Researchers at North Carolina State University have created an elastic, self-healing wire that can reconnect at the molecular level after being severed.
Photo of self-healing, liquid-metal wire.
The wire displays the ability to reconnect where cut in both the liquid-metal core as well as within the polymer sheath.
“Because we’re using liquid metal, these wires have excellent conductive properties,” says Dr. Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper on the work. “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.”
How they did it
The group created tiny tunnels, referred to as “microfluidic tunnels”, in a self-healing polymer using solid wire. They then filled each channel with a liquid-metal alloy of indium and gallium to create a liquid-metal wire in a stretchable polymer sheath.
Now, when this wire is severed, the liquid metal oxidizes to create, more or less, a “skin” that prevents the rest of it from leaking out the sheath. When both severed pieces are put back together, the liquid metal reconnects and the sheath re-forms its liquid metal bonds, with a complete self-healing time period of just 10 minutes.
“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 says.
Specifically, the technique can be used when creating complex, three-dimensional structures: a sheath can be cut into various sections to meet the needs of the structure, and then reconnected at various angles, whereupon the channels will align back together.
The video below shows the process in action:
Research Paper
Dickey’s team put together a paper on the project entitled “Self-Healing Stretchable Wires for Reconfigurable Circuit Wiring and 3D Microfluidics”. It was published online in Advanced Materials and is available for download (purchase required). ■
Story via: ncsu.edu
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