Objective evaluation of wearable thermoelectric generator: From platform building to performance verification

Abstract

Wearable thermoelectric generators can harvest heat from the human body to power an intelligent electronic device, which plays an important role in wearable electronics. However, due to the complexity of human skin, there is still no unified standard for performance testing of wearable thermoelectric generators under wearable conditions. Herein, a test platform suitable for a wearable thermoelectric generator was designed and built by simulating the structure of the arm. Based on the biological body temperature regulation function, water flow and water temperature substitute blood flow and blood temperature, the silicone gel with some thickness simulates the skin layer of the human arm, thus achieving the goal of adjusting the thermal resistance of human skin. Meanwhile, the weight is used as the contact pressure to further ensure the reliability and accuracy of the test data. In addition, the environment regulatory system is set up to simulate the outdoor day. Actually, the maximum deviation of the performance of the thermoelectric generator worn on the test platform and human arm is ∼5.2%, indicating the accuracy of objective evaluation.

Optimized thermal design for excellent wearable thermoelectric generator

“…The detailed test conditions are shown in Fig. S9 † 51 . When the hot end of the generator touches the simulated arm with different contact pressures (1.6 kPa, 0.8 kPa, and 0 kPa), an output voltage instantly appears, and then stabilizes.…”

“…S9. † 51 When the hot end of the generator touches the simulated arm with different contact pressures (1.6 kPa, 0.8 kPa, and 0 kPa), an output voltage instantly appears, and then stabilizes. For the w-TEGs with a FF of 40%, as the contact pressure is reduced from 1.6 kPa to 0 kPa, the stabilized output voltage drops greatly from 45.1 mV to 37.2 mV for the w-TEG with the PI substrate (Fig.…”