Improvement of shoulder peak effect in graphene/silicone rubber strain sensors by nanosilica

Conducting polymer composites (CPCs) typically exhibit shoulder peak phenomena in their resistive response signals, which greatly limits their practical application as strain sensors in the field of vibration damping. In this paper, nanosilica (SiO2) nanoparticles were incorporated into graphene (GR)/methyl vinyl silicone rubber (VMQ) composites to obtain the optimum content of SiO2 to eliminate the shoulder peak phenomenon. The results showed that the shoulder peak phenomenon of the resistance response signal of the composites disappeared after the addition of 30 % SiO2, which explained the mechanism of eliminating the shoulder peak phenomenon. Meanwhile, the tensile strength and Young's modulus of the composites were improved, and excellent resistance-strain response properties were obtained, including a wide sensing range (＞200 %), high sensitivity (GF = 839.02), fast response time (37 ms), and good durability and stability (9000 cycles at 50 % strain). It shows that the strain sensor has great potential for health monitoring in the field of vibration damping.