MASTER IN ADVANCED ARCHITECTURE 2016/17
GRAPHENE-COMPOSITE Graphene-Composite project at the architectural scale that speculates about scenarios where the material is implemented in an innovative way
DIGITAL MATTER || INTELLIGENT CONSTRUCTIONS 016 017 research team
GELDER VAN LIMBURG STIRUM, JAVIER LÓPEZ-ALASCIO HERVÁS, RICARDO MAYOR LUQUE, THANOS ZERVOS tutors areti Markopoulou - DMIC Leader ALEX DUBOR - FABRICATION Expert ANGELOS CHRONIS - Computational Expert
graphene composite
research team : Javier Lรณpez-Alascio Hervรกs, Gelder Van Limburg Stirum, Ricardo Mayor Luque, Thanos Zervos
tutors areti Markopoulou - DMIC Leader ALEX DUBOR - FABRICATION Expert ANGELOS CHRONIS - Computational Expert
JUNE 2017 BARCELONA
abstract This project is a study of graphene as an embedded material inside traditional building materials. The research aims to examine the innovative possibilities of graphene applications that haven’t been done before in architectural design or fabrication processes. To support the findings of this research, the evidence is based on multiple experiments. The conducted research aims to improve the quality and the performance of the prototypes with feasibility tests and to see how they can be further developed. This study could fill a gap and lead to a greater understanding of graphene within the architectural scale. Different types of methods improved the performance of the graphene for the purpose of thermal and electrical properties through additive manufacturing methods. Drawing from the analysis of the research, outcomes indicate that graphene composites are able to produce heat through electro-thermal conductivity and have the possibility to create a network to transfer data. The graphene composites could be part of a system that enables a structure to perform off-grid to become passive and self-operating. Summarising, it is believed that the use of graphene enhances the performance of material composites, which is part of our long-term research goals. The outcomes of this project are considered to be novel and enhance the knowledge and understanding of graphene incorporated into architecture. Key Terms: Graphene, heat, electro-thermal conductivity, data, graphene composites.
contents 1.1. 1.2. 1.3. 1.4. 1.5.
INTRODUCTION HYPOTHESIS RESEarch question graphene state of the art
2.1. 2.2. 2.3. 2.4. 2.5. 2.6. 2.7. 2.8. 2.9.
research methodology 3d printed graphene - pla composites viscous graphene nanoplates - pcl - benzilic alcohol composite graphene nanoplates - pvp - composite on elastic surfaces cast graphene nanoplates - pvp - clay composite cast graphene nanoplates - pvp - cement mortar composite solar experiments of pasive heating uniform clay - graphene - pvp composite functionally graded material of graphene and clay
3.1. 3.2.
potential uses of graphene in AN ARCHITECTURAL ENVIRONMENT CONCLUSION
BIBLIOGRAPHY
Acknowledgements As part of the research studio Digital Matter Intelligent Construction of the Masters in Advanced Architecture, Senior Faculty and Academic director Areti Markopoulou, Fabrication Expert Alexandre Dubor and Computational Expert Angelos Chronis, have played a vital and supportive role in our project and due to their contribution and constant feedback, we were sufficiently guided throughout the two term studio. We would also like to show our gratitude to Giovanni Perotto, from the Italian Institute of Technology - IIT-, for his scientific knowledge and experience with graphene, which is considered by us as a great contribution to our project. We also thank Kunal Chadha for his help with robotic fabrication and Chenthur Raaghav Naagendran for sharing his experience with graphene. Finally we thank the members of the jury of each of our presentations, who’s feedback was extremely valuable for our work.
Introduction This research is part of the Research Studio Digital Matter-Intelligent Construction of the Master in Advanced Architecture program at the Institute for Advanced Architecture of Catalonia. The research studio focuses on material intelligence and inventive architecture. We are embedding innovative thinking and designing with an unknown material in the field of architecture. Researching the role of graphene as the newly discovered material and how this is related to innovative architecture are the reasons for undertaking this study. Investigating how fabrication techniques and computing can be integrated in designs that lead to performing prototypes that question existing systems in architecture is the challenge and our aim of this two term studio.
Hypothesis The hypothesis encourages a complex answer and summarises the significant issues the research will investigate. The following hypothesis is the core of this project: ‘Integrating graphene with traditional building materials enhance their thermal properties’
Research Question To guide the research process, a structured research question is required which is pushing innovative architectural thinking. The study investigates the significance of the use of graphene and how it can be applied. For provable argumentation, this exploration will examine the following research question: ‘How can embedding graphene as part of a composite with traditional building materials be innovative?’
graphene Graphene can be obtained from graphite, which is easily derivable from natural sources in substantial quantities. Graphene consists of a flat monolayer of carbon atoms firmly packed into a 2D honeycomb lattice1-6. Carbon-based systems show an extensive amount of possibilities with structures with an equal amount of varieties of physical properties. Graphene has properties of soft matter and is an interesting combination of being a semiconductor and a metal, as it is impermeable making it one of the most versatile systems in matter research. The given that graphene can be derived from Earth’s resources makes it a very appealing material for research7. Currently graphene is still an expensive material as even basic research still has to be further developed, however the prospects are that in the near future prices will drop making the material much more affordable and widely available. Graphene is compatible with a wide variety of polymers, it therefore can be used as a material for the production and embedment of graphene composite materials. When mixing graphene with other materials the hydrophilic and hydrophobic balance should be controlled. This procedure is an up-and-coming method for the production of graphene nanoplatelets in composite materials, a field in which graphene is to be expected to play an important role in the near future8. Prototypes with different forms of graphene have been made during the course of the studio. For the majority of the experiments that have been conducted the focus has been on working on amphiphilic graphene nanoplatelets with polymers.
