Preparation and performance of CNT impregnating 3D Ethylene-Propylene Side By Side (ES)/PET nonwoven-based flexible pressure sensors

To address the challenges associated with low sensitivity, complex production processes, and insufficient breathability of flexible sensors, this study developed a three-dimensional nonwoven material made of polyethylene-polypropylene (Ethylene-Propylene Side By Side, ES)/polyester (PET) fibers through needle punching and thermal bonding techniques. The material was then impregnated with carbon nanotubes (CNTs), leading to the successful development of a high-performance CNT impregnating three-dimensional thermally bonded nonwoven-based pressure sensor. The impact of different CNT impregnation processes on sensor performance was comparatively analyzed. The findings indicate that the three-dimensional ES/PET nonwoven-based flexible pressure sensor exhibits a high sensitivity of up to 0.375 kPa⁻¹ and a detection range of 0-214.53 kPa. After 2100 compression cycles, the sensor demonstrate excellent stability and repeatability, with a response time of 48 ms and a recovery time of 122 ms. In practical applications, this sensor can accurately identify subtle physiological activities such as breathing, swallowing, and finger bending, showing potential for widespread use in sports, medical, and virtual reality fields.