The role of solid particles and carrying liquid conductivities in the electrorheological effect

An explanation is proposed for the electrorheological effect under fields based on the fact that the field distribution is controlled by the conduction properties (linear and nonlinear) of both the solid particles and the carrying liquid. A simplified analysis gives an expression for the attraction force between two very slightly conducting spheres in contact, immersed in a dielectric liquid, as a function of the imposed field and the ratio of conductivities. The predictions are confirmed by a large-scale experiment and qualitatively account for some observations on an electrorheological fluid.