Soft robotic fish swims as gracefully as a real fish; revolutionizes robot paradigm

If the argument that art imitates life holds true, than MIT’s fish-like soft robot ― a robot powered by fluid flowing through flexible channels ― is art. Researchers from the prestigious university are boasting that their soft robotic fish is the first self-contained, autonomous soft robot in the world, capable of precisely mimicking fish body movement. By precisely convulsing its body and changing direction split second, the robot can execute escape maneuvers with the same gracefulness as real fish.

Soft robots are significant for a number of reasons; first, soft exteriors grant robot designers much more wiggle room for establishing a smoother motion-planning system, which is typically inefficient and rigid as a result of robot seeking a collision-free trajectory for its movement. Secondly, collision will pose minimal threat to the robot or its environment and in some cases, even help the robot reach its destination faster.

“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,” explains Daniela Rus, a professor of computer science and engineering, director of MIT's Computer Science and Artificial Intelligence Laboratory and one of the fish-robot builders.

But the most important reason for developing soft robots, according to Professor Rus, is 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.” The flexible curvature of the fish robot’s body is what enables it to replicate fish escape maneuvers in the first place.

The robot was primarily built by MIT Department of Electrical Engineering and Computer Science graduate student, Andrew Marchese, with assistance from Professor Rus. Publishing his paper in Soft Robotics ― yes, there’s a science journal for this ― Marchese explains that the robot works with the help of carbon dioxide canister located in the fish’s abdomen. Both sides of the fish’s tail is bored with a long, undulating channel, so when the carbon dioxide from the canister is released, the abdomen causes the channel to inflate, bending the tail in the opposite direction.

Controlling the fish’s action is matter of manipulating only two control parameters: the duration of abdomen inflation almost completely dictates the fish’s bend angle. Secondly, the nozzle diameter is what determines the speed of the robots movement. An interesting fact worth pointing out is how this system parallels a real fish’s biology, implying that artificially engineered behavior may shed some light on how mechanisms in nature function.

Marchese constructed the robot using MIT’s 3-D printer lab, to build fabricate the mold used to cast the fish tail and head. These molds were then filled with silicone rubber and polymer ring to provide flexibility as well as protect the inner electronics from water.

Story via MIT