MIT researchers have developed insect-sized drones that have acrobatic and resilient traits to withstand the physical challenges of real-world flight.
The drones are powered by a new soft actuator that allows them to withstand wind gusts, obstacles and general uncertainty while flying. Researchers envision that one day these drones could aid humans by pollinating crops or performing machinery inspections in cramped spaces.
Typically, drones require wide open spaces because they are not nimble enough to navigate confined spaces and are not robust enough to withstand collisions.
“If we look at most drones today, they’re usually quite big,” said Kevin Yufeng Chen, assistant professors at MIT. “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? The challenge of building small aerial robots is immense.”
While large drones are powered by motors, they lose efficiency as they shrink, meaning pint-sized drones require a different construction from traditional variants. An alternative is using a rigid actuator built from piezoelectric ceramic materials. These allowed the tiny robots to take flight but they were fragile.
MIT designed a more resilient tiny drone using soft actuators instead made of thin rubber cylinders coated in carbon nanotubes. When voltage is applied to the carbon nanotubes, they produce an electrostatic force that squeezes and elongates the rubber cylinder, causing the drone’s wings to beat fast.
These actuators can flap nearly 500 times per second, giving the drone insect-like resilience, MIT said.
“You can hit it when it’s flying, and it can recover,” Chen said. “It can also do aggressive maneuvers like somersaults in the air.”
The tiny drones weight just 0.6 grams, about the mass of a large bumble bee and looks like a tiny cassette tape with wings. MIT is working on a new prototype as well that is shaped like a dragonfly.
While the drones are current tethered, untethering the robots from a wired power source would allow these devices to function in real-world environments and applications.
Additionally, Chen said the next steps are to add more to the drones so they can be useful in industry and agriculture as well as potential other applications such as artificial pollination of crops or completing search-and-rescue missions following a disaster. These are challenging applications for large-scale robots and drones.
The full research can be found in the journal IEEE Transactions on Robotics.