压力/温度复合柔性触觉传感器用导电橡胶的外场特性

External Field Characteristics of the Conductive Rubber Used as the Multi-Pressure-Temperature Flexible Tactile Sensor

分析了不同填料用量及种类对导电橡胶外场特性(压力、温度)的影响。结果表明,导电网络密度的增大与损伤使得导电橡胶呈现"电阻-负压力系数"(NPC)和"电阻-正压力系数"(PPC),热膨胀和热扰动共同作用使得导电橡胶呈现"电阻-负温度系数"(NTC)和"电阻-正温度系数"(PTC)。热膨胀起主导表现出PTC效应,热扰动起主导则表现出NTC效应。填料用量与种类对于导电橡胶的外场特性影响显著,炭黑(8%)(质量分数,下同)和石墨(5.2%)并用填充导电橡胶,同时消除了PPC和NTC效应,可用于制作压力/温度复合柔性触觉传感器用敏感材料。

External field characteristics of conductive rubber were analyzed for the dosage of filler and the type of filler. Under the uniaxial compression field,＇negative pressure coefficient of resistance＇ （NPC） existed when the density of conductive network rose and ＇positive pressure coefficient of resistance＇ （PPC） appeared when the conductive network was destroyed. It discovered that the resistivity changed along with the temperature mainly subjected to the thermal expansion and the thermal disturbance. ＇Positive temperature coefficient of resistance＇ （PTC） appeared when the thermal expansion took the leading role; if the thermal disturbance took the leading role,and then ＇negative temperature coefficient of resistance＇ （NTC） would appear. It is concluded that the resistivity characteristics of the conductive rubber upon external fields are resulted from the change in both the fraction and type of the filler. Avoiding the PPC and NTC effect,carbon （8%） and graphite （5.2%） blended in conductive rubber are able to fabricate the sensitive material for multi-pressure-temperature flexible tactile sensor.