Veröffentlichungen und Präsentationen

Flexible wearable thermoelectric generators are promising self-powered energy sources for wearable electronics because they can directly convert the small temperature difference between the human body and ambient air into electrical power. However, conventional wearable thermoelectric generators suffer from a fundamental trade-off: thin and flexible devices provide good conformability, but they usually cannot maintain a sufficient temperature gradient across the thermoelectric legs. In this work, we introduce a stair-shaped wearable thermoelectric generator architecture and investigate its thermal and electrical performance using a finite element model implemented in COMSOL Multiphysics. The COMSOL model enabled systematic parametric optimization of the device architecture, including substrate thermal conductivity, electrode geometry, and thermoelectric-leg dimensions. The simulations revealed that the dominant performance loss in the first-generation device originated from thermal short-circuiting through the Cu foil electrode and Kapton substrate. By replacing the Cu foil with a Cu wire electrode and introducing a low-thermal-conductivity aerogel substrate, parasitic heat leakage was strongly suppressed, and heat flow was preferentially redirected through the thermoelectric legs. This geometrical thermal management strategy allowed the device to maintain a large effective temperature gradient while preserving a highly flexible and conformable structure. The predictive capability of the COMSOL model was verified experimentally. Under identical thermal boundary conditions, the optimized simulation predicted an output power of approximately 2.62 μW, in excellent agreement with the measured value of 2.6 μW. The fabricated stair-shaped device achieved an effective temperature gradient of approximately 13.3 K under an applied temperature difference of 14 K, demonstrating highly efficient preservation of the available thermal driving force. Compared with the first-generation design, the optimized configuration increased the open-circuit voltage from 1.1 mV to 4.0 mV and enhanced the output power from 0.5 μW to 2.6 μW. These results demonstrate that COMSOL-based multiphysics simulation can serve not only as an analysis tool, but also as a predictive design framework for overcoming coupled thermal–electrical–mechanical constraints in next-generation flexible wearable thermoelectric generators.