Scientists at Brown University have developed a robotic wing to study the intricacies of bat flight. The team created the wing because bats are so light — and uncooperative — that attaching them to monitoring equipment negates their ability to fly. Using a complex system of joints, a flexible silicone elastomer membrane, servo motors, and a pulley system, the researchers were able to achieve the same weight-to-thrust ratio of a regular wing, and finely tune the frequency of the flapping motion to better understand what affect it has on flight. It's nowhere near as intricate as a regular bat wing, which has 25 movable joints and 34 degrees of freedom, but it's still able to mimic bats' wing-folding motion that helps the creatures gain altitude and change flight direction extremely quickly.
The focus of this US Air Force-backed research wasn't to develop a full robotic bat — the weight of the batteries and motors would make actual flight impossible — but the project is still in its early stages. The team will continue to run tests, and hope that future technological advances will allow further degrees of freedom to be added. We're a long way off a world populated by bat drones, then, but the research could help the team and others to develop and refine new and novel ways of flight.