An ultrastretchable and multifunctional hydrophobic/electrostatic dual-crosslinked hydrogel for self-healing flexible touch panel and sensor

Hydrogels have emerged as promising candidates for the next generation of flexible electronics for human-machine interaction, owing to their excellent biocompatibility, safety, and flexibility. In this work, a novel hydrophobic/electrostatic dual-crosslinked hydrogel, polyacrylic acid-divinylbenzene-liquid metal (PAAD-LM) hydrogel, was synthesized for the first time by a facile one-step γ-radiation method. PAAD-LM hydrogel exhibits remarkable stretchability (elongation at break of 5257 ± 170%, areal strain of > 7000% without break), self-healing capability, and excellent responsiveness as flexible touch panel and strain sensor. The hydrogel-based device demonstrates versatile functionalities, including painting, keyboard and mouse control applications, high-sensitivity recording of various human body movement signals, and VR smart gloves. The function of the hydrogel-based device is converted successfully through circuit and program design. With its stretchable and self-healing properties, PAAD-LM hydrogel holds great potential for advanced multifunctional wearable electronic devices. This work also provides novel insights into the synthesis of high-tensile, sensitive and multifunctional hydrogels.