Imagine a runner who doesn’t need to carry a stopwatch
or cell phone to check her time: She could just gaze at the glowing
stopwatch display on the back of her hand. Such human-machine
interfaces are no longer science fiction, but they still have a way
to go before becoming mainstream. Now, researchers reporting in ACS
Materials Letters have developed a stretchable light-emitting
device that operates at low voltages and is safe for human
skin.

