Preparation and Performance Optimization of High-Strength, Tough, and Conductive Poly(vinyl alcohol)/Polyacrylamide/Polyaniline Hydrogels.

Conductive hydrogels have garnered considerable attention owing to their lightweight, high conformability, excellent sensitivity, and cost-effectiveness, making them highly suitable for applications in wearable flexible electronics, bioelectrodes, flexible sensors, and smart textiles. Compared with traditional rigid sensors, flexible sensors exhibit unique advantages in sensitively detecting pressure on uneven surfaces, which is attributed to their distinctive flexibility. This paper systematically investigates the structure, morphology, and properties of poly-(vinyl alcohol)/polyacrylamide/polyaniline-(PVA/PAM/PANI) conductive hydrogels, as well as the interrelationships among these characteristics, to identify the optimal preparation process. The goal is to develop a flexible pressure sensor with shock resistance, high sensitivity, fast response, and stable performance. The PVA/PAMX/PANI (X = 12) conductive hydrogel exhibited the best mechanical properties in the series, with a tensile stress of 0.0285 MPa, a modulus of 154.1 kPa, and a fracture toughness of 257.4 kJ/m3, alongside a stable response and recovery time of 488 and 317 ms, respectively. Furthermore, it exhibits a gauge factor of 1.33 (tensile strain) and 0.0283 Mpa-1 (compressive pressure), indicating an excellent strain-sensing capability. Upon application of pressure, the hydrogel demonstrates a corresponding change in electrical resistance. This electromechanical responsiveness renders it promising for applications in electronic skin, flexible sensors, and wearable devices.