Self-reconfigurable robots are a long way from liquid metal T1000 CGI Terminator robots, but still, it's impressive to watch a robot reassemble itself after being kicked apart. See CKbot pull itself together in the video below.
(Self-reconfigurable robot video)
CKbot is made up of 15 modules arranged in groups of five; each cluster has a module with a camera, a blinking LED and an accelerometer to reconstruct itself. The remaining modules have embedded proximity sensors.
When kicked apart, the camera modules start looking for the unique LED signature, and then each cluster starts moving toward the others.
In his amazing 1920 short story The Metal Monster, Abraham Merritt imagines a robot that is constructed of smaller metal pieces able to move on their own.
Faster the cubes moved; faster the circle revolved; the pyramids raised themselves, stood bolt upright on their square bases; the six rolling spheres touched them, joined the spinning, and with sleight-of-hand suddenness the ring drew together; its units coalesced, cubes and pyramids and globes threading with a curious suggestion of ferment.
With the same startling abruptness there stood erect, where but a moment before they had seethed, a little figure, grotesque; a weirdly humorous, a vaguely terrifying foot-high shape, squared and angled and pointed and ANIMATE—as though a child should build from nursery blocks a fantastic shape which abruptly is filled with throbbing life.
Again the sibilant rustling—and cubes and pyramids and spheres were gone.
"Goodwin!" he whispered. "What—what were they?"
"Metal," I said—it was the only word to which my whirling mind could cling—"metal—"
"Metal!" he echoed. "These things metal? Metal—ALIVE AND THINKING!"
(Read more about Abraham Merritt's living metal cubes)