A responsive supramolecular hydrogel with robust mechanical properties for actuator and strain sensor

Responsive hydrogels hold great promise for applications such as biological tissue engineering, controlled drug release, soft actuators, and intelligent sensors. However, the design and construction of robust responsive hydrogels using a simple method remains a significant challenge. Herein, a non-covalently crosslinked responsive hydrogel was constructed by introducing carboxyl-Zr 4+ metal coordination to the hydrophobic association network of P(AA- co -LMA) hydrogel through a facile one-pot polymerization method. The incorporation of multiple reversible interactions, including hydrogen bonding, metal coordination, and hydrophobic association, resulted in a responsive hydrogel with exceptional mechanical strength (≈2.92 MPa), outstanding flexibility (elongation>1000%), and rapid response to pH alterations. Furthermore, the hydrogel also presented good ionic conductivity due to the abundant movable ions, as well as high sensitivity and stability. As application demonstrations, the supermolecular hydrogel had been successfully used in actuating and strain sensing. This work establishes an effective design strategy for creating tough and multifunctional responsive hydrogel.