At North Carolina State University, researchers have created wires that are both conductive and capable of being stretched eight times their original length without losing any of their effectiveness. This is achieved using a polymer tube that is super elastic and filled with liquid metal. In the future, these wires could be used in chargers and headphones.
The stretchy wires are created using tubes of elastic polymer. These stretchable tubes are then filled with a liquid indium and gallium metal alloy, which provides conduction for electricity. The previous methods used to create these stretchable wires had a problem with either low conductivity or a low ability to stretch.
NCSU's Assistant Professor of Chemical and Biomolecular Engineering Dr. Michael Dickey offered this statement. "Previous efforts to create stretchable wires focus on embedding metals or other electrical conductors in elastic polymers, but that creates a trade-off ... 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."
Because the metal in the tubes stays in a liquid state, there is one problem with the wires: when nicked or otherwise damaged, that liquid metal leaks out. This is a problem that the researchers say needs to be addressed before the wires can be used in consumer products, like your earbuds. Once that issue is corrected, however, actual production of the wires will be simple.