patterns in oscillating sessile drops,
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EuroPhys. Lett. 98 (2012) 34003.
[HIGHLIGHTS] Photocatalysis is based on the use of light activated catalysts in chemical conversion. Practical application is limited because of problems in light management, such as mismatch
Prof. dr. Guido Mul
in catalyst sensitivity and solar spectrum, the limited ability of photo-excited states to induce
“We strive to be a major player in
electron transfer reactions, and lack of efficient light exposure of catalysts in reactors. The
the solar to fuel research arena,
Photocatalytic Synthesis (PCS) group aims at understanding the role of both the physical and
making use of the expertise
chemical properties of innovative materials in establishing photocatalytic transformations,
and outstanding facilities of the
to allow improved catalyst design. We also study the effect of process conditions and reactor
MESA+ institute to construct
geometry on performance, to establish operation of devices with high efficiency. Fields of
nanostructured materials and
application we target are: 1) conversion of CO2 and H2O to hydrocarbons, 2) alkane activation,
devices.”
and 3) purification of waste streams (air and water).
Photocatalytic Synthesis Revealing the operation mechanism of a solar to fuel catalyst Photocatalytic conversion of CO2 and H2O to fuel-like molecules is an ideal reaction to store solar energy in the form of chemical energy and to close the carbon cycle (the solar to fuel process). One of the most efficient inorganic photocatalysts for this process is based
Figure 1: Overview of the multiple batch reactor used to
on a silica matrix functionalized with isolated Titania sites, known as Ti-SBA-15 (SBA-15 is a silica matrix with regular channels). Little
study solar to fuel chemistry of up to 12 photo-catalysts
is known about the nature of the intermediates involved in the reaction, and the ways these are formed and decomposed to the final
simultaneously. Analysis of the gas phase products is performed
products. We have performed a systematic study of the light induced reaction of potential intermediates (H2, CO, CH2O (formaldehyde))
by micro-Gas Chromatography.
over the Ti-SBA-15 catalyst, using an advanced set-up for photocatalysis evaluation (Figure 1). Based on the results, we believe in a mechanism for CO2 reduction in which CO and formaldehyde are important intermediates, and in which transient Ti–OOH species are likely involved (Figure 2). We currently explore mild steam treatment of the catalyst, to create a higher effective quantity of accessible sites. Surface modification of SBA-15 with Lewis bases (primary, secondary, and tertiary amines) to enhance CO2 adsorption is another direction we pursue. This increases the probability of electron transfer from the photo-excited sites to CO2, which is most likely the rate limiting step.
Figure 2: Illustration of the global description of the mechanism of solar to fuel synthesis over catalytic Ti-centers (Ti-OH) embedded in a silica matrix, yielding methane, ethane, and ethylene by conversion of CO2 and H2O.
HIGHLIGHTED PUBLICATION: C. Yang, J. Vernimmen, V. Meynen, P. Cool, G. Mul, Journal of Catalysis 284 (2011) 1-8
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[highlights] The research field of the Physics of Interfaces and Nanomaterials (PIN)
(a)
group involves controlled preparation and understanding of interfaces, low-dimensional (nano)structures and nanomaterials. We focus on systems
(b)
Figure 1: (a) Sum of two consecutive LEEM frames with acquisition time 80 ms. The light grey area refers to the mesa which has collapsed into a hemisphere (dark area) in the second
Prof. dr. ir. Harold J.W. Zandvliet
that (1) rely on state-of-the art applications or (2) can potentially lead to
“Emerging nanoscopic techniques, such
nanometer length scale the material properties depend on size, shape and
as low energy electron microscopy and
dimensionality. A key challenge of our research activities is to obtain control
He ion microscopy, have provided us
over the properties in such a way that we are able to tailor the properties for
with new insights that went far beyond
(device) applications, ranging from nano/micro-electronics, nano-electro
our wildest expectations.”
mechanical systems and wettability to sustainable energy related issues.
future applications. Our research interest is driven by the fact that on a
Physics of Interfaces and Nanomaterials
frame. (b) Cartoon of the process.
Ultrafast decay of Pb-islands on Ni(111) The morphology of thin films is subject to a sometimes complex interplay between kinetics and thermodynamics of the film-substrate. A nice, unanticipated example of the possible intricacy of processes underlying the evolving morphology was observed during the growth of Pb/Ni(111) at 474 K: 38 monolayers high Pb-mesas develop, which only cover 31% of the substrate. These flat-topped islands are stabilized by quantum well states in the Pb-film, i.e. standing waves with the lead Fermi wavelength. Slow heating makes the Pbmesas collapse into hemispheres at ~525 K, i.e. well below the melting temperature. Figure 1 illustrates this process. The collapse is incredibly fast: a billion Pb-atoms move within 2 milliseconds over hundreds of nanometers! This spectacular diffusivity outnumbers the values for atomic events, as obtained from SPM and first principle calculations, by six orders of magnitude! Improved knowledge of physics at the mesoscopic length scale must be developed to understand the process.
Knudsen gas provides nanobubble stability Figure 2: Knudsen gas streaming and nanobubble geometry. (a) The broken symmetry created between one solid surface and
Surface nanobubbles are a recent discoveries in interfacial physics. They are nanoscopic gaseous domains that form at the solid/liquid
one ‘leaky’ liquid/gas interface leads to bulk upwards flow in the
interface. The fundamental interest focuses on the fact that they are surprisingly stable to dissolution, lasting for at least 10 orders
Knudsen gas. (b) The tangential component of the bulk Knudsen
of magnitude longer than the classical expectation. We provide a model for the remarkable stability of surface nanobubbles to bulk
gas flow drives a bulk liquid flow due to the continuity of shear
dissolution. The key to the solution is that the gas in a nanobubble is of Knudsen type. This leads to the generation of a bulk liquid
stress at the liquid/gas interface. (c) Finally, due to conservation
flow which effectively forces the diffusive gas to remain local. Our model predicts the presence of a vertical water jet immediately
of mass, this gas-rich liquid stream circulates upwards at the
above a nanobubble, with an estimated speed of a few m/s in good agreement with our atomic force microscopy measurements.
bubble apex and back around to the three-phase line, effectively transporting the diffusive outfluxing gas back to the three-phase line for re-entry.
HIGHLIGHTED PUBLICATIONS: T.R.J. Bollmann, R. van Gastel, H.J.W. Zandvliet, B. Poelsema, Anomalous decay of electronically stabilized lead mesas on Ni(111), Physical Review Letters 107(13) (2011) 136103. [2]. T.R.J. Bollmann, R. van Gastel, H.J.W. Zandvliet, B. Poelsema, Quantum size effect driven structure modifications of Bi films on Ni(111), Physical Review Letters 107(17) (2011) 176102. [3]. J.R.T. Seddon, H.J.W. Zandvliet, D. Lohse, Knudsen gas provides nanobubble stability, Physical Review Letters 107(11) (2011) 116101. [4] J.R.T. Seddon, E.S. Kooij, B.
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Poelsema, H.J.W. Zandvliet, D. Lohse, Surface bubble nucleation stability, Physical Review Letters 106(5) (2011) 056101.
[HIGHLIGHTS] Men has been able to design, build and integrate electronic circuits very
Prof. dr. ir. Hajo Broersma
successfully, but it is a huge challenge to build complex, fault tolerant
"Evolution has a huge impact
managed to do this through a relatively simple process of evolutionary
on living organisms and their
testing and modifying, and it succeeded to do so in a universe of great
successful survival. Now is the time
physical complexity. Within the Programmable NanoSystems (PNS) group
to apply fast computer-controlled
we explore the theoretical and experimental possibilities of using systems of
evolution to dead matter in order to
nanomaterials as a black box for computational tasks by developing genetic
produce energy-efficient and useful
and evolutionary algorithms to control and modify the external impulses that
components for our future survival."
will be used to (re)configure the computational properties of the material.
systems for more complicated functionality. Interestingly, nature itself has
Figure 1: a schematic illustration of the set-up.
Programmable NanoSystems NASCENCE: Nanoscale Engineering for Novel Computation using Evolution
Figure 2 (a): a prototype interface.
NASCENCE is a FET research project within the framework of the Call FP7-ICT-2011.9.6 Unconventional Computation (UCOMP). The aim of this project is to model, understand and exploit the behaviour of evolving nanosystems (e.g. networks of nanoparticles, carbon nanotubes or films of graphene) with the long term goal to build information processing devices exploiting these architectures without reproducing individual components. With an interface to a conventional digital computer we will use computer controlled manipulation of physical systems to evolve them towards doing useful computation. During the project our target is to lay the technological and theoretical foundations for this new kind of information processing technology, inspired by the success of natural evolution and the advancement of nanotechnology, and the expectation that we soon reach the limits of miniaturisation in digital circuitry (Moore's Law). The mathematical modelling of the configuration of networks of nanoscale particles combined with the embodied realisation of such systems through computer controlled stochastic search can strengthen the theoretical foundations of the field while keeping a strong focus on their potential application in future devices.
