Harvard’s RoboBee Flies Using Solar Power

Harvard’s RoboBee Flies Using Solar Power

In the future, you may have to wonder if that insect buzzing around your head is even an insect at all. Researchers at the Harvard Microrobotics Lab have developed a new version of their amazing RoboBee, a micro-drone based on the flight mechanisms of bees. Past versions of the RoboBee needed external power to fly, but the new RoboBee has its own solar panels for untethered flight.

The goal with the RoboBee is to keep the entire package small and light. That makes the device ideal for surveillance, search and rescue, and environmental monitoring. In 2016, Harvard showed off a version of the RoboBee with two wings and tripod feet that could fly for short distances and land safely. However, it had no way of generating power, so untethered flight was out of the question.

The new RoboBee has been dubbed “RoboBee X-Wing” for its arrangement of four wings in an x shape. Adding the extra set of wings, along with less obvious changes to the actuator and transmission ratio, made the robot much more efficient. That gave the designers enough headroom to add onboard power generation via a small solar panel array.

Above the wings, the RoboBee has four small solar panels that generate power. The solar panels are the smallest commercially available with a mass of just 10 milligrams each. They generate 0.76 milliwatts per milligram when in direct sunlight, but there are no batteries to store power as that would add too much mass. All together, the RoboBee weighs just 259 milligrams — less than a quarter as much as your average paperclip.

In a recent test at Harvard, the RoboBee became the lightest vehicle to sustain powered flight thanks to some overhead halogen lamps. Unfortunately, the halogen lamps used in the test represent more light than the robot would ever get in real life. It would take about three times more solar radiation than Earth receives to power the RoboBee for outdoor flight. The current design also lacks a remote control or steering system. It just flies upward as long as it gets power.

Despite the shortcomings, this is still a significant milestone in the decade-long development of the RoboBee. As solar panel technology improves, the team may be able to supply the robot with enough power via the sun to fly outdoors. At that point, the RoboBee could stay in the air indefinitely.