Bacteria-scale robots that can run for months without human control are no longer a lab fantasy. Researchers have now built fully programmable micro-machines, smaller than a grain of salt, that can ...

It’s a bizarre sight: With a short burst of light, a sponge-shaped robot scoots across a tiled surface. Flipped on its back, it repeatedly twitches as if doing sit-ups. By tinkering with the light’s ...