Figure 2 (b): the material disc with a micro-electrode-array.
Members of the consortium have already demonstrated proof of principle by the evolution of liquid crystal computational processors for simple tasks, but these earlier studies have only scraped the surface of what such systems may be capable of achieving. With this project we want to develop alternative approaches for situations or problems that are challenging or impossible to solve with conventional methods and models of computation. Achieving our objectives fully would provide not only a major disruptive technology for the electronics industry but probably the foundations of the next industrial revolution. Overall, we consider that this is to be a highly adventurous, high risk project with an enormous potential impact on society and the quality of life in general. Apart from the Programmable NanoSystems group, other UT groups involved are NanoElectronics, Mathematics of Computational Science, Formal Methods and Tools, and Computer Architectures for Embedded Systems. The other EU consortium partners involved in the NASCENCE project are located in Durham, Lugano, Trondheim and York.
Figure 2 (c): a film of nanotubes on the array.
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[highlights] Prof. dr. Detlef Lohse
The Physics of Fluids (PoF) group is studying
“The physics of fluids
and macro-scale. We use both experimental,
is very different on the
theoretical, and numerical techniques and we
nano- and micro-scale
do both fundamental and applied research. Our
as compared to the
main research areas are:
macro-scale and offers
n Turbulence and Two-Phase Flow
various challenges of both
n Granular Flow
fundamental and applied
n Biomedical Application of Bubbles
character.”
n Micro- and Nanofluidics
various flow phenomenona, both on a micro-
Physics of Fluids Order-to-disorder transition in a coffee stain Figure 1: Coffee stains with their characteristic dark rings on a desk.
When a droplet containing suspended particles, such as coffee, evaporates, a ring-shaped stain is left behind on the substrate; see Fig. 1. This coffee-stain effect was first explained by Robert Deegan et al. [1]: in an evaporating drop with a pinned contact line, a capillary flow is generated to replenish the liquid that has evaporated from the drop edge. This flow drags along the particles, which are then deposited at the contact line. We have studied the dynamics of the ring stain formation in water drops with polystyrene particles [2]. As shown in Fig. 2, the remaining stains showed a remarkable structure: in the outermost layers of the stain, the particles have aggregated in a crystalline way, whereas further inwards the particle packing becomes very disordered. To explain this peculiar particle ordering, it is crucial to understand the dynamics of the droplet evaporation. To this end, we filmed the droplets simultaneously from the sides and from below, and performed micro-PIV to measure the velocity field inside the droplets. A rushhour of particles was observed during the last moments of the droplet’s life: the particle velocity increases dramatically as the droplet height decreases to zero. This temporal divergence of the velocity can be understood quantitatively from simple mass conservation. This is induces a diverging radial velocity at the of the droplet life. The order-to-disorder transition in the remaining stain can be explained by this rush-hour behavior in the particle velocity. Particles that
Figure 2: a) A water droplet containing 1-micrometer polystyrene
arrive early, when the deposition rate is still low, have time to arrange by Brownian motion and form an ordered structure. Particles that
particles on a glass slide. b) The ring-shaped stain of particles
arrive during the rush hour have no time for such arrangement and form a jammed, disordered pattern. We can predict when the order-
left on the substrate after the droplet has evaporated. c) The
to-disorder transition will occur by comparing the particle diffusion time to the typical arrival time. A critical particle speed is obtained
same stain 50x enlarged. Particles in the outermost layers have
when these two timescales are equal: particles that arrive at a lower speed will form the ordered phase, particles with a higher speed
arranged in a crystalline way, whereas the inner layers have a
the disordered phase.
disordered structure. d) The stain 2x further enlarged, to show the crystalline structure of the particles.
HIGHLIGHTED PUBLICATIONS: [1] A.G. Marin, H. Gelderblom, D. Lohse, J.H. Snoeijer, Order-to-Disorder Transition in Ring-Shaped Colloidal Stains, PRL 107 (2011) 085502. [2] D.P.M. van Gils, S.G. Huisman, G.W.H. Bruggert, C. Sun, D. Lohse, Torque Scaling in Turbulent Taylor-Couette Flow with Co- and Counterrotating Cylinders, PRL 106 (2011) 024502. See also: Pysics Today, January 2011. [3] J.R.T. Seddon, H.J.W. Zandvliet, D. Lohse, Knudsen Gas Provides Nanobubble Stability, PRL 107 (2011) 116101. [4] J.R.T. Seddon,
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E.S. Kooij, B. Poelsema, H.J.W. Zandvliet, D. Lohse, Surface Bubble Nucleation Stability, PRL 106 (2011) 056101.
[HIGHLIGHTS] Granular materials, like sand, flour or iron ore, are among the most frequent materials in nature and are the most processed substance in industry, second only to water. Their often counterintuitive behavior however is distinctly
Dr. Devaraj van der Meer
different from that of molecular matter and remains far from understood. The
"What fascinates me in granular matter
Physics of Granular Matter and Interstitial Fluids (PGMF) group employs a
is that in many aspects it resembles an
combination of experiments, analysis and numerical techniques to attain to
ordinary molecular fluid or solid. And at
a profound understanding of the physics of granular flow. Special attention is
the same time it adds a complete new
given to unraveling the intricate role of the interstitial fluid, the gas or liquid
dimension of unexpected or even mind-
that resides within the pores between the grains. The group is embedded into
boggling phenomena."
the Physics of Fluids group.
Physics of Granular Matter and Interstitial Fluids Smoluchowski-Feynman ratchet in a granular gas Molecular motors, such as those responsible for tensing and relaxing your muscles, move in a strange manner: They propel themselves forwards despite - or thanks to - a continuous bombardment of the randomly moving molecules in their surroundings. This random movement is called Brownian motion and a well-constructed motor at the nanoscale actually makes use of this to generate a directed movement (and therefore work). In 1912 the physicist Marian Smoluchowski - as a gedankenexperiment - introduced a clever device that is a classical example
Figure 1: Smoluchowskiâ&#x20AC;&#x2122;s gedankenexperiment with the vanes
of such a motor. It consists of a series of vanes mounted on an axis, which are set in motion under the influence of the molecular
on the right, the ratchet and pawl on the left and in the middle a
bombardment. As this motion would take place in both rotational directions, Smoluchowski devised a second element, a ratchet
pulley with a weight.
and pawl. This would ensure that the axis could only rotate in a single direction and could therefore perform work, for example by pulling a small weight up. However, in 1963 Richard Feynman demonstrated that the second law of thermodynamics would prevent the device from working in a system that was in a state of thermal equilibrium. With this, the gedankenexperiment appeared to have been consigned to the waste bin. Yet the objection formulated by Feynman does not apply to a system that is far from thermal equilibrium, such as a granular gas that is created by vigorously vibrating a container filled with beads on top of a shaking device. Using both experiments and numerical simulations we have successfully demonstrated that Smoluchowskiâ&#x20AC;&#x2122;s device works superbly in this environment. In addition we found an unpredicted feature: the interplay of the moving vanes and the granular gas spontaneously creates a convection roll within the system. This roll breaks the symmetry on its own accord, without the need of introducing a ratchet and
Figure 2: Smoluchowski's device is brought to life in a granular
a pawl to force the broken symmetry.
gas: a top view of the experimental device in operation (left) and a side view of the simulation (right).
HIGHLIGHTED PUBLICATIONS: [1] S. Joubaud, D. Lohse, D. van der Meer, Fluctuation theorems for an asymmetric rotor in a granular gas, Phys. Rev. Lett. 108 (2012) 210604. [2] P. Eshuis, K. van der Weele, D. Lohse, D. van der Meer, Experimental realization of a rotational ratchet in a granular gas, Phys. Rev. Lett. 104 (2010) 248001.
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[highlights] The Quantum Transport in Matter (QTM) group is founded in 2011 by the appointment of its chair prof. dr. ir. Alexander Brinkman. It is the aim of the group to explore the electronic transport effects of
Figure 1: Top: Atomic force micoscopy image of the smooth surface of the topological insulator bismuth-telluride (Bi2Te3). Bottom: Electron microscopy image of the superconductor
Prof. dr. ir. Alexander Brinkman
quantum phenomena in materials and electronic
"It is fascinating to exploit quantum
nanotechnological and thin film technological
effects such as entanglement
developments within MESA+ and with advanced
and non-locality in materials and
electronic transport experiments a quantum
electronic devices."
mechanical dimension is given to the research.
devices. The research in the group builds on recent
Quantum Transport in Matter
â&#x20AC;&#x201C; topological insulator nano sandwich. The spacing between the Nb superconducting electrodes on top of the Bi2Te3 flake increases (from left to right: 50, 100, 150, 200, 250 and 300
Superconducting topological nanostructure first step towards Majorana fermion
nanometer).
