Discover the Lightning-Fast Soft Robot Mimicking Manta Ray Grace!

Scientists in the United States have drawn inspiration from the elegant, bird-like movements of manta rays to develop a swift robot that adeptly navigates through water.

They assert that their design for a soft, aquatic robot is ideal for intricate and unstructured settings, such as deep-sea exploration and environmental surveillance both at the surface and underwater.

The newly developed soft robot achieves a speed of 6.8 body lengths per second.

“The earlier model was limited to swimming on the water’s surface,” explains Jie Yin, an associate professor of mechanical and aerospace engineering at North Carolina State University and the lead author of a study detailing the research in Science Advances.

“Our upgraded robot can swim vertically throughout the water column.”

The fins, resembling those of a manta ray, are affixed to a flexible silicone structure containing a chamber that can be filled with air.

By inflating the chamber, the fins bend similarly to the downstroke of a manta’s fin movements. Releasing the air from the chamber allows the fins to quickly revert to their original position.

A power source and air pump float on the water’s surface, linked to the robot via a slender air hose.

Co-author Jiacheng Guo, a PhD candidate at the University of Virginia, remarks: “We studied the swimming patterns of manta rays and were able to replicate that behaviour to dictate whether the robot ascends, descends, or holds its position within the water column.

“As manta rays swim, they generate two jets of water that propel them forward. Mantas change their path by modifying their swimming style,” Guo explains.

“We implemented a comparable method for regulating the vertical motion of this swimming robot.”

Yuanhang Zhu, co-author and an assistant professor of mechanical engineering at the University of California, Riverside, notes that the downward water jet created by the robot is stronger than the upward jet.

“When the robot flaps its fins rapidly, it ascends,” Zhu states.

“However, by decreasing the actuation frequency, it enables the robot to slowly sink between flapping, allowing it to either descend or maintain depth.”

The air chamber remains inflated longer when the robot flaps its fins at a higher frequency, leading to increased buoyancy.

The research team demonstrated that their manta-inspired robot was capable of navigating obstacles on both the surface and the bottom of a tank. It was also adept at carrying a load on the water’s surface, including its air and power supply.

“This represents a highly sophisticated design, but the basic principles are quite straightforward,” states Yin.

“Using just a single actuation input, our robot can traverse a complex vertical environment.

“We are currently focusing on enhancing lateral movement and investigating alternative actuation modes, which will significantly boost the system’s capabilities. Our aim is to achieve this while maintaining a design that embodies that graceful simplicity.”