Researchers at Ivy League Dartmouth College have built a 250 micrometers-long robot that propels itself like a caterpillar: it scrunches its body up behind it and then takes a ‘step’ forward. It turns by planting a silicon “foot” down and pivoting around it.
One other notable thing about this robot is that it does not use wheels, or hinged joints. It will tend to stick to surfaces that it is placed on.