Abstract: Functional polymers and advanced manufacturing can address urgent needs in energy, environment and healthcare. I will present our research on molecular engineered polymers with desired thermal and electronic properties, and provide fundamental insight into how structure controls these properties. I will also discuss how the science and engineering of these materials are transformed by advanced manufacturing. 1) Traditional polymers are both electrically and thermally insulating. The discovery and development of electrically conductive polymers has led to innovative electronic applications. Analogously, the development of thermally conductive polymers would open up a diverse array of thermal applications ranging from electronics cooling, biomedical sensors to energy storage and conversion. I will summarize our recent work on understanding and manipulating thermal transport in polymers. First, stretched polyethylene films transfer heat four times faster than stainless steel. Second, we have designed and developed amorphous polymers with a 10-fold increase in thermal conductivity by chemical vapor deposition technique. 2) Supercapacitors have seen increasing attention in applications of powering miniaturized electronic devices. But it remains challenging to manufacture thin-film supercapacitors with high energy density, because the necessary components scale poorly and are ill-suited for in-plane geometries. Starting with the fundamental theory of the physical and chemical processes that occur in charge storage capacitors, I will discuss advanced nanocomposites for ink formulations, and a printed thin-film supercapacitor with improved energy density. I will conclude with a brief discussion of future research that will further develop functional polymers and integrated systems by advanced manufacturing.
Biography: Dr. Yanfei Xu is an assistant professor in the Mechanical and Industrial Engineering Department at University of Massachusetts Amherst. She has worked on polymers for thermal management applications at Massachusetts Institute of Technology. Prior to joining MIT, she worked on printable organic electronics, and secured Marie-Curie fellowships with major European institutions and companies, including the Max Planck Institute for Polymer Research, Humboldt University, University of Cambridge, Italian National Research Council, Université de Strasbourg, and the headquarters of BASF SE. For her work on printable energy storage devices, she was awarded “Featured Speaker on Accelerating the Commercialization of Global Innovation, Techconnect World Innovation 2015”. She was also awarded “Top 10 Reviewers for The Royal Society of Chemistry, JMCC 2016” and “Top 100 Most Influential Scientific Researchers, P. R. China, 2009.”