High-performance flexible thermoelectric generator with hydrogel-copper foam cooling for self-powered wearable electronics

作者：Hejia Wang, Wei Wang, Gang Li, Dessalegn Abera Waktole, Zhengxing Zuo, Boru Jia, Huihua Feng, Mengyu Wang, Shuai Shao · 发表于：Case Studies in Thermal Engineering · 年份：2025 · DOI：10.1016/j.csite.2025.106835 · 被引用次数：6 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Advanced Thermoelectric Materials and Devices、Advanced Materials and Mechanics

Flexible thermoelectric generators (FTEGs) harvesting body heat offer a sustainable energy solution for wearables but traditional FTEGs suffer from insufficient power density under natural convection. This study introduces an innovative FTEG with hydrogel-copper foam composite sinks to boost heat dissipation and power output. The hydrogel, embedded in copper foam, leverages the foam's high thermal conductivity and the hydrogel's three-dimensional porous structure to enhance evaporative cooling, while the addition of LiCl enables a long-lasting evaporation–hygroscopic cycle. The FTEG achieves a power density of 167.7 μW/cm 2 (2.5 m/s wind speed, ΔT = 20 °C) and 95.4 μW/cm 2 under natural convection, 29 × higher than previous results using traditional cooling sinks. The FTEG maintains excellent flexibility, with less than 1 % internal resistance changes after 1000 bending cycles. It successfully powers an electrocardiogram (ECG) sensing system in real-time, generating 83 mV and 840 μW under natural convection using an LTC3108 chip and AD8233 sensor, with 27.98 % power conversion efficiency. The system operates solely on body heat, eliminating the need for batteries or supercapacitors. These results highlight the FTEG's potential for sustainable, efficient wearable electronics.