Mighty Morphin’ Turtle Robot Goes Amphibious by Shifting Leg Shape

Future machines that navigate complex real-world conditions may be possible thanks to a new turtle robot.

The Amphibious Robotic Turtle (ART) can change its limbs from turtlelike flippers to tortoiselike legs. The senior author on the paper is a roboticist from Yale University. The system has four limbs and can transition between a flipper state for swimming and a leg state for walking.

When hot and cool, the morphing limbs are surrounded by a material that is flexible. In order to change the limb's shape, built-in copper heaters need to be used. Then a soft robotic "muscle" under the swells or deflates, shifting a flat flipper into a rounded leg. The new shape is formed by the cooling and hardening of the polymer. The soft robotic limbs attach more traditional "hard" robotic shoulder joints, which incorporate three electronic motors so ART can "crawl" or "crap" on land as well as "Paddle" or "flap" in water. The robot's electronic components are protected from water by sealed tubes. A 3D-printed shell gives the robot a streamlined shape and a space that can hold air or ballast.

A roboticist who did not contribute to the new study says that ART's ability to transform is due to the integration of both soft and traditional robotic devices. When using traditional robotic techniques, there are very strict, rigid modes of movement. You might be able to do something that is more fluid with these techniques.

It's possible that adaptive techniques will eventually allow robots to walk across the many different surfaces and environments found in the real world. The team found that ART uses the same amount of energy as a robot.

The current prototype of the robotic tortoise requires a tether to communicate, and its movements are slow and awkward. These issues are being improved by the researchers. I'm excited to see how far they've come I am interested to see what comes out of this group in the future.