Solid freeform fabrication of novel piezoelectric ceramics and composites for transducer applications

Novel piezoelectric ceramic and ceramic/polymer composite structures were fabricated by solid freeform fabrication (SFF) for transducer applications. SFF techniques including fused deposition of ceramics (FDC) and Sanders prototyping (SP) were utilized to fabricate a variety of complex structures directly from a computer aided design (CAD) file. Novel composite structures including volume fraction gradients (VFG) and staggered rods, as well as actuator designs such as tubes, spirals and telescopes were made using the flexibility provided by the above processes. VFG composites were designed to suppress the intensity of side lobes in the acoustic beam pattern of a transducer. Several innovative designs were realized for the strain amplification in piezoelectric actuators using the FDC technique. The design, fabrication and electromechanical properties of these composites and actuators are discussed in this paper.