1. “Nature Mater”. 2007, 6, 183–191. 2. “Nature Mater” 2007, 6, 332–333. 3. S. Watcharotone, D. A. Dikin, S. Stankovich, R. Piner, I. Jung, G. H. B. Dommett, G. Evmenenko, S. E. Wu, S. F. Chen, C. P. Liu, S. T. Nguyen, R. S. Ruoff, Nano Lett. 2007, 7, 1888–1892. 4. X. Wang, L. J. Zhi, K. Muellen, Nano Lett. 2008, 8, 323–327. 5. J. C. Meyer, A. K. Geim, M. I. Katsnelson, K. S. Novoselov, T. J. Booth, S. Roth, Nature 2007, 446, 60–63. 6. M. Shigami, J. H. Chen, W. G. Cullen, M. S. Fuhrer, E. D. Williams, Nano Lett. 2007, 7, 1643–1648. 7. A. H. Castro Neto , F. Guinea , N. M. R. Peres , K. S. Novoselov , and A. K. Geim, The Electronic Properties of Graphene, 2009, 1-55. 8. J. Shen, Y. Hu, C. Li, C. Qin, M. Ye, Synthesis of Amphiphilic Graphene Nanoplatelets, small 2009, 5, No. 1, 82–85.
State of the art Although graphene is considered the material of the future, its research and applications have not yet reached the construction industry. This paper focuses on the potential of developing graphene-embedded composites to enhance the electrical and thermal performance of traditional and widespread construction materials such as concrete and clay. A number of performing prototypes were fabricated at different stages of the study using different approaches for embedding graphene nanoplatelets into clay and mortar. Our experimentation with these composites has led to the conclusion that there is significant potential in enhancing the thermal and electrical properties of traditional materials. These first tests demonstrate both the achievable performance as well as the feasibility of producing such composites without access to a professional grade laboratory.
RESEARCH METHODOLOGY Focusing on the thermal and electrical properties of graphene, a series of experiments were carried out, testing different composites of graphene and other materials in a search of a building material with the optimum characteristics. In every phase of the research a prototype was produced as a proof of concept which was later gone through different tests. These tests were focusing on measuring the electrical conductivity of each composite or geometry, the thermal conductivity and heat distribution and the potential use of the prototype in an active or passive heating system. All the experiments were carried out in a non professional grade lab, where different fabrication technics and testing methods where employed in each phase to achieve conclusions that would lead to the next experiment. The forms of graphene used for this experiments were pre made graphene – polymer compounds and graphene nanonplates. These research phases and the conclusions drawn from them are described bellow.
3D PRINTED GRAPHENE – PLA – PCL COMPOSITES The first phase of the research focused on the use of graphene composites with biodegradable polyesters. Already made composites of graphene - Polylactide (PLA) and graphene – Polycaprolactone (PCL) were 3d printed in different patterns. The goal of this phase of experimentation was to test the two different composites in terms of their material properties, but also make a geometrical investigation in order to understand how different patterns would affect the result of the experiment. Four patterns where produced, each one with a different density. The overall size of each prototype was 70 mm x 100 mm.
!"##$%&'(')*!
!
"#$%&'()*+
,-./0121! ! ! ! !!!!3#$ 456!!!!!!!!!!!!!!!!!!! ! ! !!!!7#$ 819:9;:<:;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!>?#ȍ ! ! !
!"##$%&'(')+!
!
@#$%&'()*+
,-./0121! ! ! ! !!!!3#$ 456!!!!!!!!!!!!!!!!!!! ! ! !!!!7#$! 819:9;:<:;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!">#ȍ ! ! ! !!!
!"##$%&'('),!
!
A#$%&'()*+
,-./0121! ! ! ! !!!!3#$ 456!!!!!!!!!!!!!!!!!!! ! ! !!!!7#$! 819:9;:<:;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"7#ȍ
!"##$%&'(')-!
!!!!!!!!!!B##$%&'()*+
,-./0121! ! ! ! !!!!3#$ 456!!!!!!!!!!!!!!!!!!! ! ! !!!!7#$! 819:9;:<:;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!3>#ȍ !! !!
!
Figure 1. graphene - PLA patterns
Testing: Voltage of 9.52 Volts of direct current was applied to the two ends of the prototypes, along their long axis. A thermal camera was recording the increasing temperature of the surface and the distribution of heat in the prototype.
Conclusions: The polyester - graphene composites had inadequate results in terms of conductivity, with the densest pattern having a resistance of 0.350 KΩ along it’s length. Also the presence of the polyester in the composite, was compromising significantly the performance of the prototype in terms of heat resistance.
