MIT‑EPFL bio‑inspired robot swims underwater then takes flight

Researchers at MIT in the United States and EPFL in Switzerland have built a 250‑300 gram bird‑scale robot, dubbed FAAV, that can swim underwater, dive, launch from the surface and then fly using flapping wings. The device mimics diving birds such as gulls and puffins, employing flexible wings that bend passively in water and flap up to 11 Hz in air. It is neutrally buoyant and can break the water‑air interface at an angle of about 70°, completing the transition in under a second with eight to ten wingbeats.

Tests in a water tank and on Lake Geneva showed the robot reaching nearly 1 m/s underwater and about 6 m/s in flight. The team released open‑source CAD files, noting that the robot can be built for roughly US$300. While it is not yet autonomous, the researchers envision amphibious drones for oceanographic sampling, coastal monitoring, iceberg tracking and maritime infrastructure inspection.

The project, described in a Science paper, highlights a new engineering approach to crossing the density gap between water and air and provides a physical model for studying the biomechanics of diving birds.