Robojelly is a hydrogen-powered robot that mimics the look of movements of a real jellyfish.It is five-foot and seven inches wide, 170 pounds. This projects are funded by U.S. Naval Undersea Warfare Center and the Office of Naval Research. The robot began as a biomimetic jellyfish robotic project at Virginia Tech. The goal is to place self-powering, autonomous machines in waters for the purposes of surveillance and monitoring the environment. Large jellyfish robots could also be used to study ocean life, map ocean floors and monitor ocean currents. Robojelly is helping engineers and biologist understand the function of various parameters found on jellyfish. It allows them to vary different components and analyze their role. This would otherwise be impossible on the natural animal without disabling natural functions. Dr. Yonas Tadesse, assistant professor of mechanical engineering at UT Dallas and lead author of the study says, "To our knowledge, this is the first successful powering of an underwater robot using external hydrogen as a fuel source." Look the video
in the source.