Army of a million microscopic robots created to explore on tiny scale

A troop of a million walking robots could enable scientific exploration at a microscopic level. Researchers have developed microscopic robots before, but they weren't able to move by themselves, says Marc Miskin at the University of Pennsylvania. That is partly because of a lack of micrometre-scale actuators – components required for movement, such as the bending of a robot's legs. Miskin and his colleagues overcame this by developing a new type of actuator made of an extremely thin layer of platinum. Each robot uses four of these tiny actuators as legs, connected to solar cells on its back that enable the legs to bend in response to laser light and propel their square metallic bodies forwards.