Piezoresistive Sensor Based on Conductive Polymer Composite With Transverse Electrodes

Abstract

To improve the sensitivity and reduce the thickness of the pressure sensor based on conductive polymer composite, a piezoresistive sensor probe with a novel structure called transverse-electrodes-probe (TEP), which is different from the traditional sandwich-structure-probe (SSP), is designed. As the composite and the two electrodes are located in the same layer/three layers of TEP/SSP, TEP is thinner than SSP. The resistivity of TEP increases with the increase in the pressure, contributing to the increasing tendency of the resistance, and the increasing extent of the resistivity of TEP is larger than that of SSP during compression. The uniaxial direction of the electrodes in TEP/SSP is perpendicular/parallel to that of the pressure. Consequently, the thickness of the composite in TEP/SSP is invariant/decreased and the cross-sectional area of the composite in TEP/SSP is decreased/invariant with the increase in the pressure, contributing to the increasing/decreasing trend of the resistance of the composite during compression. The effect of the change in the dimensions on the resistance for TEP/SSP is consistent/opposite with/to the effect of the change in the resistivity. The experimental results verify that the sensitivity of TEP is higher than that of SSP.