Researchers have recently developed nature-inspired morphing wings that can help drones recover from mid-air collisions.
By examining the wings of birds and bats, the researchers, from Stanford University, have created a mechanism that could allow future flying robots to easily squeeze between obstacles, such as branches of a tree, and fully recover after accidental hard impacts.
The researchers created one of the first mechanisms in which the morphing of the wing was completely passive, requiring no actuation to fold or unfold, making the wing much lighter and more reliable.
The robotic wing was modeled on bat and bird wings and was made using carbon fiber and Mylar film.
The pin joint connected the arm wing and the hand wing. The arm wing attached to the body of the robot at the shoulder joint, which initiated the flapping. The complete wing set had a wingspan of 400 mm and a length (chord) of 80 mm.
The wrist joint of the wing was hinged so, as the rest of the wing flapped, the hand could freely fold and unfold over the arm, much like origami folding, without any actuation.
The researchers performed theoretical, numerical and physical simulations on the robotic wing and successfully demonstrated that when the wing flapped, the folded hand wing was able to unfold back to the full wingspan configuration passively.
The hinged wrist joint also allowed the robotic wing to temporarily morph its hand when it came into hard contact with a rigid object.
This finding would greatly help make flapping winged drones much more robust. This was essential if they ever want to safely fly through a forest or land in a tree like a bird. The Office of Naval Research wanted researchers to find solutions to enable drones to fly in such cluttered environments, and this was a promising step forward.
