Everyone, say hello to RoboBee. RoboBee is inspired by the biology of a fly – otherwise, it's exactly what it sounds like. And it is amazing.
RoboBee is the world's first controllable, flying, insect-scale robot. At just 80 milligrams, it weighs about as much as a large grain of sand. Needless to say, you can't grab the parts for this little bugger at your local Radio Shack. Electronics are tricky at the scale of insects. They're too big for traditional silicon-based systems, and way too small for conventional machining methods. So how do you go about building something like this – a flying robot with a wingspan of just three centimeters:
Answer: you develop a brand new manufacturing methodology – one that can turn super-stiff, super-strong carbon-reinforced composites into itty-bitty flying-robot parts. Every single electromechanical component of RoboBee's submillimeter-scale anatomy was built from the ground up, using a technique Harvard researchers call "smart composite microstructures," or SCM. RoboBee's flight muscles, its thorax, even its two ethereal, wafer-thin wings – all of them were built using SCM. In the latest issue of Science, a team led by engineer Robert Wood shows us what happens when you bring all of those components together, and set RoboBee's wings flapping at 120-beats per second:
This tiny robot does more than fly. It hovers like a hummingbird. It pirouettes in place about a vertical axis. It flits from side-to-side with purpose and control. RoboBee may be tethered to its power source, but its flight is otherwise unconstrained and – dare we say it – graceful. It is absolutely incredible, and Wood knows it.
"This is what I have been trying to do for literally the last 12 years," he said in a statement. "We had to develop solutions from scratch, for everything," explains Wood. "We would get one component working, but when we moved onto the next, five new problems would arise. It was a moving target."
"It's really only because of this lab's recent breakthroughs in manufacturing, materials, and design that we have even been able to try this. And it just worked, spectacularly well."
RoboBee owes its unprecedented flight mechanics to its wings, which can be controlled independently through artificial muscles assembled from ceramic. These muscles rely on piezoelectric movement, a phenomena by which materials like ceramic expand and contract when exposed to an electric field. RoboBee's wing hinges translate this expansion and contraction into wing-flaps that can be manipulated with remarkable specificity.
Roll torque is generated by flapping one wing with longer strokes than the other (above, C); pitch torque by moving the average stroke angle of both wings forward or backwards (above, D); and yaw torques by cycling through a range of stroke speeds, or alternating the angle at which the wings flap (above, E). Bring them all together, and you get the formidable miniature flying machine seen here. Slap some motion-tracking retroreflectors on its forehead and three of its feet, and suddenly RoboBee is one of the most exciting new methods for studying insect flight mechanics researchers have developed in years:
"Now that we've got this unique platform," said Wood, "there are dozens of tests that we're starting to do, including more aggressive control maneuvers and landing."
"I want to create something the world has never seen before," adds graduate student Kevin Ma, first author on the paper describing RoboBee's flight and development. "It's about the excitement of pushing the limits of what we think we can do, the limits of human ingenuity."
Check out the paper for yourself in the latest issue of Science.