Na na na na na na na na bionic-BATMAN! Boffins build bat-like electro-stimulated drone wings
Current makes polymer change shape POW! See the vid BLAM!
Scientists at the University of Southampton and Imperial College London have developed a wing made from polymers that flex when current is supplied, which could seriously increase the flight time of small drones by mimicking nature.
The wing is made of a polymer that can change its shape mid-flight using the battery power of the drone. Much like Batman's memory cloth cape, the material can be made more rigid with electrical current, then relax as the current lessens.
The team was inspired by bats, which use a skin membrane known as the patagium for their wing material. This flexes in flight, making the bat aerodynamically more efficient, and they applied the same principle to making wings for a micro air vehicle (MAV).
"We've successfully demonstrated the fundamental feasibility of MAVs incorporating wings that respond to their environment, just like those of the bats that have fueled our thinking," said team leader Professor Bharath Ganapathisubramani of Southampton's Aerodynamics and Flight Mechanics Group.
"We've also shown in laboratory trials that active wings can dramatically alter the performance. The combined computational and experimental approach that characterised the project is unique in the field of bio-inspired MAV design."
The team demonstrated the material with a small drone designed for flight using ground effects – the increased lift and reduced drag that aircraft and wingsuit skydivers obtain flying close to the ground.
The 50-cm (20-inch) wide drone resembles the so-called Caspian Sea Monster, an experimental ground effects aircraft developed by the Soviets in the 1960s to fly about 10 metres (33 ft) across water and deliver troops and cargo to the battlefield.
The new drone uses a similar technique, although the results from the test video look somewhat sketchy. However, the team now want to scale up their designs and see how much more efficient they can make the MAV.
"This is a paradigm shift in the approach to MAV design. Instead of a traditional approach of scaling down existing aircraft design methods, we constantly change the membrane shape under varying wind conditions to optimise its aerodynamic performance," said Dr Rafael Palacios of Imperial's Department of Aeronautics. ®