Robocasting of Three-Dimensional Piezoelectric Structures

Robocasting is a solid freeform fabrication (SFF) technique based on the direct writing of highly concentrated colloidal gels. Similar to other SFF techniques, robocast-ing offers facile assembly of complex three-dimensional geometries and a broad pallet of ceramic, metallic, and polymeric materials from which to design devices. Here, robocasting is used to assemble lead zirconate titanate (PZT) skeletons for direct use or to create epoxy-filled composites suitable for hydrostatic piezoelectric sensors. PZT composites labeled by connectivity (3—3, 3—2, 3—1) are demonstrated. For such composites, the piezoelectric hydrostatic figure of merit (

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) increases by up to 60-fold compared with bulk PZT. Ultimately, SFF allows for rapid iteration, prototyping of designs, and assembly of unique PZT skeletons. Sandia is a multipro-gram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-ACO4 — 94AL85000.