Convergence Issue 32

FALL 2023

The magazine of engineering and the sciences at UC Santa Barbara

FOCUS ON:

new funds for MRL

THE NSF REINVESTS IN THE 30-YEAR-OLD LAB THAT MADE UCSB A MATERIALS GIANT

BOLD ACTION ON CYBERSECURITY DESIGNING HUMAN-AI PARTNERSHIPS TO HARDEN CRITICAL CONNECTED SYSTEMS

Q&A WITH UMESH MISHRA

THE AFFABLE NEW DEAN ARTICULATES HIS ENTREPRENEURIALLY INFORMED VISION

CONTROLLING “FLOPPY” ROBOTS AN INNOVATIVE APPROACH GETS RESULTS

Message from the Deans

he proof is in the pudding runs the old line, which means it’s in the doing. It’s also in the funding, or even the RE-funding, in the case of the UC Santa Barbara Materials Research Laboratory (MRL), one of twenty Materials Research Science and Engineering Centers (MRSECs) in the United States. For more than thirty years, pioneering work from the UCSB MRL’s revolving series of Interdisciplinary Research Groups (IRGs), has earned the lab a worldwide reputation for materials-science excellence while garnering cover articles in major journals, educating students, propelling startups, and even leading to a Nobel Prize (Alan Heeger, chemistry, 2000). Last spring, the National Science Foundation (NSF) awarded the MRL its seventh consecutive funding grant, a major accomplishment, especially given that every six years, existing MRSECs must re-enter an open national competition to receive more funding. A MRSEC’s research must continue to be on the very leading edge, or it will disappear. Umesh Mishra The NSF model has become increasingly collaborative over the decades, Dean and Richard A. Auhll Dmaking UCSB, characterized by the highly collaborative interdisciplinary Professor, College of culture upon which its superb STEM reputation has been built, increasingly Engineering qualified as a MRSEC host. Our cover story (P. 18) tracks the long history and continuing legacy of this stellar facility and the people who make it work. As in every issue of this magazine, you’ll read about other projects involving researchers from various disciplines combining their efforts to great effect. For instance, mechanical engineering professors Elliot Hawkes, an expert in soft robots, and Igor Mezić, a dynamical systems and control-theory expert, took a novel approach to control the movements and actions of soft robots. Read about what they did and why it matters on page 30. On page 12, we tell you about the new Pathfinder Chemical Engineering Teaching Lab. It provides undergraduate students from any discipline across UCSB the opportunity to dip a toe into chemical engineering for a quarter to see if it might be a promising path for them. Don’t miss our coverage on page 13 of another major NSF award, a $20 million grant that puts UCSB as the lead of the new ACTION Institute. The eleven-university collaboration is aimed at combining the abilities of humans and artificial intelligence to develop a revolutionary approach to cybersecurity. Elsewhere (P. 28), you’ll learn about how researchers in the lab of materials professor and department chair, Omar Saleh, used engineered DNA nanostars to dig into intriguing phenomena suggesting that the phase-change-induced characteristics of some unique droplets might make them useful in developing new materials. We hope you enjoy these and the other articles in this issue. Sincerely,

Scan to read Convergence online

Fall 2023

Pierre Wiltzius Susan & Bruce Worster Dean of Science, College of Letters & Science

CONTENTS 2

Message from the Deans

News Briefs A collection of news from UCSB engineering and the sciences.

Faculty Q & A: Umesh Mishra The new dean shares his entrepreneurial vision for the COE. Meet our New Faculty Five assistant professors and one full professor join the COE ranks. Experimenting with ChemE A new teaching lab gives undergraduate students a taste of the discipline. Bold ACTION on Cyberdefense UCSB leads a new effort combining humans and AI to protect critical connected systems.

FOCUS ON: The MRL at 30 The pioneering materials-science lab receives a seventh consecutive round of NSF funding.

Champion of Engineering Wenbin Jiang: a generous alumnus with a feel for photonics.

The Beneﬁts of Collaboration UCSB and ASML: a partnership for essential technology.

Can “Phase-Change” Droplets Deliver New Materials? Omar Saleh’s lab investigates some intriguing phenomena.

Hard Thinking on Soft Robots A pair of UCSB professors combine their disparate talents to great effect in controlling “ﬂoppy” robots.

The Magazine of Engineering and the Sciences at UC Santa Barbara Issue 33, Fall 2023 Director of Marketing: Andrew Masuda Editor/Writer: James Badham Art Director: Brian Long Graphic Designer: Lilli McKinney UCSB Contributors: Sonia Fernandez, Harrison Tasoff Cover Illustration: Artist’s concpt of the edge — and the overlapping elements — of collaboration (page 18), by Brian Long Photography Contributors: Jeff Liang, Lilli McKinney, Matt Perko /ucsb.engineering /ucsbengineering /UCSBCollegeofEngineering /ucsbengineering

College of Engineering 3

NEWS BRIEFS CHIPS ACT FUNDING COMES TO UCSB UC Santa Barbara will play a major part in the effort to bolster semiconductor manufacturing in the United States and develop its competitiveness in the global market. The campus is a member of the California Defense Ready Electronic and Microdevices Superhub (California DREAMS), one of eight Microelectronics Commons regional innovation hubs established by the Department of Defense in October. The agency’s ﬁrst awards, worth a total of $238 million, are intended to advance the discovery, innovation, and fabrication of domestic microelectronic technology, such as circuits and chips, with funding from the “Creating Helpful Incentives to Produce Semiconductors (CHIPS) and Science Act.” Passed in 2022, the bipartisan federal bill will provide about $250 billion to invest in semiconductor research and development, build the semiconductor manufacturing sector in the United States, and educate and train the workforce expected to propel the industry forward. “We are extremely proud to join with other leading research universities and industry partners in Southern California as part of this united effort,” said Umesh Mishra, dean of the UCSB College of Engineering. “Our involvement is a testament to the university’s strong reputation in the semiconductor industry, which was built to a signiﬁcant extent upon decades of innovation and cutting-edge microelectronics developed on our campus. We look forward to contributing our expertise to the hub.” The hub is a coalition of research and industry organizations having the shared goal of accelerating the development and manufacturing of microelectronics in the U.S. Led by the University of Southern California, the hub also includes UCSB, UCLA, UC San Diego, UC Riverside, UC Irvine, Caltech, Pasadena City College, North Carolina Agricultural and Technical University, Morgan State University, Northrop Grumman, Boeing, Lockheed Martin Aeronautics, Raytheon, Teledyne Technologies, HRL Laboratories, and PDF Solutions. “We are enthusiastic to be a part of this hub team, and we look forward to the start of the program,” said Jonathan Klamkin, a professor of electrical and computer engineering and director of the UCSB Nanofabrication Facility, a key component of the DREAMS Hub.

CLIMATE SCIENCE IS CATCHING UP, SAVING LIVES A group of climate scientists at UC Santa Barbara and their colleagues are beginning to catch up with, and even get ahead of, climate change. In a commentary for the journal Earth’s Future, Chris Funk and co-authors assert that predicting the droughts that cause severe food insecurity in the Eastern Horn of Africa (Kenya, Somalia, and Ethiopia) is now possible, with months-long lead times that allow for measures to be taken to help millions of the region’s farmers and pastoralists prepare for and adapt to the lean seasons. “We’ve gotten very good at making these predictions,” said Funk, who directs the Climate Hazards Center, a multidisciplinary alliance in the UC Santa Barbara Geography Department. In the summer of 2020, CHC researchers predicted that climate change, interacting with 4

Fall 2023

Scan the QR code above to watch a viedo about the Nanofabrication Facility at UC Santa Barbara.

naturally occurring La Niña events, would bring devastating sequential drought to the Eastern Horn of Africa. The region normally has two wet seasons per year, in spring and fall, but an unprecedented ﬁve rainy seasons in a row failed. Eight months before each of those failures, the CHC anticipated droughts. Fortunately, agencies and other collaborators paid heed to those warnings and took effective actions, Funk said. The forecasts helped to earmark hundreds of millions of dollars within the U.S. Agency for International Development (USAID) to assist millions of people facing starvation. Ten years priot to that, predictions of sequential droughts for the same region made by researchers who were collaborating with the USAID– supported Famine Early Warning Systems Network went largely unheeded. The result, Funk said: “More

than 250,000 Somalis died. It was just horrible.” At that time, however, the group’s long-range weather prediction capabilities were still in their infancy, and the forecasts were not yet able to predict rainfall deﬁcits in the region. Now, Funk explained, “Following our [predictive] success in 2016-’17 and extensive outreach efforts, the humanitarian relief community appreciates the value of our early-warning systems.” While investments in early-warning systems and adaptation measures may be costly initially, Funk said, they are relatively inexpensive when compared to post-impact, response-based alternatives such as humanitarian assistance and/or funding safety-net programs. “Flooding still happens, drought still happens, people still get hurt, but we can try to reduce the harm.”

Photograph by Thomas Yu

NEW CHAIRS FOR COE DEPARTMENTS

Race-ready Gauchos (clockwise from top left): Anirudh Kumar, Cesar Castillo, Roger Torres Aguilar, Matthew Lin, Ryan Nguyen, Tim Schmuelling, Jason Wei, Nicholas Rivelle, Tien Nguyen, Raaghav Thirumaligai, Aran Sandhu, Stephen Wong, Owen Liu, Nikunj Parasar, Dylan Pratt.

REVVING UP THE GAUCHO RACE TEAM Inactive since 2009, the Gaucho Race team returned to action in 2023, giving a new generation of mostly engineering students at UC Santa Barbara the chance to gain valuable hands-on experience in all phases of designing, engineering, and building a formula-type electric vehicle. As part of UCSB’s official SAE International (formerly the Society of Automotive Engineers) student chapter, the students’ main focus this year was simply to participate in the Formula SAE Electric Competition, held each year at Michigan International Speedway. Re-igniting the race team was the idea of team president Nick Rivelle, a former English major-turned engineering student. He started with a small group, which grew thanks to word-of-mouth interest and support from a few faculty advisors, including Kirk Fields, who helped students get hands-on experience with the brand-new computerized equipment in the College of Engineering Machine Shop. The students not only had to work together on the year-long project, but also had to find funding; they managed to raise more than $30,000. That valuable experience enabled the students to forge connections and build relationships with industry sponsors. The effort to complete the single-passenger vehicle came down to the wire and was accomplished thanks to several marathon all-night work sessions. It rolled on its own power only on the night before Rivelle set out from Santa Barbara for Michigan, towing the vehicle on a flatbed trailer purchased on CraigsList. In the end, the car was unable to compete, because it failed to meet some of the stringent competition guidelines. But this first year back after a fourteen-year hiatus served to reignite interest among students, who plan to renew their efforts during the current academic year. The actual machining of the custom parts was done under the supervision of the COE Machine Shop staff, specifically with the help of shop superintendent Marty Ramirez, staff members Andy Weinberg and Josh Bowie, and teaching assistants Joe Sandoval and Braden Beitel. “We could not have completed the project without them,” Rivelle said. Looking ahead, he adds, “We haven’t had students who were interested before. Now, it’s up to them to keep the momentum going.” To that end, most of the team, including Rivelle, will be returning this year, determined to run their car on the track.

Three new department chairs were named in the UC Santa Barbara College of Engineering last summer. They are: Divyakant “Divy” Agrawal, Computer Science; Michael Gordon, Chemical Engineering; and Omar Saleh, Materials. Agrawal, a distinguished professor in computer science, came to UCSB in 1987 and has held multiple leadership roles in the department, college, and campus, including as department chair during the dotcom boom and as director of Engineering Computing Infrastructure. He represented UCSB system-wide as chair of the Graduate Council on the Coordinating Committee of Graduate Affairs. A recognized leader in the areas of databases and distributed systems, he is a fellow of several prestigious professional societies. During his second term as chair, Agrawal intends to respond to the economic dominance of technology companies, which is creating a tremendous demand for computer-science education, both at the undergraduate and graduate levels. He plans to prioritize faculty hiring in strategic areas to meet those demands while continuing to enhance the department’s burgeoning research reputation. Gordon, who came to UCSB in 2007, has held department- and campuslevel leadership positions for the past several years. He has served as the department’s Vice Chair for Undergraduate Education since 2018, overseeing the department’s program review and successful ABET accreditation renewal. He chaired the UCSB Committee on Admissions, Enrollment and Relations with Schools, and, at the UC level, served for two years on the Board of Admissions & Relations with Schools. He is currently co-chair of UCSB’s Western Association of Schools and Colleges accreditation committee, which oversees the accreditation reaffirmation process. His priorities as chair include continuing to hire top-level faculty to meet student needs and reflect new frontiers of research in chemical engineering, maximizing the department’s visibility in the field, increasing outreach for department recruitment and support, maximizing inclusivity and diversity in the department, and providing more hands-on learning opportunities and support for undergraduates. Since joining the UCSB faculty in 2005, Saleh has held multiple key campus-level leadership roles that have prepared him to become the department chair. He served as director of the Biomolecular Science and Engineering (BMSE) Program, successfully completed a program review for BMSE, and spent three years on the Academic Senate’s Committee on Academic Personnel, serving as vice-chair and chair for the panel that makes recommendations on faculty appointments, promotions, and non-routine merit advancements. Among his top priorities are the continued strategic hiring of faculty and maximizing the support of graduate students.

