A method for the preparation of uniform gel-disks for enzyme and cell immobilisation, as well as for characterisation of gel mechanical stability, is described. The apparatus comprises a stainless steel base unit and glass parallel plates, designed to permit easy and fast production of multiple homogeneous gel sheets of variable thickness.

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Devices and machines which perform additive manufacturing (adding material in a layer-wise or bead-wise manner to produce complex structure rather than removing material through machining) are maturing and entering the commercial market. While small prototype parts are routinely made using these devices, a number of industries, including biomedical and aerospace, are considering using these techniques for production parts. New materials which take advantage of the unique capability of additive manufacturing are beginning to evolve. Hybridization of materials at smaller scales now becomes possible with the precision of additive manufacturing devices. However, the fundamentals of structural performance of materials that can be produced by these methods are still to be explored and understood.. The current effort focuses on characterizing and describing the fundamental processing of hybrid materials produced using a combination of laser sintering of metals combined with polymer infusion of advanced carbon fabric. Ultimately, the work seeks to develop a fundamental understanding of the structural mechanics of these novel graphite-metal materials produced through hybrid processes. By understanding development and location of weak structural planes, effects of voids and discontinuities, load transfer from nano to macro scale, reinforcement distribution, gradients in properties, and effects of residual stress, a complete materials design process beginning with structural requirements and ending with material and process selection can be developed. This paper will summarize the first experimental steps taken to process and fabricate a metal-to-composite hybrid joint using a combination of additive manufacturing and conventional composite processes. Experimental conditions are described and morphology of the resulting hybrids is discussed. Future plans for testing are described.

The realization of aerospace vehicle technologies demanding extreme service conditions is facilitated by the development of materials with greater oxidative stability at high temperatures. Thermal performance of polymer composites can be increased by incorporating a hybrid (organic-inorganic) resin as a thermal barrier coating. One such resin system, meta-poly (carborane-siloxane-arylacetylene) ( m-PCSAA), developed by the U.S. Naval Research Laboratory, shows potential for such application and is further investigated in this work. The resin has a low viscosity (0.1 Pa s) with large processing window (2.5 h) from 100°C to 230°C. These processing characteristics are advantageous for infusion processes or the inclusion of fillers for coating applications. Curing was accomplished in two stages, corresponding to two exothermic reactions. After the first curing stage, the resin exhibits elastomeric behavior, and after the second curing stage is rigid with a high glass transition temperature (∼330°C). The materials exhibited high char yields (89%) in air at 1000°C and may be useful in space or for attritable technology. No cracks were observed during long-term service at 288°C, but significant degradation and cracking were observed after aging at 316°C. The materials exhibited high coefficients of thermal expansion; 186.9 and 168.6 μm/(m∙°C) after first and second curing stage respectively. Similar to epoxies and polyimides, the resin acquired up to 3% moisture at 70°C and 85% relative humidity.

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