Fabrication of PZT microspheres for application in electrorheological fluids

The fabrication of PZT microspheres using the sol-gel method, together with a flame treatment process, is reported. As a useful application, the microspheres were used in electrorheological (ER) fluids. It was found that the PZT-microsphere ER fluids exhibit strong ER effect, with the static yield stress increasing linearly with the electric field at low field and saturating at high field. With the addition of PbTiO3 nanoparticles, the bi-dispersed microsphere-nanoparticle system was found to exhibit saturation static yield stress in excess of 6 kPa. The method can be used to fabricate large ferroelectric/ferromagnetic spherical particles using other materials. 7 refs