Kathleen J. Stebe, a professor of chemical engineering at Johns Hopkins University, uses surfactants to control the stress response of liquid-vapor interfaces. Surfactants are molecules that absorb on fluid interfaces and change the surface tension. The coupling between interfacial physico-chemistry and mechanics is complex. Surfactants can make a fluid interface tangentially immobile or restore interface mobility. They can oppose thermocapillary motion or create conditions that favor it. The mechanisms for these varied responses have been established using experimentation, numerics, and theory.
As a Radcliffe fellow, in collaboration with researchers at Harvard University, Stebe will exploit surfactants in emerging technologies ranging from assembly of nanoparticles to microfluidics. These systems are characterized by small lengthscales, and their dynamics are dominated by their bounding surfaces.
Stebe earned her PhD in chemical engineering from the Levich Institute at the City University of New York, then held a postdoctoral position at Université de Technologie de Compiègne supported by a Bourse Chateaubriand. She was awarded the Frenkiel Award from the American Physical Society-Division of Fluid Dynamics in recognition of her research. In 1991, she joined the faculty at Johns Hopkins, where her research program has been supported with grants from the National Science Foundation, NASA, private foundations, and industry. She holds joint appointments in biomedical engineering, materials science and engineering, and mechanical engineering.