One of the tower robots in Hod Lipson's lab in the process of replicating itself. The cubes in the tower can twist and move because each one is split in half. Tiny motors and magnets allow the cubes to swivel and hook up with their neighbors.
At Johns Hopkins University, Gregory Chirikjian has been using LEGOs to make simple self-replicating robots. Like the machines at Lipson's lab, these robots can also only put together a few ready-made parts.
For years, scientists have dreamt of making robots that can self-reproduce. Someday, such a machine could be sent to explore a distant planet, where it could clone itself. Now, researchers say they've come up with primitive robots that can self-replicate.
In the current issue of the journal Nature, Hod Lipson from Cornell University describes robots in his lab with a limited ability to self-reproduce. The machines aren't the humanoid contraptions many people conjure when they think of robots -- Lipson's robots consist of a stack of three white plastic cubes that stand as a simple tower.
Each cube has an electronic brain that holds a blueprint for building new towers. If you feed one of these robot towers new cubes, it will make a copy of itself in just a couple of minutes.
Lipson says his robot is still way too dependent on humans to take any kind of interplanetary journey. "They're dependent very much on having cubes supplied in a very particular place and particular time," Lipson says. "They have a lot of constraints."