Bioelectronic Innovations, Empowered by Chemistry

Bioelectronic Innovations, Empowered by Chemistry

UD Professor Laure Kayser received an NSF CAREER award to further her group’s materials science research

Whether it’s a smartwatch that can detect irregular heartbeats or a continuous glucose monitor, electronics that can interface with biology have already started to revolutionize the future of healthcare. But while the potential of these devices is far-reaching, the materials that make up future bioelectronics have to meet several different criteria — such as not causing damage or irritation to skin and avoiding toxic metals, for example.

Creating new organic, biocompatible materials that can interface with living systems is Laure Kayser, assistant professor in the Department of Materials Science and Engineering at the University of Delaware’s College of Engineering. Now, thanks to an award from the National Science Foundation (NSF), she and members of her lab will continue their fundamental research on a new class of polymers that could pave the way for future applications in human health.

The Kayser Lab specializes in designing, synthesizing and characterizing new plastics and polymers that can conduct electricity while safely interfacing with living systems. By working at the intersection of chemistry, polymer science and materials engineering, her lab is able to develop innovative design and synthesis approaches for creating new types of plastic materials.

Kayser, who holds a joint appointment in the Department of Chemistry and Biochemistry in the College of Arts and Sciences, said that what sets her group apart from others in the field of organic bioelectronics is a strong foundation in organic chemistry and their ability to make any material they want instead of only being limited to what’s currently available.

“We do modern chemistry, including chemistry that is not necessarily typically used in the field, and apply it to materials science,” said Kayser. “Because we have a background in chemistry and synthesis, we can make any material, characterize it, establish structure-property relationships and tailor it so the material can be interfaced with biology.”

Design rules for electronic highways and ionic waves

Starting in July, Kayser’s group will be investigating a new type of organic bioelectronic material. With a five-year, $654,206 Faculty Early Career Development Program (CAREER) award from NSF, her lab will study the fundamental properties of polymers that have properties inspired by living systems and also meet the criteria for being able to be incorporated into bioelectronic devices.

For this project, the lab will be studying derivatives of PEDOT:PSS. This polymer belongs to a class of materials known as organic mixed ionic electronic conductors, which have the unique ability to conduct both electrons and ions.

This is a necessary yet difficult to achieve property for bioelectronics: Typical electronic devices, such as laptops or cell phones, use electrons to transmit signals, while systems in biology, such as nerves, use ions. This difference in communication methods makes it difficult to “translate” signals from electronic devices into ones that a cell or organ can interpret.

Laure Kayser (right), an assistant professor in the College of Engineering’s Department of Materials Science and Engineering and doctoral candidate Vidhika Damani working in the lab with PEDOT:PSS, a polymer with the unique ability to conduct both electrons and ions.

Laure Kayser (right), an assistant professor in the College of Engineering’s Department of Materials Science and Engineering and doctoral candidate Vidhika Damani working in the lab with PEDOT:PSS, a polymer with the unique ability to conduct both electrons and ions.

There are also engineering challenges in creating this class of materials, Kayser explained. “There are very different design rules whether you want a material to be an electronic conductor or an ionic conductor,” she said. “For example, electronic conductors are very well ordered — like a highway for electrons to travel down. But if you want to make a good ionic conductor, ions usually like to be on a floppy, almost liquid environment, so more like a wave.”

Members of the Kayser lab, including doctoral students Chun-Yuan Lo, Vidhika Damani, Dan My Nguyen, and Elorm Awuyah, were instrumental in getting preliminary results for the proposed research. The team recently published a paper in Polymer Chemistry (which was also featured on the journal’s May 21st 2022 cover), where they determined the role of different chemical properties in PEDOT:PSS and how they could be changed to make the material more efficient in bioelectronic devices, a key finding that showcased how the group’s expertise in this field could be applied to PEDOT:PSS.

Through the CAREER award, the lab will continue studying derivatives of PEDOT:PSS to gain a solid, fundamental understanding of how to control both electronic and ionic conduction. The long-term goal is to develop design rules for fabricating bioelectronic devices with this class of materials in the future.

