Polymers are usually the go-to material for thermal insulation. Think of a silicone oven mitt, 

or a Styrofoam coffee cup, both manufactured from polymer materials that are excellent at 

trapping heat.

Now MIT engineers have flipped the picture of the standard polymer insulator, by fabricati

ng thin polymer films that conduct heat—an ability normally associated with metals. In 

experiments, they found the films, which are thinner than plastic wrap, conduct heat better 

than many metals, including steel and ceramic.

The  team's  results,  published  in the  journal  Nature  Communications,  may  spur  the 

development of polymer insulators as lightweight, flexible, and corrosion-resistant alternativ

es  to  traditional  metal  heat  conductors, for applications  ranging  from  heat  dissipating 

materials  in  laptops  and  cellphones,  to  cooling  elements  in  cars  and refrigerators.

"We think this result is a step to stimulate the field," says Gang Chen, the Carl Richard 

Soderberg Professor of Power Engineering at MIT, and a senior co-author on the paper. "Our 

bigger vision is, these properties of polymers can create new applications and perhaps new 

industries, and may replace metals as heat exchangers."

Chen's co-authors include lead author Yanfei Xu, along with Daniel Kraemer, Bai Song, Jia

wei Zhou, James Loomis, Jianjian Wang, Migda Li, Hadi Ghasemi, Xiaopeng Huang, and 

Xiaobo Li from MIT, and Zhang Jiang of Argonne National Laboratory.