Ion-Mediated Nanoengineering Enables Superflexible and Mechanically Robust Wood-Based Aerogel.

Abstract

Flexible aerogels combining mechanical adaptability and functional performance are crucial for next-generation wearable electronics. However, their practical deployment is constrained by the intrinsic strength-flexibility trade-off. Here, we propose an ion-mediated nanoengineering-based fabrication strategy to construct flexible wood-derived aerogels with outstanding mechanical robustness and ionic conductivity. Partial delignification preserves the wood's load-bearing hierarchical honeycomb framework while exposing cellulose chains for interactions with ionic liquids. This interaction reorganizes the hydrogen-bonding network among cellulose chains through extensible ionic bridges, thereby enhancing cell wall elasticity and imparting ionic conductivity. Benefiting from the preserved wood scaffold and ionic liquid-induced nanoscale reconstruction, the resulting aerogel withstands 90% compressive strain, 180° bending, and 720° twisting, while reaching a compressive strength of 1.75 MPa, far exceeding most flexible aerogels. Moreover, its ionic conductivity enables stable piezoresistive sensing of diverse human motion signals, showing great promise in flexible sensing and wearable electronics.