New department chairs (from left): Omar Saleh, Divyakant Agrawal, Michael Gordon. 5

CLEANING UP BY REUSING PLASTICS Eliminating single-use plastics is a major challenge of our time, and in recent years, UC Santa Barbara chemical engineering professor Susannah Scott has been hard at work trying to give plastics a longer life. In a paper published in the journal Chem, Scott and colleagues from UCSB, Cornell University, and the University of Illinois, Urbana-Champaign, describe a way to speed up an innovative process they developed previously for turning polyoleﬁns, the most common type of polymer in single-use packaging, into valuable alkylaromatics. Those, in turn, are used to make surfactants, the active components of detergents and other useful chemicals. “You’re getting another use out of the carbon that went into the plastics,” said Scott, the Mellichamp Chair in Sustainable Catalytic Processing. In their previous work, the researchers debuted a catalytic method to break the strong carbon-carbon bonds that make plastic so hard to degrade, then rearranged the molecular chains into alkylaromatic rings. The original process was effective but slow and yielded relatively few alkylaromatic molecules. “In this paper, we show how to do it much better,” Scott said. “It just screams along. It makes the alkylaromatics faster, and we can tune it to make the right-size molecules.” While the method originally took 24 hours to transform plastic into alkylaromatic molecules, the improved process can complete the task within a couple of hours and at moderate temperatures requiring little energy. The ultimate goal is to bring the process into wide use, incentivizing chemical companies to transform the resulting alkylaromatic molecules into surfactants, which can then be formulated into soaps, washing liquids, cleansers, and other detergents. To determine if the method is truly sustainable, it will have to undergo a life-cycle assessment, in which the energy spent and the greenhouse gases emitted are calculated at each step. If it passes muster, the method could displace existing fossil-fuel-intensive processes that go into creating surfactants from scratch.

A Million Miles Away tells the compelling life story of UCSB alumnus José Hernandez.

GAUCHO ASTRONAUT’S JOURNEY FEATURED IN AMAZON FILM The spring 2021 issue of Convergence magazine included an article describing a planned Netflix film, a biopic about UCSB alumnus José Hernandez (MS ’86), who started life as a migrant farm worker in California and Mexico and eventually spent fourteen days in space in 2009 as a flight engineer aboard a NASA Space Shuttle mission to the International Space Station. The film, titled A Million Miles Away and eventually produced by Amazon, was released in September. “It feels surreal that I have a movie based on my life story,” said Hernandez, who was turned down eleven times before being admitted to NASA’s astronaut program. “I hope it becomes an inspirational classic and empowers the viewer to believe that with hard work, preparation, and perseverance, anything is possible.” Hernandez described seeing his life’s story depicted in a film as “a very humbling experience,” adding, “It was great working with the filmmakers, who did an incredible job of telling my story!” Professor Susannah Scott, Mellichamp Chair in Sustainable Catalytic Processing. 6

Fall 2023

TRESA POLLOCK INVENTED THE TRIBEAM. NOW A NEW ONE IS COMING TO UCSB. In 2020, we told you about a first-of-its-kind tomography instrument called the TriBeam. Developed by UC Santa Barbara materials professor Tresa Pollock and collaborators, the TriBeam includes an extremely fast, femtosecond (10-15-second) laser, an ion beam, and an electron beam, making it possible to acquire, layer-by-layer, a unique set of information about materials’ chemistry and structure. The TriBeam is now being commercially produced by Thermo Fisher Scientific, the world’s leading microscope manufacturer, and Pollock and her UCSB colleagues have secured a roughly $2 million National Science Foundation grant to acquire one of the new commercial instruments. Pollock, a world-renowned metallurgist and the ALCOA Distinguished Professor of Materials, says that the new instrument, called the Helios G5 PFIB TriBeam Microscope, “will dramatically enhance our ability to address challenging scientific problems in electronic, magnetic, structural, and softmaterial systems; broaden community access to this technique via formation of a national training and data-sharing hub; and increase access of a broad spectrum of researchers to the unique 3D multimodal datasets generated by the TriBeam platform.” The new TriBeam’s dual-wavelength laser capability will greatly speed up the acquisition of 3D datasets, enabling advances in the design of bio-derived

thermoelectric gels and in understanding behavior related to friction and wear of ﬂuoropolymer metaloxide composites, while providing new insights on the subcellular structures in heart tissue and cardiomyocytes derived from induced pluripotent stem cells. Importantly, the new terabyte (TBG)-scale datasets, combined with the existing 100-TB datasets, will provide missing 3D data need to train machine-learning algorithms that will change the paradigm for materials discovery.

The original TriBeam developed in Tresa Pollock’s lab (left) and its commercially produced progeny.

AWARDS FOR ADVANCES IN PHOTOVOLTAICS Thuc-Quyen Nguyen, a professor of chemistry and biochemistry at UC Santa Barbara, recently received two major professional honors recognizing her work in developing novel materials to beneﬁt society. One was the de Gennes Prize from the Royal Society of Chemistry, which cited her “seminal contributions to the development of organic semiconducting materials and device physics of organic photovoltaics to mitigate climate change.” The award comes with a grant and an invitation to speak at universities across the United Kingdom and Ireland. Nguyen was also awarded the Wilhelm Exner Medal by the Wilhelm Exner Foundation of the Austrian Trade Association. It recognizes an individual whose discoveries have “directly or indirectly promoted the economy in an outstanding way.” Nguyen’s research is centered on organic semiconductor materials, often in pursuit of making organic photovoltaics (OPVs) that are more efﬁcient, last longer, and have a reduced environmental impact. Her solutions include carbon-based materials that are expected to form the basis of completely new technologies and are part of what is sometimes called the Organic Electronics Revolution. OPVs convert sunlight into electricity, but

most commercial photovoltaics use silicon wafers, made at very high temperatures in cleanroom environments. Nguyen’s group makes organic photovoltaics using carbonbased materials processed from chemical solutions at room temperature. OPVs are a thousand times thinner than silicon solar cells and can be made into various sizes, shapes, and colors; they can be semi-transparent, lightweight, and ﬂexible. “OPVs are ideal solutions to reduce the carbon footprint of skyscrapers and highrise buildings,” Nguyen said. “They can be wrapped around the exteriors of buildings or used to coat glass windows and greenhouses to generate energy.” The honors are more than academic for Nguyen, who grew up in Vietnam lacking clean water, electricity, or enough food. She immigrated to the United States with her family at 21, speaking little English and having no money. She hopes that her story can inspire young students, especially those from developing countries. “Awards come with responsibilities,” she says. “These honors are not only for me, but also for the many women — especially those in Vietnam and developing countries — whose education or career dreams were shattered by life challenges.”

Professor of chemistry and biochemistry Thuc-Quyen Nguyen. 7

Faculty

QA &

UMESH MISHRA

A Conversation with

Umesh Mishra The personable and highly respected longtime UCSB professor shares his vision for building on the greatness of the COE 8

Fall 2023

In July, after 33 years as a professor of electrical and computer engineering at UC Santa Barbara, Umesh Mishra began his tenure as the eighth dean of the UCSB College of Engineering. Raised in India by his father, an electrical engineer, and his mother, one of the first female doctors in the state of Odisha, he was educated in India and the United States, earning his PhD at Cornell University. He has won multiple prestigious awards and brings deep insights from his experience as an entrepreneur. Mishra is currently chief technical officer and board chair of Transphorm, which he co-founded in 2007, and he previously co-founded Nitres (1996), the first company to develop gallium nitride LEDs and transistors. We spoke with the new dean in September.

Convergence: The College of Engineering (COE) is more than fifty years old. How do you assess where we are and where we are going? Umesh Mishra: Starting from Robert Mehrabian, we’ve had a continuum of excellent deans, who led the college rapidly into the top echelons of engineering schools. He established the Materials Department, now one of the very best in the world, while choosing not to have an undergraduate materials degree. That must have been a difficult choice, but it led to materials’ becoming a stellar research department and faculty members’ being able to participate in the undergraduate education of students in other disciplines. Later, Venkatesh “Venky” Narayanamurti made the college more entrepreneurial and added a Certificate in Entrepreneurship, which grew into our unique and reputed Technology Management Department. He also emphasized computer science and computational engineering, both areas of immense importance today. Those are just a few examples of my predecessors’ many wise actions. I think that we’ve reached a point now when we have two choices: we can either cruise on our current trajectory or fire the afterburners. I see a unique opportunity to fire the afterburners. Our college has matured and translated several critical technologies in physical electronics materials and devices, soft materials, and polymers. More recently, however, the world has been rocked by the rapid rise of artificial intelligence, machine learning, big data, and the emergence of nontraditional computing, such as quantum computing. We have a unique opportunity at UCSB to apply those computing platforms across disciplines to serve a host of societal needs that are becoming more acute: sustainability writ large and climate change, automation and the future of work, security in a hyperconnected world, improving health and the quality of life, as just a few examples. C: What do you see for the COE moving forward? UM: I think we can reach the next level of greatness if we do two things. The first is to learn from our history. A lot of the things that we’re good at today evolved more organically than organizationally, from the bottom up. Look at quantum computing, for which we’ve become well known. It came out of physics on campus, but it arose out of connections among multiple departments: physics, materials, electrical and computer engineering, and computer science. Being closely connected to the sciences, as we are, is of huge value for us in engineering. Because of what was done thirty years ago, we’re positioned to do well in quantum computing, as evidenced by the NSF Quantum Foundry at UCSB. We should continue to encourage this sort of organic, bottom-up path setting while responding in an agile manner to opportunities that arise. The second is to increase our brand value and

recognition worldwide so that we can increase the pipeline of exceptional faculty and students for whom the COE is their go-to academic enterprise. C: What’s the key to that kind of “organic” growth? UM: For science to bridge the gap to technology requires that people talk to each other and be willing to work together and contribute something that might not be their core competency. Because we do that, we are able to, as I say, punch above our weight. In my own research group, we want everyone to be comfortable as both a leader and a follower. If you think you’re always the leader, it’s easy to become narcissistic, and if you think you’re always a follower, nobody listens to you. But if you can span the two, you’ll be much more effective. Communication, the key to collaboration, requires humility, a willingness to play second ﬁddle in some domains. That doesn’t mean you’re weak or a pushover. The culture of a college is built by people who are strong but also humble. I want to hire people like that. I’m not necessarily chasing the smartest person in the room, if that person undermines our culture. We want extremely bright, passionate people who believe in our culture. C: Do you have any big goals that you would like to accomplish as dean, something that would make you say, “That made a difference. I’m proud of that.” UM: Three things: fund and build more research space, including Engineering III; develop a hybrid/ online master’s program in areas of strength to expand our impact; and expand our entrepreneurial focus. I believe that engineering has three purposes: to develop technology, to deploy science to develop technology, and to deploy technology for the service of mankind. I would consider my tenure as dean a major success if, at the end of it, we were deploying our technology to serve mankind. I believe that we can leverage our collaborative culture to generate prototypes of products, which can then be taken into the marketplace through small companies. I’d like to see a collaborative prototyping center that brings in people from across campus, including the humanities, ﬁne arts, and the social sciences, which can contribute so much to industrial design and to our understanding of the social acceptance of technology. We want to hire the best faculty and attract the best students to deliver an education that has the same goal at every level: to teach students how to use science to develop technology and take it to market. C: Does that vision connect to diversity? UM: Diversity is fundamental to everything. As we innovate for social impact, we are doing so for all human beings of every kind from every place and background. If we have a diverse campus, our graduates will develop technology informed by and serving the needs of a diverse population.

