ananyo writes "A robot as small as a housefly has managed the delicate task of flying and hovering the way the actual insects do. The device uses layers of ultrathin materials that can make its wings flap 120 times a second, similar to the rate that a housefly manages. The robot's wings are composed of thin polyester films reinforced with carbon fibre ribs and its 'muscles' are made from piezoelectric crystals, which shrink or stretch depending on the voltage applied to them. Weighing in at just 80 milligrams, the tiny drone cannot carry its own power source, so has to stay tethered to the ground. It also relies on a computer to monitor its motion and adjust its attitude (abstract). Still, it is the first robot to deploy a fly's full range of aerial motion, including hovering (there's a video in the source)."