Thermal Transport Phenomena in Engineering and Biomedical Microdevices

Temperature and heat flow play a key role in the performance of several microdevices of engineering and biomedical interest. In some cases, for example in semiconductor microprocessors, heat generation is an undesirable effect that must be carefully mitigated to ensure safety and reliability. In other cases, for example in micro-PCR (Polymerase Chain Reaction) devices for DNA amplification, temperature is the driving enabler of the device functionality. It is critical to understand thermal transport at the microscale to maximize the performance and reliability of such microdevices.

This seminar will summarize recent research results based on a number of experiments that investigate thermal phenomena in microsystems. Microheater structures have been microfabricated and thermally characterized. These devices enable precise control of microscale temperature distribution on a variety of substrates. Very high spatial and temporal temperature gradients have been obtained for microheater devices. These capabilities have been used for measurement of thermophysical properties of materials of interest for electrochemical energy conversion. Since thermal properties typically exhibit size-dependence at small scales, and are also often anisotropic, these measurements help understand the fundamentals of thermal transport in these devices. Further, thermally-driven interactions of DNA and proteins with inorganic surfaces have been studied. Response of a growing neuronal axon to an imposed temperature gradient in its microenvironment has been measured, indicating the possibility of thermally-driven control of axonal growth direction.

Ankur Jain is an Assistant Professor in the Mechanical and Aerospace Engineering Department at the University of Texas, Arlington where he directs the Microscale Thermophysics Laboratory. His research interests include microscale thermal transport, bioheat transfer, electrochemical energy devices, semiconductor thermal management, etc. He previously held research and development positions in leading semiconductor companies including AMD and Freescale Semiconductor, and at Molecular Imprints, a nanomanufacturing startup company. He received his Ph.D. (2007) and M.S. (2003) in Mechanical Engineering from Stanford University, and his B.Tech. (2001) in Mechanical Engineering from the Indian Institute of Technology (IIT), Delhi with highest honors. His laboratory has received funding support from National Science Foundation (NSF), Office of Naval Research (ONR), Department of Energy (DoE) and Indo-US Science & Technology Forum (IUSSTF).