As a college, we must reflect society and truly embrace diversity. Otherwise, we can become isolated, elitist, out of touch, and irrelevant. I was raised in India with the caste system and inequality all around us. I grew up with a strong mother who became one of the first Indian medical doctors in my home state, while it was still British India. Women, like people from many underserved groups, especially minorities, have always had the ability to do great things, but they have too often lacked opportunity. We have to embrace the many diverse backgrounds and cultures people have and try to afford the opportunity for this great UCSB education to as many of them as we can. That requires working hard at DEI. One advantage of being a small school is that we can recruit in person to address underrepresentation. I intend to visit high schools with [COE associate dean of undergraduate studies] Glenn Beltz and others and to evangelize about why UCSB is a place where a student from an underrepresented minority group will feel welcome, comfortable, and supported. I think that recruiting is the only way to move the needle on underrepresentation. We cannot expect to reach our destination in a year — or even five years. We have to be glad just to move the needle continuously. When I used to go mountaineering in the western Himalaya Mountains, my teacher always told me, “Don’t look up to the summit, because it’s too far away.” He advised, instead, to look down to see how far I’d climbed, and then just to take the next step. So, when I look at these mountains of important DEI issues, I know we have to keep climbing and not get disheartened by how distant the goal might be. If we work toward it, steadily and with focus, every step we take will be a win. C: What are some of the most important lessons you bring to academia as a tech entrepreneur? UM: In some ways, the College of Engineering is like a medium-sized business made up of numerous small businesses, with each faculty member running their own “company.” Maybe the most important thing I‘ve learned is that a successful business of any size requires a clear vision and a differentiated brand, and what I want to develop for the COE is a vision that is very clear but also broad enough so as not to box people in. The other element is the culture; a business that lacks a vision cannot develop a culture and will fail. Once you have clarity of vision and clarity of culture, then you have the energy to take your vision and spread it with willing partners. We have a great foundational culture in the college. Lastly and very importantly, as in any small business, we need to continually raise funds via philanthropy and other means, and the synchronicity between a differentiated and meaningful vision and a highly functioning culture can free us up to do that. 9

eet

O U R N E W FA C U LT Y

The arrival of new faculty members continues at the UC Santa Barbara College of Engineering, which has hired ﬁve more promising assistant professors and one fulll professor since the Spring 2023 issue of Convergence went to press. Three have already started, and the others are set to begin in January 2024.

MARLEY DEWEY

M A R YA M M A J E D I

DAHLIA MALKHI 10

Fall 2023

MARLEY DEWEY

Bioengineering After completing her postdoctoral fellowship at the University of Pittsburgh, Marley Dewey joined UCSB’s new Bioengineering Department as an assistant professor. She earned her bachelor’s degree in chemical engineering from the University of Maine and completed her doctoral studies in materials science and engineering at the University of Illinois Urbana-Champaign. “I think it’s exciting to be a part of something that’s new, because you get to put in your own ideas and what you’re passionate about,” said Dewey, who is also eager to help build the department’s graduate curriculum and culture. Dewey’s research spans the areas of human health and the environment, looking at how cellular signals may inﬂuence bone cancer and how to create biomaterials to improve and accelerate bone repair. The university’s strength in engineering, culture of collaboration, and shared-use facilities were among the biggest reasons why she was thrilled to join the UCSB faculty. “My research involves tissue engineering and regenerative medicine, which is why I’m extremely excited to be part of a top-tier university that has leading-edge research in materials, microbiology, and marine biology,” said Dewey. “Interdisciplinary research helps professors like me because it offers other expertise. If there’s a project that I want to get involved with and my lab doesn’t have that particular expertise, another lab on campus does. And together, we can accomplish something that, apart, we would never be able to do.” In one of Dewey’s interdisciplinary projects, based on the strong resemblance between bleached coral reefs and biomaterials she observed during her graduate-school research aimed at repairing bone, she is investigating whether “the principles we use to design materials for bone can be modeled to mimic the

composition of coral,” making it possible to design biomaterials to repair dying coral reefs.

M A RYA M M A J E D I

Computer Science The Computer Science Department welcomed Maryam Majedi as an assistant teaching professor in fall 2023. Prior to joining the UCSB faculty, she completed her postdoctoral work at the University of Toronto and was a senior lecturer of information technology at the University of Southern California. Majedi said that there were many reasons why she could not wait to start her new position. “I am most grateful to have the opportunity to join a department that supports my research, features strong and knowledgeable faculty members, and attracts high-quality students who are eager to learn,” said Majedi, who completed her PhD at the University of Calgary, working in the area of data privacy. In her primary research, Majedi examines how to integrate ethics concepts into computerscience courses. She hopes to collaborate with other UCSB faculty to develop ethics modules covering key concepts, such as privacy, discrimination, bias, and fairness, and to expand those efforts by creating a cross-campus initiative aimed at making ethical considerations the cornerstone of education in an array of technologyfocused disciplines. “The idea is that when students graduate from our department, they will have a rich understanding of ethical matters that could arise from the design and development of their products,” she explained. “I want to train students to be responsible technology developers who will help to build public trust in technology and, hopefully, become leaders in designing ethical and equitable technology.”

DAHLIA MALKHI

Computer Science Dahlia Malkhi will join the Computer Science (CS) Department as a full professor in January 2024. Her research spans broad aspects

of the reliability and the security of distributed systems, with a focus on blockchains and advances in financial technology. “I’m passionate about the two sides of technology: being part of the innovative product process and bringing real-world impact through these advancements,” said Malkhi. “I’ve spent my career bringing these two worlds together, and I’m excited to carry this experience back into an academic setting.” Malkhi has spent two decades bringing scientific innovation to fruition, while establishing herself as a world expert in reliable and secure distributed systems. She has served as chief research officer and distinguished scientist at Chainlink Labs, chief technical officer of Diem Association, lead researcher at Novi Financial, partner/principal researcher at Microsoft Research, associate professor at The Hebrew University of Jerusalem, and senior researcher at AT&T Labs. In addition to co-founding VMware Research, she is also the co-inventor of HotStuff, a pioneer in blockchain design, and of Flexible Paxos, the technology behind Log Device. Malkhi, who received her bachelor’s, master’s, and doctoral degrees in computer science from The Hebrew University of Jerusalem, says that she looks forward to returning to UCSB, which was the first campus she visited as a graduate student. “Some of the faculty members in the department literally welcomed me as a graduate student during a visit about two decades ago, and now they’re welcoming me as one of their colleagues. I look forward to collaborating with them and with everybody else,” she said. “I love the culture of the department, and I am honored and thrilled to join the CS family at UCSB.” Malkhi has received numerous prestigious recognitions in her career, including the Outstanding Technical Achievement Award from the IEEE Computer Society’s Technical Community on Distributed Processing and election as a fellow of the Association for Computing Machinery.

TYLER MEFFORD

C A R O LY N M I L L S

QIAN YU

Chemical Engineering After spending seven years in the Materials Science and Engineering Department at Stanford University, first as a postdoctoral scholar and then as a senior staff scientist, Tyler Mefford will join the UCSB Chemical Engineering Department in January 2024. “I’m extremely excited,” said Mefford, who earned his PhD in chemistry from The University of Texas at Austin and his bachelor’s degree from Stanford. “UCSB has one of the strongest chemical engineering departments in the country, and I think that allows us to recruit and train some of the best students, who can then become leaders in the renewable-energy economy.” Mefford works in the field of electrochemistry, seeking a clean pathway to reducing greenhouse gas emissions in manufacturing, chemical production, and energy storage for the grid. Specifically, his work is focused on designing materials to improve electrochemical energy storage, and conversion technologies that utilize the low-cost electrons generated from renewable energy sources, such as solar and wind. “Accelerating the transition to renewables requires an ability to store the energy to be used later on demand,” he says, adding that he looks forward to being a part of UCSB’s collaborative culture and partnering with faculty who work on catalysis, polymers, and electrochemical processes. “UCSB is not only home to some of the leading researchers in my field, but it also has some of the best facilities for characterizing materials, developing new materials, and enabling translatable and impactful solutions for renewable energy.”

Scan to watch a video and hear why the new faculty are eager to join UCSB’s College of Engineering.

CA RO LY N M I L L S

Bioengineering Nearly ten years after completing a bachelor’s degree in chemical engineering from UCSB, Carolyn Mills is returning to campus as an assistant professor in the Bioengineering Department. With an eye to an array of applications, she is interested in re-engineering biological systems at the molecular level to enable a more sustainable circular economy. That may include molecules that are used in vaccines and others involved in chemical transformations. “I am happy to be able to come back to the place where my interest in research got its start,” said Mills, who earned her PhD in chemical engineering from the Massachusetts Institute of Technology. “Research was never on my radar until I took a class as a sophomore with Professor Scott Shell, who encouraged us to spend the summer doing something to improve our resumes for our future career. He offered to write letters of recommendation, which eliminated big barriers for us to get involved. That was my ﬁrst summer doing any research, and I haven’t stopped since.” Mills recently completed her postdoctoral work at Northwestern University, where she became involved with a Diversity, Equity, and Inclusion Committee on campus, organizing an inaugural symposium to highlight the research accomplishments of those holding underrepresented identities in Northwestern’s chemical engineering, chemistry, and materialsscience research communities. She received the Chemical and Biological Engineering Department’s Distinguished Postdoctoral Service Award for her efforts. Mills looks forward to returning to UCSB’s interdisciplinary environment in the new Bioengineering Department. “Coming back to UCSB is a wonderful opportunity to give back to the College of Engineering and a community that gave so much to me,” she said. “I am thrilled to be part of the world-class College of

Engineering and a department that I’m sure is going to be one of the best in the country.”

QIAN YU

Electrical and Computer Engineering Joining the faculty of UCSB’s Electrical and Computer Engineering Department in July 2023 felt like a homecoming of sorts to new assistant professor Qian Yu. After receiving his bachelor’s and master’s degrees at the Massachusetts Institute of Technology, Yu earned his PhD in electrical and electronics engineering from the University of Southern California. “I spent so many years in the area before coming to UCSB, and I already knew several faculty members here, so coming to UCSB was really like coming home,” said Yu, who completed his postdoctoral research at Princeton University, where he worked on machine-learning theory. “I am proud to be part of such a well-regarded department and college, and I am looking forward to establishing collaborations with my new colleagues.” Yu works in the field of information theory, also known as the mathematical theory of communication, an area of research focused on data processing and measurement in the transmission of information in communication systems. He primarily studies the fundamental limits of physical systems by developing new mathematical tools to improve the efficiency and accuracy of communication and computation designs. In his previous work, he contributed significantly to breakthroughs in coded computing to provide resiliency, security, and privacy in large-scale distributed systems. “I established the first set of optimal error-correcting codes for computational tasks that went beyond linear computation," he explained. "They provided a rigorous and important theoretical foundation to analyze the optimality and effectiveness of general computing designs." 11

Experimenting with Chemical Engineering A new teaching lab gives students from across campus hands-on experience in a discipline that may be unfamiliar to them

new Chemical Engineering Department teaching laboratory, called the Asbury Pathﬁnder Lab, is home to a novel quarter-long course, ChemE 5: Introduction to Chemical Engineering Design, which gives freshmen students and others the chance to become familiar with the discipline through an immersive handson experience. The lab was made possible by an endowment from chemical engineering alumnus Douglas Asbury (’82). ChemE 5 grew out of a seminar course (ChE 1A) that was introduced in 2016 as an orientation to chemical engineering. Joe Chada, the department’s ﬁrst tenure-track teaching professor, recalls that when he arrived in 2018, “The department realized that students were getting to their sophomore year without knowing what chemical engineering is really about. They were just listening to seminars from faculty within the department and a few local companies.” In fact, the department’s curriculum did not include a lab course until the second half of a student’s junior year. Now there are two undergraduate labs, including the Robert G. Rinker Teaching Lab for juniors and seniors, which Chada manages as well. Regarding ChemE 5, he says, “We thought it would be better to have a hands-on course much earlier to prepare and excite them for their sophomore-level courses by learning some fundamental chemical-engineering concepts and gaining a sense of the kinds of calculations they would do in the discipline.”

