Assessment of the stability and electrical parameters of composite hydrogels in water and alkaline electrolyte

Conductive hydrogels are widely applied in bioelectronics, sensors, and energy systems due to their flexibility, porosity, and ionic conductivity. However, their electrical properties strongly depend on composition and testing conditions. This study investigates the electrical stability of pure and particle-loaded poly (N-isopropylacrylamide) (PNIPAAm) hydrogels prepared using different solvent systems (water, 1.3 wt% and 3 – 4 wt.% poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS)). Measurements were performed in a controlled two-electrode configuration to ensure controlled testing conditions and reproducibility. The effects of working medium (water or 0.1 M KOH), conductive filler (carbon black), and solvent composition on ionic and electronic conductivity were systematically evaluated. Repeated soaking led to significant changes in impedance, which correlated with morphological evolution observed by SEM. The results demonstrate that the electrical response of conductive hydrogels is highly sensitive to composition and processing history, emphasizing the need for consistent experimental conditions in their characterization.