“Our lab’s focus is to understand deeply how chemical structures affect the electronic properties of those materials,” said Kayser. “Through this grant, we’re going to learn a lot about these materials — some of these ideas might fail, but we’ll learn something along the way.”

Materials science outreach and education

With this CAREER award, Kayser will also be leading different outreach and educational initiatives for both high school students and undergraduates.

Part of this work will include connecting with female students at local high schools. This will be done through both a materials science-focused outreach program as well as a mentorship program, where graduate students and senior undergraduate students will be paired with high school students to provide support throughout the college application process.

Researchers in Laure Kayser’s lab recently published a paper in Polymer Chemistry (featured on the May 21st 2022 cover) where they determined the role of different chemical properties in PEDOT:PSS and how they can be changed to make the material more efficient in bioelectronic devices.

Researchers in Laure Kayser’s lab recently published a paper in Polymer Chemistry (featured on the May 21st 2022 cover) where they determined the role of different chemical properties in PEDOT:PSS and how they can be changed to make the material more efficient in bioelectronic devices.

Kayser will also be working with Sheldon Hewlett, an assistant professor who leads instruction and teaching in the materials science and engineering department, on integrating research into undergraduate curriculum. With support from the CAREER award, junior year materials science students will conduct a polymerization of PEDOT:PSS, including synthesis, purification and characterization, as part of a laboratory module. There will also be opportunities for students to address additional research questions during the course module, as well as funded research programs for those who are interested in carrying their work into the summer.

Along with introducing students to the process of polymerization, Hewlett added that this project will allow students to work with a class of materials in a laboratory course that they are likely to encounter in their career. “Not only will this award give us an opportunity for students to do real research, but it also provides students with a novel material system to work with,” said Hewlett. “You don’t see a lot of lab courses working with these polymers at this level — of making a material from start to finish, and then characterizing it afterwards.”

Making new discoveries through ‘great fundamental science’

“Chemistry will be central to the discoveries that Laure Kayser’s research group will advance on plastics and other polymeric materials through this NSF CAREER award,” said Joel Rosenthal, professor and chair of the Department of Chemistry and Biochemistry. “Rather than simply tweaking or studying materials that already exist, the Kayser lab is adept at leveraging synthetic chemistry to discreetly control the composition, and by extension, the properties of new polymers for various applications, including bioelectronics. I’m incredibly excited to see how her group’s work will continue to develop over the next several years.”

Joshua Zide, professor and chair of the Department of Materials Science and Engineering, added, “Professor Kayser is a fantastic contributor to the Materials Science and Engineering Department, and we are lucky to have her. Her research translates the chemistry to myriad important applications, and the perspective she brings is a huge benefit to the whole department.”

While Kayser is excited about the potential of her research to potentially impact a wide range of applications and fields, she is also looking forward to the “great fundamental science” that this CAREER award will enable her group to do.

“It’s a relatively hot area that is going to continue growing, so it’s a good place for us to be leading the pack,” she said. “I’m hoping that by learning more about the fundamentals of these materials, it might inspire others to explore different molecular designs and how they can be translated into devices. Overall, I think we’re going to make lots of really cool discoveries.”

| Photos by Evan Krape |

The TuFF Age

The TuFF Age

UD researchers tackle new task in making complex material more viable for building aircraft

TuFF — Tailored Universal Feedstock for Forming — is a strong, highly aligned, short-fiber composite material that can be made from many fiber and resin combinations. Created at the University of Delaware’s Center for Composite Materials (CCM), it can be stamped into complex shapes, just like sheet metal, and features high-performance and stretchability up to 40%.

Since its introduction, CCM researchers have explored applications for TuFF, from materials for repairing our nation’s pipelines to uses in flying taxis of the future.

Now, armed with $13.5 million in funding from the U.S. Air Force, UD mechanical engineers and co-principal investigators Suresh Advani and Erik Thostenson along with industry collaborators Composites Automation and Maher and Associates are working on ways to improve manufacturing methods for TuFF.

“I am really excited at the opportunity to mature the TuFF pre-pregging process and demonstrate high-throughput composite thermoforming for Air Force relevant components,” said David Simone of the U.S. Air Force.

The goal is to enable lighter-weight composites to become cost-competitive with aluminum for creating small parts found in air vehicles.

