US researchers on Thursday unveiled a small, flying robot about the size of a house-fly that can execute the tricky maneuvers of the ubiquitous insect. The first of its kind, the flying robot is providing researchers with new ways to study the flight of nature's smallest flying insects, according to a study published in the journal Science. The tiny robot weighs only 80 milligrams and is about half the size of a paperclip. Its two wafer-thin wings flap almost invisibly, 120 times per second. In test flights, it can fly for over 20 seconds without ever approaching a crash. The demonstration of the first controlled flight of an insect- sized robot is the culmination of more than a decade's work, led by researchers at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering at the Harvard University. "This is what I have been trying to do for literally the last 12 years," said Robert J. Wood, professor of engineering and applied sciences at the SEAS. "It's really only because of this lab's recent breakthroughs in manufacturing, materials and design that we have even been able to try this. And it just worked, spectacularly well." To build such a tiny robot with little flapping wings, the researchers had to use some nontraditional approaches. The wings, for example, were made from special piezoelectric materials, which can convert an electric charge to a mechanical stress. And the robot must remain connected to a small power source by a wire because there are no off-the-shelf solutions for energy storage that are small enough to be mounted on the robot's body. Interestingly, the tiny flying robot eats up about 19 milliwatts of electricity during its flight, which is about as much as a real flying insect does. "The successful flight of the robotic fly demonstrates the feasibility of artificially approximating the flight apparatus of flying insects -- particularly Diptera in form and function and motivates future studies in miniaturized power, sensing, and computation technologies," the researchers noted.