This Airborne Jellyfish Isn't Lost, It's a Drone

Technology

Posted by erika rae | 17 Jan 2014 | Comments (1)

A jellyfish-inspired drone might not garner as much media buzz as the Amazon Delivery Drones or make an Hollywood entrance like the Star Trek promotion featuring a batch of "Hummingbird" drones, but its design is noteworthy for other reasons.

According to a story on National Geographic, researchers at New York University have created a drone design that mimics the movements of a jellyfish in action (click through to view the unembeddable video of the design in flight). Applied Mathematician Leif Ristroph was looking to create a device inspired by insect wings, but ran into a few issues with the idea:

Insects have built-in sensors and feedback that help them stay upright. Drones based on insect wings need the same support. But motors, sensors and batteries add weight, which becomes problematic for people looking to design smaller and smaller drones. I wanted to design something that had stability without the stability-sensor needs.

Switch out these benign aquatic jellyfish for a slew of jellyfish drones and you've got the opening scene to a horror film

Like all animals that move through air or water, jellyfish need thrust to stay upright and stable. With this in mind, Ristroph decided to flip the wings downward so they force air toward the ground instead of having them open to the sides. Doing this allows some self-stability without extra sensors weighing the drone down. But how does that small adjustment make all the difference? Brad Gemmel, an ecologist from Austin, Texas, explains the physics behind a jellyfish's movement:

"For smaller species that are a few centimeters in size, they use jet propulsion. The animal contracts its umbrella-shaped bell, squeezing out water behind it and creating a doughnut-shaped ring of water called a vortex. That vortex pushes the jellyfish forward. Larger jellyfish add a movement called rowing to their jet-propulsion capabilities. Rowing is when the loose edge of their bell flaps around, creating additional vortices that help to generate thrust. Those loose edges almost push against the fluid like a rower pushes an oar against the water."

There you have it. Currently, the drone needs to be connected to a power supply to stay in-flight, but Ristroph is working on fine-tuning the design for a wire-free future. I can't tell if it would be more shocking to encounter one of these gadgets on a swim or in the air. If anything, the design gives me flashbacks to those tough-to-beat water levels of Mario Bros. featuring the pink, floating jellyfish killers.