Integrating dual heat sources to enhance thermoelectric generator power output

The escalating demand for sustainable power sources for wearable electronics necessitates innovative solutions. This study tackles the challenge of sustainably powering wearable electronics, addressing the limitations of traditional batteries. The approach utilizes a thermoelectric generator with a flexible and stretchable substrate that integrates the photothermal effect and human body temperature as a heat source. A unique strategy is employed to achieve this, involving the combination of 10 g of polydimethylsiloxane, 0.5 g of carbon nanotubes powder, 1 g of base curing agent, and 1.15 g of ethyl acetate mixture used as the novel substrate material. The proposed composite substrate is paired with p-type and n-type thermoelectric legs of bismuth antimony telluride (Bi_0.4Sb_1.6Te₃) and bismuth selenium telluride (Bi_1.7Te_3.7Se_0.3), respectively. This innovative design ensures high flexibility, stretchability, and conformability, facilitating seamless integration into wearable electronic devices. Experimental validation and simulation-based studies reveal a power density of 166.29 μW/cm², sufficient for powering small-scale wearable electronics. The thermoelectric generator coupled with a novel composite substrate showed 65.6 % stretchability, further underscoring its durability and adaptability. The critical finding lies in the dual heat source integration, which collectively boosts power output and ensures year-round performance, pushing the boundaries of wearable energy harvesting technologies.