British scientists have revealed a prototype for a new kind of flying robot that can fly without motors, rotating gears and other complex mechanics typical of traditional drone designs. Instead, the new technology is inspired by nature and based on replicating what allows insects to fly.

Instead of relying on propellors, the innovative flying robot’s wings “buzz” like those of an insect like a dragonfly and are powered by a revolutionary new kind of electric “muscle”. The prototype unveiled by the University of Bristol team that developed it has a wingspan of about 15cm – roughly the same as that of a large dragonfly. It weighs about 5kg and can fly at 1.6mph.

The team is now working on smaller, faster versions with the ultimate ambition of building a tiny bluebottle-sized model that is both fast and nimble. Possible applications include using tiny flying robots in disaster situations such as looking for survivors in collapsed buildings, or in commercial scenarios like monitoring hard-to-reach infrastructure or crop pollination.

The electric “muscle” that powers the wings is called a liquid-amplified zipping actuator, or Laza for short. The technology allows the robot to fly far more quietly than drones, whose propellors raise a distinctive whine. That’s a quality that could foreseeably catch the interest of security services and the military.

The team recently published a study in the Science Robotics journal that showed how their Laza-powered robot wings can offer more power than an insect muscle of the same weight.

Source: The Times

Dr Tim Helps, who was the study’s lead author, comments:

“It’s very challenging to beat nature. If we can produce more power than insect muscle it means that potentially we can have better performance than an insect — which is super, super exciting.”

The robo-wing acts like a negatively charged electrode and reacts to two positively charged electrodes positioned above and below it. An electric charge is fed to the upper then lower positive electrodes in quick succession which results in an electrostatic attractive force which makes the wing oscillate at high speed. The speed of the wing’s full movement is 13 times a second in the prototype and the Bristol University team say that they have achieved speeds of up to 70 times a second in experiments. That kind of speed would work perfectly for the smaller, faster robots they hope to eventually build.

The electric muscle behind the innovation also includes liquid dielectric which lies between the wing itself and the upper and lower electrodes, providing insultation where they meet the robot’s ‘body’. With the liquid dielectric, the electrical charge leads to sparks flying between the electrodes which neutralise the attractive force. The wing also oscillates like a vibrating beam as it moves up and down which allows it to store elastic energy, optimising the amount of power required.

The Laza have been shown to be able to oscillate for more than a million cycles which opens up the possibility of the robots being capable of long-haul flights.

Dr Helps explains:

“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 off-shore wind turbines.”