Construction of Dual Cross‐Linked Conductive Hydrogels: Combining Toughness, Anti‐Swelling, And Self‐Healing Properties to Achieve Amphibious Multifunctional Sensing

Conductive hydrogels attract much attention in applications such as flexible electronics and wearable sensors. However, the swelling characteristics of conductive hydrogels in aqueous environments not only limit their long-term application but also adversely affect their performance. This study has developed a tough, anti-swelling, highly conductive dual-network water gel. Polyacrylic acid (PAA) and polyvinyl alcohol (PVA) are used as the backbone, with Zr⁴⁺ introduced to form metal chelation with the carboxyl groups of acrylic acid (AA), and borax forming a dynamic borate crosslinking structure with the PVA network. The prepared hydrogel exhibits a tensile strength of up to 0.92 MPa, toughness of 3.35 MJ m^- ³, a conductivity of 3.28 S m^-1, and excellent self-healing capabilities (with a self-healing efficiency of up to 99.17%). Its internal multi-crosslinked structure gives it excellent mechanical properties and swelling resistance in marine environments, providing the conditions for hydrogel sensor (PAZr-4 sensor) to function as highly efficient amphibious sensors. The PZAr-4 sensor is used to monitor human movement in a simulated seawater environment. At the same time, a sensor array is constructed using this hydrogel as the basic unit. It is combined with machine learning algorithms to accurately and in real time track the movement of objects on its surface.