Modulating the sensitivity of a flexible sensor using conductive glass fibre with a controlled structure profile

Abstract Flexible sensor has been researched a lot recently because the device has the capability to hold both excellent flexibility and outstanding sensitivity. In this study, we reported a method to modulate the sensitivity of a flexible composite sensor using graphene-coated glass fiber with a controlled structure profile in polydimethylsiloxane. The morphology and electromechanical properties of the sensor were studied. The results showed that the sensing behavior of composites was strongly dependent on the bending direction and embedded depth of graphene-coated glass fibre in the matrix. A gauge factor (Ratio between the resistance change and applied strain to the composites) of 7.3 was achieved when the sample with a lowest embedded depth in the matrix was subjected to a bending angle of 68° (tensile strain 2.2%). Such sensitivity was maintained under the cyclic mechanical deformation. The findings of this paper demonstrated that by simple controlling on the engineering structure of constituent material, it could regulate the sensitivity of sensor with one dimensional fibre reinforcement. The mechanism behind such observation was revealed based on the experimental results and a bending model. The potential application of the composite sensor for detecting finger motion was demonstrated as well.