VISCOUS GRAPHENE NANOPLATES– PCL – BENZILIC ALCOHOL COMPOSTITE This phase of experiments focused on a manually made mix of graphene nanoplates, PCL and benzilic alcohol. The goal of this phase was to attempt the creation of a graphene composite that would have most of the electrical properties of graphene but also give us control over it’s viscosity. The changes in viscosity where related to the presence of benzilic alcohol in the composites. The different mixes where later placed on elastic surfaces (PCV sheet, LATEX sheet, silicone sheet) in order to measure changes in resistance in relation with elastic expansion of the prototype in the direction of the current.
!"#$"%&'()*)+,!!
!"#$"%&'()*)+-!!
"#$%&'('!!!!!! ! ! !!!!!!!!!!!!!!!!)*+ ȍ ,-.!!!!!!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!/*+ 012&3&31!4'(561623!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!781 9':6:;6<6;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!>**ȍ !
!
!
!"#$"%&'()*)+.!!
"#$%&'('!!!!!! ! ! !!!!!!!!!!!!!!!!)*+ ȍ ,-.!!!!!!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!/*+ 012&3&31!4'(561623!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!)*81 ȍ 9':6:;6<6;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!7*?***ȍ ! ! ! !
"#$%&'('!!!!!! ! ! !!!!!!!!!!!!!!!!)*+ ȍ ,-.!!!!!!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!/*+ 012&3&31!4'(561623!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!)781 ȍ 9':6:;6<6;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!)?***?***ȍ ! ! ! !
!"#$"%&'()*)+/!! "#$%&'('!!!!!! ! ! !!!!!!!!!!!!!!!!)*+ ȍ ,-.!!!!!!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!/*+ 012&3&31!4'(561623!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!@*81 ȍ 9':6:;6<6;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!>?***?***ȍ ! ! ! !
!"#$"%&'()*)+0!! "#$%&'('!!!!!! ! ! !!!!!!!!!!!!!!!!)*+ ,-.!!!!!!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!/*+ 012&3&31!4'(561623!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!7*81 ȍ 9':6:;6<6;=!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!AB0B!! ! !
!
Figure 2. Mixes of different viscosity
Testing: The different mixes where placed in glass cases and then tested by applying voltage with electrodes. Then they where placed on the elastic surfaces and the same measurements where made in different positions of expansion.
COMPOSITE 02
COMPOSITE 01! ! "#$!%&''(!
!
!
!
!!!!!!!
!!!!
)*!$*)+,$-.#.-/
01('2!3&''(! !
!"#$%&
COMPOSITE 03! ! !
!
!!!!!!!
!!!
)*!$*)+,$-.#.-/
Figure 3. Viscous mixes on elastic surfaces
3456789!'!
!
!!!!!!!
!!!!
)*!$*)+,$-.#.-/
Figure 4. Glass case
Conclusions: These tests showed very inadequate results of electrical properties, as the presence of benzilic alcohol was severely compromising the conductivity of the composite.
GRAPHENE NANOPLATES – PVP COMPOSITE ON ELASTIC SURFACES By removing the benzilic alcohol from the mix, control over the viscosity of the mix was lost, but the electrical properties of graphene became again present. The same setup with the elastic surfaces was repeated to try the resistance of graphene in different expansion positions.
COMPOSITE 02
COMPOSITE 01! ! "#$!%&''(!
!
!
!
!!!!!!!
!!!!
)!*+,!-ȍ!
./('0!1&''(! ! )*!+2!-ȍ
COMPOSITE 03! ! !
!
!!!!!!!
!!!
1345678!'!
!
!!!!!!!
!!!!
)*!92!-ȍ
Figure 5. Composites on elastic surfaces
Testing: Having the electrical properties present again, measurements with application of voltage were possible on the prototypes. The measurements in different expansion phases were repeated.
Figure 6. Conductivity test with LED light.
Conclusions: The conductivity of the mixes was adequate to create a basic electrical circuit. The loss of viscosity control though didn’t allow to the composite to have any elastic behavior as it broke when expanded.
CAST GRAPHENE NANOPLATES – PVP - CLAY COMPOSITE
This phase of experiments was the first of the investigation of brittle materials and graphene composites. In this case two different types of prototypes where produced. The first type is a volume of homogenous mix of the brittle material (clay) and graphene. PCL is added to the mix as a binder between the hydrophobic graphene nanoplates and the wet clay. The wet mixes were forced into an acrylic casts and let to dry. The second type included two cast clay layers with a graphene nanoplates – pvp mix circuit between them.
Figure 8. Isometric drawing of the casts
!"#$%&'&(1()/#0()*+$*,-.&
"+<79+. )/#0 !"#$%&'&(()*+$*,-.& )/#0
)/#0 !"#$%&'&(()*+$*,-.& )/#0
!"#$%&'"$! "#$%!!!!!!!
!
!
!
!!&''(
!"#$%(%)*#+,-'-
!"#$%(%)*#+,-'-%!.*!/.0!
"#$%!! ! ;<$=-*5*! ?@?! !
"#$%!! !
!
