Robot jellyfish sucks up power from the water

Robojelly - a robot jellyfish that feeds on water - could aid in underwater search and rescue operations, say its creators.

Researchers at Virginia Tech and the University of Texas at Dallas built Robojelly from materials known as shape-memory alloys, which return to their original shape when bent. Eight moving segments wrapped in carbon nanotubes and coated with a platinum powder replicate the jellyfish's natural opening-and-closing method of propulsion.

The robot is powered by heat produced from chemical reactions between the oxygen and hydrogen in the water and the platinum powder, which causes the alloys to change shape. "To our knowledge, this is the first successful powering of an underwater robot using external hydrogen as a fuel source," says Yonas Tadesse, who led the research, published in the journal Smart Materials and Structures today.

More work is needed to make the hydrogen-powered robot fully functional, however. The video above shows an electricity-powered Robojelly swimming freely in a tank of water, but the hydrogen-powered version has so far only been tested while clamped to the bottom of the tank. The researchers' next step is to figure out a way to deliver hydrogen to each segment separately, allowing them to be controlled individually, so that the robot can move in different directions.

source : newscientist