We've seen plenty of robots inspired by nature, but this robot jellyfish developed by researchers from University of Texas at Dallas and Virginia Tech goes one big step beyond mimicking a jellyfish's movements. It's powered by hydrogen, which means that it could potentially stay underwater for prolonged periods of time and constantly refuel itself from the water around it. That, the researchers say, could make it ideal for underwater surveillance or search and rescue operations, but they still have a fair bit of w