Tough Hydrogel Reinforced by Meta-Aramid Nanofibers for Flexible Sensors

Hydrogels exhibit significant promise for advanced flexible sensing applications owing to their intrinsic softness, biocompatibility, and customizable functionalities. Nevertheless, their limited mechanical strength poses a critical barrier to practical implementation. In this study, we engineered a mechanically robust alginate/chitosan (SA/CS) hydrogel reinforced with meta-aramid (PMIA) nanofibers. The resulting composite hydrogel achieves a tensile strength of 16.8 MPa, substantially exceeding the performance of conventional biomass-derived hydrogels. When employed as a flexible sensor, the hydrogel demonstrates exceptional pressure-sensing capabilities, featuring high sensitivity (178.41 MΩ/MPa below 5 kPa), rapid response kinetics (0.4–0.8 s), and sustained stability (>200 cycles). Leveraging these properties, we successfully monitored vocal cord vibrations and finger motion trajectories, highlighting their potential for biomechanical sensing applications.