Researchers have created microscale robots less than 1 millimeter in size that are printed as a 2D hexagonal 'metasheet' but, with a jolt of electricity, morph into preprogrammed 3D shapes and crawl.

Fidget poppers are an example of "bistability," as the popped circles rest in one of two stable states. Purdue University researchers have taken this idea to its extreme, building robots that can be ...