Mechanical engineer Raphael Zufferey's lab at MIT contains a giant tank filled with bright turquoise water, an array of fans that can whip up a powerful wind, and small flying robots perched everywhere you look.It's the robots that are the stars of the show here and they're inspired by diving seabirds like the Atlantic puffin, which uses its wings to both fly and swim."These puffins solve this really challenging task of moving in air, in water despite the huge difference in density," says Zufferey.He and his colleagues wanted to see if they could build a bird-sized robot that could also move through both mediums and transition between them.It's something no one had ever done before.In a paper published Thursday in the journal Science, they describe the engineering of just such an aerial-aquatic robot.
It weighs about half a pound and its wingspan measures not quite three feet, tip to tip."This is a beautiful robot," says Glenna Clifton, an animal movement biologist at the University of Portland in Oregon who collaborates with roboticists but wasn't involved in this research project.She says the robot offers insights into what makes the flight biology of diving birds unique.It also has many potential applications including observing the coastal ocean and monitoring something like a remote coral reef.
The robot could fly to the reef — or something else like a pod of whales or an algal bloom — and then sample the water and collect data.Such bio-inspired robots are fertile ground to learn about both nature and engineering."The biology inspires the robotics," says Clifton, "but then also the robotics are used to understand the biology."Creating this robot took two years.
"Thinking of a wing that could operate in both [air and water] somewhat efficiently seems implausible," Zufferey recalls thinking.But he and his colleagues were undeterred.They based the robot's overall body plan on a diving bird, but made a couple of key departures.First, they decided not to inc...