How Darpa’s Tiny Robotic Hummingbird Hovers and Films

By beating its wings back and forth, the UAV creates lift by deflecting air downward, creating an area of high pressure directly below the wings and low pressure above. Bob Sauls

In 2006, Darpa, the Department of Defense’s R&D arm, commissioned AeroVironment, a company specializing in remote aircraft, to create an unmanned aerial vehicle (UAV) small enough to fly through an open window. AeroVironment had already built the 4.5-foot-wingspan Raven, which first saw combat over Afghanistan in 2003, but making a UAV so much smaller took five years and 300 different wing designs.

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Click here to discover how the hummingbird flies and rolls._

Finally, AeroVironment has a working prototype: the 6.5-inch-wingspan Nano Hummingbird. “It was never our intention to copy what nature has done; it’s just too daunting,” says Matt Keennon, the UAV’s head researcher. The camera-equipped bird beats its wings 20 times a second, whereas hummingbirds clock up to 80. Still, it can hover like the real thing, plus perform rolls and even backflips. Here’s how the bird flies.

Wings

A skeleton of hollow carbon-fiber rods is wrapped in fiber mesh and coated in a polyvinyl fluoride film.

Camera

The camera angle is defined by the pitch of the Nano’s body. Forward motion gives the operator a view of the ground, aiding navigation. Hovering is good for surveying rooms.

Body

It weighs 18.7 grams (less than an AA battery). The craft is remote-controlled, but an onboard computer corrects speed and pitch.