Novel piezoelectric ceramics and composites for sensor and actuator applications

Novel piezoelectric ceramic, and ceramic/polymer composite structures were fabricated by solid freeform fabrication (SFF) for sensor and actuator 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. Many novel and complex composite structures including volume fraction gradients (VFG), staggered rods, radial and curved composites, and actuator designs such as tubes, spirals and telescoping were made using the flexibility provided by the above processes. Radial composites with various connectivities in the radial direction were made for towed array applications. VFG's were incorporated into some of these designs, with the ceramic content decreasing from the center towards the edges. Many new designs are also being used to manufacture high authority actuators utilizing the FDC technique. The telescoping actuation of the device is the summation of actuation of all individual tubes making of the actuator, therefore, increasing the number of the tubes which are the driving component of the actuator will further enhance the displacement. The design, fabrication and electromechanical properties of these sensor and actuator structures are discussed in this paper.