!!!!!!!!!!!!!!!!!!!!!!!!!!&''(
"+<79+.C ;<$=-*5*! ?@?! ! )$.*<!!!!
! ! !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!>/( ! ! !!!!!!/( ! ! !!!!:/(
! ! !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!:/( !!!!!!!!!!!!!!!!!!!!!!!!!!!!>/( ! ! !!!!!!/(
)/#0
Figure 7. Geometry types for prototypes
!"#$%&'&(()*+$*,-.&
)*+,-.!!
)/#0
2*3+3.+4+.%!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!56!765897.+4+.% ! ! !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!/'01,
Figure 9. Clay prototypes
)*+,-.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!/'01,!
)*+,-.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!&&D0:,!
2*3+3.+4+.%!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!A''B'''ȍ ! ! ! !
2*3+3.+4+.%!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!&E>'ȍ ! ! ! !
Testing: The prototypes were tested with electrodes, connected to the pieces with silver paste. Measurements of resistance along the prototypes length were made in both types and recordings were made with a thermal camera.
Conclusions: The homogenous composite showed satisfying results in terms of coherence and conductivity, as it was conductive enough to create electrical circuits and presented similar mechanical properties to normal clay. The prototypes with the separate graphene â&#x20AC;&#x201C; pvp circuits between the two distinct layers of clay presented even better conductivity values, but they were incoherent as pieces, as their mechanical properties were seriously compromised by the cracks created by the graphene circuit.
Figure 10. Thermal tests of the prototypes.
CAST GRAPHENE NANOPLATES - PVP – CEMENT MORTAR COMPOSITE Next step of the research was to replace clay with cement mortar. This decision was based on the advantages of using cement in construction over clay and cement mortar’s ability to be easily cast. The same type of acrylic casts was employed to create the first prototypes, that included both types of homogenous mix volumes and pieces with an integrated graphene – pvp circuit.
Figure 11. Different cement prototypes
Figure 12. Pattern 1
Figure 13. Pattern 2
Figure 14. Pattern 3
Figure 15. Pattern 4
Figure 16. Pattern 5
After the first phase of experimentation, a series of more complicated prototypes were created, made by two cement slabs, shifted in two directions to interlock in a repetitive building system as bricks. A metal mesh reinforcement connected the two slabs and a graphene â&#x20AC;&#x201C; pvp circuit in the shape of a cross was in the middle. The circuit was exposed in the shifted areas of the brick, allowing to connect with the cross circuit of the next one. The circuit was also reaching the sides of the brick with five cylindrical connections of the same composite. These connections were important for conductivity measurements in different parts of the prototypes.
Figure 17. Interlocking prototypes with the cross graphene pattern.
Figure 18. Prototype with cross graphene pattern.
Figure 19. Isometric explosion of the prototype and the cast.
Figure 20. Drawing of the prototype and the cast
Figure 21. Drawing of the un - casted prototype
The fabrication method of this brick was based on a laser – cut plywood cast. The faces of the cast were covered with Vaseline to avoid breaks while un-casting. The casting included three phases. Firstly, one of the slabs is casted and the four metal reinforcements are placed with half of their height exposed to be later embedded in the next slab. Before the mortar dries completely, the graphene – pvp cross circuits is applied on the mortar surface and when it begins to solidify the next slab is cast on top. Finally, when the piece is un-casted, the parts of the cast that create the cylindrical holes are removed and the holes are filled with graphene – pvp composite to create the ten side connections.
Figure 22. Isometric drawing of a modular surface composed by the cement mortar brick. The connected cross shaped patterns of the bricks are visible forming a grid, embedded in the concrete slab.
Figure 23. Photographs of the final prototype and the tilling arrangement.
Testing:
Voltage of 32.5 Volts was applied to different positions on the brick and the resistance and amperage values were recorded. A thermal camera recorded the distribution of heat in the mortar mass.
Figure 24. Tests with the thermal camera of the prototypes
Figure 25. Tests with the thermal camera of the shifted slabs prototype
While investigating the idea of a circuit of graphene â&#x20AC;&#x201C; pvp and clay composite, inside a volume of a brittle building material, the production of heat in relation with the material properties and the current passing through the circuit were simulated in a simplified way. The simulation of the variable section wire resistance is aiming to perform as a tool, helping the design process of the different patterns and speculating the heat production performance of the prototypeâ&#x20AC;&#x2122;s circuit patterns.
Figure 26. Left to right: 1.Parametric model of a non uniform section conduction representing the graphene composite circuit, 2. Graph of Restistance per section along the lengh of the conductor, 3. Graph of heat production along the lenght for the given values of voltage applied and amperage, 4. Visual representation of the heat production along the length.
Conclusions:
The first phase prototypes with mortar presented worst results than the ones with clay, as they had lower conductivity values and the ones with a distinct graphene circuit in the middle were cracking. The second phase prototypes with the metal reinforcement were structurally satisfying and the conductivity of the graphene â&#x20AC;&#x201C; pvp composite was adequate for an electrical circuit. The heat produced from the brick after applying power was enough to render it comparable in terms of power consumption to existing heating systems. The problems observed in this process were mostly deriving from the shrinkage of the graphene â&#x20AC;&#x201C; pvp composite that compromised the bricks structure and the circuits reliability and also from the complexity of the fabrication process.
