A flapping wing robot that is more efficient than the insect that its inspired from

Researchers at the University of Bristol in the U.K. have designed a flying robot that flaps its wings and can generate more power than a similar-sized insect, which it was inspired from. The robot could pave way for smaller, lighter, and more effective drones, the researchers claimed in an institutional press release. 

When it comes to flying robots, researchers have relied largely on propeller-based designs. Even though it is well known that bio-inspired flapping wings are a much more efficient method of flying, replicating them in a flying object has been challenging. As the researchers stated in the press release, the use of motors, gears, and complex transmission systems to achieve the flapping movement adds to the complexity as well as the weight of the entire system, which has many undesired effects. 

Led by Jonathan Rossiter, the Professor of Robotics at the University of Bristol, a team of researchers has now successfully demonstrated a direct-drive artificial muscle system that can achieve the flapping wing motion without using rotating parts or gears.

Called Liquid-amplified Zipping Actuator (LAZA), the mechanism consists of an electrode dipped in a liquid dielectric and moved up and down by activating electric fields above and below it, using oppositely charged electrodes. The team then added passively pitching wings to rectify the net directional thrust generated by the flapping motion. 

Dr. Tim Helps, one of the developers of the LAZA system said, "With the LAZA, we apply electrostatic forces directly on the wing, rather than through a complex, inefficient transmission system. This leads to better performance, simpler design, and will unlock a new class of low-cost, lightweight flapping micro-air vehicles for future applications, like autonomous inspection of offshore wind turbines."

The researchers tested the system for over one million flapping cycles to demonstrate that the flying robots built with this mechanism could undertake long-haul flights. They also found that their prototype generated more power compared to an actual insect muscle that it was inspired from and demonstrated a flying speed of 2.32 feet per second (0.71 meters per second). 

"Making smaller and better performing flapping-wing microrobots is a huge challenge. LAZA is an important step toward autonomous flying robots that could be as small as insects and perform environmentally critical tasks such as plant pollination and exciting emerging roles such as finding people in collapsed buildings,” added Rossiter in the press release.