New Shape-Shifting Robot Turtle Can Navigate Land and Sea

(Image: Baines et al/Nature) You know all about robot dogs and robot crabs, but have you ever seen a robot turtle? A group of engineers at Yale University and West Chester University have created a mechanical turtle that morphs to traverse land or water. Their hope is that the robot will help humans explore “treacherous” shores.

The team used biomimetic design—which takes inspiration from an animal’s morphology, propulsion techniques, and stride—to combine key physical features from a sea turtle and a land-dwelling tortoise. The resulting machine, dubbed the Amphibious Robotic Turtle (ART), is capable of navigating both animals’ environments.

“Animals that primarily inhabit one ecological niche tend to exhibit specialized body plans,” the engineers write in the journal Nature. “Environmental specialization also holds true for mobile robots, which are typically confined to operate exclusively on land or in water.” ART breaks this mold. With its buoyant body and legs that can morph into “flipper mode,” ART can not only navigate land and sea, but also smoothly transition between both terrain.

(Image: Baines et al/Nature)

ART’s limbs consist of an internal “muscle” and a malleable outer layer. The outer layer is a composite polymer material that’s stiff at cooler temperatures but becomes malleable when warm. When ART needs to morph from turtle to tortoise mode or vice versa, built-in copper heaters heat the limbs from the inside out, allowing the composite polymer to soften. The aforementioned robotic “muscle” then swells to turn a flat flipper into a cylindrical leg (or deflates to do the opposite). The legs cool and stiffen one to two minutes after the copper heaters turn off, allowing for plenty of time to transform. Conventional robotic shoulder joints are what move each individual limb, facilitating ART’s swimming and walking capabilities. PVC pipes surround ART’s internal modular chassis to protect it from water, while the robot turtle’s lightweight 3D printed shell gives it buoyancy.

At its fastest, ART can “swim” at 0.083 meters per second (m/s) and walk at 0.03 m/s. This is a bit slow compared with its biological muses: Sea turtles typically cruise through the ocean at 0.5 m/s, while tortoises walk at about 0.16 m/s. ART’s engineers admit in their paper that they’ll probably need to tweak the robot’s gait to help it pick up speed and appear a bit more graceful. Their prototype also requires a power and communication tether. This would be impractical in the real-world scenarios ART is meant for, like exploration and ecological monitoring. Still, ART offers a peek at what multi-terrain soft robots could look like or accomplish.

Now Read:

• MIT: Taxing Robots Might Stave Off Job Loss, Income Inequality
• San Francisco Legislators Approve Use of Lethal Police Robots
• MIT Is Working on Self-Assembling Robots