Harvard scientists have introduced what may be the cutest flying robots ever: a bio-inspired insect-sized aircraft dubbed RoboBee that pushes flight-worthy craft into their smallest wings yet.
"To our knowledge this is the smallest flying robot so far," said Pakpong Chirarattananon, co-lead of the paper in Science describing the 80-milligram robot with a 3-centimeter wingspan that's hardly bigger than a penny.
Building such a tiny flying robot required marshaling an enormous amount of ingenuity -- and several engineering breakthroughs -- to overcome the challenges of working on the sub-millimeter level. Nuts and bolts prove unmanageable, and turbulence becomes a much bigger issue on such a small scale.
The researchers came up with a way to build the robots by tracing out patterns in flat sheets and then folding them into the desired shape. This approach allowed them to use different materials in sheets that they could glue together with relative ease.
The method is "a bit like the approach you use with origami," Chirarattananon said. "And that enables us to create something that's small and precise."
The researchers had to build their own "muscles" for the tiny robotic bug. They came up with a tiny piezoelectric actuator -- thin ceramic strips that squeeze when a current is run through them, allowing the aircraft to flap its wings at 120 times per second.
The robots still don’t have their own brains -- even cellphone-sized microchips are too big for them -- and they don’t have their own power source. The tiny bugs had to be tethered with tiny power cords and they lasted about 10 to 15 minutes before the hinges on their wings gave out.
But once scientists come up with a way to give the bugs their own brains and energy source, such robo-flies could become very useful as tiny search-and-rescue vehicles inside buildings, Chirarattananon said, and perhaps even handy to help pollinate plants as colony collapse disorder continues to plague honeybee hives.