New conductive wire stretches 8 times original length

Researchers at North Carolina State University have created wire that retains its conductivity even when stretched as much as eight times its length. The wires are composed of a thin tube of elastic polymer filled with a liquid metal alloy of gallium and indium.

“Previous efforts to create stretchable wires focus on embedding metals or other electrical conductors in elastic polymers, but that creates a trade-off,” says Dr. Michael Dickey, an assistant professor of chemical and bio-molecular engineering at NC State and co-author of a paper on the research. “Our approach keeps the materials separate, so you have maximum conductivity without impairing elasticity.”

While making the stretchy wires is relatively easy, Dickey says solving the problem of the liquid metal leaking out of the polymer if the wires are damaged will have to be address before they find their way into popular electronics like headphones or phone chargers or used to make electronic textiles.

The paper, “Ultrastretchable Fibers with Metallic Conductivity Using a Liquid Metal Alloy Core,” is published online in Advanced Functional Materials. The research was funded by a National Science Foundation (NSF) CAREER award and the NSF’s Research Triangle Materials Research Science & Engineering Center.
www.ncsu.edu