Move Over Flubber, Here Comes ‘Thubber’
Representing a breakthrough in creating soft, stretchable machines and electronics, a thermally conductive rubber material has been developed by Carmel Majidi and Jonathan Malen of Carnegie Mellon University.
The findings were published in Proceedings of the National Academy of Sciences.
The new material, nicknamed ‘thubber,’ is an electrically insulating composite that exhibits an unprecedented combination of metal-like thermal conductivity and elasticity similar to soft, biological tissue that can stretch over six times its initial length.
Majidi, an associate professor of mechanical engineering, said: “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.”
Applications could extend to industries like athletic wear and sports medicine – think of lighted clothing for runners and heated garments for injury therapy. Advanced manufacturing, energy, and transportation are other areas where stretchable electronic material could have an impact.
“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 Malen, an associate professor of mechanical engineering. “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.”
The key ingredient in ‘thubber’ is a suspension of non-toxic, liquid metal microdroplets. The liquid state allows the metal to deform with the surrounding rubber at room temperature.
When the rubber is pre-stretched, the droplets form elongated pathways that are efficient for heat travel. Despite the amount of metal, the material is also electrically insulating.
To demonstrate these findings, the team mounted an LED light onto a strip of the material 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.
Majidi said: “As the field of flexible electronics grows, there will be a greater need for materials like ours. We can also see it used for artificial muscles that power bio-inspired robots.”
More information: EurekAlert!
