Abstract:
Understanding and manipulating heat transfer in various materials are essential to intentionally design energy-efficient devices and systems and limit deleterious effects of high or low temperatures on system performance. Nano-engineering offers unique opportunities to obtain previously unachievable properties for diverse applications, ranging from thermoelectric energy conversion and thermal insulation that demands ultra-low thermal conductivity to micro-electronics cooling that, in contrast, desires ultra-high thermal conductivity. Meanwhile, nano-engineering also imposes challenges in the scientific understanding because continuum theories break down at such small length scales. There are also substantial difference between the transport processes in hard and soft materials. Despite significant effort, in-depth understanding of basic thermal transport processes at the nanoscale is limited, impeding the development of novel thermal applications. In this talk, I will present our computational and experimental efforts to deepen our fundamental understanding of nanoscale thermal transport processes in both hard and soft materials and unveil their direct impacts on macroscopic thermal conductivity. I will show examples where we push the lower and higher boundaries of thermal conductivity as well as achieve switchable thermal conductivity and thermal rectification in single materials.

Bio:
Dr. Zhiting Tian is an Assistant Professor of Mechanical Engineering at Virginia Tech since 2014. She received her Ph.D. in Mechanical Engineering under the supervision of Prof. Gang Chen at MIT in 2014. She received her M.S. in Mechanical Engineering from Binghamton University in 2009 and her B.S. in Engineering Physics from Tsinghua University in 2007. Her group seeks fundamental understanding of nanoscale thermal transport processes in various materials using both simulations (ab initio and classical calculations) and experiments (ultrafast laser and x-ray techniques). Her most recent awards include 2017 Dean’s Award for Outstanding New Assistant Professor, 2017 3M Non-Tenured Faculty Award, 2016 Virginia Tech Scholar of the Week, and 2016 Virginia Tech Undergraduate Research Advisor Award.