Advani explained that when it comes to making aircraft materials more cost-efficient, reducing a material’s weight even a mere kilogram, just 2.2. pounds, will reduce fuel consumption and emissions and can result in thousands of dollars in savings over time.

This is because aircraft are heavy. A Boeing 747, for example, weighs a whopping 404,600 pounds. A B2 Stealth Bomber in the U.S. Air Force, meanwhile, tips the scale at over 43,000 pounds.

“In general, the aerospace industry wants to reduce weight and replace metals,” said Advani, George W. Laird Professor of Mechanical Engineering. TuFF is a good option because the material can achieve properties equivalent to the best continuous fiber composites used in aerospace applications.

Advancing TuFF thermosets

Until now, most of the work around TuFF has focused on thermoplastic composite materials that melt when heated, becoming soft and pliable, which is useful for forming. By contrast, TuFF thermosets have a higher temperature threshold, making them useful for aerospace applications. But TuFF thermosets have manufacturing challenges, too, including the long manufacturing times necessary to make a part.

In this new project, Thostenson and Advani will work on ways to improve the viability of thermoset TuFF composites. To start, the researchers will characterize the starting materials’ mechanical properties to understand how to make TuFF thermosets reliably and consistently. The research team will explore whether they can make the material in a new way, using thin resin films and liquid resins. They will test the limits of how the material forms and behaves under pressure and temperature, too.

“How does it stretch during forming in a mold? What shapes can we make? When does it tear or thin or develop voids that can compromise material integrity?” said Advani.

Having a database for such properties and behaviors will be useful in understanding TuFF material capabilities and limits, and to inform efforts to model and design parts with TuFF.

Thostenson, professor of mechanical engineering, is an expert in structural health monitoring of materials. He will advance ways to embed sensor technology into TuFF thermosets. This would allow the researchers to see from the inside how the material is forming and curing during its manufacture, in hopes of being able to gauge—and improve— the material’s damage tolerance.

It’s intricate work. To give you an idea of scale, a single layer of TuFF material is approximately 100 microns thick, about the diameter of the average human hair. The carbon-nanotube sensors Thostenson plans to integrate into the material are smaller still—one billionth the width of a human hair.

“This would allow us to do health monitoring for the materials and parts during service life, but you could also imagine using sensor technology to detect a defect during manufacturing,” said Thostenson.

While it remains to be seen whether this is possible, Thostenson said having this ability could result in real cost savings for manufacturing methods, where real-time knowledge of how a material is curing could help the researchers speed up production. Additionally, if there is a material failure, such as a tear, the sensors could point the researchers where to look in the process.

The research team also plans to develop a virtual modeling system to refine the material-forming process through computer simulation instead of by trial and error. In this way, the team will better understand each step in the material-forming process, enhancing the team’s ability to make TuFF materials consistently and reliably — a must for aerospace applications.

“I am hoping this work will allow us finally to make composites cost competitive with the metal industry,” said Advani.

In addition to Thostenson and Advani, the team includes, from CCM, Jack Gillespie, Dirk Heider, Shridhar Yarlagadda, Thomas Cender, John Tierney and Pavel Simacek, along with four to five graduate students.

Fine-Tuning Touch Technology

Fine-Tuning Touch Technology

UD’s Charles Dhong gets $1.9 million to develop new tactile aids

Bumps and lines make up touch-based technology such as Braille. But the human sense of touch is keen enough to detect differences that are much smaller. Research by Charles Dhong and his group at the University of Delaware has found that humans can feel differences in the chemical composition of a surface, down to the substitution of a single atom.

That ability is one focus of Dhong’s work as an assistant professor in the Department of Materials Science and Engineering and the Department of Biomedical Engineering at UD. He explores new possibilities for tactile technologies and the mechanical forces that affect the perception of touch.

Dhong presented research on this at the American Chemical Society’s national meeting in San Diego on Wednesday, March 23. And he and collaborator Jared Medina, associate professor in UD’s Department of Psychological and Brain Sciences, have new support for development of higher-quality tactile aids for people with visual impairments. The $1.9 million grant, which started in February and continues for five years, is from the National Eye Institute in collaboration with the National Federation of the Blind.