Figure 27. Graph of energy consumption per square metre.
Figure 28. Graph of temprerature change per energy amount converted.
SOLAR EXPERIMENTS OF PASIVE HEATING Two bricks were created with a wood cast for this experiment. One of them was solely made out of cement mortar and the other one was identical in dimensions but included a graphene â&#x20AC;&#x201C; pvp pattern inside. The goal of this experiment was to expose the one side of each brick to a heat source and measure the temperature change of the other side after a given period of time to observe differences in heat conduction, related to the presence of graphene.
Figure 29. Photograph of the solar experiment setup.
Testing: Two plywood boxes were constructed and painted white. They both had a slope with the dimensions of the section of the brick, so it could be positioned with half of itâ&#x20AC;&#x2122;s volume inside the box and the rest of it being exposed to the sun. The inside of the box surrounding the brick was filled with heat insulation of expanded polyurethane to avoid heat leaks. Both boxes were left exposed to the sun and temperature measurements of both the inside and the outside part were taken by a laser thermometer in equal amounts of time.
Figure 30. Exploded drawing of the experiment apparatus.
Conclusions: Although the differences in temperature where not extreme between the two pieces, the measurements gave promising results for a passive heating system, showing that the presence of graphene made the cement mortar conduct heat faster that the brick that was made solely by mortar.
Figure 31. Solar experiment graph.
Figure 32. Solar experiment data.
UNIFORM CLAY – GRAPHENE – PVP COMPOSITE Taking into consideration the problems deriving from having a separate graphene circuit in the bricks volume, the research was focused on homogenous composites. Cement mortar was once again replaced with clay, which had presented better properties in previous experiments when homogeneously mixed with the graphene – pvp composite. A series of bricks were manufactured again, aiming to find the optimized formula for the mix, using the least graphene nanoplates possible to achieve the best performance in terms of conductivity and heat production. The fabrication process of this phase was still manual, but the properties of the composite were already trying to match the demands of a mixture that could be potentially 3d printed or extruded.
Non conducti uctivity ucti
Figure 33. Homogenous graphene - clay prototypes.
Using the composite of clay – graphene and pvp, a catalogue of brick shapes was created and taxonomized depending on geometry factors. The functional criteria for the creation of these geometries were based on heat generation and radiation and potentially air circulation in a structure composed of these units.
Figure 34. Catalogue of brick shapes
Figure 35. Second phase graphene - clay homonegous prototypes.
Developing the idea of air circulation in a radiator â&#x20AC;&#x201C; like structure, the system evolved into a column form that would allow the air to pass through it while heated and circulate in the interior space of a building. The column would generate heat in an active way, with voltage applied to itâ&#x20AC;&#x2122;s top and bottom side. The vertical direction of the current, is defined by the extruded shape of the structure, rendering it a geometry with a uniform section in the vertical axis and therefor a predictable performance when electricity is applied.
Figure 36. Diagram of the air circulation setup
Figure 37. Isometric drawings of the radiator wall.
Figure 38. Elevation of the radiator wall.
Figure 39. Diagram of possible arrangements of the wall created by the modules.
Testing: The bricks were tested once more with electrodes connected to the piece with silver paste. When a satisfying mix was achieved, an acrylic apparatus was constructed to create pieces of the material with precise dimensions. These pieces were then tested with a direct current, equally distributed across their section to measure their resistance and then knowing their precise dimensions, the resistivity of the material was extracted to characterize it.
Figure 40. Prototypes of the radiator bricks.
Conclusions: The performance of this clay â&#x20AC;&#x201C; graphene â&#x20AC;&#x201C; pvp composite was ideal for the conductivity and heat production properties the research was aiming for. After achieving a mix in which the concentration of graphene could be controlled, the research focused on an investigation of functionally graded materials (FGM). The previous focus on creating a wall system that would replace the heating and electrical installations of a building, is now replaced by an interpretation of form through the prism of the properties of gradient materials.
Figure 41. Hand drawing of a wall being the core of a structure, containing information, producing heat and transfering data.
Functionally graded material of graphene and clay The research focuses at this point on functionally graded materials, which constitute a very important part of contemporary material science for reasons connected with their advantages in terms of property and material optimization. Functionally graded materials (FGM) are those in which composition and structure change over the volume, resulting in corresponding changes in the properties of the material, trying to optimize the properties of both components, depending on the specific use demanded for the result. The creation of a functionally graded material with graphene and clay aims to exploit grapheneâ&#x20AC;&#x2122;s properties of thermal and electrical conductivity by achieving the optimum coherence of the composite and minimizing the amount of graphene used. At this point the mixture that has been developed is a functionally graded material of graphene and clay. The fabrication of the gradient is classified as constructive, and the result is a stepwise graduation, with each step consisting of a different concentration of graphene. In comparison with composites, functionally graded materials are singular multi materials that vary their consistency gradually over their volume. The use of multi materials is expected to become prevalent in both fabrication and construction and will facilitate innovative architecture through merging different materials that will be fused together three-dimensionally. Thinking about material behaviour and building technique has become crucial as an integral and defining part of the design process and methodology (##). With the latest prototype we were able to establish one gradient going from the bottom to the top with the composites, with technology that is on the rise multiple gradients can be achieved in different axis.
