MIT gets inspiration from insects for next-generation drones

We've all been standing outside at some point and had tiny flying insects like gnats continually flying around our face or ears no matter how many times we swat them away. Small flying insects have incredible agility that allows them to avoid swatting hands and other obstacles as they fly through the air. MIT Assistant Professor Kevin Yufeng Chen has constructed a new flying robotic system that approaches the agility of insects in the air.

Chen works in the Department of Electrical Engineering and Computer Science and the Research Laboratory of Electronics. He is developing insect-sized drones that have incredible dexterity and resilience. The flying robots are powered by a new type of soft actuator, allowing them to withstand the bumps and bruises that come with real-world flight. Chen foresees a future where the small and nimble flying machines could help humans with tasks like pollinating crops or inspecting machinery in cramped spaces.

Most flying drones have to operate in open spaces due to their lack of nimbleness, preventing them from navigating confined spaces. They also lack the robustness required to survive collisions with other objects. Building small drones requires fundamentally different processes compared to larger drones. Motors typically power large drones, but those motors are inefficient when shrunk down to sizes required for smaller drones.

Chen and his team designed a more resilient small drone using soft actuators instead of hard and fragile units used in other flying machines. The soft actuators used are made of thin rubber cylinders that are coated in carbon nanotubes. Applying voltage to the carbon nanotubes makes them produce an electrostatic force that squeezes and elongates the rubber cylinder. When that voltage is applied repeatedly, the drone wings beat at a rapid pace.

Chen says the actuators can flap nearly 500 times per second, giving the small drone the resilience of an insect, allowing it to bump into objects, recover, and continue flying. The drone weighs only 0.6 grams, making it approximately the same mass as a large bumblebee. It resembles a small cassette tape with wings, but the team is working on a new design shaped like a dragonfly.