Typically, drones require wide open spaces because they're neither nimble enough to navigate confined spaces nor robust enough to withstand collisions in a crowd. "If we look at most drones today, they're usually quite big," says Chen. "Most of their applications involve flying outdoors. The question is: Can you create insect-scale robots that can move around in very complex, cluttered spaces?" According to Chen, "The challenge of building small aerial robots is immense." Pint-sized drones require a fundamentally different construction from larger ones.
MIT researchers have developed a tiny drone with soft actuators that can flap nearly 500 times per second, allowing it to be more resilient to mid-flight bumps and nimble enough to fly like a bee. MIT Assistant Professor Kevin Yufeng Chen led the project to build an insect-like drone that uses soft actuators rather than hard, fragile actuators. "The soft actuators are made of thin rubber cylinders coated in carbon nanotubes," explains MIT. "When voltage is applied to the carbon nanotubes, they produce an electrostatic force that squeezes and elongates the rubber cylinder. Repeated elongation and contraction causes the drone's wings to beat fast."
Insect-like drones have taken one large step closer to becoming a practical reality. Researchers at Harvard, MIT and the City University of Hong Kong have developed tiny insect-inspired drones that can not only maneuver in extremely tight spaces, but withstand bumps if things go wrong. The key is a switch to an actuation system that can flap the drones' wings while surviving its share of abuse. To date, drone makers wanting to go this small have had to ditch motors (which lose effectiveness at small sizes) in favor of piezoelectric ceramic-based rigid actuators. The new drones rely on soft actuators made from rubber cylinders coated with carbon nanotubes.
Kevin Chen, an assistant professor at the Massachusetts Institute of Technology, envisions a time when his insect-sized drone could be used as a search and rescue robot -- to find survivors in disaster debris that bigger drones couldn't reach. Kevin Chen, an assistant professor at the Massachusetts Institute of Technology, envisions a time when his insect-sized drone could be used as a search and rescue robot -- to find survivors in disaster debris that bigger drones couldn't reach. The reason it's so hard to kill a mosquito is that they move really well. Scientists are trying to build a robot with that kind of agility. And these tiny but mighty flying robots could be used in life-and-death situations, such as finding people in a collapsed building.
DRONES could learn a thing or two from the birds and the bees. If an aerial robot loses a part mid-flight, you would expect it to crash. But it could stay airborne by mimicking fruit flies, which can keep flying even after a catastrophic loss of limb. To uncover the insects' secret, biologists placed flies with a clipped wing into a wind tunnel and analysed their movements using high-speed cameras. They used this data to run simulations of the flies' wing motion.