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.

The T-1000 in Terminator 2 could change shape at will, morph its hands into blades or turn parts of its body into a fluid to move through metal bars. “I saw this movie when I was a child—it was like, ...