Plant‐Cell‐Wall‐Inspired Robust, Conductive, Composite Hydrogels via Low‐Temperature 3D Printing

Abstract

Hydrogels combining high mechanical performance and excellent electrical conductivity hold great promise in flexible electronics and biomedical engineering, yet achieving a balance between these properties remains challenging. Inspired by plant cell wall architecture, a biomimetic composite hydrogel is constructed via low‐temperature 3D printing based on poly(vinyl alcohol) (PVA), sodium lignosulfonate (LS), and TEMPO‐oxidized cellulose nanofibers (TOCNF), endowing the material with enhanced energy dissipation capability. Built on single‐component hydrogel systems without additional crosslinkers or reinforcing fillers, the hydrogel inherits the advantages of each constituent, while the incorporation of Zn 2+ ions provides ionic conductivity and generates dynamic coordination interactions within the polymer network. The resulting hydrogel exhibits outstanding mechanical properties, including tensile strain exceeding 1600%, tensile strength up to 2.20 MPa, and toughness over 24 MJ·m −3 , as well as high electrical conductivity of up to 2.13 S·m −1 . Furthermore, structural alignment regulation enables differentiated sensitivity, with hydrogel‐based strain sensors achieving maximum gauge factors of 6.99 under tension and 6.53 under compression. Owing to these features, the hydrogel shows great potential for wearable motion sensing and visual feedback, robotic arm control, electrocardiogram (ECG) monitoring, and electronic skin writing, providing a promising platform for flexible bioelectronic devices and human–machine interfaces.