Chada, who received the UCSB Academic Senate’s Distinguished Teaching Award for 2022’23 and describes the facility as a “hybrid lab and teaching space,” designed a biodiesel laboratory experience for the course. It exposes students to industrially relevant situations and processes, and provides hands-on training on modern equipment. Four teams of three students at a time can occupy the lab’s individual work stations, each of which is equipped with a benchtop reactor and fume hood. The course ﬁlls an important gap. “When students are just starting out as freshmen in engineering or some other STEM discipline, they can’t yet visualize the different pieces of equipment or the processes they’re used for, so we need to show them,” Chada says. “The intention with this course is for students to be able to come into it not knowing what our discipline is and to try it out and then make a more informed decision as to whether they’d like to keep going. It’s not an easy course, but it’s also not meant to be extremely rigorous. It strikes a balance between being welcoming and authentic. “I wanted the lab to be about addressing authentic problems,” he continues. “It’s challenging, and the students have a lot of deliverables to complete, but we’re there to support them, and the class doesn’t require a lengthy lab write-up. It’s you as a student doing real experiments to see how it feels to be an engineer.” Once students have been trained on the

equipment and learned safety protocols for the lab, they get to the engineering. “At the beginning of the course, we talk about how we need to switch our energy and emission landscape, and we suggest that biodiesel is one of many potential avenues to explore.” To that end, the students run a transesterification reaction to turn vegetable oil and alcohol — they use ethanol in the lab — into biodiesel and glycerol, then separate the biodiesel, the glycerol, and the ethanol. The ethanol is recycled for use in future courses. The glycerol is considered a waste product that a real processor would have to pay to discard or burn, so instead, the students run a saponification reaction to make customized bars of soap from it. The crowning achievement is using the biodiesel to run a small Stirling engine. “Because it’s not a large-enrollment course, we have a lot of flexibility in our instruction,” Chada says. “Students are learning procedures and equipment, and there’s down time during many of the heating or cooling steps when we can demonstrate other processes and equipment that they’ll see later in the ChemE curriculum, so they get to connect some dots. We bring in equipment from research labs to demonstrate the exciting stuff that happens on campus and how their experiments relate to current research trends.” Currently the class runs in spring and fall quarter, and there is space for more students, Chada notes, saying that he can accommodate 72 students in up to six sections per quarter.

Students in the Asbury Pathﬁnder Lab use modern equipment to perform standard chemical-engineering processes and get an authentic sense of the discipline. 12

Fall 2023

Taking Bold

ACTION

to Bolster Cyberdefense Cyberattacks have become increasingly common, sophisticated, and costly. Researchers at the new NSF-funded, UCSB-led ACTION Institute intend to team humans and AI to protect mission-critical systems and infrastructure.

Paralyzing a City The attackers in the New Esperanza scenario aim to create uncertainty and chaos by shutting down the city’s water- and power-distribution infrastructure, which are controlled, respectively, by the Great Aqueduct and the Las Palomas power plant. The control systems for both are integrated with New Esperanza’s smart-city system, which incorporates open-source software to monitor and distribute power, water, and other services. The nation-state actors gather intelligence about the targets, identify open-source software used in the smart-city system, and then use false identities to contribute a vulnerable software component to the project, which goes undetected. They use credentials obtained from underground forums to connect to the virtual private network (VPN) of the aqueduct system, gain entry to various connected systems, introduce and exploit a vulnerability to obtain administrative access to the main server and upload a wiper malware component, all in ways beyond the ability of the systems to detect. After a few more steps, the attackers cause the power plant to cease operations, ACTION ﬁgures: Institute director, Giovanni Vigna (right), and his co-PIs (from right), João Hespanha, Christopher Kruegel, and Ambuj Singh, lead an eleven-university collaboration to develop new AI-human partnerships intended to revolutionize cyberdefense.

he proposal that UC Santa Barbara researchers submitted to the National Science Foundation (NSF) for a grant to develop new ways of combating cyberattacks, with artificial intelligence (AI) as a main component, included a hypothetical attack scenario. In it, a group of individuals aligned with a hostile nation-state launch a sophisticated multiphase attack against key infrastructure elements of a fictional city: New Esperanza. The scenario is a chillingly realistic representation of how sophisticated hackers can gain access to inadequately defended cyberconnected systems. The proposal succeeded, and last May, UCSB was named the lead institution in a five-year, $20 million NSF grant to pursue new approaches to cybersecurity linking humans to AI agents, and multiple agents to each other. UCSB computer science professor Giovanni Vigna is the institute’s director. He is joined by fellow co-PIs (and UCSB professors) Christopher Kruegel (computer science), who has worked with Vigna on seminal research in the areas of intrusion detection, malware analysis, and threat intelligence; Ambuj Singh (computer science), a renowned expert on machine learning on networks and human-AI teaming; and João Hespanha (electrical and computer engineering), a world expert in control systems, game theory, and optimization. In addition, the NSF Institute for Agent-based Cyber Threat Intelligence and OperatioN (ACTION) brings together 21 other top AI researchers from ten other U.S. universities in a collaborative effort to develop revolutionary new forms of integrated cyberdefense. Vigna describes the ACTION Institute researchers as “some of the very best people in AI and security, who have been at the forefront of expanding the foundations of AI, machine learning, game theory, and computer security.” They and each of their institute colleagues will work primarily in one of eight highly integrated and interdependent research thrusts — four each in foundational AI and cybersecurity.

Fall 2023

There are simply not enough people to monitor what’s happening in a network of mind-boggling complexity, make sense of it, and identify and resolve problems in a timely fashion.

such that the smart-city system cannot be controlled. Simultaneously, they activate malware that they installed, shutting down the aqueduct and blocking water ﬂow to New Esperanza. The city is paralyzed, and chaos ensues. Details of the attack included in the NSF proposal highlight multiple fail points at which suspicious or otherwise anomalous activity went undetected, exactly the kind of vulnerabilities that can bring down the operations of any connected entity that is inadequately protected. ACTION Institute researchers plan to bring forward innovations in AI and its application to cybersecurity that will protect critical infrastructure from sophisticated attacks like this one.

Fighting Back: Challenges of Time and Scale Currently, the task of defending against cyberattacks depends largely on the skills, intuitions, and experience of human defenders, who must attend to all the elements of a typical cyberdefense life cycle: risk assessment and prevention, detection, attribution, and response and recovery. As a result of the ever-increasing number, complexity, and sophistication of cyberthreats, however, the effectiveness of humans who staff the thousands of security operations centers (SOCs) at the nation’s hospitals, ﬁnancial institutions, government agencies, and other large connected entities can no longer respond with adequate speed or at sufﬁcient scale to combat next-generation threats. There are simply not enough people, Vigna says, “to monitor what’s happening in a network of mind-boggling complexity, make sense of it, and identify and resolve problems in a timely fashion.

HARDEN: UCSB Leads Project to Combat “Weird Machines”

In another high-level cybersecurity project, UC Santa Barbara is one of two universities among eight groups (the other six are corporations) included in a new Defense Advanced Research Projects Agency (DARPA) project, called Hardening Development Toolchains Against Emergent Execution Engines (HARDEN). UCSB computer science (CS) professor Tevfik Bultan is the PI, with UCSB CS professors Yu Feng, Christopher Kruegel, and Giovanni Vigna as co-PIs. They are joined by collaborators at Purdue University. The four-year, $2.2 million project is intended to advance methods to improve defenses against a specific kind of attack at the firmware level. Firmware, the lowest level of code in a computer, even beneath that of the operating system, executes critical functionalities and is susceptible to what are called emergent behaviors. Cyberattackers increasingly target firmware, which runs when computers boot up, in order to dodge security protections before they are activated. Compromising these basic building blocks of a computing system destroys the trustworthiness of a computer — or a device, such as a tablet used as an aircraft pilot’s “electronic flight bag.” Emergent behaviors result in what are colloquially described as “weird machines,” which means, essentially, that an attacker exploits flaws in a computer’s code to compromise a feature and create unexpected behaviors, allowing the attacker to operate the system in ways never intended. They can then use that first compromised feature to attack and compromise another feature, and so on. This “compositional” method of accumulating compromised elements of the firmware — and the resulting emergent behaviors — can be hard to identify and is especially dangerous, because, first, it allows benign features built into the system by the manufacturer to be exploited by an attacker, and, second, while the emergent behaviors are ephemeral, they are robust, and the chains that drive them are portable between implementations created independently by different vendors. “Emergent behaviors make a computer more susceptible to attack by allowing it to be used in a way it is not meant to be used,” Bultan says. “We want to discover these kinds of attacks and mitigate them by hardening the system against them.” DARPA says that HARDEN aims to develop pioneering formal methods and automated software analysis to “deny hackers the ability to turn parts of modern computing systems against the whole.”

Signposts to action: The ACTION Institute AI stack will allow intelligent agents to (from left) learn and reason about new facts, interact with humans and other AI agents, and engage in tactical and strategic planning in the face of uncertainty.

“Solving that time-and-scale problem will require automation,” he adds, “but it has to be smart automation, and that means AI.” The ACTION Institute is part of a $140 million investment by the NSF, in collaboration with other federal agencies and stakeholders, to establish seven new National Artificial Intelligence Research Institutes, itself part of a broader federal effort to advance a cohesive national approach to AI-related opportunities and risks. Says Vigna, “The ACTION Institute mission is to find new AI concepts and constructs that can be used to create new security applications that will change how mission-critical systems are protected against sophisticated, ever-changing security threats.” That will occur on two broad fronts: one is fundamental AI research — finding new ways for AI to model and reason about knowledge; the other is creating interaction and integration between and among humans and autonomous AI agents.

Stacking the Defense ACTION Institute researchers aim to accomplish their mission by building a new AI stack, “a set of integrated tools that work together like a package that allows you to build AI-powered applications,” Vigna explains. The AI stack will provide ways for intelligent agents to learn new facts and reason about them, communicate with humans and with each other, and support the planning of their actions. These basic AI capabilities become the building blocks for developing security intelligent agents, such as agents that identify vulnerabilities in software before they are exploited, or intelligent agents that are able to suggest an effective remediation procedure after a breach has been detected. One notable aspect of this AI stack is its focus on logical reasoning: While current AI approaches to cybersecurity mostly focus on machine learning (that is, the learning from large amounts of data), the vision brought forward by the ACTION Institute focuses on being able to apply deductive and inductive reasoning on what is observed in a computer

This new AI stack will need to operate in a world where attackers also use automation and AI to overcome cyberdefenses. Designing security systems must therefore involve reasoning about how the actions of one AI agent will affect the behavior of another agent. 15

network. This will support novel ways to understand the security posture of critical systems and deploy effective protections. “This new AI stack will need to operate in a world where attackers will also use automation and AI to overcome cyberdefenses,” João Hespanha explains. “Designing security systems must therefore involve reasoning about how the actions of one AI agent will affect the behavior of another. This type of reasoning is needed to make sure that whatever protection mechanisms we deploy to protect our systems do not create a completely new vulnerability.”

Reasoning & Human-Agent Teams Intelligent security agents, deﬁned in the proposal as “[non-human] entities that employ reasoning, learning, and collaboration to perform one or more cybersecurity functions,” will leverage the stack’s capabilities to serve their functions in an uncertain, dynamic adversarial environment, with the agents following a new paradigm of continuous lifelong learning, both autonomously and in collaboration with human experts. “We want the AI to continuously learn new facts, because computer networks are complex, evolving systems, and the intelligent agents need to continuously update their knowledge to be effective” Vigna says. “That capability is in its infancy right now, but work from the institute will bring it forward in an interesting way.” “Over time,” the NSF proposal reads, “these intelligent security agents will become increasingly robust and effective as adversaries change modes of operation, more capable of composing defense strategies and tactical plans in the presence of uncertainty, more collaborative with each other and with humans for mutually complementary teaming, and better able to adapt to unfamiliar attacks.” The research is aimed at producing a major shift: “providing breakthroughs in AI necessary to evolve the current human-driven and human-paced security process into an agent-driven autonomous process… that continuously improves the security and resilience of computer systems… to ensure the conﬁdentiality of sensitive data and the protection of critical services, saving billions of dollars and, in some cases, human lives.” “This concept of autonomous intelligent agents that are capable of reasoning, and, at the same time, focusing on security, is new,” Vigna says. “Right now, there’s nothing like that. There is no autonomous agent that is able to talk to other autonomous agents.”

Responding to evolving threats requires reasoning and acting based on small amounts of data and adapting to untrainable and unspecified scenarios. In the case of security, humans and AI may have different perspectives on the implications of actions. This is where the synthesis of humans and AI becomes useful.

