A Dual Chemical Cross‐Linked Network PAAS/PANI Conductive Hydrogel for Wearable Strain Sensors

ABSTRACT Conductive hydrogels demonstrate broad prospects in the field of wearable strain sensors due to their good flexibility, electrical conductivity, and biocompatibility. However, the complexity of practical application environments imposes higher requirements on the comprehensive properties of such materials, including electrical conductivity, mechanical strength, self‐healing, and adhesion. To address this, this study introduces the conductive polymer polyaniline (PANI) into a sodium polyacrylate (PAAS) hydrogel matrix, successfully constructing a PAAS/PANI conductive hydrogel with a dual chemically cross‐linked network via a one‐pot method. Experimental results indicate that the incorporation of PANI not only effectively enhances the electrical conductivity of the hydrogel but also improves its mechanical properties. When the PANI content reaches 7.5 wt%, the hydrogel exhibits good overall performance: its tensile strength reaches 314 kPa, the elongation at break reaches 872%, and the electrical conductivity reaches 2.46 S m −1 . In terms of sensing performance, the material also demonstrates outstanding characteristics: under 600% tensile strain, its gauge factor (GF) reaches 4.52, along with negligible hysteresis and rapid response and recovery speeds. Additionally, the PAAS/PANI hydrogel possesses good thermal stability, self‐healing properties, adhesion, and biocompatibility. Based on this hydrogel, the constructed wearable strain sensor can accurately, stably, and real‐time monitor various human joint movements.