A high packing density micro-thermoelectric power generator fabricated by electrochemical MEMS technology

Abstract

A new micro-thermoelectric power generator module with high packing density of film thermoelectric legs has been proposed, in which a larger number of p-type and n-type thin-film thermoelectric legs are electrically connected in series. Based on the new module, two micro-thermoelectric power generators are fabricated by the electrochemical MEMS technology. The two micro-thermoelectric power generators containing 160 film thermocouples are all fabricated with a size of 25mm (length) × 4mm (width) × 1mm (thickness), but the size of their thermoelectric legs are different, the size of the thermoelectric legs are 3.6mm (length) × 0.4mm (width) × 20μm (thickness) and 3.6mm (length) × 0.4mm (width) × 50μm (thickness), respectively. The open circuit voltage Vopen-circuit, the maximum output power and the corresponding power density of the two micro-thermoelectric power generators with a constant temperature difference ΔT=20K at room temperature is 630mV, 35μW, 357μW/cm3 and 660mV, 77μW, 770μW/cm3, respectively. The result shows that the thickness of the film thermoelectric materials have important influence on the performance of the micro-thermoelectric power generators.