A wearable electromagnetic-triboelectric-thermoelectric hybrid energy harvester driven by a coaxial counter-rotating transmission mechanism

Abstract Harvesting energy from the environment to power wearable microelectronic devices can greatly promote the large-scale deployment of 5G networks and has become a hot research topic both domestically and internationally. A wearable electromagnetic-triboelectric-thermoelectric hybrid energy harvester (ETTH) driven by a counterweight has been proposed by this work, which can efficiently harvest the vibration energy and temperature difference heat energy generated by the human body. The electromagnetic generator (EMG) and triboelectric nanogenerator (TENG) are composed of six sets of magnets and coils, as well as fluorinated ethylene propylene and polyamide 6 which are integrated in disk A and disk B respectively. A coaxial counter-rotating transmission mechanism connects Discs A and B, ensuring that the EMG and TENG operate at twice the frequency of the environment’s vibration. Fan blades are mounted on the disk A, which drives their rotation to enhance heat dissipation of the thermoelectric generator (TEG). At a vibration frequency of 1.5 Hz, the output power of the EMG and TENG is respectively 2.2 mW and 127.7 μ W, with the optimal loads of 1.6 kΩ and 30 MΩ. At an ambient temperature of 10 °C, the output power of TEG is 589.7 μ W with the optimal load of 8.2 Ω. Through the coaxial counter-rotating transmission mechanism and the collaboration between TENG and TEG, ETTH achieves significantly higher energy harvesting efficiency compared to other wearable harvesters and can provide reliable power for various load sizes. It provides an effective solution for powering wearable electronic devices.