Bi₂Te₃-based flexible micro thermoelectric generator with optimized design

Abstract

We demonstrate and discuss the performance of fully integrated and flexible micro thermoelectric generators (μTEGs}. The devices are fabricated with a low-cost microfabrication process based on electrochemical deposition of a thermoelectric material into a polymer mold. Overall system optimization is demonstrated by means of NiCu and p- and n-type Bi2Te3-based μTEGs. Influences of design, material, fabrication, and performance parameters on device performance are explained by means of measurements and model calculations. The fabricated devices generate up to 2.6* 10-3 μW · -2 · K-2 for devices with NiCu thermocouples and up to 0.29 μW · cm-2 · K -2 for Bi2Te3-based generators in planar state. Mechanical testing on NiCu μTEGs demonstrated functionality of the generator when bent to curvatures down to 7.5 mm. This allows for enhanced thermal contact to nonplanar surfaces. © 2009 IEEE.