Multiscale Simulations and Ultrafast Characterization for Nanoscale Heat Conduction

Ronggui Yang, S.P. Chip and Lori Johnson Faculty Fellow,Associate Professor

Department of Mechanical Engineering, Faculty Fellow, Materials Sciences and Engineering Program

Interfacial thermal transport plays an important role in the reliability and efficiency of both electronic and energy conversion systems. Significant progress has been made over the past two decades on understanding nanoscale thermal transport, developing modeling and characterization tools, and applying some of the findings for technical innovations. Using thermoelectric energy conversion as an example, we will show in this talk that a deep understanding in nanoscale thermal transport can lead to the discovery of nanostructured materials that merits high thermoelectric efficiency yet scalably manufacturable. We will then talk in detail our recent efforts an progresses in building multiscale-multiphysics simulation and ultrafast laser-based experimental platforms for the study of phonon transport in nanostructured materials, including the very first experimental demonstration of quasi-ballistic phonon transport using soft X-ray pump-and-probe measurement, which leads to many ongoing development of phonon mean free path spectroscopy worldwide. This talk will also highlight some of our recent understanding on thermal transport of polymers at interface.

Dr. Ronggui Yang is the S.P. Chip and Lori Johnson Faculty Fellow in Engineering, an Associate Professor of Mechanical Engineering, and a Faculty Fellow in Materials Science and Engineering program at the University of Colorado at Boulder. Dr. Yang received his Ph.D with Prof. Gang Chen in Mechanical Engineering from MIT in February 2006. Since January 2006, he started his faculty career as an assistant professor at CU-Boulder and has been promoted to associate professor with early tenure in summer 2011 (two-year ahead of the normal clock at CU-Boulder). Prior to MIT, he had a master’s degree in MEMS from UCLA in 2001, a master’s degree in Engineering Thermophysics from Tsinghua University in Beijing in 1999, and a Bachelor’s degree in Thermal Engineering from Xi’an Jiaotong University in 1996. His research interests are on the fundamentals of nanoscale transport phenomena and the applications of micro/nanotechnologies for energy conversion, storage and thermal management. Dr. Ronggui Yang has published more than 80 journal papers, delivered ~60 invited seminars and is associated with >130 invited and contributed conference talks and posters that garnered numerous best paper/presentation/poster awards. His journal papers are highly cited with an annual citation > 500 times in 2012 according to ISI Web of Science (~700 annual citation in 2012 according to Google Scholar). His innovative research has won him numerous awards including 2010 ASME Bergles-Rohsenow Young Investigator Award in Heat Transfer, an NSF CAREER Award in 2009, the MIT Technology Review’s TR35 Award and the DARPA Young Faculty Award in 2008, the Goldsmid Award for Research Excellence in Thermoelectrics in 2005, and a NASA Tech Brief Award for a Technical Innovation in 2004. He has also won the Provost’s Achievement Award (2012), the Dean’s Performance Award (2010), the Woodward Outstanding Faculty of Mechanical Engineering (2011) and the Outstanding Research Award in Mechanical Engineering (2008 & 2013) from the University of Colorado at Boulder. He has been endowed with the S.P. Chip and Lori Johnson Faculty Fellow for 2013-2017 and the Sanders Faculty Fellow for 2008-2012. Dr. Yang regularly serves as a reviewer for about 50 prestigious academic journals including Science, Nature, Physical Review Letters, Nano Letters, ACS Nano, Physical Review B, ASME transactions and IEEE Transactions. He is a proposal reviewer for for federal/non-profit funding agencies of US and ten other countries including China and European Research Council. Dr. Yang is an active member of ASME and has distinguishable services to ASME being a track/topic/symposium organizer or a session chair for hundreds of technical sessions for ASME conferences. Dr. Yang is currently the Vice Chair of the Nanoengineering for Energy and Sustainability Steering Committee of ASME Nanoengneering Council and the founding Vice Chair of the K-9 Technical Committee on Nanoscale Thermal Transport of ASME Heat Transfer Division.

Time:December 23, 2013 2:00-3:30 PM

Location:Room 412,School of Aerospace, Tsinghua University