Researchers have created tiny functional, remote-powered, walking robots, developing a multistep nanofabrication technique that turns a 4-inch specialized silicon wafer into a million microscopic robots in just weeks. Each one of a robot's four legs is just under 100-atoms-thick, but powered by laser light hitting the robots' solar panels, they propel the tiny robots. The researchers are now working on smart versions of the robots that could potentially make incredible journeys in the human body.