Heat Storage Thermoelectric Generator for Wireless IOT Sensing Systems

Abstract

This paper demonstrates a new approach using a thermoelectric generator (TEG) which converts thermal energy from ambient temperature fluctuations into electricity for the power source of portable devices. Theoretical modeling and experimental validation of a thermoelectric generator integrated with a phase change material (PCM) are reported in this paper. The proposed device converts the ambient temperature variations into a temperature difference on the TEG using a PCM, thus temperature variations can produce electrical energy. The maximum output power can reach 0.6 mW which corresponds to a power density of 37.5 µW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> under the ambient temperature variants from 5°C to 35°C (using the temperature-controlled oven). The electric power generated by TEG can be stored in a capacitor via a DC-DC converter. The maximum output power and the storable energy in the capacitor are 30 µW and 500 mJ, respectively, under ambient temperature fluctuations near room temperature. The investigation in this work could possibly lead to high potential for battery-free wireless sensing systems.