“AI agents are typically good at well-deﬁned tasks when there is lots of training data,” Ambuj Singh observes. “But responding to evolving threats requires reasoning and acting based on small amounts of data and adapting to untrainable and unspeciﬁed scenarios. In the case of security, humans and AI may have different perspectives on the implications of actions. This is where the synthesis of humans and AI becomes useful. The basic idea behind the integrated approach, Singh adds, is that, “We need to have agents everywhere to prevent or repel an attack in time and at scale. We believe that the extensive domain knowledge, logic-based reasoning, human-agent, and agent-agent interactions enabled by our AI stack will provide all of those capabilities.”

Trust, Ethics, and the AI Landscape The work of developing the AI stack comes with tremendous challenges. For instance, Vigna says, “When you have agent-to-agent interaction, you have autonomous agents that are going around your network ﬁxing things, and they have to talk to each other. If only one person programs all of them, it’s easy, but an intelligent agent at UCSB might have to communicate with, say, an agent at UC Irvine or in a completely different realm, maybe at a ﬁnancial

Humans working at security operations centers like this one, depicted via an AI-driven illustration app, can simply not keep up with the escalating scale of cyberattacks.

Fall 2023

institution, about a concerning pattern of activity so that they can look for it. “Before an agent can do that, however, we have to make sure that we preserve the privacy of the people involved by not disclosing, for example, that a specific human user went to a specific website. At the same time, we want to create some useful knowledge that can be used by other people can use to protect themselves. Properly configuring these agent-to-agent interactions to balance those needs is hugely important.” ACTION Institute researchers begin their work keenly aware of that challenge and an array of others associated with AI-enabled functionalities, from biases learned from existing datasets to “hallucinating” largelanguage models. Above all, Vigna says, “We want to have ethical AI. We don’t want it to be making decisions that could cause harm — and not necessarily even physical harm; it could be something simple like having your computer cut out from the internet because an AI agent made the wrong decision. We want to be sure that decisions are made with a human in the loop, but in an efficient, targeted way that makes the best use of that person’s capability.” “If you use AI wrong,” Kruegel adds, “you can hurt entire classes of people, and that has occurred, so we have to be careful about what we encode in the agent’s knowledge, what we learn from data, how we learn it, and how we align it to conform to the highest ethical values. Developing AI that is ethical and trustworthy is not an option; it’s the only thing you can do, and it is ingrained in this community. Of course, AI is a tool, and a tool can be misused. That’s why we have to be extremely careful.” With UCSB — home to the Center for Responsible Machine Learning — as the lead institution, ACTION Institute researchers will be focused on developing AI that is ethical and equitable every step of the way.

Collaboration and “Polarizing” Interest The NSF established the seven new AI institutes simultaneously with the idea that the researchers in different domains would support each other and extend the value of their expertise through collaboration. “What the NSF wants, and what we also want is to deliver, in terms of research, more than what would result from giving twenty $1-million grants to twenty people,” Vigna says. “We want something that comes out of the synergy of creating these cohorts of people from AI and from security and having them work together. The basic idea of our institute is to combine two

cultures — one that is looking for new ways to do AI and another that is looking to use AI in new ways to improve security. We hope that by putting them in the same room, something amazing will result. Synergies will be really important to the success of this project.” Vigna hopes, too, that the institute will serve as a kind of North Star for AI-focused security research, providing a general direction in which to aim research done by people even beyond the institute who are involved in efforts that may be related, even if they are not entirely aligned. “When you create an institute with a speciﬁc emphasis, you create almost a gravitational pull toward the topic that makes other people understand that this is important,” Vigna explains. “I’m already seeing it. I might go to a conference about designing AI security, and people realize, ‘Oh, so this is happening,’ and they get pulled into it. I hope that the institute can become a nexus for both the AI and cybersecurity communities, polarizing interest and motivation around the topic, and aligning disparate interests.”

A Stack at Market? At the end of each year of the project, researchers will build increasingly sophisticated prototypes and use testing environments similar to that in the hypothetical New Esperanza model to test and demonstrate the stack’s evolving capabilities. “Once you have a prototype that can demonstrate the abilities of what you’ve developed, it’s much easier to transfer technology to industry, which is where it can have a real impact,” Vigna notes. “Our ultimate goal is to demonstrate what can be accomplished by innovating both AI and cybersecurity; it’s not our job to turn these ideas and prototypes into a product. We hope that the big security vendors will pick up the techniques and approaches we develop and transfer them to a commercial product. That would be a fantastic outcome.”

Education, Workforce Development, Community Engagement Mindful of the deepening presence of AI in every area of life, the resulting need to expand the pool of AI experts, and the fact, noted in the proposal, that “Early engagement is key to diversifying the STEM pipeline,” ACTION Institute leaders have outlined innovative educational plans and workforcedevelopment tools targeted at the K-12, undergraduate, graduate, and postgraduate levels. The aim in terms of younger students, reads the NSF proposal, is to “nurture our youth’s love for learning and cultivate their independent learning skills.” The institute will also design and implement two yearly competitions centered around AI and security, one focused on high school students, and one devoted to undergraduate and graduate students. These “Capture The Flag” competitions, which were pioneered by UCSB’s Security Group and have been run by it for more than twenty years, have demonstrated their effectiveness in exciting students about the possibilities of combining cybersecurity and artiﬁcial intelligence. It is those students, many of whom are only in grade school now, who will play crucial roles in designing and implementing future versions of AI defenses “stacked” against sophisticated attacks.

Education is key to expanding the pipeline of AI-knowledgeable cybersecurity experts.

FOCUS ON: MRL The Leading Edge of Collaboration

NSF renews funding for 30-year-old UCSB Materials Research Laboratory 18

Fall 2023

hirty years ago, the Materials Research Science and Engineering Center (MRSEC) — aka the Materials Research Laboratory (MRL) — in the UC Santa Barbara College of Engineering received its ﬁrst funding grant from the National Science Foundation (NSF). This fall, the MRL reached a signiﬁcant milestone by securing a seventh consecutive round of funding — $18 million for six years — making it one of the oldest continuously funded MRSECs. The genealogy of the nation’s twenty current MRSECs began in 1960, in the wake of the former Soviet Union’s launch of the Sputnik 1 satellite in 1957, inaugurating the space race. The Advanced Research Programs Agency (ARPA), within the U.S. Department of Defense, announced the creation of three new “Interdisciplinary Laboratories” (IRLs) — at Cornell University, the University of Pennsylvania, and Northwestern University. Funding was provided to “establish an interdisciplinary materials research program and…furnish the necessary personnel and facilities” to do so. Prior to that, governmentfunded materials-research grants had gone almost exclusively to individual principal investigators (PIs). The IRL program was moved to the NSF in 1972. The following year, eight more labs were established and renamed Materials Research Laboratories (MRLs). Workforce development became part of the mission, and from then on, the proposals from MRL candidates were to be judged according to updated criteria that included an institution’s ability “to foster coherent, multidisciplinary and multi-investigator projects requiring the expertise of two or more materialsrelated disciplines.” These so-called “Thrust” groups, now called Interdisciplinary Research Groups (IRGs), have transformed materials research and graduate education. The NSF’s MRL competition of 1992 led to the start of just one new center: the MRL at UC Santa Barbara, which began operation in 1993, the year all MRLs were renamed Materials Research Science and Engineering Centers. Another change that year was that, going forward, all MRLs/MRSECs would be required to engage in an open national competition to win a successive round of funding. An institution’s research would thus have to remain on the very leading edge. The late materials professor Anthony Evans led the initial UCSB proposal submission, and emeritus materials professor (Sir) Anthony Cheetham served as director of the new center through 2005. In 1997, the MRSEC moved into a new dedicated building — the Materials Research Laboratory (MRL), which is the physical headquarters for the MRSEC but also houses instrumentation and facilities, as well as faculty

whose work is not directly associated with it. Cheetham was followed as director by materials and chemistry professor Craig Hawker, who served through 2016, and then by current director and distinguished professor of materials and chemistry, Ram Seshadri. Cheetham recalls there being “great excitement when we won the competition for a new NSF-funded Materials Research Laboratory in

“

As a result, our facilities became the envy of many top campuses around the nation, while enhancing not only the quality of the MRL’s own research, but also that in other areas of science and engineering.

1992,” to become the tenth MRL in the nation. “At the time,” he remembers, “UCSB’s shared facilities for materials research were very modest, aside from in the area of electron microscopy, so I persuaded my colleagues that we should plan a substantial multi-year investment in new instrumentation for X-rays, NMR [nuclear magnetic resonance] spectroscopy, computing, and so on. This consumed more than one-third of our total initial budget, and we continued to spend at that level for at least a decade. As a result, our facilities became the envy of many top campuses around the nation, while enhancing not only the quality of the MRL’s own research, but also that in other areas of science and engineering, since everyone on campus could purchase access to the facilities.” The early years of the MRL saw many impressive successes, including from the Thrust on Conducting Polymers, which culminated in Alan Heeger’s being awarded the 2000 Nobel Prize in chemistry. That and numerous other pioneering outputs, together with successes both within and outside the MRL, Cheetham says, “led to UCSB’s being ranked number one in the nation in materials science by ScienceWatch for the periods 1993-’97 and 1998-2002.” The Materials Department has remained in the top ﬁve ever since.

Director lineage (from left): Sir Anthony Cheetham became the ﬁrst MRSEC director in 1993, followed by Craig Hawker and current director, Ram Seshadri.

FOCUS ON: MRL

Interdisciplinary Research Groups While shared instrumentation and facilities make UCSB an especially good fit as a MRSEC host institution, IRGs generate a somewhat similar benefit in terms of maximizing the contributions of individual faculty members. The 21 previous IRGs at UCSB have led to dozens of groundbreaking findings achieved through novel approaches in wide-ranging fields of inquiry linking the MRL to departments across campus. Under the umbrella of biomimetics came long-term studies on the biomineralization processes that marine creatures use to strengthen their shells and even their jaws, as well as the chemistry and mechanics of how mussels create the waterproof glue they use to adhere to rocks in turbulent tidal zones. MRSEC IRGs have led to groundbreaking work on templating block co-polymers and block copolymer lithography, and to equally impressive results in numerous other materials fields. Multiple start-ups have been generated out of IRGs. Uniax, founded by Heeger and UCSB alumnus Paul Smith, was purchased by DuPont in 2000, and professors of electrical and computer engineering Umesh Mishra (now COE dean) and Steven DenBaars used a MRSEC seed grant to pursue some of the first gallium nitride (GaN) research on campus. They founded Nitres in 1996, which in 2000 was sold to LED manufacturer Cree (now Wolfspeed). GaN is, of course, what UCSB materials professor Shuji Nakamura previously used to develop the blue LED, for which he won the 2014 Nobel Prize. Apeel, the hugely successful company that developed and sells an all-natural plantbased coating to extend the shelf life of fresh produce, also has roots in the MRL/MRSEC, with founder James Rogers having earned his PhD in materials at UCSB. Motivated by fundamental chemistry research performed in an IRG, Craig Hawker developed a general synthetic toolbox based on Click Chemistry. Then, inspired by those foundational studies, he and his former PhD student Eric Pressly created the active ingredients that became the patented basis for Olaplex, a product — and a successful company — that has changed the hair-care industry. Hawker recalls developing the science for the company in Pressly’s garage lab and working alongside the founders of Apeel as “a magical time.” The latest round of MRSEC funding supports two IRGs, which include nine faculty who are new to the MRSEC. IRG-1 — Electrostatically 20

Fall 2023

Mediated Polymer Processing — is focused on exploiting the charge inherent in ions to create unique materials, while IRG-2, titled Bioinspired Plasticity, is aimed at expanding the theoretical and experimental knowledge of soft materials called hydrogels. “It’s not about what we’re doing individually as researchers,” says Christopher Bates, an associate professor of materials, associate director of the MRL, and co-PI on IRG-1. “It’s about what we can do as a community of researchers tackling problems together in ways that we wouldn’t normally think about individually.” “The biggest advantage of the MRL is its ability to bring people together,” adds Rachel Segalman, a professor of chemical engineering and materials on IRG-1. “Nobody involved with the MRSEC is in it for any other incentive than that they want to be in the same room with experts in their ﬁelds who are generating novel and exciting ideas as a team. The MRSEC provides that intellectual space.”

