Air Force Research Laboratory-funded researchers from several universities are studying the flexible, flapping wings of bats (as well as birds and certain insects) in order to mimic desirable biological attributes towards micro air vehicle improvements in agility, speed, and adaptability.

If successfully transitioned, this research could ultimately lead to small, remote-controlled (i.e., unmanned) aircraft with the capacity to navigate in complex environments such as forests, caves, building interiors, and tunnels.

AFRL manages two projects on biologically inspired flight. Both efforts are part of the 2007 Multidisciplinary University Research Initiative, which provides funding for topics that rely on expertise from multiple disciplines.

Dr. Kenny Breuer, a fluid mechanics professor from Brown University, and Dr. Wei Shyy, an aerospace engineering professor from the University of Michigan, each lead a MURI project.

Though their respective teams focus on different biological and engineering aspects of this challenge, they share the same overall goal of understanding bat flight and its potential applications to MAV operations.

Dr. Breuer is working various efforts to unlock the mysteries of this complex biological system. One such activity involves the collection of video footage and associated measurements. As the bats fly in a wind tunnel, researchers videotape the creatures and measure the fluid velocities in their wakes.

Another effort targets the investigation of flight properties in different environments and among varying bat species. From the results of his own experiments and others, Dr. Breuer has accordingly constructed engineering models that mimic specific features found in bat flight.

Among his MURI partners are colleagues from Oregon State University, the Massachusetts Institute of Technology, and the University of Maryland; their own innovations include developing computational methods for simulating complex, moving, flexible structures; mapping the neurophysiology of bat sensor and motor systems; and creating control systems that might be of use in devising MAV technologies.

Meanwhile, Dr. Shyy's team comprises faculty and students from the University of Michigan, as well as a cohort from the University of Florida and University of Maryland. Focused primarily on MAV hovering and forward flight modes, his team has thus far placed particular emphasis on learning how and why flexible wing structures affect lift and thrust generation, especially in unsteady environments.