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Ceramic Structure (ceramic + structure)
Selected AbstractsDirect Ink Writing of Three-Dimensional Ceramic StructuresJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2006Jennifer A. Lewis The ability to pattern ceramic materials in three dimensions (3D) is critical for structural, functional, and biomedical applications. One facile approach is direct ink writing (DIW), in which 3D structures are built layer-by-layer through the deposition of colloidal- or polymer-based inks. This approach allows one to design and rapidly fabricate ceramic materials in complex 3D shapes without the need for expensive tooling, dies, or lithographic masks. In this feature article, we present both droplet- and filament-based DIW techniques. We focus on the various ink designs and their corresponding rheological behavior, ink deposition mechanics, potential shapes and the toolpaths required, and representative examples of 3D ceramic structures assembled by each technique. The opportunities and challenges associated with DIW are also highlighted. [source] Microwave Bandgap in Multilayer Ceramic StructuresJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2006Bo Li A multilayer ceramic structure with a photonic bandgap (MC-PBG) was fabricated by a method of tape casting combined with screen printing. The MC-PBG structure is a two-dimensional array with either rectangular or hexagonal metal coils in a ceramic matrix. The metal coils are connected to the base metal layer in the ceramic substrate to form a monolithic body. The surface-wave dispersion properties of these MC-PBG structures were measured. A stop band, which is significantly influenced by the symmetrical characteristics of the inductor,capacitor (LC) arrays, was found in both the structures in the frequency range of 2.0,3.5 GHz. Because of their effective surface-wave suppression, MC-PBG structures can be used as high-performance antenna substrates to enhance the broadside gain of patch antenna devices. [source] Feasibility Study of a Thick-Film PZT Resonant Pressure Sensor Made on a PreFired 3D LTCC StructureINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2009Marina Santo Zarnik This paper discusses the feasibility of a piezoelectric resonant pressure sensor made of lead,zirconate,titanate (PZT) thick films on a preprocessed 3D low-temperature co-fired ceramic structure with a deformable diaphragm. Numerical and experimental analyses were carried out. Two different thick-film PZT compositions were characterized. Using experimentally evaluated material properties, a finite-element analysis showed the trends and facilitated the decisions in the design phase of the sensor. [source] Microwave Bandgap in Multilayer Ceramic StructuresJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2006Bo Li A multilayer ceramic structure with a photonic bandgap (MC-PBG) was fabricated by a method of tape casting combined with screen printing. The MC-PBG structure is a two-dimensional array with either rectangular or hexagonal metal coils in a ceramic matrix. The metal coils are connected to the base metal layer in the ceramic substrate to form a monolithic body. The surface-wave dispersion properties of these MC-PBG structures were measured. A stop band, which is significantly influenced by the symmetrical characteristics of the inductor,capacitor (LC) arrays, was found in both the structures in the frequency range of 2.0,3.5 GHz. Because of their effective surface-wave suppression, MC-PBG structures can be used as high-performance antenna substrates to enhance the broadside gain of patch antenna devices. [source] Fabrication of High-Strength Continuous Zirconia Fibers and Their Formation Mechanism StudyJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2004He-Yi Liu Continuous zirconia fibers with a nanometer ceramic structure and a tensile strength up to 2.8 GPa were fabricated by pyrolyzing polyacetylacetonatozirconium precursor fibers through a special atmosphere heat treatment. DSC-TGA, GC-MS, IR, SEM, and TEM were used to study the fiber transformation mechanism during heating. Results showed that special atmosphere heat treatment could make the organics in the fibers come out directly without carbonization and remove them almost entirely under 400°C, and the obtained zirconia fibers had few defects, good continuity, and high strength. [source] Printed Origami Structures (Adv. Mater.ADVANCED MATERIALS, Issue 20 201020/2010) Bok Y. Ahn, Jennifer Lewis, and co-workers report on p.,2251 a new method for creating complex 3D structures that combines direct-write assembly with a wet-folding origami technique. Planar lattices composed of a titanium hydride ink are printed, and then folded, rolled, or molded into the desired shape. These 3D objects are then transformed into metallic or ceramic structures by thermal annealing. [source] Development and Simulation of an Embedded Hydrogen Peroxide Catalyst Chamber in Low-Temperature Co-Fired CeramicsINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 5 2007Donald Plumlee Satellites in the range of 10,50 kg require small propulsion devices to perform station-keeping tasks in orbit. Low-temperature co-fired ceramic structures provide a unique platform to produce a reliable, low-cost micropropulsion system. The design uses microchannels embedded in the ceramic substrate to create a nozzle and embedded catalyst chamber. A hydrogen peroxide monopropellant is injected into a silver-coated catalyst chamber structure. The monopropellant decomposes into hot gas, which is expelled through the nozzle producing thrust. A thermal energy balance and a kinetic model is presented along with performance testing. [source] Direct Ink Writing of Three-Dimensional Ceramic StructuresJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2006Jennifer A. Lewis The ability to pattern ceramic materials in three dimensions (3D) is critical for structural, functional, and biomedical applications. One facile approach is direct ink writing (DIW), in which 3D structures are built layer-by-layer through the deposition of colloidal- or polymer-based inks. This approach allows one to design and rapidly fabricate ceramic materials in complex 3D shapes without the need for expensive tooling, dies, or lithographic masks. In this feature article, we present both droplet- and filament-based DIW techniques. We focus on the various ink designs and their corresponding rheological behavior, ink deposition mechanics, potential shapes and the toolpaths required, and representative examples of 3D ceramic structures assembled by each technique. The opportunities and challenges associated with DIW are also highlighted. [source] | ||||||||||