Topological insulators and superconductors are two very special electronic materials. Topological insulators are electrical insulators in the bulk but conduct at the surface. The surface conduction has the special property that the spin of the electrons is coupled to the direction in which they move. A superconductor conducts electricity without resistance. MESA+ researchers have now realized a sandwich nanostructure of a Bi2Te3 topological insulator in between two Nb superconductors (see Figure 1). By combining measurements at large magnetic fields at the HFML in Nijmegen with electrical measurements at low temperatures it could be shown that the surface of Bi2Te3 indeed behaves topologically. By measuring so called Josephson effects (see Figure 2) they have shown that a supercurrent can flow from one superconductor to the other through a topological insulator surface state over a distance of the order of 100 nm. In 1937 the Italian physicist Ettore Majorana predicted the existence of fermionic particles that could be their own anti-particle. Theory predicts that a superconducting topological insulator might host these particles. The realized nanostructures therefore now form an important technological platform to investigate the presence and properties of these particles. Majorana fermions bear the potential of reducing the problem of decoherence of quantum states and these particles could experimentally open up the new field of topological quantum computation.
Figure 2: The color-coded resistance is measured as function of current (horizontal axis) and microwave irradiation power (vertical axis). This 'Bessel-peacock' image results from the ac Josephson effect.
HIGHLIGHTED PUBLICATION: M. Veldhorst, M. Snelder, M. Hoek, T. Gang, V. Guduru, X. Wang, U. Zeitler, W.G. van der Wiel, H. Hilgenkamp, A. Brinkman, Josephson
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supercurrent through a topological insulator surface state, Nature Materials 11 (2012) 417. [arxiv preprint cond-mat\1112.3527 (2011).]
[HIGHLIGHTS] The research program of Semiconductor Components (SC) deals with siliconbased technology and integrated-circuit devices. Scope of the group is “More than Moore” microtechnology. Our aim is to contribute to this emerging field by developing low-temperature processing techniques, adding functionality
Prof. dr. Jurriaan Schmitz
to completed CMOS microchips, and developing novel devices. The research
"Microchips are great, but we want
comprises thin film deposition; the integration of new components (such as silicon
them better still. In the EE-group
LED’s and elementary particle detectors) into CMOS; and advanced device physics
Semiconductor Components we study
and modelling. The group has strong ties with Philips, NXP Semiconductors, ASM
new materials and new device concepts
International, and the CTIT-group IC-design. The Dutch Technology Foundation
for integrated circuits."
STW and the Ministry of Economic Affairs are the main funding sources.
Semiconductor Components Measurement of the temperature of a substrate surface In many new processes, employed in integrated circuit manufacturing and solar cell production, a condition is created where
Figure 1: Top view of a metal pattern on a thin layer of silicon.
temperature equilibrium is disturbed on purpose. Examples include plasma processing, laser treatments and rapid thermal
The resistance from bottom to top will decrease when the gaps
anneals. It is often difficult to determine the temperature at the surface of the substrate under treatment; while the surface
close during a high-temperature treatment.
temperature is a critical parameter for the result of this treatment. A kind of temperature dosimeter was developed by postdoc Erik Faber to solve this problem. The dosimeter has a resistance that will change permanently and in a predictable manner when it is heated up. A resistive structure is made on top of the substrate, that consists of two films, typically silicon and a transition metal. Upon heating, a diffusion-limited chemical reaction takes place leading to the thinning of the original films and the formation of a new alloy. The resistance change is a direct measure of the amount of diffusion that has taken place. The effect of resistance change is strongly enhanced by forming structures with a submicrometer gap (as shown in figure 1). The gap closes upon high-temperature annealing by the same process as described above. Figure 2 exemplifies how the resistance evolves over time in this gap-type resistive structure. Figure 2: Typical resistance evolution over time during
The approach has been patented in 2010 and led to several journal and conference publications. This research was sponsored by
annealing at 350 °C. The higher two curves show experiments
the Dutch Technology Foundation STW.
where the layer thicknesses in the bilayer were incorrectly chosen for the effect to occur. The bottom curves show distinct changes in resistance, each representing the closure of one of the gaps. The resistance change observed in this experiment is permanent, allowing for measurements after the hightemperature step in a dedicated probe station.
HIGHLIGHTED PUBLICATIONs: [1] E. Faber, R.A.M. Wolters, J. Schmitz, On the kinetics of platinum silicide formation, Applied Physics Letters 98(8) (2011) 082102. [2] E. Faber, R.A.M. Wolters, J. Schmitz, Novel test structures for dedicated temperature budget determination, IEEE Transactions on Semiconductor Manufacturing, in press (2012).
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[highlights] The Soft matter, Fluidics and Interfaces (SFI) group is addressing interfacial phenomena that are relevant for transport processes. Careful interfacial design and fabrication will allow manipulating (multiphase) flow on a (sub)micrometer level. Fabrication of well-defined structures is a crucial aspect, in order to study the
Prof. dr. ir. Rob G.H. Lammertink
fundamentals of interfacial phenomena. The connection between
â&#x20AC;&#x153;Understanding and
to dominate at small length scales. A fundamental understanding
optimizing processes at
at the microscopic length scale is required to understand and
the interface.â&#x20AC;?
manipulate transport phenomena.
microfluidics and interfaces is evident as interfacial phenomena start
Soft matter, Fluidics and Interfaces Advanced microreactors for clean water Microreactors have very large surface to volume ratios, enabling the development of more efficient processes. We develop advanced microreactors with integrated membrane technology for multiphase processes (Gas-Liquid-Solid systems). These reactors were utilized for catalytic reduction and photocatalytic oxidation reactions in water, which are of great importance for water treatment. In collaboration with the PCS, CPM and IM groups, we fabricated, analyzed, and characterized hybrid microreactors. Porous stainless steel hollow fibers were covered with carbon nanofibers with high surface area as catalyst support. Subsequently, a palladium catalyst was deposited for catalytic hydrogenation of nitrite ions in water. These reactors showed superior reduction properties of nitrite ions, Figure 1: Porous stainless steel hollow fiber decorated with
even in the absence of palladium catalyst and hydrogen gas, thanks to the reductive properties of the reactor material itself.
carbon nanofibers (CNFs) and deposited palladium catalyst.
For oxidative processes, the Porous Photocatalytic Membrane Microreactors (P2M2) concept benefits from a stable gas-liquid-solid interface by the use of a porous membrane and a reduced light path for multiphase photocatalytic reactions. This reactor has tailored surface properties with a hydrophobic porous membrane support and a hydrophilic photocatalytic microchannel. We applied these reactors for photocatalytic degradation processes. Additional membrane-assisted oxygen supply increased the reactor performance drastically, even at dilute concentration of oxygen.
Figure 2: P2M2 (porous photocatalytic membrane microreactors) during operation under UV-Light.
HIGHLIGHTED PUBLICATIONS: [1] H.C. Aran, S. Pacheco Benito, M.W.J. Luiten-Olieman, S. Er, M. Wessling, L. Lefferts, N.E. Benes, R.G.H. Lammertink, Carbon nanofibers in catalytic membrane microreactors, Journal Of Membrane Science, 381(1-2) (2011) 244-250. doi:10.1016/j.memsci.2011.07.037. [2] H.C. Aran, D. Salamon, T. Rijnaarts, G. Mul, M. Wessling, R.G.H. Lammertink, Porous Photocatalytic Membrane Microreactor (P2M2): A new reactor concept for photochemistry, Journal Of Photochemistry And
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Photobiology A-Chemistry (2011) doi:10.1016/j.jphotochem.2011.09.022.
[HIGHLIGHTS] Prof. dr. Arie Rip
The department Science, Technology and Policy Studies (ST PS) investigates the dynamics
“Bridge the gap between innovation
and governance of science, technology and innovation from an interdisciplinary social science
and ELSA (Ethical, Legal and Social
perspective. Our research covers ongoing dynamics, historical developments and future-oriented
Aspects).That’s our aim, so we focus
studies. Studying such dynamics is a goal in itself, but also an important prerequisite for policy
on what happens in and around the
recommendations and exploring strategic implications for innovation actors. In the area of
nano-world, rather than on public
nanotechnologies, studies (funded by NanoNed, NanoNextNL, European Union) have focused on
responses to nanotechnology.
Constructive Technology Assessment in various domains as lab on a chip, deep brain implants,
And we work towards improving
food packaging, and drug delivery. We also study organizational and institutional issues like
the anticipation on embedding of
collaboration in science, practices of responsible innovation, promises and concerns, and sectoral
nanotechnology in society."
implications. In 2011, three PhD theses on issues of nanotechnology and society were completed under supervision of Arie Rip. A number of new PhD and postdoc projects have started, supervised by Kornelia Konrad and Stefan Kuhlmann.
