Thin Film 0-3 Polymer/Piezoelectric Ceramic Composites: Piezoelectric Paints

In this paper we summarize our investigation of the electrical properties of thin-film 0-3 polymerceramic composites. The main objective of this study was to demonstrate the principle that a piezoelectric 'paint' can indeed be prepared. Two polymers, an acrylic copolymer and a polyurethane, were utilized in our research. Both were loaded with 60-70 volume percent PZT and a coprecipitated PbTiO,. The addition of various surfactants and dispersing agents to the acrylate-based composites was necessary to aid in dispersing the ceramic particles in the polymer matrix. The hydrostatic strain and voltage coefficients, along with the 'figures of merit' for PZT-filled acrylic and polyurethane composites were found to be significantly larger than values reported previously for other 0-3 polymer-PZT composites. For acrylic copolymer-coprecipitated PbTiO, composites, the hydrostatic coefficients were found to be roughly 50% larger than the comparable PZT-filled materials. For example, g, d, ranged from about 1260-1380 x 10-15 m2/N for PZT-filled and from about 1970-2140 x 10-15 mZ/N for PbTi0,-loaded acrylic composites. The electrical properties of the PbTi0,-filled polyurethane were comparable to those of the corresponding PZT composites.