IRG-1 (clockwise from bottom left): Rachel Segalman, Megan Valentine, Thuc-Quyen Nguyen, Craig Hawker, Glenn Fredrickson, Christopher Bates, Michael Chabinyc, M. Scott Shell, Mengyang Gu.

IRG-1: Electrostatically Mediated Polymer Processing “From a synthesis perspective, it’s challenging to incorporate ions into materials, although some materials have achieved that,” observes Bates in describing the research arc of IRG-1. He cites disposable diapers, which are made of a polymer material that has a lot of ionic charges added to it, as one example of the relatively few materials that effectively incorporate ions. Urine, which contains primarily water and salt ions, can be absorbed by the material thanks to negative charges in the polymer, which attract the strongly dipolar water molecules. One of the projects in IRG-1 is aimed at compatibilizing plastics. Different types of plastics are used to make different kinds of products. During recycling, all of one type of plastic — indicated by the label on the container — gets melted down and reprocessed into a new material. “If you were to melt different kinds of plastic together, however, the result would be a bad product with terrible properties that behaved nothing like the original plastic,” Bates says. “Thus, when you recycle, you have to separate the different kinds of plastics. Now imagine that a plastic had a plus charge on it somewhere. That plus charge really wants to be near a minus charge. So, imagine another plastic that has a minus charge on it. If they are reprocessed in the same bin, they’ll like each other enough, because of the plus and minus charges, to interact. The resulting plastic would have much better properties than different types of plastic would if they

terns r In

RSEC Sum

were co-processed today. You take advantage of the ions to bridge the dissimilarity in the products.” “The interactions in these systems are strong because water is not there to shield the forces between ions,” explained M. Scott Shell, a chemical engineering professor and co-leader of IRG-1. “As a result, we believe these kinds of interactions can be used to produce new properties in materials that have yet to be explored. It is a beautifully simple but potentially powerful and underexplored materials-design approach.” The project is based on theory and simulations that chemical engineering and materials professor and IRG-1 member Glenn Fredrickson has developed, suggesting that if just a single positive charge is added to plastic A and one minus charge to plastic B, it’s enough to make them compatible with each other. “You don’t need a lot of charges,” says Fredrickson. “You just need a sprinkling of charge on the dissimilar polymers, ideally with no counter-ions. The charges can be installed either at the time of polymer preparation, or by a reactive blending approach. Part of the IRG-1 effort will be determining the most effective approach, also factoring in cost constraints.”

Juan Herrera

Holden Orias

IRG-2: Bioinspired Plasticity Materials science has long been dominated by solid-state crystalline materials, which have greatly beneﬁted the world, enabling modern semiconductor electronics and major advances in steel and other building materials, according to Omar Saleh, professor and chair of the UCSB Materials Department and co-leader of IRG-2. “But those materials are not good at interfacing with soft, squishy humans,” he says. “In our IRG, we are trying to learn from and be inspired by biology to think about how to produce new soft materials having new characteristics and corresponding new performance.

KC Sims

Essa Shamsan

We asked the following four students about the value of their internships with MRL-affiliated faculty this past summer. Juan Herrera, a fifth-year-senior mechanical engineering major at The University of Texas at El Paso, spent the summer working with postdoctoral researcher Neil Brodnick in mechanical engineering professor Samantha Daly’s lab. The work was part of a project for the U.S. Navy to characterize a new 3D-printed steel and determine its strength relative to traditional forged steel. He says that he found the lab meetings to be especially interesting: “Everyone presents their work, the group members ask each other lots of questions, and their questions show that everybody cares and is interested in others’ work even if it’s not related to their’s. It seems to be ingrained in them that, just because something seems unrelated to your work now and you may know nothing about it, you never know when it will become relevant to you.” Holden Orias, now a senior at Amherst University, did his internship in Craig Hawker’s group, working closely with PhD student Ronnie Garcia. Orias created hydrogel networks and characterized how they degraded, a process related to developing new biodegradable “inks” for 3D printing. He says he learned a great deal from the lab’s open-ended research environment. “Ronnie talked to me a lot about how graduate students have to improvise and adapt,” he said. “Having to stop and retool as we discovered new things or found that certain things didn’t work made the experience more challenging and thought-provoking.” He also appreciated “having access to the genius of the people here and seeing how human and accessible they are.” He recalled Hawker starting a mid-summer lab meeting by asking, “Did anyone do the ‘Barbenheimer’ double-feature over the weekend?” KC Sims, a senior majoring in biochemistry at Jackson State University in Mississippi, spent the summer working primarily with her mentor, Athenia Arias, a graduate student in the lab of materials professor Cyrus Safinya. Sims contributed to a project aimed at developing a drug delivery system based on lipid protein synthesis. While Sims is a confident student, she says that Arias’s ability to explain complex concepts, and having just a few people in the lab, provided the personal attention unavailable in large classes and gave her the hands-on experience that grew her confidence in some areas. “A lot of times I’ve found in science that I ‘know’ something intellectually but am a little less confident when I have to apply it, so I’ve appreciated being able to get that practice to give me that confidence and that stronger foundation I wasn’t able to gain before.” Essa Shamsan is a fifth-year biochemistry major at UCSB who did his summer internship in the Dow Materials Lab through UCSB’s California Alliance for Minority Participation (CAMP) program. His work involved developing synthetic peptoid coblock polymers. For him, the lab was a clarifying and skills-building experience. “Working in the lab helped me realize that I enjoyed the experimental process enough to want to go to grad school prior to entering industry,” he said. “That decision was clarified out of this experience. I also learned to think outside the box experimentally. In the beginning, it was hard to adjust to going from the kind of premade lab procedures we’re given in our undergraduate labs to having to come up with a bunch of procedures and design the experiment. Working in a research lab has helped me fine-tune my ability to do both.” 21

FOCUS ON: MRL Polymers infused with water — hydrogels — will be a main focus for Saleh, his co-leader, UCSB assistant materials professor Angela Pitenis, and their collaborators in IRG-2. But they will also study non-polymer materials having various structures. The water, which is what makes such materials hydrogels and enables them to be more bio-inspired, also adds a broad range of aqueous biochemistry, Saleh says, noting, “Adding water makes things much richer and more complicated and, therefore, gives us a lot to work with mechanically and chemically.” “The mechanical properties of soft materials are complex and not well understood, however,” Saleh adds. “Our goal in IRG-2 is to explore new ways to create, analyze, and model the mechanics of such materials, and to embed new functions into them to improve and expand their mechanical properties, functionality, and application.” The work, like all of the research undertaken in the MRSEC, requires an interdisciplinary approach that challenges members to take their research in new directions. “The point of any IRG is that researchers should not be doing only what they’re already an expert in, ﬁrst, because that’s not cutting-edge and, second, because NSF won’t fund it,” says Saleh. “The nine of us in our group are going to be stretched in some way while also bringing our own expertise. I work at the nanoscale, Angela works a lot at a larger scale with friction at interfaces, and we also have synthetic chemists, people with expertise in the interfacial mechanics of soft materials from a polymer perspective and the physics of biomolecules, as well as theorists. “We’re looking at things like living cells or tendons and noting that they are mechanically quite interesting, and that they couple that mechanical behavior with chemical behavior to create interesting feedback routines, in which a chemical reaction occurs and changes the mechanics, or a mechanical reaction occurs and changes the chemistry. Inspired by what living materials do, we want to create hydrogels that are slightly closer to biological materials and might lend themselves to use as medical devices or implants.”

Shared Facilities and Instruments More than one hundred faculty groups from UCSB and other universities, as well as nearly sixty companies, have used the shared campus facilities supported by the MRSEC. According to Ram Seshadri, “A disproportionate amount of our MRSEC funding goes to facilities [continuing the trend initiated by Cheetham in 1993]. We have six facility staff people and four PhDs who assist internal and external users, design and maintain experiments, and interpret data. We put money into facilities that could otherwise be used by faculty to pay PhD students and postdocs. It’s an example of faculty sacriﬁcing in their own labs in order to support the greater UCSB research community.” Further, he notes, “Facilities are not created for the exclusive use of the MRSEC, so the whole world is welcome to come and use them — and they do.” As an example of the beneﬁts of the shared-facilities model, Seshadri explains that when a professor comes to UCSB and receives funds to purchase startup instruments for their lab, they might purchase a reasonably high-ticket item, which they then contribute to the facility, so that it belongs to everybody. After that, even the person who contributes the equipment pays the same user fee as everyone else to keep it maintained and pay support staff. In return, users, including PIs who contribute instruments, gain access to a broad range of other instruments that their startup funds would not allow them to purchase — instruments that are always maintained and for which training is always available. “No one professor working in a traditional, more ‘siloed’ environment could come close to acquiring the vast array of instruments we have at UCSB, many of which are operated by the MRSEC,” Seshadri says. 22

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The initial instrument came as part of Seshadri’s startup, and four others were purchased to meet the heavy demand, something, Seshadri notes, ‘that would never happen with the single-PI model.’

IRG 2 (clockwise from bottom left): Angela Pitenis, Cristina Marchetti, Javier Read de Alaniz, Joan-Emma Shea, Matthew Helgeson, Yang Yang, Omar Saleh, Sho Takatori, Robert McMeeking.

The Materials Research Laboratory Building, home of the UCSB MRSEC.

While having no priority for instrument users can, Seshadri notes, “end up placing a lot of pressure on one instrument,” the shared model allows UCSB to buy a second one or even a third one. That happened with the several low-temperature instruments that are in the low-temperature lab downstairs from Seshadri’s ofﬁce. The initial instrument came as part of Seshadri’s startup, and four others were purchased to meet the heavy demand, something, Seshadri notes, “that would never happen with the single-PI model.” In 2020, following a meeting at UCSB in 2018 that brought together representatives from MRSECs and national laboratories, Amanda Strom, manager of the MRSEC’s TEMPO Laboratory, joined Seshadri and colleagues at Cornell University and the University of Minnesota to co-author a paper, published in the MRS Bulletin, describing a broad array of beneﬁts arising from a shared-facility model. Naming just a few of them, the authors wrote that shared facilities: •

•

Increase the visibility of accessible instrumentation, which aids in recruiting and retaining faculty and attracting competitive graduate students and postdoctoral fellows. Give interested faculty a voice on equipment acquisitions, avoid redundant purchases, and maximize equipment usage. Minimize expenses, increase revenue, and spread costs across a wide range of instrumentation. Enable institutions to build and leverage long-term relationships with vendors to access competitive pricing on equipment and maintenance. Serve as communication hubs for research groups and become a magnet for industrial collaborations and associated employment opportunities. Allow researchers to improve their knowledge of analytical science, making them more competitive in the job market.

In contrast to the self-interest and depleted resources underlying the famous economic theory known as “the tragedy of the commons,” Seshadri refers to the culture of communal sharing, so highly developed and effectively implemented at UCSB and in the MRSEC, as “the comedy of the commons,” adding, “I like to quote [UCSB chemical engineering professor and nuclear magnetic resonance expert] Brad Chmelka, who says that if another university wanted to hire him, he would need a $40 million startup to match all the shared facilities he has access to here.”

Education and Outreach The MRSEC model is aimed at efficiency, to get the most benefit by sharing resources, facilities, and intellectual muscle. Seshadri believes that UCSB stretches the model as far as possible, education and outreach being a case in point. “At UCSB, we squeeze so much out of the MRSEC,” he says. “For instance, we have two full-time staff — [academic coordinator] Dotti Pak, who is also a research scientist in the UCSB Marine Science Institute, and [research intern coordinator] Julie Standish — plus several other people to support the NSF-mandated education and outreach programs, which at UCSB are quite a bit larger than those run through most MRSECs.” The programs provide undergraduate research opportunities, graduate student and postdoctoral mentoring, transferable professional skills training, outreach to K-12 students and teachers, and community outreach. Every summer, a group of student interns who are incoming university freshmen or undergraduates in university STEM programs spend a month working in a lab with an MRL-affiliated faculty member. The experience provides them with the opportunity to interact with graduate students and work closely with a PhD student or postdoctoral researcher. (See sidebar on page 21.) The center leverages collaborations with other institutions that benefit undergraduate and graduate students, including the Partnerships for Research and Education in Materials, which

provides student exchanges and research opportunities between UCSB and two minorityserving institutions, Jackson State University in Mississippi and The University of Texas El Paso; as well as another student-exchange partnership with Chalmers University of Technology in Sweden. Events such as Family Science Night and hands-on workshops reach nearly 4,000 K–12 students annually, more than 60 percent of whom are underrepresented minorities. Dozens of teachers also participate in MRSEC-funded research opportunities and workshops, building relationships with campus researchers and developing their science curricula. The MRSEC also supports more than ﬁfty undergraduate interns who conduct research at UCSB each year. A survey of former interns showed that 65 percent of them went on to attend graduate school, 48 percent were female, and 39 percent were underrepresented minorities. “I received an email the other day from a student who completed a summer program and recently graduated from college. She described the experience as ‘life changing’,” said Pak. “Our programs open doors by introducing participants to research experiences and to our research community. Feeling like a part of a supportive community is extremely important for everybody, especially underrepresented minority students.”

