Resistivity Temperature Dependence of Force-sensitive Sensing Composites Filled with Mixed Conductive Filler

The study of the resistivity temperature dependence of silicone rubber-carbon-black force-sensitive sensing composites mixed with different concentrations of carbon fiber was presented,and the conductive mechanism was discussed.The experimental results indicate that the resistivity of composite materials reduce nonlinearly from 330 Ω.cm to 109 Ω.cm,with the increase of carbon fiber.Due to the addition of carbon fiber,the resistivity temperature dependence of composites changes from negative temperature coefficient of resistance(NTC) to positive temperature coefficient of resistance(PTC).The resistivity of composites increases at first,then decreases as temperature increasing due to the increase of carbon fiber loading.On heating and cooling cycles,the hysteresis loop appeares on the resistivity-temperature curve for composites.The width of hysteresis loop increases at first,then decreases as temperature increasing due to the increase of carbon fiber loading.