Science, Technology and Policy Studies Nano in food packaging: current dynamics and future scenarios The extent to which, and how, nanotechnologies are taken up in an application domain, here food and food packaging, depends on the specific conditions within the industry (including customers and end consumers) and the more or less successful coordination of activities of relevant actors within the sector. Anticipation, particularly with the help of scenarios, is important for a critical assessment of the potential and impacts of nanotechnologies, and for supporting stakeholders in developing appropriate strategies. Such scenarios will also include presently less visible actors which may become important in the near future. The article argues that engagement of business and other actors in such anticipatory activities is important, and that this needs proper preparation
Actors involved in food packaging – schematic presentation and
and timing to be effective. Scenarios are used in strategy-articulation workshops. To draw up such scenarios requires analysis of
interacting at a scenario workshop.
ongoing societal and technological developments, drawing on an understanding of general patterns in innovation processes so as to map dynamics and do “controlled speculation” about possible futures. The current situation in the food packaging sector is one of cautious uptake of nanotechnology because of concerns over possible concerns of consumers. Also, business actors are waiting for others to make the first move. Attempts to break through this “waiting game” will have different repercussions. The scenarios trace possible outcomes of such attempts. One possibility is a shift away of research from long-term advanced packaging solutions to more short-term applications, eventually resulting in a decrease of interest in nano for food packaging. A second scenario shows how proactive regulation may support trust, but also create a competitive advantage for big firms compared to smaller companies. In a third scenario researchers and industrialists create nano-platforms, which expand into a broader forum linking also critical NGOs and pharmaceutical companies, thus creating trust and momentum for further developments.
HIGHLIGHTED PUBLICATIONS: [1] H. te Kulve, A. Rip, Constructing Productive Engagement: Pre-engagement Tools for Emerging Technologies, Sci Eng Ethics (2011) 17:699-714. [2] M. Ruivenkamp, Circulating Images of Nanotechnology (21 April 2011). [3] H. te Kulve, Anticipatory Interventions in the Co-evolution of Nanotechnology and Society (21 April 2011). [4] C. Shelley-Egan, Ethics in Practice: Responding to an Evolving Problematic Situation of Nanotechnology in Society (13 May 2011).
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[highlights] At Transducer Science and Technology (TST) we specialize in 3D nano- and micro fabrication, combining top down lithography
Prof. dr. ir. Gijs Krijnen
based methods with directed- and self-assembly. We invent new
â&#x20AC;&#x153;The fabrication of complex 3D
fabrication techniques and acquire fundamental understanding on
micro- and nano-objects is going to
the underlying physics. We demonstrate the techniques on various
be a main challenge for the near
devices and develop the science of working principles and design,
future. A combination of photo-
with the aim to ultimately transfer this knowledge to industry. We
lithography based technologies with
work on three generations of fabrication technologies -MEMS,
self-assembly is one potential solution
nanotechnology and self-assembly- thus covering the range
to this challenge.â&#x20AC;?
between fundamental research and application.
Transducer Science and Technology Combustion of oxygen-hydrogen mixture in nanobubbles Figure 1: (left) Planar Pt electrodes after the alternating pulse process . Visible destruction of electrodes due to reaction in
How small can the combustion chamber of an engine be? It is largely believed that it cannot be very small, and has to be larger
the bubbles is in good correspondence with the current density.
than, say, 100 micrometers, or so. This is because the heat needed to sustain a fast chemical reaction escapes via the chamber walls
(right) AFM image of the destructed area on the electrode.
more efficiently for small chambers, and temperatures required for combustion cannot be reached. Our research showed that this
Significant displacement of the material is visible.
truth is not universal and combustion can proceed in chambers as small as 100 nanometers or even less. Using electrolysis of water we produced small bubbles containing a mixture of oxygen and hydrogen. This is possible when short voltage pulses of alternating polarity are applied to the electrodes, producing each gas periodically in the same location. The faster the polarity switches, the smaller formed bubbles are. We discovered that for a switching time smaller than 25 microseconds the reaction in the bubbles is ignited spontaneously. This switching time results in the formation of bubbles smaller than 150 nanometer in diameter, which subsequently explode. A sudden disappearance of visible gas production was observed for switching frequencies higher than 20 kHz, while for single polarity pulses the visible gas was produced in accordance with expectations. The disappearance of gas was accompanied by a
Figure 2. Schematic explanation of the process. (left) Voltage
considerable destruction of platinum electrodes, as shown in Figure 1 (left). Atomic force microscope image shows that this is due
pulses of alternating polarity produce bubbles containing
to material displacement (Figure 1, right). The destruction was weaker for a tough material such as tungsten and stronger for a soft
mixture of both gases. (middle) If the pulses are short, the
material such as gold. Interferometric measurements showed that the gas concentration in liquid is reduced periodically in correlation
bubbles will be small enough to explode. Optical images of
with the voltage pulses (Figure 2, right). With the help of an external probe positioned nearby the electrodes the thermal effect of the
gold electrodes before and after the process are presented.
reaction was measured. The precise mechanism of the reaction in the nanobubbles is not clear yet, but it is likely that fast microseconds
(right) The graph shows the current in the system (red) and the
dynamics and high Laplace pressure in nanobubbles are involved.
vibrometer signal (blue). The signal peaks correlating with the current demonstrate periodic decrease in gas amount in the liquid due to the reaction.
HIGHLIGHTED PUBLICATIONS: [1] V.B. Svetovoy, R.G.P. Sanders, T.S.J. Lammerink, M.C. Elwenspoek, Combustion of hydrogen-oxygen mixture in electrochemically generated nanobubbles, Physical Review E 84 (2011) 035302(R). [2] L.A. Woldering, L. Abelmann, M.C. Elwenspoek, Predicted photonic band gaps in diamond-lattice crystals built from silicon truncated tetrahedrons, J. Appl. Phys. 110 (2011) 043107; http://dx.doi.org/10.1063/1.3624604. [3] W.W. Koelmans, A. Sebastian, L. Abelmann, M.
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Despont, H. Pozidis, Force modulation for enhanced nanoscale electrical sensing, Nanotechnology 22 (25) (2011) 1-9.
MESA+ ANNUAL REPORT 2011
[SCIENTIFIC PUBLICATIONS]
MESA+ Scientific Publications 2011 PHD THESES
Boogaard, A. (2011, January 12). Plasma-enhanced chemical vapor deposition of silicon dioxide : optimizing dielectric films through plasma characterization. University of Twente (186 pag.). Prom./coprom.: Prof.dr.ir. R.A.M. Wolters & A.Y. Kovalgin.
Abdulla, S.M.C. (2011, April 06). Integration of Micro-cantilevers with Photonic Structures for Mechano-optical Wavelength Selective Devices. University of Twente (170 pag.). Prom./
Boogaard, A.J.R. van den (2011, December 13). Ion-enhanced growth in planar and structured
coprom.: Dr.ir. G.J.M. Krijnen.
Mo/Si multilayers. University of Twente (104 pag.). Prom./coprom.: Prof.dr. F. Bijkerk.
Andreski, A. (2011, September 15). Superconducting Circuits with Pi-shift Elements. University
Bos, J.A. van der (2011, January 14). Air Entrapment and Drop Formation in Piezo Inkjet Printing.
of Twente (344 pag.). Prom./coprom.: Prof.dr.ir. J.W.M. Hilgenkamp.
University Twente (119 pag.). Prom./coprom.: Prof.dr. D. Lohse & Dr. M. Versluis.
Andricciola, P. (2011, December 21). Interpretation of MOS transistor mismatch signature
Boschker, J.A. (2011, February 04). Perovskite oxide heteroepitaxy; strain and interface
through statistical device simulations. University of Twente (149 pag.). Prom./coprom.: Prof.
engineering. University of Twente (142 pag.). Prom./coprom.: Prof.dr.ing. D.H.A. Blank & Prof.
dr. J. Schmitz & H.P. Tuinhout.
dr.ing. A.J.H.M. Rijnders.
Al-Hadidi, A.M.M. (2011, February 25). Limitations, improvements, alternatives for the silt
Bruijn, S. (2011, April 27). Diffusion phenoma in chemically stabilized multilayer structures.
density index. University of Twente (196 pag.). Prom./coprom.: Prof.dr.ir. W.G.J. van der Meer
University of Twente (114 pag.). Prom./coprom.: Prof.dr. F. Bijkerk.
