Nonlinear characteristic of pressure/temperature sensor based on conductive rubber filled by carbon black

The nonlinear characteristic of the conductive rubber filled by carbon black used for pressure/temperature sensor was analyzed by the impact of the strain and resistivity on the negative pressure coefficient of resistance(NPCR) and the positive temperature coefficient of resistance(PTCR). It concludes that nonlinear change of resistivity has a great impact on the nonlinear characteristic of NPCR and PTCR. When the volume fraction of carbon black is close to the critical volume fraction, the resistivity is highly sensitive to the change of the volume of composite, and the nonlinear characteristic of NPCR and PTCR is strong. Because the compression coefficient is larger than the expansion coefficient and the deformation process of conductive barbon black/rubber under pressure and temperature is different, the nonlinear characteristic of NPCR is stronger than PTCR.