Recyclable, high strength and electrical-mechanical self-healing wearable ionic hydrogel sensor

Abstract

Ionic hydrogels are ideal materials for wearable sensors on the human body, typically requiring excellent mechanical properties, adhesion, self-healing, and sensing capabilities. However, traditional methods to enhance the mechanical properties of ionic hydrogels often compromise their self-healing and sensing performance. Considering this, in this study, we developed a high-strength, recyclable hydrogel with a wide monitoring range, formulated from acrylic acid, hexahydrate aluminum chloride, and polyquaternium-10. By employing a simple freeze-thaw process, the tensile strength of the hydrogel was significantly increased from 0.3 MPa to 1.89 MPa, and the elongation at break was enhanced from 900 % to 1400 %. Additionally, the hydrogel demonstrates exceptional adhesion to various substrates and possesses mechanical-electrical dual self-healing properties. The hydrogel's broad strain detection range (1%–400 %) further underscores its potential for high-performance sensing applications. Furthermore, the reconfigurable, high-density supramolecular network of hydrogels enables the reprocessing of discarded material into value-added products through a straightforward water swelling treatment. We believe that our approach offers a straightforward and efficient strategy for enhancing the mechanical properties of acrylic acid-based hydrogel sensors and, more significantly, contributes to the sustainable utilization of hydrogel materials.