炭黑填充导电橡胶的力敏传感器灵敏系数

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

以通用有效介质理论为基础,给出了炭黑填充导电橡胶(炭黑/橡胶)的力敏传感器灵敏系数计算方程。采用该方程并结合应变和压阻效应对"负压力-电阻特性"(NPC)的影响程度,分析了力敏导电炭黑/橡胶的灵敏系数和工作原理。结果表明:炭黑体积分数在临界体积分数附近时,力敏导电炭黑/橡胶的灵敏系数在2.5～13之间,其工作原理主要为压阻效应。当炭黑体积分数在渗流区时,灵敏系数在2.5～4.5之间,其工作原理与接触压力的大小有关。压力较小时,其工作原理主要为压阻效应;压力较大时,其工作原理主要为应变效应。炭黑体积分数在传导区时,灵敏系数在2.0～2.5之间,其工作原理主要为应变效应。

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.