Dynamic non-covalent synergistic zwitterionic hydrogel for wearable strain sensing and human-machine interaction

A biomimetic triple-synergistic Zn-ICH hydrogel is developed for wearable strain sensing. • The hydrogel mimics extracellular-matrix-inspired multiple weak interaction coupling. • Zn-ICH integrates toughness, ionic conductivity, adhesion, and anti-freezing ability. • The sensor enables reliable human motion monitoring and real-time HMI control. • Zn-ICH also shows promise for flexible zinc-ion energy-storage devices. Inspired by the synergistic coupling of multiple weak interactions in natural extracellular matrices, here a triple-synergistic biomimetic double-network ionic conductive hydrogel (Zn-ICH) strategy is proposed to achieve high-performance flexible strain sensors with balanced comprehensive properties. Specifically, the rigid polyacrylamide/sulfobetaine methacrylate (PAM/SBMA) covalent network provides structural stability under large deformations, while the reversible Zn 2+ -sodium alginate (Zn 2+ -SA) dynamic coordination network enables efficient energy dissipation, and the zwitterionic glycerol hydration microenvironment ensures continuous ion transport, robust interfacial adhesion and wide-temperature tolerance, breaking the inherent performance trade-offs of conventional conductive hydrogels. The Zn-ICH-based strain sensor exhibits a gauge factor of 0.93–1.29 over 0–500% strain, enabling reliable detection of human motions and physiological signals. Furthermore, the constructed wearable human-machine interaction system enables stable and near-real-time robotic arm actuation with a motion synchronization accuracy of 99%. Additionally, when used as a zinc-ion capacitor electrolyte, the Zn-ICH hydrogel enables the flexible device to deliver a specific capacity of 150 mAh·g −1 at 0.3 A·g −1 and maintain 95% capacity retention after 5000 cycles. This work establishes a universal design principle for multifunctional conductive hydrogels, offering broad application prospects in wearable electronics and flexible energy storage. Download: Download high-res image (432KB) Download: Download full-size image