Soft 3D-Printed Robot Is Agile Even on Sand and Rocks

As a headless robot crawls over a pile of pebbles, its jointless, rubbery legs carefully but confidently sample the terrain in steady, yet unrushed movements that resemble a turtle's. The robot's ability to reliably walk across different types of surfaces is unique, and so is the fact that its elaborately shaped legs were created with a 3D printer, according to the engineers who developed the bio-inspired creature.

"With soft robots, you can do a lot of things that are difficult for a hard robot," said Mike Tolley, a mechanical engineering professor at the University of California, San Diego, who led the research. "[F]iguring out exactly how to place parts of your body or get around in a very unpredictable environment becomes a lot easier when your body is soft."

The combination of soft and stiff materials enables living creatures to adjust to the irregularities in terrain that frequently stop current rigid robots in their tracks. [The 6 Strangest Robots Ever Created]

But the new robot, which will be presented at the IEEE International Conference on Robotics and Automation in Singapore next week, is a big step forward in robotic agility, according to Tolley.

In a video made by the researchers, the robot can be seen nimbly creeping into a narrowing corridor, just like a real animal would. Its four legs, positioned in an "X" shape, can alternate between walking, climbing and crawling — or even a type of motion that resembles swimming. The robot can move forward and backward, and can rotate and move sideways without needing any sensors to "see" the environment, the scientists said. Its speed, however, is rather modest — about 0.8 inches (20 millimeters) per second.