Faculty and Staff

• Alphabetical List
• Emeritus Faculty
• Affiliated Faculty
• Staff Directory
• Summary of Research

• Search MatSE   Go Domains Sitesearch
  

• Profile
• Research
• Publications
• Awards

Thermal management is a critical issue in a wide variety of applications of thin films materials from state-of-the-art microprocessors to turbine engines. In non-metals, heat is carried by thermally excited vibrations of the lattice. The lifetime or coherence of these lattice vibrations have a complex dependence the microstructure of materials; at nanometer length scales, the transfer of heat at interfaces becomes the controlling factor. Our group studies the basic science of thermal transport in materials with a particular emphasis on the thermal conductance of solid-solid and solid-liquid interfaces. We have recently developed new and powerful methods of characterizing nanoscale thermal transport using ultrafast laser metrology of precisely controlled thin film multilayers and suspensions of metallic nanoparticles.

We are developing and applying novel methods for probing the thermodynamics of material interfaces with water. The bending of microfabricated cantilevers gives a quantitative measurement of the aqueous interface stress; i.e., the derivative of the free energy with respect to elastic deformation. A highly sensitive optical probe of surface curvature is providing data on the changes in polymer thin film stress produced by changes in the composition of aqueous suspensions. Thermodiffusion, the transport of mass in a temperature gradient, is being applied to polymer-nanoparticle suspensions. The Soret coefficient gives a measure of the local change in water enthalpy that is produced by the proximity of a solid surface. Rutherford backscattering spectroscopy is used to measure the partitioning of ions and heavy metal contaminants in commercial RO and nanofiltration membranes.

Applications of lasers with pulse durations of less than 1 picosecond are becoming common in a wide variety of science and engineering disciplines. We are using ultrafast lasers to develop new methods for probing the thermophysical properties of materials, to determine the rate at which energy is exchanged between various elementary excitations in a solid, and to study the limits for the rates of melting and crystallization.