Current technology recreates tactile sense using tiny motors and electricity. But the bumps and buzzes they generate are not that good at mimicking the real thing.

A new approach to controlling perception of texture could have many applications, Dhong said. It could make it possible to design new types of surfaces or provide improved integration of the sense of touch into virtual reality environments. It could also improve existing devices, such as Braille displays, or provide feedback to surgeons conducting surgery remotely.

“When you touch an object, you’re feeling its surface, and you can change how it feels by changing the friction between that surface and your finger. That’s where the chemistry comes in,” Dhong said. “We think materials chemistry could open the door to recreating more nuanced sensations, whether you’re designing a product to feel a certain way or creating feedback devices for virtual reality.”

Research by Charles Dhong and his group at the University of Delaware has shown that humans can feel tiny differences in a surface, down to the substitution of a single atom.

Research by Charles Dhong and his group at the University of Delaware has shown that humans can feel tiny differences in a surface, down to the substitution of a single atom.

Progress in touch technology has lagged, in part because it involves multiple types of sensations, such as temperature and pain. In addition, some efforts to recreate touch have included systems designed to simulate a sense of moving one’s body — a complex sensation.

Dhong’s research focuses on a specific type of touch: using the fingers to detect fine textures. Some methods for evoking this kind of fine touch are already available. Your smartphone attracts your attention without sound, using a tiny vibrating device within. A refreshable Braille display for people with low vision or blindness uses an actuator to move pins up to create bumps.

This type of touch depends on a physical force — friction — which is the resistance that skin encounters as it brushes against an object. While attributes such as the contours of a surface influence friction, so does chemistry. The structure of the molecules within a substance and the properties of its surface also influence the sensation.

Dhong and his colleagues suspected that by altering only chemistry-related features, they could change how a surface feels.

In previous work, Dhong’s team asked people to touch single-molecule-thick layers of silane, a silicon-containing compound. None of the silane surfaces possessed detectable differences in smoothness.

But those who touched the surfaces could differentiate them based on chemical differences, including the substitution of one atom within each silane molecule for another, because of subtle changes in friction.

“Recent research has shown that people can detect the physical differences between surfaces at a resolution as low as 13 nanometers,” Dhong said. “Now we are saying that the sense of touch can also identify chemical changes as small as swapping a nitrogen atom for a carbon atom.”

In San Diego, Dhong presented recent work focusing on polymers, the go-to molecules for synthetic materials. Polymers are distinguished not only by their chemical formulas, but also by a characteristic known as crystallinity, which describes how neatly the chain-like molecules are organized. The polymers in these experiments had identical formulas and molecular weights. Only the degree of crystallinity differed.

In their experiments, the researchers focused on the perceived texture of thin layers of polymers. As with the silanes, they asked the subjects to slide their fingers across the polymer. This time, too, they found that people could differentiate between the polymers based only on variations in the friction resulting from subtle changes to the crystallinity of the molecules.

About the researcher

Charles Dhong, assistant professor of materials science and biomedical engineering in the College of Engineering, joined the University of Delaware faculty in 2019.

He earned his bachelor’s degree in chemical and biomolecular engineering at the University of California, Berkeley, his doctorate at Johns Hopkins University and did postdoctoral research in nanoengineering at the University of California, San Diego.

His research focuses on understanding the mechanical forces that shape the human sense of touch.

 Photo | illustration by Christian Derr, photo by Maria Errico, image of hand courtesy of Charles Dhong

Manipulating Molecules

Manipulating Molecules

Manipulating molecules is tricky business, but two University of Delaware professors have earned international recognition for “outstanding scientific and technical contributions” to their respective science and engineering fields by being named 2021 AVS Fellows.

The College of Engineering’s Joshua Zide, professor of materials science and engineering, and chemistry and biochemistry professor Andrew Teplyakov recently earned the recognition of their peers at AVS, an international organization that promotes research and communicates advancements in the fields of surface, interface, vacuum, and thin film science and technology. This major international accolade is typically bestowed to more senior researchers and shows that the University of Delaware’s engineering faculty are truly world-class.

