Inspired by the beauty and flying ability of birds, Leonardo da Vinci strived centuries ago to create a human-powered flapping-wing flying machine. But his designs, which da Vinci explored in his Codex on the Flight of Birds, were never developed in any practical way. Even today, mimicking bird flight still presents challenges due to the physiological complexity of a bird's flapping wings. For years, researchers at the University of Maryland's A. James Clark School of Engineering have been moving ever closer to faithfully imitating bird flight with Robo Raven, the first bird-inspired unmanned aerial vehicle (UAV) that has successfully flown with independent wing control. Robo Raven can also be programmed to perform any desired motion, enabling the UAV to perform aerobatic maneuvers.