A team of engineers at Washington State University, Pullman, discovered how to stretch metal films used in flexible electronics to twice their size without breaking, which they say, could lead to dramatic improvements in flexible electronics. This may advance applications in bendable batteries, robotic skins, wearable monitoring devices and sensors, and connected fabrics.

One problem is designing and manufacturing the tiny metal connections that go into flexible electronics since the metal must be able to reliably endure severe stretching and bending while continuing to conduct electricity. Manufacturers have used tiny metal springs that can stretch and still maintain connectivity, but the springs take up space and make it difficult to design complicated, high-density circuitry.

The researchers discovered that by using a metal film out of indium, a fairly inexpensive metal compared to gold, bonded to a plastic layer commonly used in electronics, they were able to stretch the metal film to twice its original length. When the pieces broke, it was actually the plastic layer that failed, not the metal.