Dynamic bonding-enabled hydrogel with broad-range strain-temperature dual responsiveness and high adhesion strength

Hydrogels have significant application value in the field of wearable sensors due to their excellent flexibility, stretchability and conductivity. However, the development of multifunctional hydrogels that combine high mechanical strength, strong self-adhesion and multi-stimulus responsiveness remains challenging. In this study, a one-pot strategy was employed to introduce quaternized polyethyleneimine salt and aluminum chloride hexahydrate into a poly(acrylic acid) hydrogel matrix, successfully fabricating a high-strength adhesive hydrogel with broad-range strain-temperature dual responsiveness. Benefiting from a dynamically reversible non-covalent bond network, the hydrogel exhibits outstanding mechanical properties (tensile strength of 0.94 MPa) and excellent adhesion to various substrates. As a flexible sensor, the hydrogel demonstrates a wide strain response range (0–400%), high sensitivity (GF = 4.4 at 0–200% strain and GF = 6.5 at 200–400% strain) and remarkable temperature-sensing capability (5–100 °C), along with self-healing properties. These advantages make it highly promising for applications in human motion monitoring and smart wearable devices.