Durable TPU/PDA/MXene Fiber-Based Strain Sensors with High Strain Range and Sensitivity

With the development of the ageing society, wearable strain sensors have great application prospects in the fields of health detection, artificial intelligence, and motion recognition. However, traditional forms of film-like strain sensors suffer from low sensitivity, adhesion, and impermeability during use, which severely limit their practical applications. To overcome these problems, we propose a strategy to fabricate polyurethane/polydopamine/MXene (TPU/PDA/MXene) composite fibers by wet spinning. Furthermore, the outside is wrapped with (PDMS), giving mechanical strength and chemical resistance. Through a simple and low-cost wet spinning process, TPU/PDA/MXene fibers are achieved in the preparation of flexible strain sensors, and they can be woven into various forms with good flexibility and comfort according to practical needs. The results indicated that the prepared flexible strain sensor exhibits a high gauge factor (GF) of 57.15 over a large strain range (300 %), which are superior to those of many fiber-based sensors. Their application properties were also measured by attaching them to fingers, wrists and knees, showing high sensitivity, mechanical durability and chemical stability, and has great potential for wearable strain sensors and flexible strain sensors in complex environments. The figure shows the preparation process of TPU/PDA/MXene composite fibers. TPU fibers were first prepared by dissolving TPU particles in a certain amount of DMF solution, but since TPU fibers are inherently non-conductive, it was necessary to surface modify the TPU fibers. PDA was polymerized in situ on the fiber surface and then placed in MXene solution for ultrasonication to obtain composite fibers. image