System-level design framework of wearable thermoelectric generators for real-world applications: integrating device architecture, thermal management, and human comfort

Wearable thermoelectric generators (WTEGs) offer a sustainable route for harvesting body heat, yet their development is constrained by three system-level challenges that extend beyond material properties alone: limited temperature gradients, trade-offs between performance and compliance, and insufficient attention to thermal comfort. This Review reframes WTEG development as a coupled human-device problem. We examine gaps in thermoregulatory modelling for device design, the evolution of architectures from rigid to stretchable formats with persistent compromises, and thermal-management strategies centred on radiative cooling and comfort co-optimization. We outline that next-generation WTEGs will require human-in-the-loop, application-specific co-design to transform laboratory demonstrations into seamlessly integrated real-world energy solutions.