Self healing, stretchable wires created using liquid metal

Researchers from North Carolina State University have developed elastic, self healing wires in which both the liquid metal core and the polymer sheath reconnect at the molecular level after being severed.

"Because we're using liquid metal, these wires have excellent conductive properties," said Dr Michael Dickey, an assistant professor of chemical and biomolecular engineering. "And because the wires are also elastic and self healing, they have a lot of potential for use in technologies that could be exposed to high stress environments." The researchers started out by creating tiny tunnels, called microfluidic channels, in a commercially available self healing polymer using solid wire. By filling those channels with a liquid metal alloy of indium and gallium, they were able to create a liquid metal wire in an elastic sheath. Because the wire is liquid, it can be stretched along with the polymer sheath. When the wires are sliced or severed, the liquid metal oxidises – forming a skin that prevents it from leaking out of its sheath. When the severed edges of the wire are placed back together, the liquid metal reconnects and the sheath re-forms its molecular bonds. "We're also excited about this work because it allows us to create more complex circuits and rewire existing circuits using nothing more than a pair of scissors by cutting and reconfiguring the wires so that they connect in different ways," Dickey concluded.