Preparation and Application of Ionic Liquid Improved Multifunctional Hydrogel with High Performance as Strain Sensors

Conductive hydrogels have emerged as promising candidates for flexible sensors in health monitoring systems. However, integrating multifunctionality, including mechanical robustness, tissue adhesion, strain sensitivity, and frost resistance, through simple fabrication remains challenging. Herein, we report a multifunctional hydrogel through incorporation of ionic liquids. The dynamic noncovalent interactions endow the hydrogel exceptional mechanical performance with a fracture stress of 0.057 MPa, ultrahigh elongation (1200%), toughness of 0.55 MJ/m3, and an elastic modulus of 0.009 MPa. The hydrogel also exhibits universal adhesion capabilities and high conductivity, even at subzero temperatures. As a flexible sensor, it accurately detects diverse biomechanical signals ranging from macroscale joint movements to subtle physiological activities. Furthermore, its skin-like compliance facilitates direct touchscreen interaction for digital writing, demonstrating its potential as artificial electronic skin. This multifunctional hydrogel provides a scalable solution for developing durable wearable sensors in extreme environments, bridging critical gaps in next-generation health monitoring technologies.