Before things like touch-sensitive robot skin or prosthetics skin can become commonplace, we first need to develop robust and reliable flexible electronics. Researchers from Switzerland's EPFL research institute have taken a big step toward that goal, by developing circuits that remain functioning while being stretched by up to four times their original length.
These flexible circuits are made from liquid metal, an alloy of gold and gallium. The gallium possesses good electrical qualities, and thanks to a supercooling process, remains in its liquid state even at room temperature.
The gold keeps the gallium in one continuous homogenous film, allowing an electrical current to flow through it unimpeded. Without the gold, the gallium would disperse into separate droplets.
The conductive alloy is distributed along nanochannels that have been etched in an elastic polymer substrate. As mentioned, the finished product can be stretched by four times without any interruption in current. It also stands up well to being repeatedly folded and twisted.
More information is available in the video below.