pigrabbitbear writes with an excerpt from an article at Motherboard: "Earlier last week we heard about the strange blob-bot, an amoeba-mimicking, pulsating, little horror of a robot. But that's nothing in the face of news that engineers at Virginia Tech have built a robotic jellyfish. As if the threat of the oceans being taken over by deadly stinging jelly cyborgs isn't scary enough, there's this: the researchers claim that, because their Robojelly is powered by a hydrogen-based catalytic reaction, rather than electricity, it could 'theoretically' power itself indefinitely. When you consider our best options for powering underwater craft are currently batteries, nuclear reactors, or tethers to the surface, a chemically-powered propulsion system is groundbreaking (and, well, a bit nerve-wracking)." The full paper is available for free (at least for 30 days; registration required).