& Dr.ir. A.J.B. Kemperman. Chen, J. (2011, July 01). Characterization of EUV induced contamination on multilayer optics. Aran, H.C. (2011, November 04). Porous ceramic and metallic microreactors - tuning interfaces
University of Twente (119 pag.). Prom./coprom.: Prof.dr. F. Bijkerk.
for multiphase processes. University of Twente (126 pag.). Prom./coprom.: Prof.dr.ir. R.G.H. Lammertink & Prof.dr.-ing. M. Wessling.
Chen, S. (2011, October 13). Silicon Nanowire Field-effect Chemical Sensor. University of Twente (126 pag.). Prom./coprom.: Prof.dr.ir. A. van den Berg & E.T. Carlen.
Bakker, G.J. (2011, July 08). LFA-1 dynamics on the membrane of leukocytes: a single dye tracing study. University of Twente (148 pag.). Prom./coprom.: Dr. M.F. Garcia Parajo & Prof.
Dagamseh, A.M.K. (2011, December 21). Bio-inspired Hair Flow Sensor Arrays: From Nature
dr. N.F. van Hulst.
to MEMS. University of Twente (173 pag.). Prom./coprom.: Dr.ir. G.J.M. Krijnen & Dr.ir. R.J. Wiegerink.
Beer, S.J.A. de (2011, May 27). Probing the properties of confined liquids. University of Twente (187 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. H.T.M. van den Ende.
Dalwani, M.R. (2011, November 11). Thin film composite nanofiltration membranes for extreme conditions. University of Twente (160 pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling & Dr.ir.
Bettahalli Narasimha, M.S. (2011, February 04). Membrane supported scaffold architectures
N.E. Benes.
for tissue engineering. University of Twente (180 pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling & Dr. D. Stamatialis.
Domanski, M. (2011, September 02). Nanofabrication methods for improved bone implants. University of Twente (174 pag.). Prom./coprom.: Prof.dr. J.G.E. Gardeniers & Dr. R. Luttge.
Bliznyuk, O. (2011, July 07). Directional wetting on patterned surfaces. University of Twente (129 pag.). Prom./coprom.: Prof.dr.ir. B. Poelsema.
Dutczak, S.M. (2011, November 11). Solvent resistant nanofiltration membranes. University of Twente (141 pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling & Dr. D. Stamatialis.
Bollmann, T.R.J. (2011, September 23). Escape from Flatland: strain and quantum size effect driven growth of metallic nanostructures. University of Twente (108 pag.). Prom./coprom.:
Duvigneau, J. (2011, February 11). Scanning Thermal Lithography for Nanopatterning of
Prof.dr.ir. B. Poelsema & J.W.M. Frenken.
Polymers. Transient Heat Transport and Thermal Chemical Functionalization Across the Length Scales. University of Twente (183 pag.). Prom./coprom.: Prof.dr. G.J. Vancso.
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[SCIENTIFIC PUBLICATIONS] Embrechts, A. (2011, May 19). Single Molecule Force Spectroscopy of self complementary
Hosseiny, S.S. (2011, July 15). Vanadium / air redox flow battery. University of Twente (163
hydrogen-bonded supramolecular systems: dimers, polymers and solvent effects. University
pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling.
of Twente (166 pag.). Prom./coprom.: Prof.dr. G.J. Vancso & Dr. H. Schönherr. Izadi, N. (2011, January 07). Bio-inspired MEMS Aquatic Flow Sensor Arrays. University of Engelen, J.B.C. (2011, January 14). Optimization of Comb-Drive Actuators [Nanopositioners for
Twente (246 pag.). Prom./coprom.: Dr.ir. G.J.M. Krijnen.
probe-based data storage and musical MEMS]. University of Twente (124 pag.). Prom./coprom.: Prof.dr. M.C. Elwenspoek & Dr.ir. L. Abelmann.
Jani, J.M. (2011, December 02). Multiphase membrane contactors and reactors. University of Twente (152 pag.). Prom./coprom.: Prof.dr.ir. R.G.H. Lammertink & Prof.dr.-ing. M. Wessling.
Eral, H.B. (2011, March 04). Colloidal suspensions under external control. University of Twente (214 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. M.H.G. Duits.
Jose, S. (2011, December 13). Reflector stack optimization for Bulk Acoustic Wave resonators. University of Twente (129 pag.). Prom./coprom.: Prof.dr. J. Schmitz & Dr.ir. R.J.E. Hueting.
Everts, F. (2011, January 28). Characterization of nanometre-scale patterns on Cu(001) and Ag(001) by means of optical spectroscopy and high-resolution electron diffraction. University
Karminskaya, T. (2011, February 16). Theory of Josephson effect in junctions with complex
of Twente (103 pag.). Prom./coprom.: Prof.dr.ir. B. Poelsema.
ferromagnetic/normal metal weak link region. University of Twente (119 pag.). Prom./coprom.: Prof. H. Rogalla & Dr. A. Golubov.
Gang, T. (2011, October 28). Assemly and Magneto-Electrical Characterization of Hybrid Organic-Inorganic Systems. University of Twente (142 pag.). Prom./coprom.: Prof.dr.ir. W.G.
Koelmans, W.W. (2011, June 17). Parallel Probe Readout. University of Twente (134 pag.). Prom./
van der Wiel & Prof.dr.ing. D.H.A. Blank.
coprom.: Prof.dr. M.C. Elwenspoek & Dr.ir. L. Abelmann.
Geskus, D. (2011, November 16). Channel waveguide lasers and amplifiers in single-
Kopec, K.K. (2011, January 28). Charged porous membrane structures for separation of biomolecules.
crystalline ytterbium-doped potassium double tungstates. University of Twente (155 pag.).
University of Twente (155 pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling & Dr. D. Stamatialis.
Prom./coprom.: Prof.dr. M. Pollnau & Dr. K. Wörhoff. Kottumakulal Jaganatharaja, R. (2011, June 29). Cricket Inspired Flow-Sensor Arrays. George, A. (2011, December 15). Sub-50 nm Scale to Micrometer Scale Soft Lithographic
University of Twente (187 pag.). Prom./coprom.: Dr.ir. G.J.M. Krijnen.
Patterning of Functional Materials. University of Twente (86 pag.). Prom./coprom.: Dr.ir. J.E. ten Elshof & Prof.dr.ing. D.H.A. Blank.
Kulve te, H. (2011, April 21). Anticipatory interventions and the co-evolution of nanotechnology and society. University of Twente (263 pag.). Prom./coprom.: Prof.dr. A. Rip.
Gomez Casado, A. (2011, July 15). Strength and dynamics of multivalent complexes at surfaces. University of Twente (157 pag.). Prom./coprom.: Prof.dr.ir. J. Huskens & Dr. P. Jonkheijm.
Lamprecht, T. (2011, June 23). Embedded Micro-Mirrors for Compact Routing of Multimode Polymer Waveguides. University of Twente (137 pag.). Prom./coprom.: Prof.dr. M. Pollnau.
Groenland, A.W. (2011, July 08). Nanolink-based thermal devices: integration of ALD TiN thin films. University of Twente (157 pag.). Prom./coprom.: Prof.dr.ir. R.A.M. Wolters & A.Y. Kovalgin.
Lee, J.S. (2011, May 20). Biodegradable polymersomes for drug delivery. University of Twente (166 pag.). Prom./coprom.: Prof.dr. J. Feijen.
Gu, H. (2011, March 18). Controlling two-phase flow in microfluidic systems using electrowetting. University of Twente (128 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. M.H.G.
Lu, Jiwu (2011, June 22). Solar Cells on CMOS Chips as Energy Harvesters. University of Twente
Duits.
(117 pag.). Prom./coprom.: Prof.dr. J. Schmitz & Dr. A.Y. Kovalgin.
Hildenbrand, N. (2011, June 10). Improving the electrolyte-cathode assembly for mt-SOFC.
Mampallil Augustine, D. (2011, September 22). Microfluidic flow driven by electric fields.
University of Twente (157 pag.). Prom./coprom.: Prof.dr.ing. D.H.A. Blank & Dr. B.A. Boukamp.
University of Twente (175 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. H.T.M. van den Ende.
Hoeve, W. van (2011, March 23). Fluid dynamics at a pinch: droplet and bubble formation in
Manukyan, G. (2011, September 16). Electrical manipulation of liquids at interfaces. University
microfluidic devices. University of Twente (128 pag.). Prom./coprom.: Prof.dr. D. Lohse.
of Twente (109 pag.). Prom./coprom.: Prof.dr. F. Mugele & Prof.dr.ir. R.G.H. Lammertink.
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[SCIENTIFIC PUBLICATIONS] Martinez Mercado, J. (2011, July 15). Clustering and Lagrangian Statistics of Bubbles. University
Stawski, T.M. (2011, December 15). Understanding Microstructural Properties of Perovskite
of Twente (120 pag.). Prom./coprom.: Prof.dr. D. Lohse.
