One thing that separates the biological world from the non-biological is its ability to reproduce. All organisms reproduce in some fashion. Now scientists at Cornell University in Ithaca, New York have created a robot that can replicate itself in minutes :). If perfected, the technique could lead to the creation of swarms of robots, with little or no input from the scientists. Once that happens, small errors in reproduction, and a drive similar to the survival of the fittest in biological evolution, might lead to better and smarter robots!

Assembling robots (Courtesy: National Geographic)The robot was constructed from cube-shaped robotic units (modules) that functioned independently. Each cube contains a microprocessor, a motor, and electromagnets. The magnets selectively weaken and strengthen connections between other cubes, thereby determining where the structure breaks and joins. The growing cube assemblies are supplied with extra cubes at two "feeding" locations. A three-module robot can replicate itself in just over a minute. A four-module robot could assemble an exact replica of itself in just two and a half minutes. The research is published in the May 12 edition of the journal Nature.
Each cube is programmed with certain building instructions, such as contact and release events. Starting with a single robot, it can seek out other such cubes and construct a replica of itself. This process can go on forever, as long as there are cubes left! However, given enough cubes, the robots might be able to reconfigure the cubes into new forms, and hence technically new robot-forms. Different cubes can also have different functionalities, for example, some could be equipped with digging tools, others with lifting tools, and so on. This will be interesting, say, for lunar missions, where depending upon the task at hand, the robots can reconfigure themselves!
The Cornell robot is just a proof-of-concept. More research is of course required. And hopefully, we wont have a breed of super-robots desperate to eliminate us humans from this planet :D:D.