3D-Printing Assisted Bidirectional π-Structured Thermoelectric Generators: Reverse-Designed Flexible Architectures...

Thermoelectric generators (TEGs) demonstrate significant potential for sustainable energy harvesting through direct heat-to-electricity conversion. Nevertheless, conventional fully encapsulated designs face critical limitations including heat dissipation inefficiencies and restricted conformability to complex curved surfaces. This investigation proposes a breakthrough bidirectional π-structured (BDπ-structure) that achieves enhanced mechanical compliance while establishing a mechano-electrical coupling criterion for abrupt curvature transitions. Through implementing a reverse design framework integrating 3D scanning and curvature distribution analysis, customized topological configurations are specifically developed and adapted to target heat source geometries. Concurrently, a novel photocurable composite with enhanced thermal conductivity (0.213 W·m^-1·K^-1) is designed through 3D-printed structural optimization, achieving 59.1% power enhancement compared to conventional encapsulated modules. Experimental validation demonstrates remarkable surface fit tightness of 90.7% (positive Gaussian) and 80.2% (negative Gaussian), translating to exceptional power output improvements of 432.7% and 253.2% relative to non-optimized counterparts. This work establishes a comprehensive framework encompassing material innovation, structural design, and system integration strategies, significantly advancing flexible thermoelectric technology for high-efficiency energy harvesting from geometrically complex thermal sources.