Sandra M. Troian
Professor of Applied Physics, Aeronautics, and Mechanical Engineering

B.A., Harvard University, 1980; M.S., Cornell University, 1984; Ph.D., Cornell University, 1987

1200 East California Boulevard
Pasadena, CA 91125
MC 128-95

(626) 395-3362
(626) 395-6106 (fax)

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Research

The Troian group investigates micro- and nanoscale transport phenomena in liquid films and interfaces as occur in many biological, physical and materials-based flows. The flow of mass, momentum and energy in ultra small structures which manifest large surface to volume ratios is highly responsive to interfacial stresses. Such stresses can be generated internally or externally through gradients in electrostatic, thermal, pressure (acoustic) or concentration fields. Nearby solid boundaries can also be modified to influence flow behavior by using modern lithographic techniques to design substrates with surface energy gradients, complex topologies, and variable adhesion or friction reduction. By tuning normal and tangential stresses at fluid/fluid and fluid/solid interfaces, it is possible to control the flow and response of small liquid-like elements in space and time. Currently, the group is focusing on shape changes, flow instabilities and phase transitions triggered by inhomogeneous force fields. To probe these phenomena at several lengthscales, we use a combination of experiment, first principles modeling, and molecular level or hydrodynamic simulations.

Current research projects include:

• Biological flows triggered by Marangoni and capillary forces
• Interfacial instabilities driven by non-normal disturbances
• Characterization of dynamic friction and slip at liquid/solid interfaces
• Microfluidics with electrowetting, dielectrophoresis or thermocapillary forces
• Confinement effects, layering transitions and instabilities in nanofilms
• Evanescent wave based sensors for micro/optofluidic devices
• Transport of lipids in nanotubes, vesicles and membranes
• Dynamics of free surface films on topologically modified sustrates
• Pattern replication by thermolithography in nanoscale polymer films

Selected Publications

Please click here for an up to date list of publications.