MIT's robo-puffin can swim underwater, then fly away
The experimental flapping-wing aerial-aquatic vehicle can dive, swim and take off again, opening a possible route to cheaper ocean research.
MIT and EPFL engineers have designed a small robot that can swim underwater and then take off into the air, borrowing the broad idea from diving birds. The flapping-wing aerial-aquatic vehicle, or FAAV, is built to move through two environments that normally demand very different machines. 1
A robot that crosses the air-water boundary
The FAAV weighs less than 300 grams and uses a central fuselage, two flexible wings and a steerable tail. A battery and waterproof electric motor drive a crankshaft that moves the wings. The wing membranes are coated with hydrophobic nanoparticles to help shed water, while the motorised tail changes angle as the vehicle dives or climbs. 1
MIT and EPFL tested the design in a water tank and at Lake Geneva. The team, led by Raphael Zufferey, measured how wing size, flapping frequency and tail angle affected the transition between swimming and flight. The best results came from medium-sized wings: flexible enough to reduce the effort needed underwater, but firm enough to keep the vehicle airborne. 1
The researchers found that the vehicle could work without feet to push against the water. A steep pitch of around 70 degrees helped it make the jump from the lake surface into the air, with speeds and wingbeat frequencies similar to those seen in real diving birds. That is useful because a machine that can launch, dive, collect data and return could be more practical than sending separate aerial and aquatic vehicles. 1
What the robot could be used for
The immediate goal is not a consumer drone. The engineers say future versions could help oceanographers, marine biologists and coastal communities sample difficult or dangerous locations. A vehicle could fly from a boat or shoreline, dive to take a measurement, return with its data and repeat the trip without the cost of a traditional research vessel. 1
The design is still experimental. The team is working on wings that can turn as well as flap, and plans to test the robot in choppy water and stronger winds. Those trials will show whether the controlled lake demonstrations translate into the messy conditions that matter for real field work. 1
Our opinion
The interesting part is not the novelty of a robot that looks like a bird. It is the engineering compromise. Air and water punish inefficient designs in different ways, yet the FAAV uses one wing system and a small motor to move between them. That makes the project a promising research platform rather than a gimmick.
The next challenge is reliability. A prototype that swims and flies in carefully chosen conditions is a long way from a robot that can find a target, survive waves and deliver useful measurements repeatedly. Still, the concept points towards cheaper, more flexible environmental monitoring, especially where a boat is too slow, expensive or risky. MIT and EPFL have demonstrated the transition; the harder question is whether the same machine can make it dependable. 1