Annular screen printed thermoelectric generators for ultra-low-power sensor applications

We report on the materials preparation and device fabrication for screen printed Bi2Te3/Bi0.5Sb1.5Te3 annular thermoelectric generators (TEGs) for use in ultra-low-power sensor applications. At a 20K temperature gradient, test couples — n& p-type 1 cm squares connected electrically in series with printed Ag traces — demonstrated an average power of 0.068nW at 26nA and 2.6mV. The material preparation leverages mechanical alloying for both the nand p-type materials in order to reduce electrical resistivity and increase device power output. Screen printed thermoelectric elements were found to have substantial challenges with mechanical failure due to cracking and delamination. This work specifically describes these challenges and corresponding mitigation strategies for screen printing the TEG slurries.