Abstract: Flexible pressure sensors have garnered significant attention in health monitoring and human-machine interaction due to their ability to precisely detect external pressure and conform to complex surfaces. However, the inherent trade-off among sensitivity, detection range, and mechanical stability severely restricts their performance enhancement and further development. In this study, wet spinning and substrate-assisted drying strategies were employed to tailor the morphology and structure of graphene fibers (GF), thereby optimizing the conductive network. As a result, dense ribbon-shaped GF with a high electrical conductivity of 3.19 × 10⁴ S m^-1, a tensile strength of up to 179.6 MPa, and a strain capability of 6.5 % were successfully prepared and employed as the sensing layer in flexible pressure sensors. The fabricated GF-based pressure sensor exhibited a high sensitivity of 30.79 kPa^-1 in the range of 0-10 kPa and maintained a sensitivity of 15.59 kPa^-1 even when the detection range was extended to 150 kPa. Moreover, it demonstrated rapid response/recovery characteristics (88 ms/72 ms) and excellent durability over 10,000 cycles. The sensor effectively detected subtle physiological signals, such as knuckle bending, wrist flexion, and pulse beating, highlighting its potential applications in health monitoring and smart wearable devices.

Key words: Graphene fibers, Wet spinning, Dense structure, Pressure sensor, Motion monitoring