ELECTRORHEOLOGICAL FLUIDS USING BIDISPERSED PARTICLES

We report very large enhancement of static yield stress for electrorhe ological fluids by adding ferroelectric nanoparticles of lead zirconat e titanate (PZT) or lead titanate (PbTiO3) to ER fluids consisting of 50 mu m glass spheres. It is found that the enhancement peaks at certa in nanoparticle/microparticle ratios for fixed solid/liquid volume fra ctions, The results are explained by calculations using an effective m edium approach, based on the physical picture that the nanoparticles m odify the properties of the liquid and solid components.