Particle size scaling of the giant electrorheological effect

This letter shows that by decreasing the size of the barium titanyl oxalate nanoparticles coated with urea, achieved through Rb doping, the giant electrorheological (GER) effect can attain a yield stress of >250 kPa. The shear thinning effect observed in Parallel-plate sandwich configuration is also reported, and attributed to the centrifugal sedimentation effect of the inhomogeneous structures induced by applied electric field. In addition, it is found from experiments that the ER effect is very sensitive to. the solid particles volume fraction. (C) 2004 American Institute of Physics.