Inspired by feather stars: underwater robot moves in 3D with only two actuators
Engineers at NC State University have built a soft swimming robot that can rise, sink, hover, swim forward and rotate using only two actuators.
Photo: Alexander Vasenin / Wikimedia Commons, CC BY-SA 3.0 (cropped and resized)
Video: YouTube · Yin Lab@NCSU · youtube.com
Researchers at North Carolina State University have taken their cue from feather stars to build a swimming robot. These marine animals can move in any direction or hover in place by coordinating their arms. The robot has four elastic wings attached to a central disk with only two pneumatic actuators; the wings bend and then snap back into their original position. The study was published in the journal Science Advances, with the University of Virginia and the University of California, Riverside, also taking part.
The robot has three modes: when both actuators pulse together, it moves like a jellyfish – rapid flapping makes it rise, slow flapping lets it hover and stopping makes it sink. When only one actuator works, one wing flutters like a tailfin and drives it forward or backward. Alternating between the two makes it rotate on its axis. According to the study, it reaches up to 1.64 body lengths per second and rotates at up to 90 degrees per second.
"Normally, you would need at least six actuators to accomplish this," says project leader Jie Yin, a professor of mechanical and aerospace engineering. Possible uses include exploring underwater spaces with an onboard camera or lifting objects underwater, alone or together with other robots. Next, the team wants to develop a fully wireless version.