At the heart of the Kourkoutis lab’s research are very large electron microscopes designed to look at very small structures, down to the atomic scale. With these powerful tools, Lena F. Kourkoutis, Applied and Engineering Physics, works across disciplines, bridging the gap between physical and life sciences. The structures she examines range from battery materials to biological systems.
After focusing on the physics of solid materials during her PhD at Cornell, Kourkoutis set out to learn how to image structures inside biological objects using a technique from biology—cryogenic electron microscopy (cryo-EM). Cryo-EM is a method typically used for viewing biological specimens in their natural state, like, for example, imaging a protein inside a cell. Kourkoutis spent her postdoctoral year learning from experts at the Max Planck Institute of Biochemistry in Germany and returned to bring cryo-EM to Cornell.
Under the Scope: Superconductors, Proteins, and Battery Elements
Kourkoutis is now working with colleagues who are interested in biological questions and is also applying cryo-electron microscopy to answer questions in basic physics, materials science, and device physics.
“This is a very powerful technique because we can look at structures that are difficult to image with other tools, and we can understand processes, on a very local scale, that are difficult to study otherwise,” she says.
One system she and her lab are exploring is the interface between liquids and solids—of electrolytes and electrodes—in rechargeable batteries. Once the researchers gain access to these internal interfaces, they will be able to use cryo-EM to capture the initial stages of battery degradation. The goal is to understand the structure and chemistry of the degradation process, and from there, to work with fellow scientists to design more durable and efficient batteries.
Cryo-EM will also be useful in answering fundamental physics questions about materials that perform differently at low temperatures as compared to higher temperatures. Specifically, Kourkoutis is interested in using the technique to examine superconductors, which have no electrical resistance below a critical temperature. Electron microscopists have so far examined these materials at room temperature. The cryo-electron microscope, however, could provide real-world insights by studying the superconductors in their cooled, effective state.
Kourkoutis and her lab are in the process of ensuring that the cryo-EM instruments and techniques work well under various circumstances. To do this, Kourkoutis has embarked on several collaborations. She works with Cornell colleagues including Lois Pollack, Applied Physics and Engineering, and Julius Lucks, Chemical and Biomolecular Engineering, who are interested in the structure of proteins and how they form. She has also worked with her sister, Sylvia Fitting (University of North Carolina at Chapel Hill), who is a neurobiologist interested in how the HIV Tat protein affects cell structure and function.
Kourkoutis selects a cell and with cryo-EM examines it at high resolution in an immobilized, natural state. “Right now we are collaborating with a number of colleagues in order to demonstrate the technique's capabilities,” says Kourkoutis. Eventually, Kourkoutis plans to start her own biology-related projects.
A First, All New Electron Microscope at Cornell
The future of electron microscopy at Cornell is especially promising. With a $2.7 million grant from the National Science Foundation, Kourkoutis is leading a team of researchers in developing a new type of electron microscope—the first of its kind—that will incorporate both the cryogenic techniques of the biology world and the resolution-enhancing tools from the materials science world.
It is especially important for research in the field of renewable energy, as well as in medicine—for studying for example breast cancer tumors and calcified aortic valves.
“Biologists have figured out how to do cryogenic electron microscopy, and materials scientists and physicists have figured out how to get to the atomic scale. We are trying to combine the capabilities of both in order to open up new possibilities,” Kourkoutis explains.
This new microscope, a cryogenic aberration-corrected scanning transmission electron microscope (cryo-STEM), will make it possible to study processes at solid-liquid interfaces with previously unfeasible spatial resolution. Researchers will also be able to examine various non-biological materials that involve soft-hard interfaces. It is especially important for research in the fields of renewable energies, as well as in medicine, for studying, for example, breast cancer tumors and calcified aortic valves.
Overall, the cryo-STEM, which is expected to be completed in 2017, is a boon to Kourkoutis’ lab and the wider research communities’ work. Its applications are broad and incredibly powerful, and it is very much fueled by questions across multiple disciplines.
“I think many of us get excited by all kinds of questions, whether it’s in physics or in biology,” says Kourkoutis. “With our new microscope we will be able to answer a broad range of questions that come up in these fields.”
Kourkoutis adds that the acceptance and encouragement she has received from Cornell has been particularly special. As a researcher who wants to do interdisciplinary work, Kourkoutis says that she has experienced tremendous support. “Cornell gives you so many opportunities to collaborate with people in different fields,” she says. “As a person who wants to start out in a new field, there are few barriers.”