Along with their writhing tentacles, octopi and squid sport another interesting feature – they swim not by swishing a tail, but by expelling a jet of water. This allows them to move very quickly and quietly. Scientists from Germany’s Fraunhofer Institute for Manufacturing Engineering and Automation have now copied this system, in a propulsion system that could ultimately find use in boats, recreational watercraft, or submarines.
The miniature prototype system consists of four joined 20 x 6-cm (7.9 x 2.4-in) elastomer balls, each with a hydraulic piston inside. Initially, water is sucked in through an opening in each ball – just as a squid or octopus draws water into its mantle. Cables integrated into the balls then cause them to contract, rapidly expelling the water.
via Gizmag
