Tuesday, April 9, 2024

Robotic sea turtle mimics a real sea turtle’s propulsion

Sea turtles are truly fascinating creatures that can glide majestically through ocean waters and maneuver like armored vehicles over rocks and sand on land. The sea turtle’s unique body shape, flipper morphology, and varied gait patterns allow them to be so adaptable to their environment.

This impressive locomotive adaptability has captured the attention of robotics experts, who seek to learn the secrets of their gait and propulsion in order to improve technology. Studying how sea turtles adapt their gaits to traverse complex and varied terrains can help researchers design more versatile robots.

Now, researchers have designed and built a robotic sea turtle that mimics a real sea turtle’s propulsion. Its front flippers move it forward, while its smaller hind flippers allow it to change direction.

The research team includes Yasemin Ozkan-Aydin, a roboticist and assistant professor of electrical engineering at the University of Notre Dame, Nnamdi Chikere, a Notre Dame electrical engineering doctoral student, and John Simon McElroy, an undergraduate from University College Dublin and a Naughton fellow at Notre Dame.

The turtle robots consist of four independently radio-controlled flippers, an electronic onboard control unit, a multi-sensor device, and a battery. Its oval-shaped body frame and flipper connectors are 3D printed using a rigid polymer. The flippers are molded from silicone to provide both flexibility and stiffness.

The robotic sea turtle was designed using data from zoological studies on the morphology, gait patterns, and flipper flexibility of multiple sea turtle species.

“To maximize adaptability and versatility, we studied the locomotion patterns of different species and incorporated the most effective aspects from each,” Ozkan-Aydin said.

The team modeled the robot on the size and structure of sea turtle hatchlings. Sea turtle babies are particularly vulnerable – it is estimated that, on average, only one out of every thousand sea turtle hatchlings make it to adulthood.

Hatchlings encounter predatory seabirds on their journey from nest to sea, and the journey has become more dangerous due to beach development and the disturbed landscape of debris.

Researchers are currently testing in varied environments on Notre Dame’s campus. “Our hope is to use these baby sea turtle robots to safely guide sea turtle hatchlings to the ocean and minimize the risks they face during this critical period,” Ozkan-Aydin said in the press release.