Robot Mimics Diving Birds, Transitions Between Flight and Underwater Swimming

Researchers at MIT and EPFL have created a "flapping-wing aerial-aquatic vehicle" (FAAV) that can transition from swimming underwater to flying in the air, mirroring the capabilities of diving birds like puffins and gulls. This robot, weighing under 300 grams, is designed to aid scientists in studying the mechanics that allow these birds to navigate both mediums, which possess vastly different physical properties.

The FAAV features a central fuselage, two flexible flapping wings, and a steerable tail. These components, including the wings, can be interchanged for different sizes to optimize performance. Through experiments conducted in a water tank and a natural lake, the engineering team identified specific combinations of wing size, flapping frequency, and tail angle that enable a smooth transition from underwater propulsion to aerial flight.

The findings, published in the journal Science, could deepen the understanding of how diving birds adapt their flight dynamics to water's significantly higher density compared to air. The development also opens the door for a new category of aerial-aquatic drones.

The researchers envision these winged robots being utilized in oceanography for sampling in remote or hazardous aquatic regions. Lead author Raphael Zufferey, of MIT's AURA Lab, described a future where such robots could be launched from boats or shorelines to fly to an area of interest, dive for measurements or samples, and return with data, offering a cost-effective alternative to traditional methods.