Buoyancy Control Package for Miniature Undersea Sensors

"Littoral antisubmarine warfare and surveillance plans incorporate a vision of a distributed network of miniature, neutrally buoyant, undersea sensors capable of maintaining a desired depth at 10 to 1,000 meters or a position on a 5 to 20 degree Celciustemperature contour. A miniature vehicle is proposed which will carry the sensor system and will equilibrate on a predetermined isothermal surface. The operation exploits a change-of-state in a control substance, which acts to both measure thetemperature and deliver work to change the vehicle buoyancy.No battery or other stored energy is used. The work done results from heat flow from the ocean thermocline. This approach can also be used to create a vehicle which cycles vertically indefinitely, a perpetual oscillator, which draws all propulsion energyfrom the thermocline. Very small devices are practical. Initial designs are for the sensor package total volume of approximately 32 ml. A provision for one time ascent to the surface for radio communication is included. The use of a large number ofsmart, expendable, miniature probes for detection of submarines in the littoral environment may prove to be an important Navy tool. If a success for the Navy, it would be procured in larger quantity, i.e., 10,000 per batch, an attractive commercialopportunity.Quantity manufacture may result in an attractive low-cost platform with application in dynamic littoral ocean observation, turbulenc