Thin film 0–3 polymer/piezoelectric ceramic composites: Piezoelectric paints

Abstract

In this paper we summarize our investigation of the electrical properties of thin-film 0–3 polymer-ceramic 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 PbTiO₃. 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 PbTiO₃ composites, the hydrostatic coefficients were found to be roughly 50% larger than the comparable PZT-filled materials. For example, g_h d_h ranged from about 1260–1380 × 10⁻¹⁵ m²/N for PZT-filled and from about 1970–2140 × 10⁻¹⁵ m²/N for PbTiO₃-loaded acrylic composites. The electrical properties of the PbTiO₃-filled polyurethane were comparable to those of the corresponding PZT composites.