Electric field structuring of piezoelectric composite materials

Electric fields can be used to assemble a random (0-3) dispersion of ferroelectric particles into a quasi 1-3 structure. The technique involved, proposed by Randall et al. [Am. Ceram. Soc. 93rd Meeting (Cincinatti, 1991)], exploits the dielectrophoretic effect. Piezoelectric materials structured in this way may have advantages over current materials for applications such as acoustic imaging and medical ultrasound. Lead titanate particles have been dispersed into an epoxy matrix, ordered into fibrils and the resin cured. The anisotropic dielectric properties of these composites are reported and the practical difficulties of using this technique to assemble ferroelectric ceramic-polymer composites discussed.