Breakthrough: Thubber may help in creating soft, stretchable machines and electronics

In a breakthrough, scientists have created a novel rubber material which has high thermal conductivity and elasticity. The material nicknamed ‘thubber’ may be helpful in developing soft and stretchable machines and electronics.

‘Thubber’ is an electrically insulating composite. It exhibits a unique combination of metal-like thermal conductivity, elasticity similar to soft, biological tissue. It can remarkably stretch more than six times its initial length.

“Our combination of high thermal conductivity and elasticity is especially critical for rapid heat dissipation in applications such as wearable computing and soft robotics, which require mechanical compliance and stretchable functionality,” said Carmel Majidi, an associate professor at Carnegie Mellon University in the US.

The applications of ‘thubber’ could be in industries like athletic wear and sports medicine such as lighted clothing for runners and heated garments for injury therapy. They can also extend to advanced manufacturing, energy, and transportation, researchers said.

“Until now, high power devices have had to be affixed to rigid, inflexible mounts that were the only technology able to dissipate heat efficiently,” said Jonathan Malen, an associate professor at Carnegie Mellon University.

“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,” said Malen.

Thubber’s key ingredient is a suspension of non-toxic, liquid metal microdroplets. The liquid state lets the metal to deform with the surrounding rubber at room temperature. The droplets create elongated pathways efficient for heat travel when the rubber is pre-stretched.

The material is also electrically insulating despite the amount of metal. An LED light was mounted onto a strip of the material in order to create a safety lamp worn around a jogger’s leg.

The “thubber” dissipated the heat from the LED, which would have otherwise burned the jogger. The researchers also created a soft robotic fish that swims with a “thubber” tail, without using conventional motors or gears.

The findings were published in the journal Proceedings of the National Academy of Sciences.