“AVS is such a fantastic professional society, bringing together academics, people in industry and at national labs, all in a wide range of fields related to electronic materials,” said Zide, who has been an AVS member for about 12 years.

Zide, who joined the College of Engineering in 2007, has focused his research on the “growth” of new materials, specifically implementing a technique called molecular beam epitaxy to produce films of new materials. By controlling the component elements in the film, his group has been able to create extremely pure films with perfect crystal structures. He also received the AVS Peter Mark Memorial Award in 2014 for outstanding early-career work.

Zide and Teplyakov were named 2021 AVS Fellows alongside about a dozen other scientists. Fellows of the society must be longstanding members and are recognized for their contributions of at least 10 years of professional impact in research, engineering, technical advancement, academic education or managerial leadership.

“It is a great honor to be a part of a very respected and celebrated group of experts in a long-standing international professional society,” said Teplyakov, who joined AVS shortly after graduate school in the mid-1990s. Teplyakov, who joined the College of Arts and Sciences in 1998, has been working with his group for many years to modify the topmost layer of surfaces with molecules that control chemical reactivity as well as the chemical and physical properties of surfaces.

Rethinking Plastics

Rethinking Plastics

UD scientists and collaborators issue urgent call to action on plastics pollution

People lived without plastic until the last century or so, but most of us would find it hard to imagine how.

Plastics now are everywhere in our lives, providing low-cost convenience and other benefits in countless applications. They can be shaped to almost any task, from wispy films to squishy children’s toys and hard-core components. They have shown themselves vital in medicine and have been pivotal in the global effort to slow the spread of the COVID-19 pandemic over the past 16 months.

Plastics seem indispensable these days.

Unfortunately for the long-term, they are also nearly indestructible. Our planet now bears the weight of more than seven billion tons of plastics, with more being produced every day. An ever-growing waste stream clogs our landfills, pollutes our waterways and poses an urgent crisis for our planet.

Four scientists have published a call to action in a special issue of Science, devoted to the plastics problem.

In a sweeping introductory article, the scientists — including two from the University of Delaware, one from the Lawrence Berkeley National Laboratory in California and another from the University of Sheffield in the United Kingdom — call for fundamental change in the way plastics are designed, produced, used and reused.

The ultimate goal: Designing, adopting and ensuring a “circular” lifecycle for plastics that leads not to a landfill or an ocean or a roadside, but to a long life of near-infinite use and reuse of the valuable resources and applications they represent.

That requires new approaches to chemistry, engineering, industrial processes, policy and global collaboration, according to co-authors LaShanda T.J. Korley, director of the Center for Plastics Innovation (CPI) at the University of Delaware and the principal investigator of a National Science Foundation (NSF) Partnerships for International Research and Education effort in Bio-inspired Materials and Systems; UD’s Thomas H. Epps, III, co-director of CPI, lead principal investigator of an NSF Growing Convergence Research (GCR) effort in Materials Life-Cycle Management and director of the Center for Hybrid, Active, and Responsive Materials (CHARM) at UD; Brett A. Helms of the Molecular Foundry at Lawrence Berkeley National Laboratory in California; and Anthony J. Ryan of the Grantham Centre for Sustainable Futures at the University of Sheffield in the United Kingdom.

“The plastics waste dilemma is a global challenge that requires urgent intervention and a concerted effort that links partners across industrial, academic, financial, and government sectors buttressed by significant investments in sustainability,” they write.

It’s a tall order that includes attention to recycling, “upcycling” (reusing materials in new added-value ways), development of new materials and recognition of the needs of under-resourced communities.

“There’s not a one-size-fits-all solution,” said Korley, Distinguished Professor of Materials Science and Engineering at UD, who has spent her career developing new plastics with specific properties. “How people live with waste and how they recycle is so different. Traveling in Europe has highlighted the stark contrast in the usage of single-use plastics, such as drinking straws and cutlery in comparison to the U.S. Across the U.S., cities and municipalities within a single state may do things differently.”

Billions of tons of plastics have been produced, but only a small fraction is ever reused. That must change, researchers say.

Complex recipes are used in many plastics, Korley said, and often include several kinds of polymers and other additives. Each component can complicate recycling efforts or make recycling impossible, which is why recyclers will accept some kinds of plastic and refuse others.

