Mechanical properties of a new electrorheological fluid

We have extended the Rayleigh identity based on a multipole expansion theory to analyze the mechanical properties of a new type of electrorheological (ER) system that consists of a novel doubly coated particle in silicone oil. The function of the inner conducting layer of the particle has been investigated. From the shear strain (θ) dependence of effective dielectric constant, the dependence of static yield stress (τs) and shear modulus (G) on the applied electric field are presented. Implications for the design of ER fluids are discussed briefly.