Dan Kohn's Blog

Electronic Products
by Jeffery Bausch

Have you ever gone to plug something in but found yourself an inch or two short of the outlet? This may soon be an inconvenience of the past thanks to some outside-the-wire thinking by researchers at North Carolina State University. They’ve developed wires that can be stretched up to eight times their original length and still function just as effectively.

What’s more, beyond connecting to a power source, the can also be used for headphones. They also present a unique opportunity when it comes to electronic textiles.

How they did it

The group started with a thin tube made of extremely elastic polymer. They then filled the tube with a liquid metal alloy made up of gallium and indium, an effective conductor of electricity.

“Previous efforts to create stretchable wires focus on embedding metals or other electrical conductors in elastic polymers, but that creates a trade-off,” explains Dr. Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper on the research.

“Increasing the amount of metal improves the conductivity of the composite, but diminishes its elasticity,” he adds. “Our approach keeps the materials separate, so you have maximum conductivity without impairing elasticity. In short, our wires are orders of magnitude more stretchable than the most conductive wires, and at least an order of magnitude more conductive than the most stretchable wires currently in the literature.”

Video

While the video below isn’t exactly the most entertaining piece of media ever created, it does demonstrate the effectiveness of the stretchable wire pretty clearly.

Outlook

Manufacturing the wire is pretty simple, but it’s still going to be some time before it hits the shelves. Dickey notes that, of the challenges the group still faces with the technology, figuring out how to minimize leakage of the liquid metal should the wires be severed absolutely needs to be addressed.

In the meantime, you can check out the group’s paper, entitled “ Ultrastretchable Fibers with Metallic Conductivity Using a Liquid Metal Alloy Core ” in the online edition of Advanced Functional Materials. Free log-in is required.

Story via: ncsu.edu