A study of the inflight movement of bats could help researchers design small flying vehicles robots called "micro air vehicles."
Over 1,000 bat species have membrane wings, which are essentially webbed fingers that are connected by a membrane; researchers looked at how these wings work in the air, an American Institute of Physics news release reported.
The team measured the movement of the bats' wings and used computer software to see how it affected surrounding air flow.
"Bats have different wing shapes and sizes, depending on their evolutionary function. Typically, bats are very agile and can change their flight path very quickly -- showing high maneuverability for midflight prey capture, so it's of interest to know how they do this," Danesh Tafti, the William S. Cross professor in the Department of Mechanical Engineering and director of the High Performance Computational Fluid Thermal Science and Engineering Lab at Virginia Tech, said in the news release.
The researchers found the wing motion was timed perfectly to "maximize the forces generated by the wing. "
"It distorts its wing shape and size continuously during flapping," Tafti said.
The phenomenon increased wing size by about 30 percent; this maximized the "favorable forces," and decreased the area when unfavorable forces were imposed.
The force coefficients are "about two to three times greater than a static airfoil wing used for large airplanes," Kamal Viswanath, a co-author who was a graduate research assistant said in the news release.
"Next, we'd like to explore deconstructing the seemingly complex motion of the bat wing into simpler motions, which is necessary to make a bat-inspired flying robot," said Viswanath. The researchers also want to keep the wing motion as simple as possible, but with the same force production as that of a real bat," Viswanath said.
"We'd also like to explore other bat wing motions, such as a bat in level flight or a bat trying to maneuver quickly to answer questions, including: What are the differences in wing motion and how do they translate to air movement and forces that the bat generates? And finally, how can we use this knowledge to control the flight of an autonomous flying vehicle?" Tafti said.
