Soon-Jo Chung, associate professor of aerospace and Bren Scholar at Caltech, holds the Bat Bot. (Image courtesy of Caltech.)
At a featherweight 93 grams, the Bat Bot has a one-foot wingspan and is capable of taking flight via flexing, extending and twisting at its shoulders, elbows, wrists and legs.
Obviously, the engineering and control that went into developing the Bat Bot is complex, requiring a level of precision beyond robots that mimic bird flight. In addition to the challenges of creating the Bat Bot’s controls, the ‘bot’s designers also had difficulty sourcing materials that could mimic the skin that forms a bat’s wings.
Modern lightweight materials might be able to lighten the loads of aircraft, but they leave something to be desired when it comes to flexibility. As a bat flaps its wings, it dynamically alters the tension on the surface of its skin between taught and loose states. This alteration of shape makes it possible for the bat’s down stroke to force air away from its wing as its skin moves from taught to loose, making each of its flaps all the more powerful.
Unfortunately, many lightweight materials like mylar and nylon are prone to fail under this type of strain.
To solve this problem, the engineers turned to a silicon-based membrane that gave the Bat Bot the flexibility required to articulate its wings through the complicated motions necessary for flight. By accurately mimicking this motion, engineers can leverage the powerful amplification that occurs when bats combine the down stroke of their arms with the flexibility of their skin.
But what’s any of this research have to do with the future of flight or robotics?
In the mind of Soon-Jo Chung, associate professor of aerospace at CalTech, the results could have wide ranging impacts. "This robot design will help us build safer and more efficient flying robots, and also give us more insight into the way bats fly," he said.
For more nature-inspired engineering, find out how Biomimicry Helps Reduce Wind Turbine Noise.