04-25-2017 | John Cumings: Thermal Transport and Dissipation Studies of Carbon Nanotubes

 Topic: Thermal Transport and Dissipation Studies of Carbon Nanotubes

Speaker: Professor John Cumings, Department of Materials Science and Engineering, University of Maryland

Date: Tuesday, April 25, 2017

Time: 10:00am – 11:00am

Location: NASA/LaRC, Bldg. 1293A, Room 222

Host: Cheol Park (cheol.park-1@nasa.gov) 48360

Abstract: Carbon nanotubes are emerging as a possible new candidate material for thermal management applications, owing to their high reported intrinsic thermal conductivity, when measured as individual nanostructures.  However, studies on bulk samples of nanotubes, solutions, and composites all show relatively low thermal

conductivity.  This is believed to be due to high interfacial thermal resistance.  I will present novel studies, in situ during transmission electron microscopy, that allow thermal properties of individual nanotubes to be interrogated.  These studies show high interfacial thermal resistance, but also a surprising ability for nanotubes to transfer heat to a substrate when carrying a DC electrical current. This will be explained in terms of a new physical phenomenon–a new mechanism of heating–that we have called remote Joule heating, and I will make connections with theories predicting the effect.  I will discuss implications for thermal transport of boron nitride nanotubes and possible areas for future work.

Bio: John Cumings received his BS in 1997 from Boston University and his PhD in 2002 from UC Berkeley.  After holding a postdoctoral research position at Stanford University, he joined the faculty of the Department Materials Science and Engineering at the University of Maryland in 2005, and was promoted to Associate Professor in 2012. Cumings has received several awards for his work, including an IBM graduate research fellowship, an NSF CAREER award, and the A. James Clark School of Engineering’s Junior Faculty Outstanding Research Award.  His research is in the area of nanomaterials and in situ transmission electron microscopy, and he has published more than 60 research articles on the topic.