Pressure Sensors Based on Densely Structured Graphene Fibers for Motion Monitoring

Piezoresistive pressure sensors have received considerable attention because of their simple structure, high sensitivity and low cost. Graphene, which is known for its outstanding mechanical and electrical properties, has shown great application potential as a sensor material. However, its durability and performance consistency in practical applications still require enhancement. In this study, magnetic graphene fibers (MGFs) are prepared via wet spinning, using graphene oxide (GO), doped with Fe3O4 nanoparticles. The resulting MGFs exhibit a high tensile strength of 58.6 MPa, a strain of 5.3% and an electrical conductivity of 1.7 x 104 S/m. These MGFs are utilised to construct a multilayer fabric for fabrication of flexible pressure sensors. The confinement within the spinning channel facilitates an ordered arrangement of GO sheets, resulting in MGFs with superior electrical and mechanical properties. The issuing MGFs pressure sensors demonstrate a wide detection range (0-120 kPa), high sensitivity (0.233 kPa-1, 0-40 kPa) and rapid response/recovery times (121 ms/158 ms). In addition, it exhibits a remarkable durability, maintaining performance over 1300 cycles, during continuous operation, with negligible degradation. This sensor shows excellent capability in monitoring human physiological activities, indicating its substantial application potential in wearable devices.