Electric Field Induced Solidification — Theory of Electro-Rheology Fluids

Abstract

There has been an enormous resurgence of interest in the field of electro-rheology (ER) fluids during the last couple of years. 1 An ER fluid consists of a suspension of fine dielectric particles in,a liquid of low dielectric constant.^2-6 Its viscosity increases dramatically in the presence of an applied electric field. Indeed, if the electric field exceeds a critical value, the ER fluid turns into a solid whose yield stress increases as the field is further strengthened. The phenomenon is completely reversible and the time scale for this transition is of the order of a millisecond. This unique property makes ER fluids attractive for many futuristic technologies, such as brakes, suspensions, transmissions, and fuel flow control devices on automobiles and airplanes.⁴