Electric Capacity Characteristic of Nanofiber/Vulcanized Rubber

Rubber material generally behaves as an electrical insulator, and vapor grown carbon fiber (VGCF) has excellent electrical conductivity. In our study, we mixed carbon nanofiber (VGCF) into styrene–butadiene rubber and investigated the relationship between strain and the electric capacitance of vulcanized rubber filled with VGCF, of which the hardness was not changed. The electric capacitance of the rubber filled with VGCF increased with VGCF content but decreased with increasing tensile strain. We confirmed that the change rate of electric capacitance is related to the VGCF content of the fillers. In order to investigate the relationship between strain and electric capacitance of rubber with VGCF, it is feasible to apply rubber composites filled with VGCF as a strain sensor.