Ceramics through Their Wet-Chemical Synthesis. University of Twente (152 pag.). Prom./ coprom.: Dr.ir. J.E. ten Elshof & Prof.dr.ing. D.H.A. Blank.
Masood, M.N. (2011, November 24). Surface modification of silicon nanowire field-effect devices with Si-C and Si-N bonded Monolayers. University of Twente (134 pag.). Prom./coprom.: Prof.
Steen, J-L.P.J. van der (2011, April 01). Geometrical scaling effects on carrier transport in
dr.ir. A. van den Berg & E.T. Carlen.
ultrthin-body MOSFETs. University of Twente (169 pag.). Prom./coprom.: Prof.dr. J. Schmitz, L. Selmi & Dr.ir. R.J.E. Hueting.
Mikkenie, R. (2011, November 17). Materials Development for Commercial Multilayer Ceramic Capacitors. University of Twente (200 pag.). Prom./coprom.: Prof.dr.ing. A.J.H.M. Rijnders & Dr.ir.
Veen, P.J. de (2011, September 30). Interface Engineering for Organic Electronics; Manufacturing
J.E. ten Elshof.
of Hybrid Inorganic-Organic Molecular Crystal Devices. University of Twente (197 pag.). Prom./ coprom.: Prof.dr.ing. A.J.H.M. Rijnders & Prof.dr.ing. D.H.A. Blank.
Odijk, M. (2011, March 04). Miniaturized electrochemical cells for applications in drug screening and protein cleavage. University of Twente (181 pag.). Prom./coprom.: Prof.dr.ir. A. van den Berg
Vereshchagina, E. (2011, December 09). Low-Power Silicon-based Thermal Sensors and
& Dr.ir. W. Olthuis.
Actuators for Chemical Applications. University of Twente (135 pag.). Prom./coprom.: Prof.dr. J.G.E. Gardeniers.
Pacheco Benito, S. (2011, October 26). Carbon Nanofiber layers on Metal and Carbon Substrates. University of Twente (134 pag.). Prom./coprom.: Prof.dr.ir. L. Lefferts.
Yang, C. (2011, June 24). Photocatalytic CO2 Activation by Water. University of Twente (126 pag.). Prom./coprom.: Prof.dr. G. Mul.
Ploeg, S.H.W. van der (2011, May 11). Characterization of Multi Qubit Systems. University of Twente (106 pag.). Prom./coprom.: Prof. H. Rogalla & Dr. A. Golubov.
Yilmaz, M.D. (2011, June 09). Orthogonal supramolecular interaction motifs for functional monolayer architectures. University of Twente (171 pag.). Prom./coprom.: Prof.dr.ir. J. Huskens.
Putten, E.G. van (2011, October 28). Disorder-Enhanced Imaging with Spatially Controlled Light. University of Twente (112 pag.). Prom./coprom.: Prof.dr. A. Lagendijk & Dr. A.P. Mosk.
Zhong, Z.C. (2011, October 12). Instability, the driving force for new physical phenomena. University of Twente (111 pag.). Prom./coprom.: Prof.dr. P.J. Kelly.
Roy, D. (2011, September 28). Characterization of electrical contacts for phase change memory cells. University of Twente (131 pag.). Prom./coprom.: Prof.dr.ir. R.A.M. Wolters.
Zhou, W. (2011, February 02). Proton-conducting solid acid electrolytes based upon MH(PO3H). University of Twente (132 pag.). Prom./coprom.: Prof.dr.ir. A. Nijmeijer & Dr. H.J.M.
Ruggi, A. (2011, June 10). Tuning brightness and oxygen sensitivity of Ru(II) and Ir(III) luminoÂphores.
Bouwmeester.
University of Twente (177 pag.). Prom./coprom.: Prof.dr.ir. D.N. Reinhoudt & Dr. A.H. Velders. Zijlstra, A.G. (2011, September 02). Acoustic Surface Cavitation. University of Twente (139 pag.). Ruivenkamp, M. (2011, April 21). Circulating Images of Nanotechnology. University of Twente
Prom./coprom.: Prof.dr. D. Lohse.
(249 pag.). Prom./coprom.: Prof.dr. A. Rip.
Segerink, L.I. (2011, November 04). Fertility chip, a point-of-care semen analyser. University of Twente (156 pag.). Prom./coprom.: Prof.dr.ir. A. van den Berg & Dr.ir. A.J. Sprenkels.
ACADEMIC JOURNAL REFEREED (RANKED BY IMPACT FACTOR â&#x20AC;ş 6)
Shelley Egan, C. (2011, May 13). Ethics in practice: responding to an evolving problematic situation of nanotechnology in society. University of Twente (168 pag.). Prom./coprom.: Prof.dr.
G. Catalan, A. Lubk, A.H.G. Vlooswijk, E. Snoeck, C. Magen, A. Janssens, G. Rispens, G. Rijnders,
A. Rip & Dr. M. Kirejczyk.
D.H.A. Blank and B. Noheda, Flexoelectric rotation of polarization in ferroelectric thin films, Nature Materials 10 (12), 963-967 (2011).
Spasenovic, M. (2011, June 30). Surface plasmon polaritons and light at interfaces: propagating
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and evanescent waves. University of Twente (130 pag.). Prom./coprom.: Prof dr. L. Kuipers &
B. Gjonaj, J. Aulbach, P.M. Johnson, A.P. Mosk, L. Kuipers and A. Lagendijk, Active spatial control
Prof.dr. T.D. Visser.
of plasmonic fields, Nature Photonics 5 (6), 360-363 (2011).
[SCIENTIFIC PUBLICATIONS] A. Perl, A. Gomez-Casado, D. Thompson, H.H. Dam, P. Jonkheijm, D.N. Reinhoudt and J. Huskens,
W.P. Voorthuijzen, M.D. Yilmaz, W.J.M. Naber, J. Huskens and W.G. van der Wiel, Local doping of
Gradient driven motion of multivalent ligand molecules along a surface functionalized with
silicon using nanoimprint lithography and molecular monolayers, Adv Mater 23 (11), 1346-1350
multiple receptors, Nature Chemistry 3 (4), 317-322 (2011).
(2011).
Ariando, X. Wang, G. Baskaran, Z.Q. Liu, J. Huijben, J.B. Yi, A. Annadi, A.R. Barman, A. Rusydi,
H.C. Aran, D. Salamon, T. Rijnaarts, G. Mul, M. Wessling and R.G.H. Lammertink, Porous
S. Dhar, Y.P. Feng, J. Ding, H. Hilgenkamp and T. Venkatesan, Electronic phase separation at the
Photocatalytic Membrane Microreactor (P2M2): A new reactor concept for photochemistry,
LaAlO3/SrTiO3 interface, Nature Communications 2 (2011).
Journal of Photochemistry and Photobiology a-Chemistry 225 (1), 36-41 (2011).
R. de la Rica, R.M. Fratila, A. Szarpak, J. Huskens and A.H. Velders, Multivalent Nanoparticle
E. Louis, A.E. Yakshin, T. Tsarfati and F. Bijkerk, Nanometer interface and materials control for
Networks as Ultrasensitive Sensors, Angew Chem Int Edit 50 (25), 5703-5706 (2011).
multilayer EUV-optical applications, Progress in Surface Science 86 (11-12), 255-294 (2011).
M. Bokdam, P.A. Khomyakov, G. Brocks, Z.C. Zhong and P.J. Kelly, Electrostatic doping of
T.W.H. Oates, H. Wormeester and H. Arwin, Characterization of plasmonic effects in thin films
graphene through ultrathin hexagonal boron nitride films, Nano Lett 11 (11), 4631-4635
and metamaterials using spectroscopic ellipsometry, Progress in Surface Science 86 (11-12),
(2011).
328-376 (2011).
S.Y. Chen, J.G. Bomer, E.T. Carlen and A. van den Berg, Al2O3/Silicon NanoISFET with Near Ideal
A.W. Maijenburg, E.J.B. Rodijk, M.G. Maas, M. Enculescu, D.H.A. Blank and J.E. ten Elshof,
Nernstian Response, Nano Lett 11 (6), 2334-2341 (2011).
Hydrogen Generation from Photocatalytic Silver|Zinc Oxide Nanowires: Towards Multifunctional Multisegmented Nanowire Devices, Small 7 (19), 2709-2713 (2011).
Y.Z. Chen, N. Pryds, J.E. Kleibeuker, G. Koster, J.R. Sun, E. Stamate, B.G. Shen, G. Rijnders and S. Linderoth, Metallic and Insulating Interfaces of Amorphous SrTiO3-Based Oxide
I. J. Minten, K.D.M. Wilke, L.J.A. Hendriks, J.C.M. van Hest, R.J.M. Nolte and J. Cornelissen, Metal-
Heterostructures, Nano Lett 11 (9), 3774-3778 (2011).
ion-induced formation and stabilization of protein cages based on the cowpea chlorotic mottle virus, Small 7 (7), 911-919 (2011).