But how can plastics be designed so that all of their components can be deconstructed for future use in other products?

This is the challenge for CPI, which Korley directs. Its focus is on “upcycling” plastics — finding ways to turn plastic waste into valuable materials such as fuels and lubricants. Researchers use catalysis and enzymes to reconstitute some kinds of plastic, such as high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polystyrene/Styrofoam, the kinds of plastics used in milk jugs, shampoo bottles, sandwich bags, coffee cups, grocery bags and food packaging.

“Different materials properties require the use of different polymers and blends and additives, which contributes to the complexity and hierarchy of waste,” Korley said.

The Science paper addresses that and much more, with an urgency that reflects the real and present dangers for a planet choked by discarded plastics that aren’t going anywhere anytime soon.

Some of those realities are grim indeed. Take the plastic water bottle that helped quench your thirst after a morning jog five years ago, for example. It will probably be with us — somewhere — for another 395 years. Slow deterioration doesn’t help us either. Scientists have found that tiny micro bits of worn-down plastic are prevalent in the water we drink and the foods we eat.

Less than 10% of plastic waste is recycled at all and less than 1% will be recycled more than once. About 12% will be incinerated. Millions of tons of discarded plastic winds up in giant swirls of debris in the ocean and the rest of it piles up in landfills, sinks into riverbeds or lies on roadsides around the world.

But Helms, a co-author from the Lawrence Berkeley National Lab, was part of the team that created a next-generation plastic called PDK (polydiketoenamine), which can be reduced back to its molecular parts and reassembled as needed.

“We’re at a critical point where we need to think about the infrastructure needed to modernize recycling facilities for future waste sorting and processing,” Helms said after the new material was announced. “If these facilities were designed to recycle or upcycle PDK and related plastics, then we would be able to more effectively divert plastic from landfills and the oceans. This is an exciting time to start thinking about how to design both materials and recycling facilities to enable circular plastics.”

The building blocks of plastics — monomers — are made up of elements including carbon, hydrogen, oxygen, nitrogen, chlorine and sulfur. These monomers are linked by chemical bonds to become polymers, which can be used in the formation of plastics to be crafted into various forms for many different uses.

The value of all those resources is lost in single-use applications, said Sheffield’s Ryan. He calls it a “convenient truth” — the convenience and cheap cost of such products make them compelling to consumers, without recognizing the inherent value and cost to the planet. Marketing strategies that claim certain plastic products are “green” and biodegradable to draw well-intentioned consumers are especially concerning to him.

“Cynical ‘greenwash’ is the biggest problem for plastics sustainability,” he said. “So I was very keen to work with LaShanda and Thomas on this. I have known them since they were Ph.D. students.”

With innovation and collaboration as pillars of the new centers they co-direct — Korley’s U.S. Department of Energy-backed CPI and Epps’ NSF-backed CHARM and GCR, Korley and Epps, the Allan and Myra Ferguson Distinguished Professor of Chemical and Biomolecular Engineering, are at the forefront of efforts to extend the life of petroleum- and bio-derived plastics and/or put them on a circular path that continues from production to first use to reconstitution to forever.

Ryan said he sees a “circular economy” as critical. He sees the value in recycling and upcycling and development of new materials, but none is a “silver bullet.” Addressing the plastics dilemma requires recognition of the true value of plastics.

“One solution is something America is not very good at — regulations, policy and taxation,” he said. “There isn’t an easy answer to the plastics problem. An unrestrained market isn’t going to provide it.

“For all of these issues where science and engineering and society intersect, the answer is always: It’s complicated.”

A more accurate perspective, in Ryan’s view, is to see the plastics problem as related to the climate change problem without allowing it to be a distraction.

“Climate change is an inconvenient truth and an invisible truth,” he said. “You can’t see what’s causing it and you can’t see carbon dioxide in the atmosphere. You don’t associate driving to the store with climate change.

“You do associate things with plastics waste — and that is a convenient truth. We have no problem taking fossil fuels and turning them into plastics. But now we need to take care of that precious plastic. Don’t just throw it away. It’s just too cheap. Because of the pollution problem, we need to give it an artificially high price.”

