Sandra M. Troian
Professor of Applied Physics, Aeronautics, and Mechanical Engineering
Research interests: Dynamics and stability of small scale, free surface and confined flows including nonlinear dynamics, self-similarity, pattern formation, non-normality and transient growth, blowup behavior and cuspidal formation; Thermal phenomena at liquid/solid interfaces, Kapitza effect, thermal rectification; Open architecture microfluidics based on thermocapillary modulation; Microscale lithographic methods based on patterned electric and thermal fields; Marangoni driven phenomena in biophysical systems; Slip behavior at liquid/solid interfaces; Space micropropulsion phenomena based on free surface flows.
Overview
The Laboratory of Interfacial and Small Scale Transport {LIS2T} in the Department of Applied Physics and Materials Science at the California Institute of Technology specializes in both fundamental analysis and engineering design of micro/nanoscale fluidic systems. Of particular interest are small scale systems dominated by large surface forces due to patterned capillary, van der Waals, Maxwell, thermocapillary and Marangoni fields. Theoretical analysis, numerical simulations (both continuum and molecular scale) and experimentation are all used to develop fundamental physical insight as well as robust design principles for application driven projects. Group focus is on formation, propagation, stability, coupling and control of nonlinear wave phenomena at the micro/nanoscale which induces rapid transport of mass, momentum and heat at moving interfaces. Systems of current theoretical interest include cusp formation in thermally and electrically driven thin films for super anti-reflecting coatings and space micropropulsion devices; nanofluidic phenomena involving Kapitza thermal jumps, layering transitions and thermal rectification in nanoscale devices; spatio-temporal parametric resonance and array formations in thin polymeric films exposed to large thermocapillary and Maxwell patterned fields; Lyapunov, modal and transient growth stability analyses of non-normal systems at zero Reynolds number; capillary and field enhanced propellant management systems for space micropropulsion applications; and solution of inverse problems for 3D lithographic patterning of nanofilms. Systems of current experimental interest include non-contact lithography of 3D micro-optical structures by patterned external fields; Marangoni wave phenomena and fractal wavefronts in biophysical systems; influence of layering transitions on slip behavior in nanoscale films; and optical wave propagation in structured polymeric waveguides.