BSST

Construction

Traditionally, thermoelectrics have been constructed as modules in which two ceramic substrates are used as the “bread” in a sandwich of thermoelectric pellets and copper connecting bars. Since it is the ends of the pellets that get hot and cold (or which are made hot and cold in power generation) it is important to keep any thermal losses between the ends of the pellets and the outside of the device as low as possible. Although ceramic is a reasonably good conductor of heat, it is an unnecessary part of the construction. BSST has designs in which the structural function of the ceramic substrates is performed by heat exchanger parts that need to be there anyway. Not only can the thermal conductivity of these structural parts be made much higher than the ceramic, but there are fewer thermal interfaces in series with the heat flow. These thermal interfaces can frequently make more of an impediment to heat flow than the inherent thermal resistance of the materials. In addition, we can tailor these structural parts to minimize thermal conductivity along the direction of flow, thus enhancing the thermal isolation effect described above.