Research On Strain Sensor Based On Graphene/Flexible Fabric Composite

In recent years,people pay more and more attention to their own sports and health,and the demand for real-time monitoring of physiological signals and motion changes is increasing.Although traditional electronic products such as smart watches have been put into use,their poor flexibility and low degree of human consideration have restricted the further development of wearable sensing devices.Under this background,the flexible fabric strain sensor based on carbon nanomaterials is an important solution with good human comfort and wide application range.In this paper,strain sensors based on graphene/flexible fabric composites were studied to improve the sensitivity,stability and linearity of strain sensors.The details are as follows:1.The graphene/fabric strain sensor was prepared in this paper by direct impregnation method.The effects of different impregnation times and different concentration of graphene oxide(GO)on the resistance of graphene/fabric composite were studied,and the effects of different process sequences of "reduction followed by impregnation" and "impregnation followed by reduction" on the properties of graphene/fabric strain sensor were also studied.The results show that when the number of impregnations is 5 and the concentration of GO is 2 mg/m L,the sensor prepared by the "impregnation followed by reduction" process sequence has the highest sensitivity with a strain coefficient of 19.3.2.The stability of flexible fabric sensor is usually poor when the sheet structure of reduced graphene oxide(RGO)is used to construct the conductive path of the sensor.In order to solve this problem,the graphene/carbon nanotubes/fabric strain sensor was prepared in this paper by using the feature of large length/diameter ratio of carbon nanotubes and fabric impregnation with RGO and carbon nanotube solutions successively.The results show that the stability of the strain sensor is improved compared with the sensor without carbon nanotubes.3.The response of flexible fabric strain sensors is usually nonlinear and their sensitivity varies with different strains.In order to solve this problem,the graphene/fabric strain sensor with pleated structure was fabricated by a process of pre stretching and then impregnating the fabric.The results show that the response of the strain sensor has good linearity compared with the sensor without pretension,and its sensitivity is basically the same in the whole strain range.Then,the graphene/fabric strain sensor with pleated structure was used to measure finger bending,pulse and throat vocalization,and good signal waveforms were obtained.It can be seen that the sensor studied in thispaper can be applied to the field of human health monitoring.