Pair of Penn profs earn NSF CAREER awards

It’s only February, but two Penn professors are already having a career year.

Zahra Fakhraai, an assistant professor in the Department of Chemistry in the School of Arts & Sciences, and Ladislav Kavan, an assistant professor in the Department of Computer and Information Science in the School of Engineering and Applied Science, have received Faculty Early Career Development (CAREER) awards from the National Science Foundation (NSF). The CAREER awards are among the NSF’s most prestigious honors, and are granted to junior investigators to support research that will serve as a foundation for their body of work. Each award comes with approximately $500,000 in funding over a five-year period.

Both researchers work in fields studying ways to gain a finer understanding and control over shape. In Fakhraai’s case, the shapes in question have to do with the random packing of atoms on a material’s surface; for Kavan, the shapes exist within three-dimensional computer simulations.  

Fakhraai’s research is based in the fact that certain materials begin to behave differently when on the molecular or atomic scale. A plastic water bottle, for example, feels solid when touched, but behaves more like a viscous liquid when zoomed in to the top one or two nanometers of its surface.

“It turns out that this is a property for a lot of different materials, but it’s not really understood where this property comes from,” Fakhraai says. “By coming up with a theory for its origins, we can design those nanomaterials to last longer or work better.”     

To test how this phenomenon impacts the overall properties of these materials, Fakhraai and her colleagues use nanoparticles as probes, watching how far the nanoparticles sink into a surface and how surrounding molecules are drawn to the probe to form a meniscus.

Fakhraai’s CAREER award will support research with probes with different geometries, such as rods and cones, to gain a more detailed mathematical understanding of these phenomena.

Kavan’s research deals with geometry that is closer to the everyday experience—the many interconnected shapes and structures of the human body—but in a way that is even more abstract. He is developing ways to more efficiently model how those shapes move and change in a simulated environment.

The entertainment world, through computer animation, special effects, and video games, has produced increasingly lifelike simulations, but the most realistic ones remain too slow, costly and computationally intensive for applications that require real-time interaction. Doctors would benefit greatly from practicing on computer models, but to be truly useful, such simulations would have to accurately render the feel of a scalpel on multiple layers of tissue, each with its own physical properties.

“Computer graphics in a blockbuster movie can make characters that look awesome, but under the surface, there’s nothing there,” Kavan says. “Likewise, in a video game, we don’t really care if a character’s hand goes through its body. If you’re simulating a surgery, however, those kinds of limitations aren’t acceptable. We’re levering the technology in those movies and video games to do something new.”

Kavan’s future work will entail developing an alternative approach to rendering these shapes, based on studying their underlying geometry. By focusing on certain geometric properties of shape deformation, such as maintaining smoothness and preventing a virtual object from intersecting with itself, more detailed, realistic, and responsive simulations could be achieved without the need for supercomputer-level processors.

Zahra Fakhraai