NC State (Robotic) Swimmer Breaks World Record
01/13/2025 08:00 AM
By Laura Rosado on SwimSwam
NC State isn't just home to a top swimming program; it's also home to a research team that creates the fastest swimming soft robots in the world.
In soft robotics, machines are designed with flexible materials. They are often controlled using "soft" methods of actuation such as pneumatics rather than rigid solutions.
Two years ago, the Yin Lab at NC State set a record for the fastest swimming soft robot at 3.74 body lengths per second. In December of 2024, the group published a paper demonstrating a new design that can reach up to 6.8 body lengths per second.
The robot itself is less than 100 mm long, meaning its top speed is under 0.1 meters per second. For comparison, Ryan Held(6'1") holds the school record in the 50-yard freestyle for NC State at 18.56. 6.8 body lengths per second at Held’s height would cover over 250 yards in the same amount of time.
The new robot takes inspiration from the shape of a manta ray. It consists of a soft pneumatic actuator (the "body") and two rigid fins. When the robot is actuated by inflating the body, the fins bend as a mimicry of the down stroke as a manta when it flaps its fins. The fins are monostable, meaning as soon as the body is deflated the fins snap back to their original position.
The monostability is the innovation of this work, as the previous "butterfly" design was bistable and required actuation for both the down- and up- stroke (NC State News). In addition, the new design has the ability to vary its depth depending on the actuation frequency. This increases both the robot's efficiency and vertical maneuverability.
"Pumping air into the chamber introduces energy into the system," says Haitao Qing, first author of the paper and a Ph.D. student at NC State. "The fins want to return to their stable state, so releasing the air also releases the energy in the fins. That means we only need one actuator for the robot and allows for more rapid actuation" (NC State News).
The next step for the team is to improve lateral movement of the system and explore new methods of actuation that does not require the device to be tethered.
Check out a video of the robot in action below:
The full list of authors consists of Haitao Qing (NC State), Jiacheng Guo (UVA), Yuanhang Zhu (UC Riverside/UVA) Yinding Chi (NC State), Yaoye Hong (NC State), Daniel Quinn (UVA), Haibo Dong (UVA), and Jie Yin (NC State).
- Read the paper describing the manta-inspired design.
- Read the paper describing the previous "butterfly" design.
Read the full story on SwimSwam: NC State (Robotic) Swimmer Breaks World Record
