A wide-range flexible pressure sensor based on MWCNTs/TPU composite conductive fibers

In this study, a flexible piezoresistive pressure sensor with a wide pressure detection range, high sensitivity, and excellent robustness was designed and proposed based on micro/nano manufacturing technology and electrospinning. The pressure-sensitive film is composed of multi-walled carbon nanotubes/thermoplastic polyurethane elastomer composite conductive fibers. The flexible pressure sensor exhibited a high pressure-detection limit of 1200 kPa. Within the pressure ranges of 65-700 kPa and 700-1200 kPa, the sensitivities were 4.02 and 1.45 kPa^-1, respectively, with corresponding linearities (<i>R</i>²) of 0.99 and 0.98, indicating excellent piecewise linear response characteristics. The response and recovery times of the sensor were 125 and 20 ms, respectively, indicating that the sensor had good fast-response characteristics. In addition, a dynamic response test of the sensor at different frequencies showed that the sensor exhibited an excellent pressure-sensitive dynamic response performance. After more than 5000 repeated loading/unloading cycles, the sensor exhibited negligible signal degradation and no observable baseline drift, demonstrating excellent durability and operational stability. The advantages of the flexible pressure sensor in wide range, high sensitivity and good durability characteristics make it have important application prospect and value in the fields of wearable devices, medical detection, robot technology and so on.