Figure 42. Manualy fabricated gradient prototypes
â&#x20AC;&#x153;In a functionally graded material(FGM) both the composition and the structure change over the volume, resulting in corresponding changes in the properties of the materialâ&#x20AC;?, Miyamoto, Y. (2000). Functionally graded materials. 1st ed. Reading: Kluwer Academic Publishers.
3d printing
At this point the research moved from the manual casting methods, to an investigation of robotic fabrication. 3d printed prototypes replaced the previous bricks, allowing the exploration of more complex geometries. The restrictions and complications of 3d printing the graphene â&#x20AC;&#x201C; pvp â&#x20AC;&#x201C; clay composite, played the leading role in the geometry design and the functionality of the brick defined the form of the gradient. Goal of this process is to experiment with the thermal and electrical properties of the gradient brick and create a performative prototype made from the functionally graded material of clay â&#x20AC;&#x201C; graphene composite. The advantages of using robotic fabrication methods are mostly the overcoming of the fabrication limitations of manual methods and the potential uses of the material and the building technique in the future. 3d printing allows the geometry to evolve without the restrictions of casting techniques and unfolds a vast gamma of construction methods.
Figure 43. First 3d printed prototype.
The fabrication strategy of the prototype was as such: The gradient was created by five layers with different consistencies of graphene. The prototype was 3d printed from a robot with a single extruder so the different mixes had to be changed manually to create the step-wise graduation in the extrusion. During the extrusion the consistency of graphene was decreasing with each mix, leading to a vertical gradient with the greatest amount of graphene in the bottom. The section included a series of curves aiming to better heat radiation performance. The curvature of this shapes decreased from bottom to top following the vertical consistency gradient. The biggest challenge of this fabrication technique was the shrinkage of the composite due to the evaporation of the water in the mix. For that reason a series of extra curvatures had to be included in the section to add elasticity to the shape, so it would transform while retracting instead of cracking.
ROBOT EXTRUDER The printing was possible due to Pylos, a research action done at IAAC by Sofoklis Giannokopoulos, which resulted in the development of an extruder with a canister of 15 L, compressed with a pneumatic cylinder. The extruder’s measurements 300x300x2000mm. It allows printing with a layer thickness between 1 and 7 mm, 6 to 30 mm in width, at a speed between 0.05 and 1 m/s. After this work, guided by Kunal Chadha, the expert in robotic fabrication at IAAC, we did few modifications in this extruder model in order to set up our fabrication Project.
3d printing test The line test was primarily focusing on the continuity of the line, creating an un-interrupted toolpath. The tests then continued to branching simulations. An optimum ratio between lines width and length was discovered. Moreover, we started our tests with a composition low in the water trying to get conclusions about cracks in final 3d print results. experiment 01 was done moving manually the extruder over the table. Furthermore, experiment 02 was our first test in Kuka Robot with the extruder. After this work, while the experiment 01 doing a straight line of 80mm in 8 layer height showed us cracks each 50 mm, the experiment 02 doing a circle diameter of 100mm showed u that we reduced the cracks each 15mm. Another conclusión from the test was that we need to avoid the straight line trying to keep less than 15 mm straight.
EXPERIMENT 01 MANUALLY MOVEMENT EXTRUDER
EXPERIMENT 02 ROBOT & EXTRUDER
MATERIAL GRAPHENE PVP WATER
LAYERS: 8 AIR PRESSURE 6 BAR LINE THICKNESS: 15 MM LINE HEIGHT: 3 MM
MATERIAL GRAPHENE PVP WATER
LAYERS: 4 AIR PRESSURE 6 BAR LINE THICKNESS: 15 MM LINE HEIGHT: 3 MM
BREAKING EVERY 50 MM
BREAKING EVERY 15 MM
LENGTH LENGTH WET
SHRINKAGE IS RELATIVE TO LENGTH AND GEOMETRY
LENGTH DRY SL
Figure 44. Extrusion parameters 1.
Then these lines were subjected to various degrees of rotation that generated overlapping, intersections, continuous lines and symmetry in order to maximize the cleanliness of the models. To sum it, cracks and shrinkage are relative to length and geometry experiment.
conclusions
01 CANTILEVERS AND OVERHANGS CASE STUDY 04
01 CANTILEVERS AND OVERHANGS ANGLE MIN > 50° AIR PRESSURE 6 BAR LINE THICKNESS: 10 MM LINE HEIGHT: 3 MM
CASE STUDY 04 ANGLE MIN > 50° AIR PRESSURE 6 BAR LINE THICKNESS: 10 MM LINE HEIGHT: 3 MM
38°
02 SHRINKAGE 02 SHRINKAGE CASE STUDY 03 MATERIAL LINE WIDTH WET: 15 MM LINE WITDTH DRY: 10 MM
CASE STUDY 03 A1 MATERIAL LINE WIDTH WET: 15 MM LINE WITDTH DRY: 10 MM
10 MM
A2 A1
A2
10 MM
A3 A3
20 MM
03 AVOID STRAIGHT SURFACE EXPERIMENTS 02 / 03 AIR PRESSURE 6 BAR LINE THICKNESS: 10 MM LINE HEIGHT: 3 MM
Figure 45. Extrusion parameters 2.
