Small insect-like robot can flip, loop and hover for up to 15 minutes

An insect-inspired robot that weighs only as much as a grape can perform acrobatics and fly much further than any previous insect-sized drone without falling apart.

In order for small flying robots to make agile maneuvers, they must be light and agile, but also able to withstand large forces. Such forces mean that most small robots can only fly for about 20 seconds before breaking down, making it difficult to collect enough data to properly calibrate and test the robots’ flight capabilities.

Now, Suhan Kim of the Massachusetts Institute of Technology and his colleagues have developed an insect-like flying robot the size of a postage stamp that can perform acrobatic maneuvers, such as double flips or trace an infinity sign, and also hover in the air for up to 15 minutes without fail.

Kim and his team adapted the design from an earlier flying robot, but they made the joints more resilient by making them connect across a larger portion of the robot than at just a single point of failure. That reduced the force through the joints by a factor of about 100, says Kim. They also used muscle-like soft actuators to move the wings rather than standard electric motors.

“If you only have 20 seconds to fly the robot before it dies, there’s not much we can tune when we’re controlling the robot,” says Kim. “By having a hugely extended lifetime, we were able to work on the controller parts so the robot can achieve precise trajectory tracking, more aggressive maneuvers like somersaults.”

This tracking meant the robot could follow complex flight paths, like tracing letters in the air. Such maneuverability could eventually be used for things like artificial pollination of plants or inspection of parts of aircraft that people can’t get to, Kim says.

However, the robot is currently unable to fly untethered, as the team has yet to miniaturize a power source and the electronics that control it – although they hope to improve this with future designs, Kim says.

“One aspect that is often not talked about much is how long the robot would last when you fly it,” says Raphael Zufferey of the Massachusetts Institute of Technology, who was not involved in the work. “People have focused a lot on battery life and how autonomous we could make it, but nobody really focused too much on how long it would mechanically last, and this paper really goes into that in detail.”