Lifecycle analysis data are key to making evidence-based decisions, Ryan said, and consumers and lawmakers can’t do that on their own. They need professionals to break down the costs and benefits and explain the options.

“It’s far more complex than most people are willing to consider,” he said.

The call to action is comprehensive.

“To achieve a more sustainable future, integration of not only technological considerations, but also equity analysis, consumer behavior, geographical demands, policy reform, life-cycle assessment, infrastructure alignment, and supply chain partnerships are vital,” the authors said.

Korley said she sees growing passion for this daunting challenge.

“These initiatives drive excitement among our students — high school, undergraduate and graduate and our postdocs,” she said. “People are passionate about doing something to better the world. And they can talk to their grandmother or their niece or nephew and explain why the work they are doing matters.”

| Graphics by Jeffrey C. Chase |

Soft Matter for All

Soft Matter for All

UD gives voice to a diverse group of early-career researchers

When picturing a research symposium, you likely imagine academics presenting on, well, inspiring research. Fair enough. But what happens when the agenda goes beyond data and discovery?

Soft Matter for All, a one-day symposium co-hosted by the Materials Research Science and Engineering Centers (MRSEC) at the University of Delaware and Princeton University was designed to go well beyond data and discovery. A virtual webinar held on Oct. 23, the event was not just an opportunity for early-career researchers from a variety of institutions to share exciting work — although it was that. Of equal significance, this symposium was a celebration of so many varied backgrounds — social, cultural, geographic — contributing to the field.

Prof. Thomas H. Epps, III

“The science was important, but a big part of the focus was showcasing diverse talent,” said Thomas H. Epps, III, who is the Thomas and Kipp Gutshall Professor of Chemical and Biomolecular Engineering, director of the Center for Research in Soft matter and Polymers (CRiSP) at UD, director of the MRSEC at UD and a co-organizer of the event. “We wanted diverse representation in terms of gender, ethnicity, disability, military background and parental status. We wanted the undergraduate students who were watching this symposium to see someone who potentially looks like them. We wanted them to say: ‘These people are doing it, so maybe I can do it, too’.”

For outsiders, any discussion of soft matter usually begins with one question: What… is it?

Prof. Sujit Datta

As a crash course for any newbies tuning in, Sujit Datta, assistant professor of chemical and biological engineering at Princeton, offered a primer: Soft materials are, technically speaking, “things that are soft and squishy,” he said. These can be biological or synthetic — think fluids (from mucus to coffee), grains (like sand and soil), polymers (the molecular spaghetti used in plastics and resins) and colloids (those tiny microbeads you sometimes see in products like shampoo). Toothpaste, hair gel, fabric, paper and the hydrogel particles that absorb water in a diaper — these are all examples of important soft materials that appear in everyday life.

“In a nutshell, they are all around you,” said Datta, who is a faculty researcher at the Princeton Center for Complex Materials.

To provide an example of how studying and developing these materials can make life better, keynote speaker Prof. Paula Hammond shared some of her research. Head of the Department of Chemical Engineering at the Massachusetts Institute of Technology (MIT), Hammond said she created a nanoparticle, a tiny sphere one one-hundredth the size of a human hair, capable of treating the most invasive and drug-resistant cancers. Now, she is working on strategies for deploying this system against ovarian cancer and glioblastoma.

Prof. Paula Hammond

A Black scientist, Hammond said participating in this particular symposium was important because its focus on diverse perspectives is a reminder of how much the discipline is enriched when disparate voices are given a platform: “We all benefit,” Hammond said. “Science gets advanced more completely and effectively, new and different problems get addressed, and young people see themselves in research role models, thus inspiring other young students of color to enter the field.”

In his address, the second keynote of the day, Joe DeSimone echoed this sentiment. The owner of more than 200 patents and a professor of translational medicine and chemical engineering at Stanford, DeSimone is the co-founder of Carbon, a California-based company advancing the 3-D printing industry. His soft-material innovations range from next-generation dentures to running shoes that actively conserve an athlete’s energy. Over the course of his career, DeSimone said, he has come to understand that “we learn the most from those we have the least in common with… A lot of times, in a lot of circles, when addressing diversity, people quickly run to the question: Does this mean we’re abandoning meritocracy? Of course not. Ability matters. But so does diversity. They are two sides of the same coin.”

