Wire can heal itself after being cut

Researchers at North Carolina State University say they've used liquid metal to create stretchable wires that are self-healing if they are cut. A stretchable polymer surrounds a conductive core of liquid metal -- an alloy of indium and gallium -- in the elastic wires, and both the liquid-metal core and the polymer sheath can reconnect at the molecular level after being severed, the researchers said. "Because we're using liquid metal, these wires have excellent conductive properties," chemical and biomolecular engineering Professor Michael Dickey said. "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." When the wires are sliced or severed, the liquid metal oxidizes, 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, the researchers said. "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 said.