A robot that can morph its limbs depending on whether it’s on land or in water has been developed by a team of Yale researchers. The amphibious robot takes inspiration from terrestrial and aquatic turtles, with potential exploration and monitoring applications in extreme environments.

“Terrestrial and aquatic turtles share similar bodies, with four limbs and a shell, but have distinctive limb shapes and gaits adapted for their specific environment,” said Rebecca Kramer-Bottiglio, lead author of the study. “Sea turtles have elongated flippers for swimming, whereas land turtles and tortoises have rounded legs for load bearing while walking.”

Dubbed ART (Amphibious Robotic Turtle), the robot features adaptable limbs that can change their shape and flexibility in response to their environment, in a process the team calls “adaptive morphogenesis.” In this process, the robot’s artificial muscles transition from the equivalent of those of a four-legged animal to flippers, allowing it to move seamlessly from running to swimming.

“Our results show that adaptive morphogenesis can enhance the efficiency of robots that locomote through multiple environments,” said Kramer-Bottiglio.

Designing multi-environment robots has gained increased interest in recent years, as innovators work to harness robotic solutions for exploration and monitoring purposes in a range of industries; from ecological monitoring to warehouse management and extreme environment exploration.

While other amphibious robot designs often require the addition of a propulsion system to the robot’s body, ART simply adapts its shape to the environment, avoiding the need to remove the robot from the environment and manually adapt its shape.