Conformation‐Modulated Lignin for Durable and High‐Output Cellulosic Triboelectric Materials Toward Self‐Powered Sensing

Cellulose‐based triboelectric sensors offer a sustainable pathway toward self‐powered electronics, yet their practical reliability is severely constrained by long‐term tribo‐induced fiber fibrillation and the resulting interfacial degradation. Herein, we report a conformation‐engineered alkali lignin (EAL) that enables simultaneous enhancement of mechanical durability and electrical output in cellulose‐based triboelectric materials. Succinic‐anhydride grafting introduces flexible aliphatic side chains into the rigid lignin backbone, granting dynamic conformational adaptability that promotes chain sliding and efficient frictional energy dissipation. This molecular strategy significantly suppresses interfacial wear, reducing the wear rate of the EAL/Cellulose composite by 52.44% after 5000 cycles. Conformation modulation also improves dielectric polarization, leading to markedly increased triboelectric performance, with the optimized device delivering high Voc, Isc, and Qsc values of 100 V, 5.26 µA, and 56.87 nC. The EAL/Cellulose‐based sensor exhibits high signal fidelity in robotic finger sliding detection and handwriting recognition, and maintains stable performance after 500 times repeated writing. In addition, the EAL/Cellulose composite demonstrates strong recyclability in a natural environment and rapid enzymatic degradability within 24 h. This work presented a conformation‐guided molecular design strategy for developing durable, high‐output, and eco‐friendly cellulose‐based triboelectric devices for next‐generation self‐powered sensing.