Layered Core-Shell Structured Yarn Containing Internal Graphene Layers for Flexible Sensors

Physical sensors with distinctive characteristics such as extreme thinness, low modulus, lightweight design, and exceptional flexibility and stretchability are garnering considerable interest. This is due to their ability to effectively measure and quantify electrical signals generated by human activities. The current methods for making sensors are complicated and call for a lot of organic solvents, which are bad for the environment as well as human health. A flexible stretch sensor is proposed, utilizing a hierarchical layer of graphene nanoplates, and is prepared through a straightforward, solvent-free method. The flexible sensors obtained demonstrate remarkable characteristics, such as a nearly linear response, low strain detection limits down to 0.1%, a substantial strain gauge factor of up to 30, and exceptional cyclic stability enduring over 1000 cycles. Also, the sensors have been successfully employed in wearable devices to detect human motions, displaying excellent sensitivity to small-range movements such as swallowing, clicking, and other small-range movements in addition to large-scale movements of the wrists, ankles, and knees. The utilization of a completely eco-friendly technique in this study, devoid of any organic solvents unlike the majority of published graphene-based sensors, underscores the tremendous potential for wearable sensors.