Clemson roboticists have designed robots that can crawl, jump and now swim. Could flight be next?
Prashanth Chivkula Ph.D. ’25 (second from left) was a graduate student at Clemson University when he began developing a fish-like robot that shows promise for helping monitor lakes and oceans or collecting water samples.
He liked it so much that he decided to stay as a postdoctoral researcher.
“I want to be a roboticist, and that’s what motivates me every day — to make robots that do something useful in the world,” Chivkula said.
Chivkula works in the lab of Phanindra Tallapragada, a professor of mechanical engineering who has led the development of multiple robots that run on centripetal force.
The robotic fish was recently in the spotlight because it has passed a major milestone. Researchers showed the robot works not only in the controlled conditions of an indoor pool but also in Lake Hartwell, where it must contend with wind and waves.
“We recently published a paper saying that the efficiency of this robot is extremely high,” Tallapragada said. “It’s about one-third as efficient as a bluefin tuna, but compared to most swimming robots, we think the efficiency is more by a factor of 20 or 30.”
To understand the centripetal energy that moves the robots, think of a dryer with a few sopping-wet clothes that stick to one side as the barrel inside spins. What happens? The dryer starts to vibrate and even takes little leaps off the ground if the barrel whirls fast enough.
In the fish robot, a spinning, unbalanced mass in the body sends energy into its tail. By changing how fast the mass spins, the team can control how it dives, turns and moves.
For Tallapragada, lifelike robots are a piece of a larger puzzle. They are the physical embodiment of the math that drives their movements.
“A lot of robotics today is perceived as designing something with motors, microcontrollers, machine learning and AI — and less importance is given to the dynamics and math, at least in the public perception,” Tallapragada said. “I want to change that a little bit by coming up with these very different kinds of mobility, which are based on mathematics.”
Now that the team has created robots that can swim, jump and crawl, it is looking to go higher — literally — with a new project that could lead to robots that fly like insects.
And maybe not even the sky is the limit. Robots moved by centripetal force could one day help explore other planets’ icy moons, where scientists believe liquid water may lie beneath the surface, Tallapragada said.
A single robot that can roll, jump, swim and fly could navigate ice, leap through volcanic vents, and dive into subsurface oceans to search for signs of life, he said.
“I just like working on these new ideas that are very different from what others are doing and seeing them come to physical action,” Tallapragada said. “Once they come into action, that gives me more motivation to go back to the whiteboard and come up with more models.”
