Engineers at MIT and EPFL in Lausanne, Switzerland, have built a robot that can both swim and fly, a design that could lead to a new class of vehicles for ocean exploration. The "flapping-wing aerial-aquatic vehicle," or FAAV, weighs less than 300 grams (about half a pound) and has a central fuselage, two flexible wings, and a steerable tail. A battery and a waterproof electric motor drive a crankshaft that pumps the wings up and down. The wings are thin membranes coated with hydrophobic nanoparticles to help wick away water, and the motorized tail changes angle to help the robot fly up or dive down.
In experiments in a water tank and at Lake Geneva, a team led by Raphael Zufferey, an assistant professor of mechanical engineering at MIT, identified combinations of wing size, flapping frequency, and tail angle that let the robot move smoothly from swimming to flying. The best results came from medium-size wings that were flexible enough to limit flapping amplitude in water yet firm enough to keep the robot aloft. A 70-degree pitch allowed the robot to leap from water into air. Unlike many diving birds, the bot did not need feet to take off from the surface.
Zufferey envisions oceanographers, marine biologists, and coastal communities launching the robot from a boat or shore to fly near an iceberg, a port facility, or a pod of whales. It would dive to take measurements or collect samples, then fly back to deliver data at a fraction of the cost of traditional methods.
The researchers are next working on wings that can turn as well as flap, and they plan to test the robot in choppy water and windy conditions. "You could send this out not just every week, but every hour," Zufferey says.
Source: MIT Technology Review · Summarized by HeadlinesBriefing