Watch out world, here's the first generation of Terminators

US researchers have devised a simple robot that can make copies of itself from spare parts.
Writing in Nature, the robot's creators say their experiment shows the ability to reproduce is not unique to biology.
Their long-term plan is to design robots made from hundreds or thousands of identical basic modules.
These could repair themselves if parts fail, reconfigure themselves to better perform the task they have been set, or even to make extra helpers.