With a flap of its wings, something resembling a bird dives into the water, swims around and soars back into the skies. But it’s not a bird, it’s a robot. And the researchers who created it think that it could be a big help in studying ocean habitats.
For years, scientists have hoped to emulate the movements of diving birds, such as puffins, to create machines that can quietly dip in and out of the water. Such robots could help researchers monitor fragile marine ecosystems, without chartering a research vessel or deploying underwater equipment.
But creating a robot that is as capable in the water as in the sky is a complex engineering challenge. Now, a team of researchers at M.I.T. have created a waterproof winged robot with all the right moves, according to a study published July 9 in the journal Science.
“There was a very good chance that this would have not been possible at all,” said Dr. Raphael Zufferey, a mechanical engineer at M.I.T. and the lead author of the study. “I took that risk because I believed that if birds could do it, with good engineering we might also be able to.”
Dr. Zufferey and his colleagues turned to the nearly 100 species of birds that find food by diving into the water, including petrels, puffins, kingfishers and murrelets. They analyzed existing data about the birds’ speeds and ranges of motion, how frequently they flap their wings, how deep they dive and even the lengths of their tails.
“The benefit of using birds as models is that they successfully perform behaviors robots are bad at or not capable of,” said Dr. David Lentink, an engineer and biologist at the University of Groningen in the Netherlands, who was not involved in the study and who also creates biomimetic robots.
The researchers then started working on the design, using carbon fiber, waterproof electronics and a host of other materials to build something that could fly and dive without getting waterlogged. Then, the challenge was getting their creation to leave the water. In order to collect data on coastal habitats or water quality, it had to be able to both enter and exit the water.
“Figuring out that transition was definitely the hardest part,” Dr. Zufferey said. “I think it took us about one year to be able to do this.”
After the researchers altered the flight angle and streamlined the body proportions, the robot was able to successfully emerge from the water. They envision many future uses: the collection of water samples near harmful algal blooms, or the video recording of endangered marine mammals.
“With its small size, the flapping-wing robot may be able to explore more remote, small marine areas that larger, heavier gliders, or unmanned underwater vehicles may be too big to access,” said Dr. Cassondra Williams, a marine physiologist at the National Marine Mammal Foundation, who was not involved in the study.
Still, before it can explore the coastline, researchers see areas for improvement, such as in the distance their false puffin can fly. Outside the lab, it is estimated the robot might be able to fly as many as four miles with its current motor and materials. Dr. Zufferey hopes the robot will eventually be able to go farther.
“There are birds that fly from Alaska to New Zealand in a single flight,” he said. “So there’s hope that we can vastly improve on this. It just takes more research.”
