Inspired by bats, researchers from the University of Southampton have designed innovative membrane wings, paving the way for a new type of unmanned Micro Air Vehicles (MAVs) with improved aerodynamic properties, which can fly over long distances and cost less.
The wings work like artificial muscles, changing shape in response to the forces they experience and have no mechanical parts, making MAVs without maintenace cost. The unique design of the wings incorporates electro-active polymers that makes the wings stiffen and relax in response to an applied voltage.
By changing the voltage input, the shape of the electroactive membrane and aerodynamic features can be altered during flight, enabling flight over much longer distances.
The wings have been tested in-flight through hands-on experimental work at the University of Southampton and computational research at Imperial College London, with funding from the Engineering and Physical Sciences Research Council (EPSRC), while the United States Air Force provided additional support.
The Southampton-Imperial team has focused on the physiology of bats – the only type of mammal naturally capable of genuine flight. They built innovative computational models and used them in making an MAV with ‘bat wings’.
The Southampton team incorporated some of these findings into a 0.5m-wide test vehicle, designed to skim over the sea’s surface and alos land there safely.
Professor Bharath Ganapathisubramani of Southampton’s Aerodynamics and Flight Mechanics Group, who has led the project, said: “We’ve successfully demonstrated the fundamental feasibility of MAVs incorporating wings that respond to their environment, just like those of the bats that have fuelled our thinking. 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 next step is to incorporate the active wings into typical MAV designs, with real-world applications over the next five years.
“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, who led Imperial’s contribution to the project.