Hybrid Living

NASA's newest robot can dive and swim for indefinite periods of time because it's powered by an unlimited resource:  the ocean's temperatures.  The robotic buoy utilizes thermal energy each time it moves from cold deep waters to warm surface waters.

The SOLO-TREC diver has been taking 500-meter dives off the coast of Hawaii collecting information on ocean salinity and currents since last November.  The robot makes three trips a day, constantly recharging itself.

The robot is outfitted with tubes of oil.  Those tubes are surrounded by a compartment filled with wax that liquifies once the robot hits warm waters.  The liquified wax expands, which squeezes the oil from the tubes into the interior of the buoy it's stored at high pressure.  The oil is then released, which drives the generator and charges the batteries.

This process produces about 1.6 Wh, which fuels the buoy's functions like water intake and expulsion, a GPS receiver, and its sensors and transmitters.

NASA plans to create a whole fleet of these robot buoys that will monitor various ocean conditions.  The next step will be to develop similar devices that would never require a battery change.

via New Scientist