Continuing a Long Arc of Success Looking back on the center’s extensive evolutionary arc from its founding as an NSF MRL to its continuation as a newly re-funded NSF MRSEC, inaugural director Anthony Cheetham says, “It is clear that the creation of the MRL at UCSB led to a step-change in both the quality and quantity of materials research on the campus. It was also pivotal in establishing UCSB as one of the world’s leading centers for advanced materials. I never imagined that it would still be going as strong as ever in 2023, more than thirty years later. Long may it continue to prosper!

Scan to learn more about the MRL’s summer research program and its impact on student interns. Few MRSECs can match the support for education and outreach services provided by (clockwise from front): Dotti Pak, Julie Standish, Mary McGuan, and Frank Kinnaman 23

An Alumnus with a Feel for Photonics

CHAMPION OF ENGINEERING

Wenbin Jiang

Wenbin Jiang has leveraged his UCSB education to create several successful companies

enbin Jiang is a seasoned entrepreneur and inventor and is currently chairman, president, and CEO of Cytek Biosciences, Inc., the most recent of several startup companies he has co-founded since receiving his PhD in electrical and computer engineering from UC Santa Barbara in 1993. His first venture was E2O Communications, a company founded in 1998 and acquired by JDS Uniphase in 2004. He has more than one hundred U.S. patents and has authored more than fifty peer-reviewed technical papers. In 2018, he provided funding for a student breakout room in Henley Hall, home to the UCSB Institute for Energy Efficiency, and he became a UCSB Trustee in 2022. We spoke with him in September.

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Convergence: What made you decide to donate generously to the COE? Wenbin Jiang: When I was at UCSB, I received so much support, including all my tuition and living expenses. Without that, I wouldn’t have been able to finish my studies or have my career. I felt very appreciative. When you have that kind of experience and are able to do something later, it’s important to give back to the school so that it can provide a great education to more people. As far as giving to Henley Hall, energy efficiency is always interesting and important from an environmental perspective. Even though it’s not directly related to what I’m doing today, it’s something I wanted to support. Individual donors are especially important at a public school like UCSB, which has a mission somewhat different from those of private institutions, which often have huge endowments. Giving to UC Santa Barbara, you help not only the school, but society as well. C: What continues to stand out for you from your experience at UCSB? WJ: The most beneficial thing for me at UCSB was being in [professor of electrical and computer engineering] John Bowers’s group. When I was selecting a topic to pursue for my PhD, John pretty much laid out a big box within the photonics and III-V semiconductor space and then gave me full freedom to decide what to do within it. Once I identified my subject, John provided all the help and support I needed to help me earn my PhD and enable me to pursue my career. Highspeed lasers were big at that time, and I wrote my dissertation on high-speed (femtosecond) vertical-cavity lasers.

C: What changes have you seen since you were here? WJ: One of the main changes I see is that the campus is a lot more crowded, with people and with new buildings, which indicates how much the school has grown and how much success the college has had in attracting students, faculty, research programs, and funding to build and expand. C: How did your education at UCSB prepare you for life as an entrepreneur, and were there other formative experiences that led you in an entrepreneurial direction? WJ: Independent study and research, the kind you do while working toward a PhD, are both great for developing ideas and concepts. Also, when I was in the program, John [Bowers] had a course called Engineering and Entrepreneurship [now taught in the Technology Management Department]. I didn’t actually register for the class; I just went and listened to the many successful entrepreneurs he invited to speak. That gave me my first understanding of what you need to be an entrepreneur, and I found it to be really helpful. One of my first jobs, at Motorola, also helped. The VP of research, who led our group, was an entrepreneur himself who had come out of Bell Labs and succeeded in his first company before joining Motorola. I gained a lot of understanding and background there. I don’t think I was a born entrepreneur. Together, my education at UCSB and my time at Motorola, which was a very innovative company that encouraged us to file for patents, kind of created a path for me. C: Was there a moment when you realized that you would become an entrepreneur? WJ: For me it was a slow migration. My intention out of school was to go into the academic space and eventually become a professor. But as I spent time at Motorola, I gradually drifted away from that, and toward the end of my five years there, we partnered closely with a startup company that did a lot of work for the project I was on. That gave some of us the idea that it was something we could try as well. C: What would you tell an entrepreneurially minded student are the keys to a successful startup? WJ: First, you have to have a great idea, probably a technology. Then, you have to think about whether that technology can become a marketable product. Will people buy it? You always need to think about the market and why customers ought to buy what you make. If there is a market, the question is, how big is it? And also, will you be able to generate enough profit to reinvest in your business and grow it? You will have to continue to innovate with new features

that will motivate your customers to come back. It’s like Apple with the iPhone; they continuously innovate so that there is always something new that brings customers back again and again. Also, when you run a business, you need to think about how your investors may exit, because they are most likely not going to stay invested in a business forever. Selling the company is one way; going public is another. Being successful in a business means having a successful exit for your investors, too.

the company. The ﬁrst six to twelve months, not much happened. People thought the technology was interesting but were not willing to invest. But if you keep going, eventually you’ll ﬁnd the person who says, “Wow, that’s great technology. I’ve been looking for something like that for a long time, and I’d like to support it.” Just don’t give up.

C: All of your companies have involved photonics, but the newest one is your ﬁrst in the biotechnology space. Can you talk about that?

WJ: The most impactful technology I started is the one I did not patent [laughs]. When I ﬁrst started E2O Communications, we focused on developing photonics technologies to drive nextgen interconnections. IBM was the leader, and the technology at that time was based on CD lasers and silicon photodetectors, which became stretched when Ethernet and ﬁber-channel standards reach Gigabit speed. So, we started to switch to VCSELs and developed a gallium arsenide photodetector on a semi-insulating substrate. We didn’t think it was worthwhile to patent a photodiode technology. When you develop an optical transmission module, you have a transmission laser on one side, a detector on the other side, and the architecture around the module. We thought, this was just a detector, so we patented everything else but missed the detector. Because of the way the detector was designed, however, it not only supported our initial goal of one gigabyte ethernet

WJ: I started Cytek Biosciences with one of my undergraduate classmates in 2014, again leveraging photonics technology, but with the goal of moving ﬂow cytometry into the 21st century. The new technology involves quite a lot of work of several UCSB Nobel Prize winners. We adopted the solidstate semiconductor laser, which grew out of Herbert Kroemer’s Nobel Prize–winning work on heterojunctions. We called on Shuji Nakamura’s work with nitrides, which enabled the blue and violet lasers used in the new technology. And the reagents our instrument supports include UCSB patented polymer dyes. It’s exciting to see so many UCSB technologies being incorporated in our tool, which was launched in 2017 and is now in almost every premier life-sciences research lab in the U.S.

C: Which of your one hundred-plus patents gives you the greatest satisfaction?

The first six months, people were not willing to invest. But if you keep going, eventually you’ll find the person who says, ‘Wow, that’s great technology. I’ve been looking for something like that, and I’d like to support it. Just don’t give up.’ C: What is one critical bit of advice you would offer entrepreneurially minded students, and what’s your advice for dealing with the inevitable adversity that comes with the territory? WJ: First, it’s important to have partners. You may think one way, and your partner may think another way. That’s good. That’s how you cover your weaknesses. You can’t be perfect, and everyone makes mistakes, but having a partner means that there is always someone over there watching you, so you make fewer mistakes. For the second part, every business has ups and downs. That’s OK. If you have a vision and a commitment and you really believe in your technology, just keep pushing, and eventually you will succeed. Just like with this company, Cytek. We started to talk to investors long before we started

and ﬁber channel, but also eventually was able to support twenty-ﬁve gigabytes based on exactly the same design concept. Today, because we didn’t patent it, and probably avoided lots of litigation, hundreds of millions of these detectors are deployed globally. They’re in almost every data center, research lab, and building. It’s the most successful product I’ve developed. I’m proud of it, but it’s not patented. C: Why did you decide to accept the offer to become a trustee, and how has the experience been so far? WJ: I was invited to join the board of trustees by Chancellor Yang in 2022. I feel really honored to be able to contribute to the growth of UCSB through this board. As a new member, I am still learning and will get up to speed soon. 25

UCSB AND ASML:

The Beneﬁts of Collaboration

n ive rs ity- indu stry partnersh ips are a regular feat u re at R1 un ivers ities like UC Sa nta B arbara, and in one pa rticularly effective example, rese arche rs in the l a bo rato r y o f UCS B p ro fesso r and Che m i cal E ng ine e r ing Department ch a ir, Mi ch ael G o rdo n , are pursuing f und a me ntal rese arch as pa rt o f a collab o ration w ith AS ML. The multin atio n al tech nology le ade r prov i des the world’s most adva nced lithog raphy te chnology, wh i ch i s cr itical to m a ss -pro ducing faster, mo re powe rf ul, and mo re e ne rgy- efficient m i c ro ch ips.

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ASML, the thirtieth largest company in the world in terms of market capitalization, plans to double its current global workforce of 39,000 employees over the next decade. That’s good news for UCSB undergraduate and graduate students who might be interested in seeking employment at the company’s research-anddevelopment centers in San Diego, San Jose, Connecticut, or the Netherlands. “We have very active university recruitment, as well as internships and constant university interactions, because we need the best talent for what we do,” says Sam Crisafulli, senior director of development and engineering at ASML San Diego. “We have many specialists, but we also rely on generalists to build, install, and support machines that have to be dependable and able to work at a customer fabrication facility more than 95 percent of the time.”

The Technology Semiconductor lithography is used to create chips that contain billions of transistors on a silicon wafer. Leading-edge chip makers might have twenty or more such machines in their fabrication facilities, each occupying up to two ﬂoors. ASML’s most advanced lithography systems use extreme (13.5-nanometer) ultraviolet (EUV) light. The light is emitted from a pulsed tin plasma generated by laser detonation and breakdown of small molten tin droplets injected into a vacuum chamber at a rate of 50,000 times per second. The droplet generator must produce ultra-stable droplets and operate for as long as possible between rebuilds. Both of those challenges must be met to ensure reproducible high-resolution lithography, maximized uptime of the EUV on the semiconductor fabrication line, and reduced wafer-processing costs. Tin droplet formation is a complex process, however, that involves engineering how tin interacts with different material surfaces in the droplet generator, where extreme pressure, temperature, and reactive gas conditions are required. Careful

In our lab, we have the time, the equipment, and t he ex pe r t ise to di g deeper i nto t he inhe re nt proble ms of droplet- su rface inte rac t ions t hat A S ML i s tryi ng to solve.

detective work is critical to gaining fundamental insights into these tin-surface interactions, which is why ASML chose to partner with Gordon, who has expertise in high-vacuum surface science, surface metrology, and plasma-surface interactions. “In our lab, we focus on characterizing, understanding, and engineering interactions that occur at surfaces in a wide range of venues, including how plasmas etch and deposit materials,” Gordon explains. “In our collaboration with ASML, we use a combination of ultra-high-vacuum spectroscopy and forensic metrology studies on actual droplet-generator hardware to try to tease out how tin interacts physically and chemically with different surfaces under a wide range of processing conditions.”

“We prefer not to focus on the fundamental science related to surface interactions of tin droplets,” says Crisafulli. “Rather, we look to leverage the expertise at partner universities and research organizations to extend our capabilities in that area.” “It’s an ideal pairing, because ASML is in the business of making, selling, and maintaining EUV tooling, rather than carrying out fundamental materials studies that require extensive characterization and microscopy equipment inhouse,” Gordon adds. “But in our lab, we have the time, the equipment, and the expertise to dig deeper into the inherent problems of droplet-surface interactions that ASML is trying to solve.”

