Soft Body Robot Burrows Underground Like a Snake

Robots can traverse the land, air, and sea. Now, you can also find them underground. Researchers at the University of California, Santa Barbara and Georgia Tech have developed a new snakebot that can burrow underground. With technology based on burrowing plants and animals, the soft robot is fast, flexible, and can easily dig through granular material, like sand.

This snakebot is a soft body robot, a robot that uses flexible materials to make it lighter and more adaptable. Since it doesn’t have rigid parts, the bot can easily bend, twist, and contort its body. Even with this, robots digging through material is a challenge due to the friction created. The snakebot can grow from the tip while the rest of the body is stationary. Researchers found that tip extension reduces resisting forces and localizes it to only the growing end. Friction over the entire surface would increase if the entire body was moving.

Another thing that makes it easy for snakebot to burrow is granular fluidization. Inspired by animals like the southern sand octopus, granular fluidization suspends particles in the fluid-like state, allowing the animal to over the resistance of sand or loose soil. Similar to the sand octopus, which shoots water into the ground to loosen sand, snakebot shoots a blast of air into sand to help it dig and remain underground as it burrows.

“Frictional force response in granular materials greatly differs from that of Newtonian fluids, as intruding into sand can compact and stress large swaths of terrain in the direction of motion due to high friction,” said Andras Karsai, a graduate student researcher in Goldman’s lab. “To mitigate this, a low-density fluid that lifts and pushes grains away from an intruder will often reduce the net frictional stress it has to overcome.”

Researchers believe the snakebot has a wide variety of applications, such as soil sampling, underground installation of utilities, and erosion control. The way it moves via tip extension could even prove useful for exploring low gravity environments. NASA is already interested in technology. The team is currently working with NASA to develop burrowing for the moon and more distant bodies.

“We believe burrowing has the potential to open new avenues and enable new capabilities for extraterrestrial robotics,” Hawkes concludes.