An overview of rapidly prototyped piezoelectric actuators and grain-oriented ceramics

Rapid prototyping (RP) has been used to fabricate a series of piezoelectric actuators, including spiral and tube actuators, to study the actuation mechanism in these geometries, and to obtain enhanced properties. PZT spiral actuators showed large displacement in mm range, and moderate blocking force. Unimorph spirals (PZT/metal shim) and dual-material (piezoelectric/electrostrictive) PMN-PT spirals were also prototyped and characterized. Tube actuators with inward and outward wall curvature showed slight improvement in axial and radial displacements compared to conventional straight-walled tube actuators. In order to improve the performance of ceramic actuators with polycrystalline microstructures, grain-oriented ceramics of bismuth titanate, lead metaniobate, and PMN-PT were investigated. Texturing was achieved by incorporating anisometric seeds into RP feedstock, aligning them during fabrication, and growing the seeds (templates) at elevated temperatures. Synthesis of anisometric seeds and pertinent processing conditions of the textured ceramics are presented. The feasibility of making net shape single crystal components was also explored. Single crystals of 0.65PMN-0.35PT were grown in FDC components using embedded (111) and (110) SrTiO3 seeds at 1250degreesC.