Screen-printed radial structure micro radioisotope thermoelectric generator

Abstract

The micro radioisotope thermoelectric generator can be invoked as a long-life power supply in low-power device applications. Improving the current, voltage and power of power sensors by enhancing the properties of thermoelectric material composites matters in low-power device applications. The micro radioisotope thermoelectric generator driven by the temperature difference between radial thermoelectric legs printed on polyimide substrate and the loaded central heat source is reported in this study. The electrical conductivity of n-type Bi2Te2.7Se0.3, p-type Bi0.5Sb1.5Te3, and p-type Sb2Te3 radial thermoelectric legs are 24.57–165.8 S·cm−1, with Seebeck coefficients of −176.6, 223.3 and 139.7 µV·K−1 respectively. Thermoelectric legs are prepared by screen printing with a paste consisting of epoxy resin and BiTe-based powders. The generator has five couples of radial thermoelectric legs, and their material properties are optimized through selecting the preliminary curing temperature. The electrical conductivity of n-type Bi2Te2.7Se0.3, p-type Bi0.5Sb1.5Te3, and p-type Sb2Te3 thermoelectric legs are 24.57–165.8 S·cm−1, with Seebeck coefficients of −176.6, 223.3 and 139.7 µV·K−1 respectively. When loaded with 1.5 W isotope heat sources, the prototype generator would generate an open-circuit voltage of 68.41 mV, a short-circuit current of 329.0 µA, and an output power of 5.81 µW at 39.20 mV. Stacking and series-parallel can harvest considerable energy.