Although it may seem erratic and graceless, bats are more efficient flyers than birds, due to an airlift mechanism that is unique to them among all the aerial creatures. This unique flight capability inspired Alireza Ramezani, a roboticist and an assistant professor of Electrical and Computer Engineering at Northeastern University, in the process of building a drone that mimics a bat’s movements.
Bats, he said, have arguably the most sophisticated flight mechanisms of any animal. “They can literally dance in the air,” said Ramezani, “This has been fascinating for me, how they play with the laws of aerodynamics to change their body morphology. It captured my attention and made me more determined to look into this problem to create robots that can copy that motion,” he said.
Unlike other aerial creatures, which have relatively firm wings that can move in only fixed directions, a bat’s wing contains more than forty joints that are overlaid by a thin elastic membrane that can stretch to catch air and generate lift in many different directions.This gives them greater agility, flexibility, and maneuverability in the air. Ramezani said these traits make bats an ideal model for designing the next generation of flying robots. These types of drones, he said, would be particularly useful for surveillance, whether inside a building or outside monitoring traffic patterns or airport security.
Ramezani and his collaborators created Bat Bot, which is an autonomous drone that can flap its wings, glide, make sharp turns, and swoop down. With a 1-foot wingspan, a Bat Bot can navigate tight spaces that larger drones can’t. It also only weighs slightly over 3 ounces, and its carbon- fiber skeleton is covered by a soft, super-stretchable silicon-based membrane.
He said he and his collaborators will focus on building an advanced version of the bat drone that perches and hangs upside down like a bat. He’s also planning to add on-board cameras and sensors that collect all kinds of data about the environments where the drone flies.“If robotic systems can hang from structures, they can harvest solar energy and once they’re fully charged, they can fly around again,” he said. “It sounds futuristic, but we’ll see how we can accomplish this.”