Q&A: Dr. Yanfei Xu, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA

Plastics are excellent thermal insulators — a quality that can be an advantage in some applications. But this property is less desirable in products such as plastic casings for laptops and mobile phones, which can overheat. Dr. Xu is a member of a team that has developed a new polymer that works as a heat conductor. The polymer, which is lightweight and flexible, can conduct ten times as much heat as most commercial polymers.