Miniaturized Thermoelectric Power Generator
Fan-Yun Chiu1,2*, Cheng-Lung Chen2, Yang-Yuan Chen2
1Department of Physics, National Taiwan University, Taipei, Taiwan
2Institute of Physics, Academia Sinica, Taipei, Taiwan
* presenting author:Fan-Yun Chiu,
Commercial microelectromechanical systems (MEMS) fabrication processes are limited to silicon-based materials or two-dimensional structures. Thermoelectric materials convert thermal energy into electricity according to Seebeck effect. By shrinking the size of the thermoelectric materials and increasing their number to several thousands in a single structure, even at low temperature gradient these devices can generate high voltages that are more compatible with electronic components. Here we show a physical technique on sapphire substrate MEMS-like structure is built that contains p-type and n-type thermoelectric materials with three-dimensional pillar structures. We demonstrate this technique by building a prototype micro thermoelectric generator. Using multi- exposure and development of photoresist layers, metallic electrodes and thermoelectric materials are fabricated in a microchip. Thick layer of P-type Bi0.4Sb1.6Te3 and N-type Bi2Te2.7Se0.3 were deposited by sputter followed by a post annealing at 250℃ for 10 hours for the main structure, and ZEM-3 was used to measure the Seebeck coefficient and electrical resistivity of the thermoelectric thick films. The proposed micro thermoelectric generator is planned for the application of wearable electronics.

Keywords: thermoelectric materials, power generator, MEMS, Seebeck effect