In the world of robotics, a faction of the field focuses on what is termed soft robotics. In the case of some MIT researchers, their soft robotics work have resulted in a form of fish made, in part, with moving fluid. Even better, the robotic fish are able to swim, which is demonstrated in a video we have after the jump.
The work is a study in soft robotics, and in particular on the use of a body that can deform -- in this case, of a fish's body that is able to curve as the robot flexes, providing it with advantages that a robot with a hinged body would not have. In this case, a channel is constructed in the fish that inflates with carbon dioxide, allowing the tail to move.
Because of the construction, the fish is able to perform escape maneuvers until it runs out of carbon dioxide, which in the current iteration is 20 or 30 maneuvers. In the future, as the technology is refined, the longevity of the device will be increased. A new design will use water instead of carbon dioxide for inflation.
Said one of the researchers who helped create the robotic fish, Daniela Rus, "We're excited about soft robots for a variety of reasons. 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."