RoboBass: New Soft Robot Can Execute Escape Maneuvers Like a Real Fish [VIDEO]

Engineers from the Massachusetts Institute of Technology have developed a self-contained, autonomous soft robot fish with a flexible spine that allows it to mimic the swimming motion of a fish. And, just like a fish, the soft robot can execute escape maneuvers by convulsing its body to change direction at speeds nearly a quick as a real fish.

Soft robots, which have soft exteriors and are powered by fluid flowing through flexible channels, are a rapidly expanding field of robotics, so much so that a new journal, Soft Robotics, has been started to keep up with the work going on in the field.

The MIT researchers report their development in the inaugural issue of Soft Robotics.

"We're excited about soft robots for a variety of reasons," said Daniela Rus, director of MIT's Computer Science and Artificial Intelligence Laboratory, and one of the researchers who designed and built the fish. "As robots penetrate the physical world and start interacting with people more and more, it's much easier to make robots safe if their bodies are so wonderfully soft that there's no danger if they whack you."

Soft robots have many advantages over their more ridged counterparts, one being that the risk of being damaged in an undue collision can be avoided. In most traditional robotics systems, planning to avoid collisions is one of the highest priorities of the engineers, Rus said.

But with soft robots, a collision won't break months or years of hard work. In fact, Rus said a collision could even be a desirable thing for a soft robot.

"In some cases, it is actually advantageous for these robots to bump into the environment, because they can use these points of contact as means of getting to the destination faster," Rus said.

For the new soft robot fish, a third advantage presented itself. "The fact that the body deforms continuously gives these machines an infinite range of configurations, and this is not achievable with machines that are hinged," Rus said.

The continuous curvature of the fish's body when it flexes is what allows it to change direction so quickly. "A rigid-body robot could not do continuous bending," she says. Additionally, the robotic fish's soft curvature is what allows it to change direction so quickly, enabling it to preform escape maneuvers like real fish. Such versatile and continuous bending is not feasible with a rigid-body robot, Rus said.

The robotic fish is powered by a carbon dioxide canister embedded with in it. The gas is shot through channels drilled into either side of its tail, causing it channel to inflate and initiate the tail bending in the opposite direction.

In its current state, the fish can perform 20 or 30 maneuvers, depending on their velocity and angle, before the CO2 canister is depleted. Just swimming on one direction actually depletes the gas canister faster than if the robot is preforming escape moves.

 "The fish was designed to explore performance capabilities, not long-term operation," said the robot's builder Andrew Marchese, a graduate student in MIT's Department of Electrical Engineering and Computer Science and lead author on the new paper.

"Next steps for future research are taking that system and building something that's compromised on performance a little bit but increases longevity," Marchese said.

“This innovative work highlights two important aspects of our emerging field; first it is inspired and informed by animal studies (biomimetics), and second it exploits novel soft actuators to achieve life-like robot movements and controls,” said Soft Robotics Editor-in-Chief Barry A. Trimmer.