Prof. LaShanda Korley

For the majority of the symposium, the (virtual) floor was opened to graduate and postdoctoral students, so that they might showcase what co-organizer LaShanda Korley, Distinguished Professor of Materials Science and Engineering at UD and co-director of the MRSEC at UD, called the “depth and breadth of soft matter research from fundamental to applied.” Eighteen presenters represented 13 institutions, including Harvard, MIT, Cornell, the Air Force Research Laboratory, Stanford, Princeton, Carnegie Mellon and the Universities of Chicago, Utah, Texas, Pennsylvania, Illinois and Alabama. For each speaker, this symposium was a chance not just to refine presentation skills (a difficult opportunity to come by during a global pandemic), but also a chance to identify potential collaborators.

“Research is not supposed to be siloed in one laboratory,” Epps said. “Not if we want broad solutions to important problems.”

Among these presenters was Victoria Muir, a doctoral candidate at the University of Pennsylvania and a self-described proud Blue Hen whose undergraduate experience as a chemical engineering major at UD “propelled me into future success,” she said. Currently, she works on strategies for repairing damaged spinal discs or damaged cartilage in the joints using microgels made of hyaluronic acid, a molecule naturally occurring throughout the body.

“When we were applying to present at this symposium, one of the questions we were asked to discuss was how our individual background, coming from underrepresented groups, really influences how we think about the sciences,” Muir said. “I know a lot of the applicants, including myself, talked about coming from a low-income household and how those perspectives encourage us to think about creating medical treatments or scientific advancements at low cost, so they can be more widely accessible.”

Justin Bobo, a doctoral candidate at Carnegie Mellon University, is using biological soft materials, such as human collagen, to engineer simulated human tissues in a lab setting. Typically, in a pre-clinical phase, promising therapeutics for things like traumatic brain injury and other conditions are tested on rats. Bobo’s hope is that his simulated tissues will provide an ethical and efficient alternative (or complement) to animals — one that leads to a greater success rate in clinical trials.

“One of the aspects of the COVID-19 pandemic has been an uptick in virtual conferences such as this one, which provide an opportunity to connect with other researchers not just from my own institution, but across the U.S.,” Bobo said. “Networking is incredibly important.”

Building this sense of community across the soft matter field was among the goals of the event, because “the more community you build, the more you create an environment where people feel they can share ideas,” said Kim Bothi, executive director of the MRSEC at UD. “It means we can work together to evolve and innovate in research, while celebrating and normalizing diversity.”

At the end of the symposium, breakout sessions allowed student attendees to connect with presenters and learn more about soft matter-focused careers in either academia or industry. Alice Amitrano, an undergraduate student from Italy studying chemical engineering at UD, said the symposium solidified her decision to attend graduate school next year. It also left her feeling empowered.

“It is great to see so many people from different areas coming together,” she said. “Every country has a different approach to STEM education that influences how scientists approach research problems, so cultural perspective is important. Also, it was great to see so many women presenting. In my major, when doing small group work, I’m often the only woman. And I’m hoping events like this encourage more of us. We have to show the men how good we are.”

If the faculty at UD have anything to do with it, there will be plenty more opportunities in the near future.

“These types of activities cannot be one-offs,” Epps said. “We are already planning the next one.”

Soft Matter for All and MRSECs

The National Science Foundation’s Materials Research Science and Engineering Center (MRSEC) program provides sustained support of interdisciplinary materials research and education of the highest quality while addressing fundamental problems in science and engineering. Each MRSEC addresses research of a scope and complexity requiring the scale, synergy and multidisciplinarity provided by a campus-based research center. The University of Delaware’s Center for Hybrid, Active, and Responsive Materials is one such program (NSF DMR-2011824). The Princeton Center for Complex Materials is also an NSF-supported MRSEC (NSF DMR-2011750). The Soft Matter for All workshop was supported by both MRSECs and Princeton University provided additional support.

| Photo illustration by Joy Smoker | Photos by iStock and courtesy of Sachiko Datta, Stanford University and Webb Chappell Photography |