These tiny drones are made of soft actuators, making them resilient. They can artificially pollinate crops or complete a search-and-rescue mission. (Image Credit: MIT)
Flying insects have proven to be incredibly acrobatic and resilient to our desire to smack them flat. Some have tried to replicate those traits but never quite got there. Now, researchers at MIT, Harvard University, and the City University of Hong Kong have developed tiny insect-like drones made of soft actuators, allowing improved durability. These could have real-world applications, which include artificial pollination or search-and-rescue missions.
Scaled-down components, like motors, are less efficient and more brittle once they start shrinking. Additionally, most insect-like MAVs (micro aerial vehicles) have piezoelectric ceramic actuators, which are more fragile. This causes them to become easily damaged in crashes, especially when wind gusts blow them around.
On the other hand, the soft actuators on MIT's latest drones are comprised of thin rubber cylinders coated in carbon nanotubes. When voltage is applied to the drone, the nanotubes generate an electrostatic force that compresses and elongates the cylinder. The cylinder shrinks back to its original state once the voltage has been turned off. Rapidly turning the electrical current on and off causes the actuator to expand and contract, forcing the attached wings to flap nearly 500 times per second as it does so. This results in a resilient flying insect-inspired drone.
"You can hit it when it's flying, and it can recover," says the lead scientist, MIT's Assistant Professor. Kevin Yufeng Chen. "It can also do aggressive maneuvers like somersaults in the air." Weighing just 0.6 grams, the prototype looks like a tiny cassette tape with wings. The four sets of wings and actuators are joined together on a rectangular frame. However, the drone is connected to an external power source. Researchers hope to lower its power consumption so that it can be equipped to fly with a small battery.
These drones could fly around complex machinery to ensure safety and functionality. "Think about the inspection of a turbine engine. You'd want a drone to move around [an enclosed space] with a small camera to check for cracks on the turbine plates," says Chen.
It can also be used to artificially pollinate crops or complete search-and-rescue missions after a natural disaster. "All those things can be very challenging for existing large-scale robots," says Chen.
Have a story tip? Message me at: http://twitter.com/Cabe_Atwell