Functional Graded Material COMPOSITION & FORM FINDING STRATEGIES The project combines 5 clay Graphene compositions changing the Graphene proportions between 30% and 5% graphene. This five compositions will be changed inside the extruder during the 3d printing process. The final functional graded material will be composed of a Graphene degradation which brings us the parameters to control the conductivity and a new molecular-scale of the material. This proposal would like to add another parameter in the fabrication process to continue the research that will be the multimaterial multi-extruder research in order to get the Functional Graded Material. The project combines 3 various postures inside the material design shape: vertical degradation material, radiation Surface, and optimisation material. Examples of this proposal come as a new addition to the additive manufacturing industry since not only it combines the 3 approaches into one, but the final aim of the project is building a performative surface.
Figure 46. Preparation of different mixes and arrangement in the extruder.
The project combines 3 various postures inside the material design shape: vertical degradation material, radiation Surface, and optimisation material. Examples of this proposal come as a new addition to the additive manufacturing industry since not only it combines the 3 approaches into one, but the final aim of the project is building a performative surface.
GE. 01
GE. 02
GE. 03
GE. 04
GE. 05
GE. 06
GE. 07
GE. 08
Figure 47. Design catalogue - Form finding possibilities of the brick
OPTIMISATION MATERIAL SHAPE
VERTICAL DEGRADATION & RADIATION SURFACE
INFILL STRATEGY
Figure 48. Design parameters
Figure 49. Form finding surface - Infil structure
Figure 50. Geometry of the brick
Figure 51.Photograph of the printing process
Figure 52.Photograph of the printing process
Figure 53.Photograph of gradient prototype (front)
Figure 54.Photograph of gradient prototype (back)
multi material printing
Multi-material 3D printing techniques are being developed to produce structures with new mixed materials with completely novel properties. This will challenge prefabrication as machine learning algorithms will also become more critical in the design process. 3D printing multi-materials in gradients achieve more optimal behaviors than traditional materials in the construction industry10. With new fabrication and printing techniques complex structures and better mechanical properties can be achieved. It has the potential to speed up innovative projects that have been previously impossible or difficult to fabricate and to make changes easily and cheaply. Printing with multiple nozzles has the same quality as printing with a single nozzle. However, multi-material additive manufacturing is still happening in microscopic and macroscopic levels and current systems still have many shortcomings11. Material distribution is optimized to space specific constraints, or simple constraints such as maximizing stiffness. The design algorithm is able to optimize geometries and can improve material distribution12.
10. Automated Architecture: Why CAD, Parametrics and Fabrication are Really Old News 11. MultiFab: A Machine Vision Assisted Platform for Multi-material 3D Printing 12. Design Automation for Multi-Material Printing
3.1. potential uses of graphene in an architectural environment This projectâ&#x20AC;&#x2122;s goal is to integrate graphene as part of a system into construction, imagining the possible uses of this material in a context of architectural design in an era of technological expansion. The properties of graphene taken into account in this investigation, were mostly electrical and heat conductivity, but also mechanical properties and solar energy conversion. The reason for focusing on electrical and heat conduction was mostly the fact that graphene hasnâ&#x20AC;&#x2122;t reached mass production yet, only allowing proper experimentation in small scale, and only in the form of nanoplatelets. The potential uses of graphene in architecture though are limitless, and the examples following are an attempt to imagine some of them in a context of expanding the limits of what is considered today as the field of architecture.
Mechanical Properties Graphene as a material with extraordinary mechanical properties, could be integrated in construction allowing a completely new type of architectural vocabulary to emerge. The infinite battle of architecture against gravity, can make a significant jump with this material, as itâ&#x20AC;&#x2122;s extreme strength in combination with its gradient mix with other materials in an era of growing computational power could allow us to achieve structures that were never possible in the past. With composite materials slender but very strong structures are able to be constructed.
Conduction This property of graphene is similar with other forms of carbon such as carbon fibres. The advantage of graphene is that being a powder, it can mix with other building materials and create gradients, allowing a huge expansion of the ways to control the heat and create complex thermodynamic systems. This property could be combined with the electrical conductivity to create active heating systems, or used in a passive way to control heat in extreme building environments.
Electric Applications The electrical conductivity of graphene is probably the one property exploited the most by now in many scientific fields. In an architectural context, there can be several uses of a conductive building material. They vary from simply replacing the electrical installations of a building with a material that could be cast or 3D printed, to turning the built environment into a computational device by integrating complex circuits into construction. The possibilities that derive from a brittlematerial with conductive properties allow buildings to become sensors, means of data transfer and potential data storage. Using such a material could mean the unification of computing and built space, as the building could be the circuits that dominate our digital environment. Graphene supercapacitors work as energy storages and graphene can also be used as data storage. Technology storage is able to support data transmission and enables possibilities for optoelectronics, which means graphene can optically transmit light and it can provide interactive information as part of computers and nanotechnology that are integrated with graphene.
