Reinventing the wheel (couldn't resist)

Apparently tired of the overtly flashy stuff, the latest robots out of Japan are simple wheels. Built by Shinichi Hirai and Yuuta Sugiyama, they are four cm in diameter and one cm thick and move by changing shape. The spokes of the wheel are made of a shape-memory alloy, a substance that shortens when heated, and the picture does a pretty good job of explaining the movement (so we don't have to). They're powered by copper wires right now, but a battery-powered version is planned, as well as a ball-shaped design using a bunch of the robots. The best part is that they weren't made for any particular reason. These guys were probably sitting in a lab one day and one of them said something like
"I like wheels. Let's see what we can do with that." And the rest was history.