Students Benefit ASML has hired multiple UCSB graduates. It also supports a senior final capstone project every year at the annual College of Engineering Capstone Expo in June. The ASML–sponsored student project took first place in the 2023 competition. Currently, the UCSB– ASML project supports one PhD student and one undergraduate student in the Gordon lab. “The students working on this project are seeing and interacting with cutting-edge technology, as ASML EUV tools have set the standard in terms of laser and plasma technology, power input, length scales, vacuum and optical hardware, and expense,” Gordon says. “It took them about fifteen years and billions of dollars to design, build, and market these amazing machines, which have revolutionized semiconductor lithography for a world with an endless appetite for ever smaller and more densely packed transistors that can provide greater and more efficient computational power. What ASML does could not be more relevant to the future of all micro-electronics, because if we can’t make the small patterns that we need — at scale and in an economical way — then we’re all stuck.” For engineering students, Gordon adds, “Working on the project is a tremendous opportunity. They get to go down to the ASML facility and see the machine; talk to the engineers, scientists, and technicians there; and see the droplet generator in action. This gives them a real sense of the impact of their work in the lab while better preparing them for careers in high-tech industries.”

Working in the ASML electrical design lab, Julia Hsu, senior mechanical design engineer, performs a ﬁrst inspection of a control board to conﬁrm the absence of manufacturing defects.

Mechanical design engineer Kelsey Sawvelle works on an ASML XLR-960ix DUV (deep ultraviolet] laser system in a DUV laser lab at ASML’s San Diego R&D center.

Can Phase Change Droplets Deliver New Materials? Omar Saleh’s lab dives into the potentially big conductivity of tiny drops

n a recent paper, materials professor and department chair, Omar Saleh, and lead author, Sam Wilken, a postdoctoral researcher in his lab, described experiments they performed on a test system of engineered DNA molecules to develop fundamental understanding of dynamics related to liquid-liquid phase separation (LLPS), a subject whose relevance to biology has gained notice in recent years. LLPS occurs when an initially low-density homogeneous solution — one having uniform compositional properties throughout — undergoes a phase separation in which macromolecules such as proteins or nucleic acids condense into dense liquid droplets. Even more recently, cellular bioengineers have discovered that LLPS may play an important role in how a cell functions. “The big idea is that LLPS inside, say, the nucleolus of a cell can modulate its function,” says Wilken. “How exactly cells function remains a large open question in biology, and this recent discovery indicates that physical processes are at work. But understanding cellular function is difﬁcult in living systems, which are complex and hard to control, so we are investigating a model system and trying to identify what are the important parameters at play in this kind of process.” In a distinct area of research, theoretical physicists recently discovered a new way to classify material structure: hyperuniformity. “The word hyperuniform indicates that there are not large variations in material structure in different locations,” Saleh explains. Crystals, such as those in semiconductor materials, are said to exhibit hyperuniformity, because their constituent atoms are arranged in highly ordered lattices. Such materials are very good at transporting light or electrons in a straight line along the lattice grid of their connected atoms, but they are also anisotropic, meaning that if electrons are transported at a different angle of, say, 45 degrees off that line, the semiconductor’s properties will change, limiting microcircuit design possibilities. While the transport properties of crystals have long been known, new materials are being discovered that display something called disordered hyperuniformity. “In a crystal, you’ll ﬁnd an atom at every lattice site, but such a periodic arrangement does not exist in a liquid, where you might have a bit of structure around a particular atom, but if you look far enough away from that

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atom, the structure appears to be disordered, or random,” Wilken explains. “A special system that displays both types of order — local randomness and long-range order — is described as disordered hyperuniform, combining essentially the best of both worlds: local isotropy [exhibiting the same disordered material properties in all directions] but, over longer distances, an ordered structure reminiscent of crystals,” he continues. “Systems displaying disordered hyperuniformity offer potentially extraordinary technological value. They could, for instance, enable the fabrication of new materials having transport properties superior to those of crystalline structures, and correspondingly fewer limitations in terms of the types of materials that could, in turn, be made from them.” In their paper, titled “Spatial organization of phase-separated DNA droplets” and published in August in the journal Physical Review X, Saleh and Wilken report a “clear and surprising experimental result: a droplet structure that is both disordered and hyperuniform.” Wilken notes that, while a handful of hyperuniform experimental systems have been described previously, “The new thing here is that we understand exactly how it becomes hyperuniform, as well as the characteristics of its hyperuniformity and what they tell us about how the system organizes itself. We describe systems that appear at ﬁrst glance to be randomly distributed but that, upon analysis, display a hidden order over long length scales — hyperuniformity.” The project involved performing experiments to uncover fundamentals relevant to the mechanisms underlying disordered hyperuniformity, which is pervasive in physics, chemistry, astronomy, and biology, and, accordingly, has applications in diverse systems in many areas of study. In their experiments, Saleh and Wilken used synthetic engineered DNA nanostars, so-called because of their shape, an approach, Wilken says, that is “very powerful, because we can precisely control the shape, the size, and the interactions of the DNA system.” They induced phase separation of the solution containing the nanostars, causing the initially free solution (of unbound nanostars) to condense and form, at the nanoscale, a dense, dynamic mesh of bound DNA nanostars — liquid

Artist’s concept illustration (left) depicts twisted helixes of engineered DNA nanostars that form uniquely ordered patterns of liquid droplets. Described as “disordered hyper uniform,” they are characterized by local randomness (as in a liquid) and long-range order reminiscent of a crystal’s lattice of atoms.

It’s an interesting multiscale problem. We have the DNA particle, on the order of nanometers; the droplet, on the order of microns, a hundred times larger; and then a scale one hundred times larger than that to determine the organization over many droplets.

droplets, which are measured in microns, and hyperuniform ordered structures consisting of many droplets. “It’s an interesting multiscale problem,” Wilken notes. “We have the DNA particle, on the order of nanometers; the droplet, on the order of microns, a hundred times larger; and then a scale one hundred times larger than that to determine the organization over many droplets. You go from essentially random liquid at the droplet scale to being very ordered on the long scale.“ The researchers were also able to see the same hyperuniform structures develop in a dissimilar system in which the microstructure and the mechanisms that drove phase separation were very different from those in the nanostar solution. The identical long-range hyperuniform structure in different systems confirms that phase separation itself, not any particular characteristics of the DNA nanostar, is what drives the formation of hyperuniform structures. Wilken notes another important discovery that came out of the research. They learned that sequence engineering of DNA allows for the creation of two separate species of DNA particles, with no cross-species binding of the two. When testing this design, Wilken found that both species phaseseparate simultaneously but result in separate droplets of DNA. “This is a powerful ability,” Wilken says. “DNA’s design flexibility makes it possible to tune microscopic interactions between DNA particles in order to fabricate a composite material from distinct droplet species.” Saleh adds to that, saying, “One can imagine using this ability to create a novel type of ‘soft alloy’ that would act as an artificial tissue, with different

types of droplets taking on specific arrangements in space and imbuing the material with novel functions.” Additionally, Saleh notes, “The surprising thing about the two-species experiment was that hyperuniformity was preserved within each droplet species, but was destroyed when combining the two species, indicating that the structure of this composite material is exceedingly sensitive to small changes in the structure of the constituent DNA particles.” Wilken sees multiple possible application areas for the findings, relating both to investigating the fundamental operation of the cell, and to fabricating devices that manipulate light in new ways. “We investigated structures undergoing well-understood equilibrium dynamics, i.e., those of dead or inanimate objects,” Wilken says. “What’s not clearly understood are the impacts on material structure of non-equilibrium dynamics, which are integral to biology, as living systems constantly consume and expend energy to stay alive. We expect, however, that we could use nanostars to probe the fluctuations that occur in living systems, because nanostars are composed of naturally occurring nucleic acids, which, we know, are compatible with biological systems.” A material composed of disordered hyperuniform DNA droplets might also have technological applications, for instance, as an engineered transport material in photonic devices. As mentioned above, the transport properties of crystals are limited by their anisotropy, such that electrons or, in a photonic device, photons, can travel on only path along the crystal lattice. Interestingly, the isotropic structures that Wilken and Saleh investigated are composed of droplets approximately one micron in size, the same length of a wave of visible light. That suggests, Wilken says, that materials comprising droplets arranged on a square lattice might be capable of transporting light in any direction in a photonic device, thus opening up new possibilities for chip architecture and materials that manipulate light in novel ways. Hyperuniform materials might very well find their way into the photonic materials that will, eventually, generate quantum bits in quantum computers, ushering in an entirely new way to solve difficult problems associated with, but not limited to, encryption, semiconductor manufacturing, and drug design. 29

Hard Thinking on Soft Robots Soft robots are inherently safer than hard robots but also much more difficult to control. Two UCSB professors partner to take a new approach.

A time-lapse photograph captures a trunklike soft robot that is made of fabric, incorporates fabric “muscles,” and is controlled by Koopman Operating Theory tossing a ping pong ball.

he robot revolution is underway. The powerful, programmable, increasingly ubiquitous machines are assembling and moving parts and products on factory floors around the world. But large, rigid, fast-moving models that do heavy work are typically relegated to cages and isolated sections of manufacturing sites because of the inherent danger they present to human operators. Previous efforts toward enabling such robots to perform safely with human collaborators have focused on software control, but that approach cannot provide absolute guarantees of safety. Soft robots offer an alternative. The low stiffness and mass inherent in their construction make them safe, but their nonlinearity (they are “floppy”), infinite freedom of movement, and potential for highly nonlinear dynamics severely complicate the task of creating models to control them. Traditional modeling and control techniques can be used to direct hard robots, which move precisely in linear ways involving right angles. Analytical and machine-learning (ML) methodologies have been applied to model soft robots, but only in somewhat limited ways, by approximating soft-robot motion that is so slow as to be nearly static, and deflections of movement that are so small as to be nearly linear — or both.

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In a paper titled “Control of soft robots with inertial dynamics,” published in the August 30 issue of the journal Science Robotics, UC Santa Barbara mechanical engineering professors Elliot Hawkes, an expert in soft robots, and Igor Mezić, a computational theoretician with expertise in control theory, describe an advance in the modeling and control of soft robots “into the inertial [i.e. high-acceleration], nonlinear regime.” That involved controlling motions of a soft continuum arm (one having no joints or mechanical pivot points) at velocities ten times larger and accelerations forty times greater than had been done before, and they did so for highdeflection shapes having more than 110 degrees of curvature. The mention of inertia in the title of the paper is especially important. “Inertia is a big ingredient that people haven’t been including previously,” Mezić says. “The robots have been moving very slowly, so slowly that inertia can basically be ignored. Our model can take inertia into account, so you can swing the arm in a realistic motion at a realistic speed and account for the motion. That’s a big step forward. The way floppy soft robots move severely complicates modeling and control theory for them. It has been a serious problem.” To take that step of including inertia, Mezić and Hawkes leveraged a data-driven learning approach for modeling, based on Koopman Operator Theory (KOT), which Mezić has used previously to understand changes in traffic flow under various conditions. The model requires less than five minutes of training (making it computationally low cost in contrast to the computationally intensive ML models applied previously by others), can be built in as little as a half-second, and is “design agnostic,” meaning that it is able to accurately control morphologically different soft robots. The study was done using two different soft robots made of fabric, each about 24 inches long, with four artificial fabric “muscles” at the four corners of the hollow trunk-like device, which is controlled by air pressure. For some experiments, such as picking up an object, a magnet was placed on the end of the continuum arm. “The model maps the input pressure of the air in the four muscles to the output shape,” Hawkes explains. “To train the model, we apply various input pressures and measure the output shapes. That’s our data.” That data is then integrated into KOT, which creates a mapping from muscle pressures to robot shape. “The result is a model that can predict the robot’s shape over time,” says Hawkes. “Not only can the model predict the shape, but it can then also tell you after the fact what inputs are required to make it go from point A to point B,” Mezić adds. “That’s important, because these inputs need to be done correctly, so that the internal muscles curve in the right way.” “You give it some inputs to move, and then the code basically produces a bunch of coefficients that tell you, ‘OK this is a relationship; if you do this on the input side, then this is what’s going to transpire,’” Mezić continues. “And then, we design the inputs so that they can match some desired goal, like throwing or catching a ping pong ball, which was one of the exercises the robot was able to complete in the study.” The project was funded by the National Science Foundation (NSF) as part of a four-year, $2 million grant within its Emerging Frontiers in Research and Innovation (EFRI) program.

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