Flapper Drones fly like birds or insects by flapping their wings. To lift the drone, the wings need to flap back and forth 12 times per second. Having four wings, just like dragonflies do, improves flight stability and power efficiency. The wings and their motion have been carefully optimized in order to maximize the flight time per battery charge.
Turns and other maneuvers are executed by altering the motion and geometry of the individual wing pairs. An onboard flight computer is needed to assist flying these drones, since a human pilot alone is unable to steer fast enough. Using information from the on-board gyroscopic sensors (which are by the way also bioinspired), the computer updates the wing motion parameters as frequently as 500 times per second.
Having full control of the body rotations (roll, pitch and yaw) and the thrust force that the wings produce, Flapper Drones can fly in any direction. They can take off vertically like a helicopter, hover and fly forward/backward or sideways by tilting their body in the respective direction. The transition can be slow and smooth, but also very agile. A Flapper Drone can accelerate from hover to fast horizontal flight and revert back to stand still in no time.