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 3.2 Bi 1.498 Sb 0.5 Te 0.002 legs, p -type Bi 0.4 Sb 1.6 Te 3 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/cm 2 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/cm 2 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.