DARPA's New Militarized Earthworm

"Meshworm is a toughened, robotic earthworm that can crawl virtually silently at a speed of about 5 millimeters per second. DARPA wants to send it into battle. Believe it or not, the Pentagon's been working on building a robotic earthworm for a while. They tried putting one together with gears. They tried with air-powered and pneumatic pumps, but the results were bulky and untenable. Then, researchers at Harvard, MIT and Seoul National University in Korea put their heads together and designed an 'artificial muscle.' It's essentially a polymer mesh that's wrapped with nickel and titanium wire designed to stretch and contract with heat. When an electric current is applied, the mesh mimics the circular muscle system of an earthworm to scoot forward."