Research On Static And Dynamic Characteristics Of Force-sensitive Conductive Rubber For Flexible Tactile Sensing

This article elaborated on the status and progress of force-sensitive conductive rubber for flexible tactile sensor. Micro-structure of force-sensitive conductive rubber was investigated by scanning electron microscopy(SEM). The network of the different fillers in the rubber matrix was analyzed. The conductive mechanism of force-sensitive conductive rubber was researched based on conductive pathway theory and theory of electron tunnel.The working principle and nonlinear behaviour of negative pressure coefficient of resistance for force-sensitive conductive rubber were discussed by general effective media theory. Measure capacity and mechanical sensitivity of force-sensitive conductive rubber were analyzed by theory of electron tunnel. Under an un-axial pressure, it concluded that reason of negative pressure coefficient of resistance for force-sensitive conductive rubber was piezoresistive effect and strain effect. The nonlinear decrease of resistivity and stress-strain nonlinear laws result in nonlinear behaviour of negative pressure coefficient of resistance. With a certain range, reducing the filling ratio of filler and increasing the thickness of force-sensitive conductive rubber can rise the measure capacity of force-sensitive conductive rubber. Mechanical sensitivity of force-sensitive conductive rubber lies on the filling ratio of filler and elastic modulus.Dynamic characteristics of force-sensitive conductive rubber was discussed by viscoelasticity of force-sensitive conductive rubber. The result shows that the response time of the conductive rubber is short and force loading and sample resistance change occur simultaneously. The peak time, steady time, rise time of resistance associate with the loss modulus after force loading. Frequency response of force-sensitive conductive rubber is well, and response amplitude relate with mechanical sensitivity of force-sensitive conductive rubber.