Boosting the Output Force of Chitosan-Polyacrylamide Hydrogel Actuators via Dual-Network Strengthening and Ion Transport Refinement

Ion-responsive hydrogel actuators exhibit tremendous potential for flexible electronics and soft robotics. However, their inherent limitations in mechanical performance and output force hamper their translation into practical applications. In this study, developed chitosan-polyacrylamide (CS-PAAM) dual-network (DN) hydrogel actuators by the integration of in situ polymerization and calcium ion crosslinking, and incorporated Fe3O4 nanoparticles (NPs) for synergistic regulation. The results demonstrate that increasing the CS content strengthens the hydrogen-bonding and ionic crosslinking networks, markedly enhancing the actuators’ mechanical strength while improving its electrochemical performance, resulting in a 79.36% elevation in output force. Concomitantly, an optimal Fe3O4 NP loading concentration further refines the ionic transport channels, yielding an additional 63.27% enhancement in output force. These performance enhancements are poised to facilitate the practical implementation of hydrogel actuators in soft robotics and wearable devices.