B.L.M. Hendriksen, F. Martin, Y.B. Qi, C. Mauldin, N. Vukmirovic, J.F. Ren, H. Wormeester, A.J. Katan, V. Altoe, S. Aloni, J.M.J. Frechet, L.W. Wang and M. Salmeron, Electrical Transport
S. Ramachandra, Z.D. Popovic, K.C. Schuermann, F. Cucinotta, G. Calzaferri and L. De Cola,
Properties of Oligothiophene-Based Molecular Films Studied by Current Sensing Atomic Force
FĂśrster Resonance Energy Transfer in Quantum Dotâ&#x20AC;&#x201C;Dye-Loaded Zeolite L Nanoassemblies,
Microscopy, Nano Lett 11 (10), 4107-4112 (2011).
Small 7 (10), 1488-1494 (2011).
G. Hlawacek, F.S. Khokhar, R. van Gastel, B. Poelsema and C. Teichert, Smooth Growth of
X.F. Sui, Q. Chen, M.A. Hempenius and G.J. Vancso, Probing the Collapse Dynamics of Poly(N-
Organic Semiconductor Films on Graphene for High-Efficiency Electronics, Nano Lett 11 (2),
isopropylacrylamide) Brushes by AFM: Effects of Co-nonsolvency and Grafting Densities, Small
333-337 (2011).
7 (10), 1440-1447 (2011).
M.A.G. Zevenbergen, P.S. Singh, E.D. Goluch, B.L. Wolfrum and S.G. Lemay, Stochastic sensing
C.C. Wu, D.N. Reinhoudt, C. Otto, V. Subramaniam and A.H. Velders, Strategies for Patterning
of single molecules in a nanofluidic electrochemical device, Nano Lett 11 (7), 2881-2886 (2011).
Biomolecules with Dip-Pen Nanolithography, Small 7 (8), 989-1002 (2011).
H.J. Chang, S.V. Kalinin, A.N. Morozovska, M. Huijben, Y.H. Chu, P. Yu, R. Ramesh, E.A. Eliseev,
A. Ruggi, F.W.B. van Leeuwen and A.H. Velders, Interaction of dioxygen with the electronic
G.S. Svechnikov, S.J. Pennycook and A.Y. Borisevich, Atomically Resolved Mapping of
excited state of Ir(III) and Ru(II) complexes: principles and biomedical applications, Coordination
Polarization and Electric Fields Across Ferroelectric/Oxide Interfaces by Z-contrast Imaging,
Chemistry Reviews 255 (21-22), 2542-2554 (2011).
Adv Mater 23 (21), 2474 (2011). M.A. Kostiainen, P. Ceci, M. Fornara, P. Hiekkataipale, O. Kasyutich, R. J. M. Nolte, J. Cornelissen, R. Truckenmuller, S. Giselbrecht, N. Rivron, E. Gottwald, V. Saile, A. van den Berg, M. Wessling
R.D. Desautels and J. van Lierop, Hierarchical self-assembly and optical disassembly for
and C. van Blitterswijk, Thermoforming of film-based biomedical microdevices, Adv Mater 23
controlled switching of magnetoferritin nanoparticle magnetism, Acs Nano 5 (8), 6394-6402
(11), 1311-1329 (2011).
(2011).
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[SCIENTIFIC PUBLICATIONS] J.D.B. Bradley and M. Pollnau, Erbium-doped integrated waveguide amplifiers and lasers,
T.R.J. Bollmann, R. van Gastel, H.J.W. Zandvliet and B. Poelsema, Anomalous Decay of
Laser & Photonics Reviews 5 (3), 368-403 (2011).
Electronically Stabilized Lead Mesas on Ni(111), Phys Rev Lett 107 (13) (2011).
R. Osellame, H. Hoekstra, G. Cerullo and M. Pollnau, Femtosecond laser microstructuring: an
T.R.J. Bollmann, R. van Gastel, H.J.W. Zandvliet and B. Poelsema, Quantum Size Effect Driven
enabling tool for optofluidic lab-on-chips, Laser & Photonics Reviews 5 (3), 442-463 (2011).
Structure Modifications of Bi Films on Ni(111), Phys Rev Lett 107 (17) (2011).
M. Brasch, A. de la Escosura, Y.J. Ma, C. Uetrecht, A.J.R. Heck, T. Torres and J. Cornelissen,
H. Ebert, S. Mankovsky, D. Kodderitzsch and P.J. Kelly, Ab Initio Calculation of the Gilbert
Encapsulation of phthalocyanine supramolecular stacks into virus-like particles, J Am Chem
Damping Parameter via the Linear Response Formalism, Phys Rev Lett 107 (6) (2011).
Soc 133 (18), 6878-6881 (2011). M.R. Fitzsimmons, N.W. Hengartner, S. Singh, M. Zhernenkov, F.Y. Bruno, J. Santamaria, R. de la Rica and A.H. Velders, Biomimetic Crystallization of Ag2S Nanoclusters in Nanopore
A. Brinkman, M. Huijben, H.J.A. Molegraaf, J. de la Venta and I.K. Schuller, Upper Limit to
Assemblies, J Am Chem Soc 133 (9), 2875-2877 (2011).
Magnetism in LaAlO3/SrTiO3 Heterostructures, Phys Rev Lett 107 (21) (2011).
A. Gomez-Casado, H.H. Dam, M.D. Yilmaz, D. Florea, P. Jonkheijm and J. Huskens, Probing
E.T. Garbacik, J.P. Korterik, C. Otto, S. Mukamel, J.L. Herek and H.L. Offerhaus, Background-
Multivalent Interactions in a Synthetic Hostâ&#x20AC;&#x201C;Guest Complex by Dynamic Force Spectroscopy,
Free Nonlinear Microspectroscopy with Vibrational Molecular Interferometry, Phys Rev Lett
J Am Chem Soc 133 (28), 10849-10857 (2011).
107 (25) (2011).
P.S. Singh, H.S.M. Chan, S. Kang and S.G. Lemay, Stochastic Amperometric Fluctuations as a
M.D. Leistikow, A.P. Mosk, E. Yeganegi, S.R. Huisman, A. Lagendijk and W.L. Vos, Inhibited
Probe for Dynamic Adsorption in Nanofluidic Electrochemical Systems, J Am Chem Soc 133
Spontaneous Emission of Quantum Dots Observed in a 3D Photonic Band Gap, Phys Rev Lett
(45), 18289-18295 (2011).
107 (19) (2011).
E.M. Benetti, C. Acikgoz, X.F. Sui, B. Vratzov, M.A. Hempenius, J. Huskens and G.J. Vancso,
Z.Q. Liu, D.P. Leusink, X. Wang, W.M.Lu, K. Gopinadhan, A. Annadi, Y.L. Zhao, X.H. Huang, S.W.
Nanostructured Polymer Brushes by UV-Assisted Imprint Lithography and Surface-Initiated
Zeng, Z. Huang, A. Srivastava, S. Dhar, T. Venkatesan and Ariando, Metal-Insulator Transition
Polymerization for Biological Functions, Adv Funct Mater 21 (11), 2088-2095 (2011).
in SrTiO3-x Thin Film Induced by Frozen-out Carriers, Phys Rev Lett 107 (14) (2011).
H.L. Castricum, G.G. Paradis, M.C. Mittelmeijer-Hazeleger, R. Kreiter, J.F. Vente and J.E. ten
G. Manukyan, J.M. Oh, D. van den Ende, R.G.H. Lammertink and F. Mugele, Electrical Switching
Elshof, Tailoring the Separation Behavior of Hybrid Organosilica Membranes by Adjusting the
of Wetting States on Superhydrophobic Surfaces: A Route Towards Reversible Cassie-to-
Structure of the Organic Bridging Group, Adv Funct Mater 21 (12), 2319-2329 (2011).
Wenzel Transitions, Phys Rev Lett 106 (1) (2011).
