Sensitive coefficient of pressure-sensitive sensor based on conductive rubber filled by carbon black

An equation of sensitive coefficient of the pressure-sensitive sensor based on conductive rubber filled by carbon black is given by general effective media theory. Sensitive coefficient and working principle of the pressure-sensitive carbon black/rubber are studied by impact of the strain and piezoresistive effect on negative pressure coefficient of resistance (NPC effect). When the volume fraction of carbon black is close to the critical volume fraction, the scope of sensitive coefficient is from 2.5 to 13 and the piezoresistive effect would be the main working principle. When the volume fraction of carbon black is within the percolation zone, the scope of sensitive coefficient is from 2.5 to 4.5 and the mainly working principle is related to the size of contact pressure. When the pressure is relatively low, the piezoresistive effect would play a main role in the work of sensor; and when the pressure is relatively high, the strain effect would play a main role. When the volume fraction of carbon black is within the conductive zone, the scope of sensitive coefficient is from 2.0 to 2.5 and the strain effect would be the main working principle.