The U.S. Navy’s Office of Naval Research is funding researchers from a handful of schools including the University of Texas and Virgin Tech to build a robot jellyfish. The projected was dubbed “Robojelly” in a paper published in the journal Smart Materials and Structures. The Robojelly is made up of a combination of silicone and other high tech materials not specified. One interesting aspect of the robot’s construction is artificial muscles. These muscles are constructed of an alloy that has shape memory, meaning the alloy when deformed remembers and returns to it’s original shape. The robot is powered by a chemical reaction when natural seawater containing oxygen and hydrogen contacts the artificial muscle. CNET News explains the process like this:
The Robojelly’s bell is made of silicone that contains ribs of springy steel. And the steel, in turn, is attached to a structure made of platinum-coated nanotubes and the shape-memory alloy, made of nickel-titanium. A valve opens, allowing seawater–and the oxygen and hydrogen gases it contains — to come into contact with the nanotube-alloy structure. The platinum reacts, generating heat that activates the shape-memory alloy and causes it to deform, pull on the steel, and close the bell. When the nanotube-alloy structure cools, the alloy returns to its shape, releasing its pull on the steel and allowing the bell to reopen–and the process to repeat.