Bats have long inspired scientists to create robots that mimic how these animals take flight.
In a new study, a team of robotics experts from California and Chicago set out to build their own robot version of the flying mammal. In the process of building the robot, however, the researchers tackle one of the problems associated with bats: their many-jointed wings.
Meet Bat Bot
Lead author Soon-Jo Chung, an associate professor of aerospace at California Institute of Technology, explained that bats use flexible membranes in their wings, which are difficult to integrate into robotics.
"Bats use more than 40 active and passive joints," said Chung. "It's impractical, or impossible, to incorporate [all 40] of these joints in the robot's design."
Indeed, bats are known to have a sophisticated power flight mechanism, in which its wings are capable of changing shape. The more than 40 active and passive joints in its wings interlock the muscles and bones to one another, producing a musculoskeletal system that creates more than 40 types of rotational directions.
Nevertheless, Chung and his colleagues managed to successfully create a design for a robotic bat that makes use of onboard electronics. Known as Bat Bot, or B2, the robot can copy the diving and swerving of the real mammal and fly even with just nine joints.
Bat Bot weighs at 93 grams and was built like a bat with a one-foot wingspan. It can change its wing shape by extending, flexing, and twisting its elbows, legs, shoulders, and wrists.
Another challenge in building Bat Bot was creating wings that can change shape while flapping, the same way a real bat's wings would do. Researchers say lightweight fabrics such as Mylar and nylon are not stretchable enough.
Because of this limitation, Chung and his team developed a custom silicone-based and 56-micron membrane that simulates bat wings.
Advantages and Potential Applications
Aerial robots derived from bats can potentially be more energy-efficient than current models of flying robots because the ultra-thin and flexible wings amplify the motion of the robot's actuators.
When Bat Bot flaps its wings, its wing membranes get filled up with air and deform. At the downward flapping motion of the wings, the wing membranes snap back to the usual shape and release the air, producing a huge amplification in power.
Furthermore, researchers argue that such bat-inspired flying robots could have advantages over traditional drones that rely on rotors. Because bat-inspired drones have soft wings, the chances for injury are less. It could also be quieter than rigid drones.
Details of the new report are issued in the journal Science Robotics.
Watch the video below.