Novel electroactive ceramic architectures by indirect solid freeform fabrication

This dissertation develops and applies processing methodologies to realize several piezocomposite hydrophone designs as a means of validating computational material structural design algorithms. Indirect Solid Freeform Fabrication (ISFF) of lead zirconate titanate (PZT) filled acrylate monomer systems has been utilized to fabricate intricate 3d PZT-air composite acoustic transducers with superlative hydrostatic response. Relevant processing details such as mold fabrication, slurry rheology, curing and binder burnout are discussed. Significant performance gains in Hydrostatic Charge Coefficient (270% improvement over solid PZT) and Hydrophone Figure of Merit (8500%) enhancement over solid PZT) are measured. Some of the optimized structures were heuristically redesigned to provide a means of probing the need for rigorous execution of the optimized design geometry. Computationally optimized structures outperformed heuristic redesigns in every case. Recommendations towards the further advancement of the computational design scheme are enumerated.; The ISFF process is utilized to fabricate low loss complex geometry periodic dielectrics, specifically Al₂O₃ electromagnetic bandgap structures, defect resonators and filters for use in the microwave range. Woodpile electromagnetic bandgap structures exhibiting a −40dB well created by ISFF and were shown to be operational at frequencies above 110GHz. Using ISFF, novel designs of planar periodic dielectric resonators with Q = 965 at 33GHz were realized in Al₂O₃. Metallodielectric filters with low insertion loss were also created. Modeling of these structures using RLC equivalent circuit analysis was performed to calculate a Q of 645.; For all ceramic systems used in the ISFF process the fidelity of the fabrication process was quantified and discussed. Feature sizes approaching 300 microns were realized in dense ceramic with a fidelity of replication of ±∼2%. The phase purity and dielectric properties after processing were gauged to be of high quality in every case.; Process modifications are incorporated and ceramic-ceramic composites with 3-3 connectivity are fabricated, Al₂O₃ + Yttria Iron Garnet magnetodielectric material systems are investigated for use as 3-3 composite impedance matched antenna structures.