Video Robot worm glows in rainbows as it crawls
Researchers have made a number of flexible, skinlike light-emitters and touch sensors in recent years. But none quite like the one reported in today’s issue of Science: A novel wormlike robot that changes colors as it inches its way forward. The device starts with three flexible plastic segments, each of which contains an air pouch under the surface, as well a light-emitting layer that beams green, yellow, or blue light. The light emitters are made from materials that gleam when plied with electricity—sandwiched between two layers of stretchy silicone and two pliable electrodes. This design allows the material to stretch five times more than previous flexible light-emitters, while still shining bright. To make the robot walk, the researchers pump air in the three pouches one at a time. As each chamber is pressurized, the outer luminescent skin is stretched, increasing the electric field across it, which in turn increases the amount of light emitted. Inflating and deflating three chambers in sequence causes the wormlike robot to scoot forward a tad. It won’t break any speed records; it can only shuffle 32 body lengths in an hour. But it puts on a nice light show along the way. Down the road, such materials may help engineers build robots that can sense their environment and send visual cues to people around them about what’s going on.