Applicability of Simplified Expressions for Design with Electro-Rheological Fluids

There are three key factors that enable electro-rheological (ER) fluids to be related to engineering hardware: off-state, which is characterised by the suspension viscosity; on-state, which is characterised by the excess shear stress; and power requirement, which is characterised by the current density. This article discusses the potential benefits of using ER fluids and outlines some of the basic design problems. Some simplified expressions are derived that permit parametric design of ER fluid-based systems.