Natural polymer carboxymethyl cellulose based strong adhesive, self-healing, and flexible conductive organohydrogel...

Scientists are especially focused on conductive hydrogels, particularly regarding flexible sensors like strain and pressure sensors. The potential uses of these flexible materials encompass electricity storage, human motion tracking, interdisciplinary robotics, and artificial skin. In contrast, its elevated response time, diminished conductivity, substantial energy dissipation, limited stretchability, and extended strain sensitivity hinder its practical application. Achieving all of these characteristics inside a single hydrogel network is a challenging job. This study has led to the creation of a flexible wearable sensor utilizing organohydrogel, facilitating instantaneous and precise observation of human movement and health-related behaviors with remarkable stability. Through the utilization of a solvent co-crosslinking approach, an elastic-textured organohydrogel is produced through the use of polyacrylamide (PAAm) and polyacrylic acid (PAAc). Additionally, the free radical graft copolymerization technique was employed to bond PAAc and (PAAm) onto the surface of sodium carboxymethyl cellulose (CMC). The role of functional groups, surface structure, mechanical characteristics, rheological characteristics, and strain-sensing characteristics of the manufactured organohydrogel was thoroughly examined. Organohydrogels exhibit exceptional mechanical properties, such as toughness, fracture stress, strain, Young's modulus, and reduced hysteresis energy (21.3 kJ/m³), due to the decrease in hysteresis throughout later cycles, as a result of their dual crosslinking structure. These hydrogels are a promising candidate for strain sensors due to their excellent conductivity (12.8 mS/cm), high sensitivity (GF = 26.3 at 900% strain), fast response time of 100 ms, strong adhesion, and quick self-healing properties. Following 560 cycles, the hydrogels maintained their stability and did not undergo any significant changes. Moreover, PAAm combined with CMC improves biocompatibility. The produced sensor exhibits enhanced sensitivity, durability, and performance, rendering it appropriate for wearable electronic sensing technology.