Airplanes don’t have feathers, but future drones might.
In a project that can be classified as mostly biomimicry, with just a hint of necromancy, a team of researchers at Stanford University built a drone that flies on wings made of pigeon feathers. The goal, ultimately, is unlocking new science for morphing wings of aircraft.
It may also reveal a new kind of velcro-style fastener. Natural bird feathers, it turns out, can passively link and decouple to create the smooth surfaces needed to direct lift in flight.
While most of the implications in the study are about understanding the science of bird flight, the research was supported by funding from the Air Force Office of Scientific Research.
Building feathered military robots are likely not the ultimate end, but militaries have long expressed an interest in adapting birds to battle. (One of the more fascinating examples comes from World War I, where carrier pigeons were outfitted with cameras that took pictures at regular intervals.)
“Using a feathered biohybrid aerial robot,” the authors wrote, “we demonstrate how both passive mechanisms make morphing wings robust to turbulence.”
The velcro-like hooks on the feathers allow wings to lock into shape, depending on the direction moved, and also allow the wings to unlock when moved in other directions. This creates the same great flexibility seen in bird wing shape during flight.
Attaching the feathers to the skeletal wings of a drone allowed the researchers to explore the aerodynamics and properties of these feathers in outdoor flight and in wind tunnels. When the feathers were tested in flight unclumped and unlinked, they were unable to provide lift or stability. The passive interlinking mechanisms of the pigeon feathers, when allowed close enough contact to work, held together, making a functionally solid wing out of many disparate parts.
The researchers “hypothesize that directional fastening may not be as critical for some silent fliers because decaying atmospheric turbulence at night.”
One direction military designers and planners could explore is feathered drones for night flights, where lower turbulence and silent flying are at a premium. At present, owl-shaped drones are fixed wing, but in the future they might lean into research done today into flexible feathered wings.
Watch a video about the feathered wing drone below: