All‐Printed, Flexible, Organic Thermoelectric Generators for Ambient Operation with Enhanced Performance under Mechanical Bending

Abstract This study reports the fabrication and characterization of bipolar, fully printed organic thermoelectric generators on flexible substrates. All fabrication and testing are carried out under ambient conditions, demonstrating the feasibility of low‐cost, scalable manufacturing. The thermoelectric performance is evaluated in both flat and bent configurations, revealing a clear enhancement under mechanical deformation. The Seebeck coefficient of a single thermocouple increases from 30 µV K −1 in the flat state to 38.9 µV K −1 when bent, while the maximum output power rises from 8.8 to 14.9 nW. The devices also exhibit good stability, retaining ≈90% of their output power after 60 days of ambient exposure. These results confirm that fully printed, flexible organic thermoelectric generators are robust and lightweight energy harvesters whose performance improves under mechanical stress, highlighting their potential for real‐world, mechanically dynamic applications.