P. Lukanov, V.K. Anuganti, Y. Krupskaya, A.M. Galibert, B. Soula, C. Tilmaciu, A.H. Velders,
A.G. Marin, H. Gelderblom, D. Lohse and J.H. Snoeijer, Order-to-Disorder Transition in Ring-
R. Klingeler, B. Buchner and E. Flahaut, CCVD synthesis of carbon-encapsulated cobalt
Shaped Colloidal Stains, Phys Rev Lett 107 (8) (2011).
nanoparticles for biomedical applications, Adv Funct Mater 21 (18), 3583-3588 (2011). J.R.T. Seddon, E.S. Kooij, B. Poelsema, H.J.W. Zandvliet and D. Lohse, Surface Bubble Nucleation D. Janczewski, N. Tomczak, M.Y. Han and G.J. Vancso, Synthesis of functionalized amphiphilic
Stability, Phys Rev Lett 106 (5) (2011).
polymers for coating quantum dots, Nature Protocols 6 (10), 1546-1553 (2011). J.R.T. Seddon, H.J.W. Zandvliet and D. Lohse, Knudsen Gas Provides Nanobubble Stability, Y. Asano, A.A. Golubov, Y.V. Fominov and Y. Tanaka, Unconventional surface impedance of a
Phys Rev Lett 107 (11) (2011).
normal-metal film covering a spin-triplet superconductor due to odd-frequency cooper pairs, Phys Rev Lett 107 (8) (2011).
D.P.M. van Gils, S.G. Huisman, G.W. Bruggert, C. Sun and D. Lohse, Torque Scaling in Turbulent Taylor-Couette Flow with Co- and Counterrotating Cylinders, Phys Rev Lett 106 (2) (2011).
J. Aulbach, B. Gjonaj, P.M. Johnson, A.P. Mosk and A. Lagendijk, Control of Light Transmission through Opaque Scattering Media in Space and Time, Phys Rev Lett 106 (10) (2011).
E.G. van Putten, D. Akbulut, J. Bertolotti, W.L. Vos, A. Lagendijk and A.P. Mosk, Scattering Lens Resolves sub-100 nm Structures with Visible Light, Phys Rev Lett 106 (19) (2011).
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[SCIENTIFIC PUBLICATIONS] R. de la Rica and A.H. Velders, Supramolecular Au Nanoparticle Assemblies as Optical Probes
Y.B. Xie, J.D. Sherwood, L.L. Shui, A. van den Berg and J.C.T. Eijkel, Strong enhancement of
for Enzyme-Linked Immunoassays, Small 7 (1), 66-69 (2011).
streaming current power by application of two phase flow, Lab on a Chip 11 (23), 4006-4011 (2011).
A.W. Maijenburg, E.J.B. Rodijk, M.G. Maas, M. Enculescu, D.H.A. Blank and J.E. ten Elshof, Hydrogen Generation from Photocatalytic Silver|Zinc Oxide Nanowires: Towards
F. Ay, I. Inurrategui, D. Geskus, S. Aravazhi and M. Pollnau, Integrated lasers in crystalline
Multifunctional Multisegmented Nanowire Devices, Small 7 (19), 2709-2713 (2011).
double tungstates with focused-ion-beam nanostructured photonic cavities, Laser Physics Letters 8 (6), 423-430 (2011).
I.J. Minten, K.D.M. Wilke, L.J.A. Hendriks, J.C.M. van Hest, R.J.M. Nolte and J. Cornelissen, Metalion-induced formation and stabilization of protein cages based on the cowpea chlorotic mottle
Visit our website (www.utwente.nl/mesaplus/publications) for the complete
virus, Small 7 (7), 911-919 (2011).
publication list.
S. Ramachandra, Z.D. Popovic, K.C. Schuermann, F. Cucinotta, G. Calzaferri and L. De Cola, Förster Resonance Energy Transfer in Quantum Dot–Dye-Loaded Zeolite L Nanoassemblies, Small 7 (10), 1488-1494 (2011).
patents
X.F. Sui, Q. Chen, M.A. Hempenius and G.J. Vancso, Probing the Collapse Dynamics of Poly(N
L.I. Segerink, A.J. Sprenkels, M.J. Koster, A. van den Berg, “Compact 2D fluorescence
-isopropylacrylamide) Brushes by AFM: Effects of Co-nonsolvency and Grafting Densities,
detection system for on-chip analysis”, 61/483,900.
Small 7 (10), 1440-1447 (2011). K. van der Maaden, J.A. Bouwstra, W. Jiskoot, N. Tas, “Method to coat an active agent to a C.C. Wu, D.N. Reinhoudt, C. Otto, V. Subramaniam and A.H. Velders, Strategies for Patterning
surface”, N2007382, 9 Sept. 2011.
Biomolecules with Dip-Pen Nanolithography, Small 7 (8), 989-1002 (2011). S. Le Gac, V.C. Stimberg, A. van den Berg, “A method for preparing a microfluidic device R. Arayanarakool, L.L. Shui, A. van den Berg and J.C.T. Eijkel, A new method of UV-patternable
comprising a series of bilayer lipid membrane sections”, 2007354, 5 Sept. 2011.
hydrophobization of micro- and nanofluidic networks, Lab on a Chip 11 (24), 4260-4266 (2011). Rottenberg, X., Jansen, H.V., Tilmans, H.A.C. & De Raedt, W.”Switchable capacitor”, EP1398811, W. Browne, J.M. Gordillo, J. Hussong, M. Kreutzer, D. Lohse, F. Mugele, P. Onck, N. Schorr and A.
10 Aug. 2011.
van den Berg, Contributors to the Netherlands issue, Lab on a Chip 11 (12), 1993-1994 (2011). Volker, A.W.F., Blokland, H., Velthuis, J.F.M. & Lotters, J.C., “Fluid flow meter using thermal E. Castro-Hernandez, W. van Hoeve, D. Lohse and J.M. Gordillo, Microbubble generation in a
tracers”, EP2100105, 12 Jan. 2011.
co-flow device operated in a new regime, Lab on a Chip 11 (12), 2023-2029 (2011). Dutczak, S.M., Cuperus, D.F. & Stamatialis, D. “Crosslinked polyimide membrane”, EP 11171318.6. C. Dongre, J. van Weerd, G.A.J. Besselink, R.M. Vazquez, R. Osellame, G. Cerullo, R. van Weeghel, H.H. van den Vlekkert, H. Hoekstra and M. Pollnau, Modulation-frequency encoded multi-color fluorescent DNA analysis in an optofluidic chip, Lab on a Chip 11 (4), 679-683 (2011).
H. Hardelauf, J. Sisnaiske, A.A. Taghipour-Anvari, P. Jacob, E. Drabiniok, U. Marggraf, J.P. Frimat, J.G. Hengstler, A. Neyer, C. van Thriel and J. West, High fidelity neuronal networks formed by plasma masking with a bilayer membrane: analysis of neurodegenerative and neuroprotective processes, Lab on a Chip 11 (16), 2763-2771 (2011).
L.I. Segerink, A.J. Sprenkels, J.G. Bomer, I. Vermes and A. van den Berg, A new floating electrode structure for generating homogeneous electrical fields in microfluidic channels, Lab on a Chip 11 (12), 1995-2001 (2011).
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MESA+ Annual Report 2011
ANNUAL REPORT 2011
[ABOUT MESA+]
MESA+ Governance Structure MESA+ Governing Board
Dr. G.J. Jongerden - Managing Director Exergy
Prof. dr. ir. A.J. Mouthaan - Dean Faculty of Electrical Engineering, Mathematics and Computer Science
Ir. J.J.M. Mulderink - Consultant Sustainable Technology
Dr. A.J. Nijman - Director Research Strategy & Business Development Philips NatLab
Prof. dr. J.A. Put - Director Performance Materials DSM Research
Dr. J. Schmitz - Vice President, Manager Process Technology Lab NXP Semiconductors
Prof. dr. G. van der Steenhoven - Dean Faculty Science & Technology
MESA+ Scientific Advisory Board
Dr. J.G. Bednorz - IBM Zurich Research Laboratory, Switzerland
Prof. H. Fujita - University of Tokyo, Japan
Prof. M. Möller - Rheinisch-Westfäische Technische Hochschule Aachen (RWTH), Germany
Prof. C.N.R. Rao - Jawaharlal Nehru Centre for Advanced Scientific Research, India
Dr. H. Rohrer - IBM Zürich Research Laboratory, Switzerland
Prof. F. Stoddart - University of California, USA
Prof. E. Thomas - Massachusetts Institute of Technology (MIT), USA
Prof. E. Vittoz - Swiss Center for Electronics and Microtechnology (CSEM), Switzerland
Prof. G. Whitesides - Harvard University, USA
MESA+ Management
Prof. dr. ing. D.H.A. Blank - Scientific Director
Ir. M. Luizink - Technical Commercial Director
Contact details
MESA+ Institute for Nanotechnology
University of Twente, P.O. Bo 217, 7500 AE Enschede, the Netherlands
+ 31 53 489 2715, info@mesaplus.utwente.nl, www.utwente.nl/mesaplus
Colophon Editing: MESA+ Institute for Nanotechnology, Miriam Luizink, Annerie van Steijn-Heesink I Design: WeCre8 Creatieve Communicatie, Enschede, the Netherlands I Photography: Eric Brinkhorst, Martin Bosker (Slightly Tilted) I Printed by: DeltaHage, The Hague, the Netherlands.
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