A robotic jellyfish dubbed "Robojelly" was created by a team of researchers at the University of Texas at Dallas and Virginia Tech. The robot runs on hydrogen, and so might theoretically run forever in an underwater environment.
The study, which was published in journal Smart Materials and Structures, details how such a device could be "ideal" for underwater research, as well as search and rescue operations. The researchers, led by Yonas Tadesse, a mechanical engineering professor at the University of Texas at Dallas, constructed the robot from carbon nanotubes and "smart materials" which can change shape or size as a result of stimulus. It mimics the movements of a jellyfish when placed in water, and also uses the water in a chemical reaction that takes place on its surface.
"To our knowledge, this is the first successful powering of an underwater robot using external hydrogen as a fuel source,” IOP quoted Tadesse as saying.
The abstract to the study states that a hydrogen and oxygen fuel source could potentially provide a higher power density than electrical sources. The reaction that powers the robot is produced by the chemical reactions that take place when hydrogen and oxygen interact with platinum on the surface 'skin' of the robot. The heat from this reaction powers its artificial muscles.
You can see the "Robojelly" in action below, and though it may seem jerky and unimpressive, Tadesse says this is only the beginning. “The current design allows the jellyfish to flex its eight bell segments, each operated by a fuel-powered SMA module," Tadesse said. "This should be sufficient for the jellyfish to lift itself up if all the bell segments are actuated."
“We are now researching new ways to deliver the fuel into each segment so that each one can be controlled individually. This should allow the robot to be controlled and moved in different directions.”