Magnetorheological fluids are suspensions composed of magnetizable particles dispersed in a non-magnetizable carrier fluid.As a smart material, MR fluids have been successfully applied as clutches, dampers and actuators in various fields.Commercial MR fluids are prepared with silicone oil and micro carbonyl iron particles with solid spherical morphology.However, recent studies indicated that using rod-like particles could fabricate MR fluids with better MR properties.Unfortunately, it is difficult to prepare iron particles with rod or fiber shape.