The Fabrication Of Flexible Strain Sensors Based On Carbon Nanomaterials

The strain sensors are widely used in various fields of human life.To achieve different functions,the materials and preparation of the strain sensors are diverse.This paper primarily explored the preparation,properties and applications of the strain sensors based on carbon nanomaterials,such as graphene,carbon nanotubes,and carbon black.First of all,we succeeded in developing the few layers of graphene which were prepared with graphite using mechanical peeling method that is easy to operate and reliable.According to the characterization results,including SEM and AFM,we could know that the thickness of graphene was 7 nm or less,which indicated the graphene was promising to be manufactured into strain sensors with high sensitivity.Then,we fabricated the flexible strain sensor utilizing the self-made graphene as conductive materials,and using PET(Polyethylene terephthalate)as substrate,which simplified the manufacturing process and performance testing.The test results proved that the graphene strain sensors possess wonderful sensitivity to detect small strain(< 1.74%),and the GF(gague factor)is up to 48.7.In order to improve the measuring range,we fabricated the stretchable strain sensors by LBL(layer-by-layer)technology,alternately coating the carbon nanotubes and carbon black on the spandex yarns.The LBL technology was easy to operate,and could promote the even distribution of the carbon nanotubes and carbon black on the yarn to improve the performance of the strain sensors.The strain sensors possess following advantages:(1)super stretchability(strain < 150%)(2)high sensitivity,the GF is up to 45.4(3)large linear response range The flexible strain sensors were used to monitor finger bending and wrist pulse beating,the results of which proved that the strain sensors were potential in monitoring human motion,and worth for us to further explore in the future.