Bird wings inspire UAVs, adaptive morphology
Assistant Professor Aimy Wissa, one of MechSE’s newest faculty members, has spent much of her life adjusting to new environments. Originally from Cairo, Egypt, Wissa traveled to the U.S. when she was 16, where she has since followed her studies from Pennsylvania to Maryland to California and now to Illinois. Interestingly, her continued work with air travel is nearly synonymous to her life.
“Growing up in Egypt, becoming an engineer was a big deal,” Wissa said. “I just loved engineering and I loved airplanes, so I decided I wanted to be an aerospace engineer.’”
Wissa earned her bachelor’s degree in aerospace engineering at Pennsylvania State University in 2008, and later graduated from the University of Maryland, where she completed her master’s and PhD. Wissa did postdoctoral work at Stanford University before moving to Illinois. During her time at Maryland, she began studying flapping wing unmanned air vehicles (UAVs), which became the focus of her PhD work.
“When I look at birds, I’m inspired to think about why our man-made drones don’t fly as well,” Wissa said. “In comparison, birds are a lot more agile and adaptable. They can easily take off, land, perch, cruise, and sometimes hover. Our equivalent in engineered vehicles is not like that, mainly because bird’s wing kinematics are much more exquisite and complex.”
In the early stages of her research, Wissa spent months poring over biology papers to familiarize herself with the unique structure of bird wings. Birds’ wings have more than 44 muscles that allow them to use both passive and active motion to control their flight pattern and respond to external stimulants.
During her PhD studies, Wissa worked with a team to design a mechanism that mimics the function of a bird’s wrist and is inspired by its passive responsiveness, allowing the wing to morph or change its shape without the need of actuators or sensors.
With this in mind, Wissa and her team began working to create UAVs that learn from nature’s solutions to solve engineering challenges.
One of her projects, known as barbule-inspired research, focuses on studying the slots between the feathers at the ends of bird wings. This wing feature is a mechanism that helps increase the flight efficiency of birds, particularly during the slow speed and high angles of attack maneuvers such as perching.
Another research project delves into the science behind birds’ covert feathers. Covering nearly all of the wing and providing it with its elegant contours, these feathers help prevent birds from stalling in air. Stalling – the inability to produce lift – is something Wissa and her team are working to prevent in UAVs.
“In my lab, the Bio-inspired Adaptive Morphology (BAM) Lab, we design and build adaptive structures that change their shape in response to external stimulants, and we study the morphology or the form and function of biological systems in order to revolutionize the way we design our engineering structures,” Wissa said. “We like to combine nature’s solutions with our expertise in engineering and design with materials. When you put these together, ‘BAM’ happens.”
Wissa said her work has both military applications, including surveillance for combat intelligence, as well as civilian applications, such as inspection of crops.
Although she has only recently moved to Illinois, she has already adjusted to the life and culture of the university. Despite leaving the flourishing culture of Cairo and moving away from the scenic mountains of Northern California, Champaign still has its benefits, according to Wissa.
“Because there are no mountains, you can see everything. And the sunset is amazing.”