Cleo Robotics Demonstrates Uniquely Clever Ducted Fan Drone

IEEE Spectrum Robotics Channel 

At last year's CES, Cleo Robotics was showing prototypes of a palm-sized drone with a design unlike anything we'd ever seen. Shaped like a donut, the Cleo drone is essentially a ducted fan, with a pair of completely enclosed propellers (one on top of the other) and then a camera, battery, and electronics housed inside the shell. It's compact (95 mm in diameter, 33 mm thick, 90 grams), elegant, and inherently safe, since the nasty spinny bits are all tucked away. With fewer motors than conventional quadrotors, it promises to be more efficient as well, and quite possibly cheaper. But if you look closely at the picture, you'll probably end up with the same question that I did: