The RoboBee Flies Untethered for the First Time

Way back in 2008, engineers from the Harvard Microrobotics Lab at the School of Engineering and Applied Sciences (SEAS) published a paper on their groundbreaking RoboBee. That first iteration of the RoboBee weighed just 60 milligrams, and proved just how small flying robots could be. The catch was that it required a tether to provide power — the RoboBee’s tiny wings just couldn’t provide enough lift to carry a power source. But now, more than a decade later, the RoboBee has finally achieved untethered flight.

Over the years, the RoboBee has been redesigned many times. There was even one iteration that could swim and launch itself out of the water using tiny explosions. But the one thing they all had in common was the power tether. Batteries simply weigh too much for the lightweight RoboBee to carry. That’s changed now, thanks to improvements to the RoboBee’s wings, actuators, transmission ratio, and super-lightweight solar cells. Those advances have let the RoboBee fly without a tether for the first time, making it the lightest vehicle in history to achieve sustained flight under its own power.

The new RoboBee weighs just 259 milligrams, which is less than a paperclip. Its four wings are capable of producing 290 milligrams of lift, using just 115 milliwatts of power. That’s roughly on par with a small LED. Because the RoboBee is so incredibly efficient, it’s able to be powered entirely by a set of six tiny solar cells. Those provide a total of about 120 milliwatts of power, which is just enough to keep the RoboBee aloft. Right now, the RoboBee’s flight can’t actually be controlled, but that’s the next step. These innovations could lead to lighter, more efficient robots.