Mechanically Robust and Anti‐Swelling Anisotropic Conductive Hydrogel with Fluorescence for Multifunctional Sensing

Abstract The intricate muscle arrangement structure endows the biological tissues with unique mechanical properties. Inspired by that, a mechanically robust and multifunctional anisotropic Polyacrylamide/Sodium alginate/Zirconium ion/Carbon dots (PAM/SA/Zr 4+ /CDs, PSZC) hydrogel is developed through the synergistic effect of mechanical‐assisted stretching, Zr 4+ metal‐coordination and CDs embedding. The resulting hydrogel exhibited an impressive tensile strength of 2.56 MPa and exceptional toughness of 10.10 MJ m −3 along the stretching direction, attributing to the oriented alignment of PAM and SA molecular chains induced by mechanical‐assisted stretching and metal‐coordination. The dense network structure endowed the PSZC hydrogel with excellent anti‐swelling performance, achieving a swelling ratio of only 1.7% after being stored in water for 30 days. The presence of Zr 4+ conferred remarkable electrical conductivity of 2.15 S m −1 to the PSZC hydrogel. Furthermore, the integration of carbon dots imparted the PSZC hydrogel fluorescence properties, rendering it visual sensing capabilities. Overall, a straightforward strategy is proposed for fabricating a mechanically robust and multifunctional hydrogel suitable for underwater sensing and visual sensing, offering valuable insights for the development of high‐performance underwater sensors.