The role of conduction in electrorheological fluids: From interaction between particles to structuration of suspensions

After a brief description of the electrorheological (ER) fluids and of their properties, we recall the basic physical processes responsible for the electrically induced interactions between particles. We then give a short review of recent work on ER effect in the case of D.C. applied fields where the conduction properties of the components play the major role. The conduction model for estimating the attraction force between two spheres is presented along with some experimental results. Finally we shortly address problems raised by the ER fluids such as the prediction of their static yield stress and of their apparent viscosity.