Researchers from England’s University of Southampton have designed unmanned aerial vehicle (UAV) wings inspired by bats in order to improve UAVs’ aerodynamic properties, provide longer flight times and make them more economical to run.
According to the university, the membrane wings – which have no mechanical parts – work like artificial muscles in that electroactive polymers cause the wings to change shape in response to the forces they experience.
By changing the voltage input, the shape of the electroactive membrane and, therefore, the aerodynamic characteristics can be altered during flight. The researchers say the proof-of-concept wing will eventually enable flights over much longer distances than currently possible.
The wings have been developed and tested in-flight through a combination of 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. The U.S. Air Force, through its European Office of Aerospace Research and Development, provided additional support.
According to the university, the wings are designed for micro air vehicles (MAVs) – UAVs that can be as small as 15 centimers across.
The Southampton-Imperial team focused on mimicking the physiology of bats. To inform and speed up the design process, the Imperial team built computational models and used them to aid the construction of a test MAV that incorporated the bat wings.
The Southampton team incorporated some of these findings into a 0.5-meter-wide test vehicle, designed to skim over the sea’s surface and, if necessary, land there safely. After extensive wind tunnel testing, the vehicle was put through its paces at a nearby coastal location.
The next step is to incorporate the active wings into typical MAV designs, with deployment in real-world applications potentially achievable over the next five years, the researchers say.
“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 optimize its aerodynamic performance,” explains Dr. Rafael Palacios of Imperial’s department of aeronautics, who led Imperial’s aspect of the project.