PARAMETERS AFFECTING LAMELLAR FORMATIONS IN ER FLUIDS: AN ALTERNATIVE MODEL FOR ER ACTIVITY

Under static conditions, ER suspensions form columns under electric field. However under the combined stimulii of a shear and electric field, the particles assemble into lamellar structures. The morphology of these structures are complex functions of electric field, shear rate, time of shear, electrode gap, particle concentration, and others. In this paper we present information regarding the field dependence, the concentration dependence, and the sequence of application of the electric and shear fields. A alternative model for ER activity, other than chain breaking, is presented which incorporates this lamellar texture.