Submersible Glider Powered By Thermal Changes

An anonymous reader writes about a new robot submersible that uses temperature differences in the sea to power operation for more than twice as long as previous, battery-dependent vehicles. "The torpedo-shaped glider moves through the ocean by changing its buoyancy to dive and surface, unlike motorized, propeller-driven undersea vehicles. To power its propulsion, the submersible gathers thermal energy from the ocean. When it moves from cooler water to warmer areas, internal tubes of wax are heated up and expand, pushing out the gas in surrounding tanks and increasing its pressure. The compressed gas stores potential energy, like a squeezed spring, that can be used to power the vehicle. To rise, oil is pushed from inside the vehicle to external bladders, thus increasing the glider's volume without changing its mass, making it less dense. The oil can be shifted inside to increase the density and sink the vehicle."

Comments

Irritating first line of article though

[Kupfernigk]

"Scientists have invented the Prius of ocean-going submersibles - a new "green" robotic glider that runs on energy absorbed from the heat of the sea, rather than batteries."

Scientists research, they discover, they do not invent. Engineers invent. Doesn't anybody in journalism know the difference between a scientist and an engineer? Also, the Prius is actually a bit like a conventional submarine - IC engine charges the batteries - and is therefore (from a marine engineering perspective) very old tech dating from before WW2. This on the other hand is seriously clever. In fact, it's like powering your car off a massive array of engine thermostats (which rely on wax as the operating means.) So a better lead in would be "Engineers have developed an energy efficient vehicle which is nothing whatever like a Prius - it uses temperature gradients in the sea to power itself."

Perhaps Microsoft deserves to take over Yahoo.