Temperature Interference Reduction for Pressure Sensor Made of Conductive Polymer Composite

To lower the temperature interference on the piezoresistive sensor made of conductive polymer composite, a differential structure composed of “positive piezoresistive and positive thermoresistive unit (PPPTU)” and “negative piezoresistive and positive thermoresistive unit (NPPTU)” is designed. The mass ratio of carbon black to silicone rubber in the composite in PPPTU is 0.06, which results in the increase of the electrical resistance of the composite with the increase of the compressive pressure/temperature. The mass ratio in NPPTU is 0.12, which results in the decrease/increase of the resistance of the composite with the increase of the compressive pressure/temperature. PPPTU and NPPTU are placed on the neighboring arms of an electrical bridge to construct a differential structure. The experimental results verify the feasibility of using the differential structure based on PPPTU and NPPTU to reduce the temperature interference.