Looks like a fish, acts like a fish, it must be a... robot?

Researchers at MIT have created a robotic fish. Unlike land-based robots, this one has all the fluidity that we would expect from a marine animal. It's called a "soft robot" and is "powered by fluid flowing through flexible channels," according to a press release.

The fish is flexible to maneuver itself out of harm's way, changing direction in a fraction of a second.

"We're excited about soft robots for a variety of reasons," Daniela Rus, director of MIT's Computer Science and Artificial Intelligence Laboratory, said in the release. "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."

"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.

Designed by MIT graduate student Andrew Marchese, the fish looks simple, but it's mechanics are hardly so.

"Each side of the fish's tail is bored through with a long, tightly undulating channel. Carbon dioxide released from a canister in the fish's abdomen causes the channel to inflate, bending the tail in the opposite direction. Each half of the fish tail has just two control parameters: the diameter of the nozzle that releases gas into the channel and the amount of time it's left open," the statement explained.

For now, the fish can perform between 20 and 30 escape maneuvers, or directional changes, before it runs out of the carbon dioxide that it relies on to function. Simple one-directional swimming exhausts the supply even faster.

"The fish was designed to explore performance capabilities, not long-term operation," Marchese said. "Next steps for future research are taking that system and building something that's compromised on performance a little bit but increases longevity."