For years now, scientists have sought to construct aerial robots impressed by bees and different flying bugs. But they’ve all the time run right into a basic drawback: Flying takes plenty of power.
Insects flap their wings, producing the thrust wanted to maneuver by means of the air by using the power saved in sturdy muscular tissues. Their robotic doppelgängers should depend on batteries, that are much less environment friendly and are usually heavy, or have to be attached externally.
Now researchers at Harvard University have constructed a brand new sort of robotic that’s able to true, untethered flight. The unit, known as the RoboBee X-Wing, is provided with 4 tiny wings fabricated from carbon fiber and polyester, and even tinier photovoltaic cells.
[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]
In bright light, its solar cells generate about five volts of electricity, which a minuscule transformer then boosts to the 200 volts necessary for liftoff. When the high voltage is applied to two components called piezoelectric actuators, they bend and contract, much as an insect’s muscles would. This drives the flapping motion of the RoboBee’s wings.
Clever engineering keeps the device small and light — about one-quarter the weight of a paper clip. This allows the RoboBee to flit about freely, whereas previous iterations of the robot could only take off, land, or perch mid-flight while leashed to a power supply.
“We wanted to keep pushing the limit on how much power we could squeeze out of the artificial muscles in the robot, and how efficient we could make the whole system,” said Noah Jafferis, a postdoctoral engineer at Harvard and one of the leaders of the research.
On Wednesday, Dr. Jafferis and his colleagues reported in Nature that the RoboBee is now able to match the thrust efficiency of similarly sized insects, such as bees.
The first time the robot took off in the lab, it lifted off with such force and speed that some of the researchers yelped in surprise. “We weren’t expecting it to take off like that at all,” said Farrell Helbling, a postdoctoral roboticist who also led research on the seminal flight.
So far, each of the RoboBee’s test flights have only lasted a couple seconds. One of the robot’s shortcomings is that it still can’t store energy. As soon as it flies out of a small, well-lit area, it slows down and falls to the ground.
But Dr. Helbling and Dr. Jafferis are confident that the robot could stay aloft for several minutes if its solar cells and circuits were given the proper tweaks.
Further advances in engineering could make microrobots even more autonomous, said F. Zeynep Temel, who works on ant-sized jumping robots at Carnegie Mellon University. And once these tiny robots are able to zip up, down and sideways outdoors, they could be used to take air quality measurements, help search collapsed buildings for survivors, or even be deployed in swarms.
“Having onboard power is the first big step to getting microrobots out of the lab and into the real world,” Dr. Temel said.