Shape shifting gives micro-aircraft its expert maneuverability

Robotic bird makes first flight

WAGENINGEN - A bird-like micro-aircraft with feathered, morphing wings took to the skies on its maiden flight recently. Its landing was even more dramatic, when the RoboSwift crashed into a tree. The craft flew for a total of about five minutes at an altitude of some 200 meters under windy conditions.

The craft weighs less than three ounces or 80 grams and spans just 20 inches or 51 centimeters from wingtip to wingtip. Its small size and onboard cameras make RoboSwift a possible soaring spy. The craft could make scientific observations of wild birds without disturbing them or hover above crowds of people or vehicles for government and law enforcement surveillance purposes. In fact, the Dutch National Police Services Agency will financially support the craft's development.

Aerospace engineering students from Delft University of Technology, in cooperation with Wageningen University, designed the craft after the common swift, which in its lifetime can fly the equivalent of five roundtrips to the moon and remain airborne continuously for 4,350 miles. The students discovered the common swift morphs its wings depending on flight conditions. The shape-shifting is what gives the bird its expert maneuverability and efficiency.

Seagulls

Like the bird, RoboSwift sports feathers, though just four on each wing. By folding these feathers over one another and sweeping them back and forth, the mini-craft morphs its wing shape and the surface area exposed to the elements in order to reduce drag. The feathery adjustments make RoboSwift a more efficient and agile flyer compared to traditional fixed-wing craft.

During its first flight, the robotic swift was even able to test the effectiveness of its avian disguise, when part way through the demonstration, a couple of seagulls flew closer to inspect it.

In the future, the craft will get lessons in bird-flying behaviors such as gliding. When gliding, the motor will be turned off and the propeller will fold up so the aircraft can fly even more quietly and save energy.

Scientists attending the American-Asian Micro Air Vehicle Competition in India where new inventions were shown, marveled at the flying Dutch robot. No other invention introduced at the competition used such innovative pioneering technology.