Abstract: An electrical power generation system has a thermal battery and a thermoelectric module positioned proximate to the thermal battery. The thermoelectric module has a first side thermally coupled to the exterior of the housing; and an electrical circuit configured to conduct electrical current from the thermoelectric module to an electrical load. The electrical circuit can be configured to conduct electrical current from the thermal battery to the electrical load while the voltage produced by the thermal battery is above a threshold and to conduct electrical power from the thermoelectric module when the voltage produced by thermal battery drops below the threshold.

Abstract: A vibration sensor for a fluid environment includes a vibrissa that can be positioned in the fluid environment. The vibrissa is joined to a cantilever body having magnets positioned thereon. Cantilever body is supported by a resilient support member in an interior hollow within a housing. Support member allows movement of body in two dimensions while supporting the body in a third dimension. Magnetic sensors corresponding to the magnets on the body are positioned on the housing for detecting movement of the body caused by the vibrissa. In various embodiments, the support member can be a membrane shielding the housing interior from environmental fluid flow.

Abstract: An acoustic countermeasure system comprises a plurality of individual countermeasure devices which act in concert to emulate a target with spatial extent. The individual countermeasure devices may be programmed to navigate into predetermined positions within a preset pattern with spatial characteristics similar to that of a target of interest, e.g., a submarine. The individual countermeasure devices are programmed to produce acoustic signals, such as in response to a ping or pulse by an incoming torpedo that collectively appears to be an echo similar to that which would come from a target having spatial extent.