A high-performance wearable thermoelectric device with epoxy resin/PA/AlN composite heat sink

Abstract

Wearable thermoelectric devices (WTEDs) have garnered significant interest for applications in personal thermal management and energy harvesting from the human body. Nevertheless, a major limitation hindering their performance is inadequate heat dissipation. To overcome this issue, this study introduces an integrated WTED architecture featuring a flexible finned heat sink based on a phase change material (PCM), which is structurally integrated with the thermoelectric unit. The heat sink is composed of epoxy-encapsulated paraffin PCM doped with high-thermal-conductivity aluminum nitride (AlN) additives, significantly enhancing the composite's effective thermal conductivity and overall thermal management capability. Experimental results validate the efficacy of this integrated design: at a temperature difference of 30 K, the device delivers an open-circuit voltage of 239.0 mV and a power output of 9212.85 µW, corresponding to a 1386% enhancement compared to a system without the heat sink. Moreover, the integrated device demonstrates markedly improved conversion efficiency even under low temperature gradients (<10 K), rendering it highly suitable for integration with boosting circuits in wearable electronics. Based on heat transfer optimization, this device achieves portable wearable cooling without fans or liquid cooling assistance. It provides up to a 4.4 °C skin temperature drop and maintains a temperature below body temperature for over 600 s. This work presents an effective, fan- and liquid-free thermal management solution with promising applications in small portable electronics and personalized cooling.