All‐In‐One Flexible Thermoelectric Yarns for Integrated Energy Harvesting, Adaptive Personal Thermal Management, and Self‐Powered Sensing

ABSTRACT Wearable thermoelectric generators (TEGs) offer a sustainable pathway to power emerging electronics by harvesting body heat, yet their practical adoption is hindered by limited energy conversion efficiency and poor thermal comfort. To overcome these restrictions, we herein develop stretchable thermo‐regulated TE yarns (STRTEYs) via coaxial electrospinning coupled with coagulation‐bath wet spinning. The resulting shell‐core nanofiber based STRTEYs exhibit high flexibility (>35%), excellent adaptive phase‐change PTM (110 J/g), long‐term stability and enhanced TE performance ( σ of 32 S/cm, S of 46 µV/K). Noteworthy, through efficient latent heat management, the STRTEYs achieve an exceptional ≈393 s extension in effective TE output duration, demonstrating remarkable synergy between PTM and energy harvesting. Furthermore, the STRTEYs maintained stable TE property ( S = 45.85 µV/K) after 5‐month storage and notably enhanced TE output via temperature difference stability. The mask integrated with STRTEYs can achieve thermal energy collection and self‐powered real‐time detection of physiological signals. In summary, the STRTEYs successfully achieved efficient integration of multiple functions including energy harvesting, adaptive PTM, and self‐powered sensing, providing a new research direction for developing advanced multifunctional TEGs and promoting their application in wearable electronics.