Although we may hear a lot about the promise of flexible electronics, there's at least one challenge that still has to be overcome – heat dissipation. After all, what good is a stretchable smartphone, for instance, if its processor gets so hot that it won't work? It was with such scenarios in mind that scientists at Carnegie Mellon University created a highly thermally-conductive rubber, known as "thubber."

Designed by a team led by associate professors Carmel Majidi and Jonathan Malen, thubber consists of a soft elastomer with non-toxic, liquid metal microdroplets suspended within it. When pre-stretched at room temperature – up to six times its initial length – those droplets form into elongated pathways that heat can easily travel through.

This means that heat could be efficiently transferred away from electronic components embedded within the thubber. At the same time, though, the material is electrically insulating.

To demonstrate the potential of the technology, the scientists mounted an LED safety light on a thubber leg strap, of the sort that might be worn by a jogger. The material safely dissipated the heat created by the light, which ordinarily would have burnt the wearer.

"Until now, high-power devices have had to be affixed to rigid, inflexible mounts that were the only technology able to dissipate heat efficiently," says Malen. "Now, we can create stretchable mounts for LED lights or computer processors that enable high performance without overheating in applications that demand flexibility, such as light-up fabrics and iPads that fold into your wallet."

Other possible applications for the technology include heated garments for injury therapy, or even artificial muscles in soft-bodied robots.

A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences.

Source: Carnegie Mellon University