Future cities The generic city model is based on needs of a computable city. This model with global and local properties can be place specific, buildings and cities can become tailor made, to create an own identity13. There are many global similarities in urban settings, however cities do differ greatly in cultural, regional and climatic characterics. Social dynamics, the decline of fossil energy, increased population density, transportation, energy, communication, water infrastructures, are all challenges to be tackled in the near future. The system implies that a city consists of basic functions and interlinked metadata to design the performance of the city. Metadata serve as criteria for the city creation and design process and to analyze impulses affecting all urban scales. Cities can be shaped by needs and desire. Outputs can be used to optimize urban design in order to achieve optimal economic and ecologic performances14. Graphene can play a vital role in the future by shaping urban and rural settings through water filtration, photovoltaic cells and biological Engineering.
13. The Hellenistic City Model Inspired by Koolhaas 14. From Bauhaus to Koolhaas
Figure 55. Wall with material and geometry gradient
Figure 56. Plan and section of spaces, where a gradient material creates a gradiet of heat distribution
3.2. conclusion Many articles have been written about the rise of graphene as a material. With our research on possible graphene applications we have touched upon a new subject by introducing graphene in the spectrum of architecture. Which resulted in rethinking digital fabrication methods and design processes. During the course of the studio weâ&#x20AC;&#x2122;ve delved into the world of science to make an attribution to this field since the research aim was to examine the innovative possibilities of graphene usages that are novel in architectural design and fabrication. The overall objective was to optimize the performing prototypes and to go through additive manufacturing methods. Integrating graphene with traditional building materials enhance the thermal properties. Moreover, the outcomes indicate that graphene composites are able to produce heat and have the possibility to become a circuit of data transmission instantly assess them to see how they can be further developed. Reason for this was to fill the research gap and for a better understanding of graphene embedded composites. Different approaches improved the performance of the multi material prototypes for the purpose of thermal and electrical conductivity. This in turn can be developed as a system that is able to become a passive and self-operating structure. We were able to establish one gradient going along the y-axis of the final prototype. The next step would be to add gradients in all axes. It is expected that working with multi materials is inevitable in both fabrication and construction and will result in innovative architecture. With different parameters the optimization of geometries and material distribution is achieved, then there is also the ability to construct very strong and slim structures. The potential use of graphene in architecture is boundless. Computing and the built environment can now merge together. Graphene has the potential to play a pivotal role in the near future shaping a new urban context.
bibliography
Geim, A. and Novoselov, K. (2007). The rise of graphene. Nature Materials, 6(3), pp.183-191. Pichler, T. (2007). Molecular Nanostructures: Carbon ahead. Nature Materials, 6(5), pp.332-333. Watcharotone, S., Dikin, D., Stankovich, S., Piner, R., Jung, I., Dommett, G., Evmenenko, G., Wu, S., Chen, S., Liu, C., Nguyen, S. and Ruoff, R. (2007). Graphene−Silica Composite Thin Films as Transparent Conductors. Nano Letters, 7(7), pp.1888-1892. Wang, X., Zhi, L. and Müllen, K. (2008). Transparent, Conductive Graphene Electrodes for Dye-Sensitized Solar Cells. Nano Letters, 8(1), pp.323-327. Meyer, J., Geim, A., Katsnelson, M., Novoselov, K., Booth, T. and Roth, S. (2007). The structure of suspended graphene sheets. Nature, 446(7131), pp.60-63. Miyamoto, Y. (2000). Functionally graded materials. 1st ed. Reading: Kluwer Academic Publishers. Ishigami, M., Chen, J., Cullen, W., Fuhrer, M. and Williams, E. (2007). Atomic Structure of Graphene on SiO2. Nano Letters, 7(6), pp.1643-1648. Castro Neto, A., Guinea, F., Peres, N., Novoselov, K. and Geim, A. (2009). The electronic properties of graphene. Reviews of Modern Physics, 81(1), pp.109-162. Shen, J., Hu, Y., Li, C., Qin, C. and Ye, M. (2009). Synthesis of Amphiphilic Graphene Nanoplatelets. Small, 5(1), pp.82-85. Andia, A. (2014). Automated Architecture: Why CAD, Parametrics and Fabrication are Really Old News. Blucher Design Proceedings, 1(7), pp.83-86. Sitthi-Amorn, P., Ramos, J., Wangy, Y., Kwan, J., Lan, J., Wang, W. and Matusik, W. (2015). MultiFab. ACM Transactions on Graphics, 34(4), pp.129:1-129:11. Hiller J. D., and Lipson H. (2009). Design Automation for Multi-Material Printing, 20th Annual International Solid Freeform Fabrication Symposium, pp. 279–287. Halatsch, J., Mamoli, M., Economou, A. and Schmitt, G. (2009). The Hellenistic City Model Inspired by Koolhaas, Session 08: City Modelling 1, eCAADe, 27, pp.279-286. Heron, K. (1996). From Bauhaus to Koolhaas (note: An interview with Rem Koolhaas). wired.com, (Issue 4.07).
IIT cientific SUPERVISION