ELECTRIC-FIELD STRUCTURING OF PIEZOELECTRIC COMPOSITE-MATERIALS

Electric fields can be used to assemble a random (0-3) dispersion of f erroelectric particles into a quasi 1-3 structure. The technique invol ved, proposed by Randall et al. [Am. Ceram. Sec. 93rd Meeting (Cincina tti, 1991)], exploits the dielectrophoretic effect. Piezoelectric mate rials structured in this way may have advantages over current material s for applications such as acoustic imaging and medical ultrasound. Le ad titanate particles have been dispersed into an epoxy matrix, ordere d into fibrils and the resin cured. The anisotropic dielectric propert ies of these composites are reported and the practical difficulties of using this technique to assemble ferroelectric ceramic-polymer compos ites discussed.