Integration of tau-shaped fins and perforated polyimide substrate for enhanced power output in flexible thermoelectric generator for human body heat harvesting

In pursuing sustainable energy solutions, there is growing interest in flexible thermoelectric generators, which can convert body heat into electricity. This study introduces a strategy to improve performance by integrating novel Tau-shaped fins as an advanced heat sink and perforated polyimide substrate to enhance flexibility. The fins are designed and optimized for maximum heat dissipation and electric power output. The Tau-shaped fins characterized by this research have a unique bend structure, offering enhanced surface area for heat dissipation and improved fluid flow dynamics compared to conventional designs. Employing numerical simulations and experimental validation, the study shows that integrating Tau-shaped fins with a flexible thermoelectric generator at a 0.708 Ω load resistance and a temperature gradient of 17 °C resulted in a maximum power output of 253.62 μW, with a power density of 188.48 μW/cm² over an effective area of 1.3456 cm², making a more than fourfold increase in power output compared to a generator without Tau-shaped fins. The findings highlight the potential of Tau-shaped fins to significantly enhance the power output of flexible thermoelectric generators, making them suitable for powering small-scale wearable electronics.