A Novel PowderMEMS Technique for Fabrication of Low-Cost High-Power-Factor Thermoelectric Films and Micro-Patterns

Thermoelectric (TE) films, which are normally fabricated by MicroElectroMechanical-Systems (MEMS) technology, are crucial for the development of micro-TE devices (e.g., Peltier coolers for hot-spot cooling, TE generators). However, achieving a significant TE property (e.g., high power factor) of TE films and a low-cost fabrication process is challenging. A novel fabrication technique named PowderMEMS to fabricate high-performance, low-cost TE films, and micro-patterns is presented in this article. The TE film is based on agglomeration of micro-sized N-type Bi2Te2.5Se0.5(BTS) powders with stoichiometric composition by the molten binder bismuth (Bi). The influence of the key process parameters (e.g., the weight ratio between the TE powder and the binder, the hot-pressing duration, and pressure) on the TE performance is investigated. The TE film exhibits a maximum power factor of 1.7 mW m-1K-2 at room temperature, which is the highest value reported so far for the state-of-the-art TE thick film (thickness > 10 mu m). Besides, the PowderMEMS-based TE films are successfully patterned to the micro-pillar array, which opens up a new MEMS-compatible approach for manufacturing micro-TE devices.

Automated summary

This article presents a novel fabrication technique named PowderMEMS for high-performance, low-cost TE films and micro-patterns. The TE film is composed of agglomerated micro-sized N-type Bi2Te2.5Se0.5 powders with a molten binder of bismuth (Bi). The influence of key process parameters on TE performance is investigated, and the TE film exhibits a maximum power factor of 1.7 mW m-1K-2 at room temperature, the highest value reported so far.