Compact night vision focal plane array cooling using FlexTEC high-ZTape

Compact, solid-state thermoelectric devices provide many advantages in refrigeration and power generation. These highly reliable devices have no moving parts, operate over a large range of temperatures, do not emit toxic/environmentally unfriendly gases and are easily integrated into thermal systems. Despite these advantages, engineering applications have been limited by the relatively low intrinsic energy conversion efficiency of the devices compared to conventional refrigeration systems. This limitation stems from the semiconductor materials comprising the thermoelectric elements (i.e. short legs of active material between the two ceramic faces). To a lesser extent, the engineered dimensions and the thermal/electrical contact resistances of the device play a role in the overall device efficiency. Increasing the intrinsic efficiency of the thermoelectric materials and providing structures that are amenable to custom engineered geometries will open up new opportunities in Army applications such as detector cooling, integrated textile (personal BDU) cooling and conformability to waste heat pipes/machinery for energy recovery. The results of the Phase I program provided a conceptual illustration of the method for fabricating consolidated nanophase high ZT composites and scaling the fabrication of the consolidated high ZT thermoelectric element arrays into a manufacturing setting. For the Phase II program, Nanohmics and Dr. Stokes will continue the development of FlexTEC high-ZTape, a conformable solid-state cooling device that promises high-efficiency, low-cost, and lightweight integration into Army thermal management systems.