Robot fish

MIT researchers are designing a school small robotic fish that could be used to explore underwater spots difficult for humans to reach. For example, they could act as remote sensors, traveling through oil pipes or shipwrecks, or collecting environmental data. The 5 to 8-inch long prototypes, made from soft polymers, mimic real fish that swim by tensing and relaxing muscles to produce a vibration in their bodies. From MIT News Office:
"With these polymers, you can specify stiffness in different sections, rather than building a robot with discrete sections," says (mechanical engineering professor Kamal) Youcef-Toumi. "This philosophy can be used for more than just fish" - for example, in robotic prosthetic limbs... Later this fall, the researchers plan to expand their research to more complex locomotion and test some new prototype robotic salamanders and manta rays. "The fish were a proof of concept application, but we are hoping to apply this idea to other forms of locomotion, so the methodology will be useful for mobile robotics research - land, air and underwater - as well," said (grad student Pablo) Valdivia Y Alvarado.
"Robots swim with the fishes"