Tendon‐Inspired Multiscale Bamboo‐Based Ionic Gel for High‐Performance Flexible Energy Conversion

ABSTRACT

Naturally rigid cellulose is an ideal mechanical reinforcement for ionogels, but its presence often hinders the migration of gel ions, affecting its application in flexible self‐powered electronics. Inspired by tendon hierarchy, we propose a three‐step strategy (delignification, ionic‐liquid induction, and UV‐crosslinking) to reconstruct bamboo across molecular‐nano‐macro scales into a multiscale bamboo ionic gel with a hard‐core/soft‐shell architecture. Density functional theory calculations reveal carboxyl–hydroxyl–ion mediated triple hydrogen bonds significantly increase the interfacial binding between bamboo fiber and gel matrix. Consequently, the gel achieves a tensile strength of 100 MPa, a toughness of 17.25 MJ m ⁻³ at 48% strain, and only ∼ 1% hysteresis variation over 1000 cycles. Furthermore, bamboo‐fiber skeleton increase conductivity (1.43 mS cm ⁻¹ ) by 472% compared to pure ionogel. It can be used as an electrode in a triboelectric device, generating an open‐circuit voltage of 366 V and a peak power density of 99.98 µW cm ⁻² , enabling highly sensitive self‐powered joint/gait monitoring. By incorporating machine learning, gel‐based triboelectric devices can perform human‐computer interaction tasks with up to 99% accuracy. This study successfully designed an ionogel with both high‐mechanical strength and efficient ion transport capability using a biomimetic strategy, demonstrating its broad potential in flexible self‐powered devices.