Design and development of a novel PVA/CS/MOP ionic conductive hydrogel for flexible sensors: fabrication, characterization, and performance evaluation

The development of advanced hydrogels with exceptional fracture strength and ionic conductivity is critical and challenging for the progress of flexible biological sensors. This study presents a novel PVA/CS/MOP ionic conductive hydrogel, which stands out due to its unique combination of remarkable fracture strength and enhanced ionic conductivity. While chitosan/PVA hydrogels have been previously established, this work focuses on a distinct fabrication method. It addresses the main scientific problem of achieving optimal fracture strength and ionic conductivity simultaneously. Chitosan (CS) is incorporated within a biocompatible polyvinyl alcohol (PVA) matrix, and subsequently, the hydrogel is immersed in muriate of potash (MOP) solution, resulting in a hydrogel with outstanding fracture strength (0.39 MPa) and stretchability (265% fracture strain). The salt soaking process effectively enhances the ionic conductivity of the hydrogel, achieving a maximum of 4.5 S m-1. Additionally, the hydrogel serves as a flexible sensor, capable of monitoring stable electrical signals and recovering after deformation, making it a promising candidate for various applications in flexible electronics and human health monitoring. This study highlights the novelty of achieving an optimized combination of fracture strength and ionic conductivity in the PVA/CS/MOP hydrogel, contributing to the advancement of flexible sensor technologies.