A wearable real-time power supply with a Mg₃Bi₂-based thermoelectric module

A wearable thermoelectric generator using human body temperature is a promising power supply for wearable electronics. Here we discuss the design and fabrication of one kind of wearable thermoelectric generator constructed by n-type Mg_3.2Bi_1.498Sb_0.5Te_0.002 legs, p-type Bi_0.4Sb_1.6Te₃ legs, polyurethane matrices, and flexible Cu/polyimide electrodes. The proposed device has a low thermal bypass and an efficient thermal contact interface, resulting in a peak power density of ∼20.6 μW/cm² when placed on a human arm at an ambient temperature of 289 K (air velocity, 1.1 m/s) and a high peak power density of 13.8 mW/cm² at a temperature difference of 50 K. In addition, it can withstand 10,000 bending cycles at a bend radius of 13.4 mm, suggesting that the proposed wearable thermoelectric generator has the potential to be a real-time power supply for certain wearable electronics in daily life.