Manufacturing & Prototyping

Templates for Fabricating Nanowire/Nanoconduit-Based Devices

Prior templating processes are being extended to finer spatial resolutions. An effort is underway to develop processes for making templates that could be used as deposition molds and etching masks in the fabrication of devices containing arrays of nanowires and/or nanoconduits. Examples of such devices include thermoelectric devices, nerve guidance scaffolds for nerve repair, photonic-band-gap devices, filters for trapping microscopic particles suspended in liquids, microfluidic devices, and size-selective chemical sensors. The technology is an extension of previous work conducted by JPL, UCSD (University of California, San Diego), and Paradigm Optics Inc., which developed a process to fabricate macroporous scaffolds for spinal-cord repair.

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Measuring Vapors To Monitor the State of Cure of a Resin

Excess curing time would no longer be needed as margin against uncertainty. A proposed noninvasive method of monitoring the cure path and the state of cure of an epoxy or other resin involves measurement of the concentration(s) of one or more compound(s) in the vaporous effluent emitted during the curing process. The method is based on the following general ideas:

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Manufacture of Regularly Shaped Sol-Gel Pellets

For mass production, an extrusion process is superior to a spray process. An extrusion batch process for manufacturing regularly shaped sol-gel pellets has been devised as an improved alternative to a spray process that yields irregularly shaped pellets. The aspect ratio of regularly shaped pellets can be controlled more easily, while regularly shaped pellets pack more efficiently. In the extrusion process, a wet gel is pushed out of a mold and chopped repetitively into short, cylindrical pieces as it emerges from the mold. The pieces are collected and can be either (1) dried at ambient pressure to xerogel, (2) solvent exchanged and dried under ambient pressure to ambigels, or (3) supercritically dried to aerogel. Advantageously, the extruded pellets can be dropped directly in a cross-linking bath, where they develop a conformal polymer coating around the skeletal framework of the wet gel via reaction with the cross linker. These pellets can be dried to mechanically robust X-Aerogel.

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Improved Fabrication of Lithium Films Having Micron Features

Dry chemicals and a dry process are used to prevent undesired reactions. An improved method has been devised for fabricating micron-dimension Li features. This approach is intended for application in the fabrication of lithium-based microelectrochemical devices — particularly solid-state thinfilm lithium microbatteries.

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Covering a Crucible With Metal Containing Channels

Metal is deposited on a sacrificial pattern that defines the channels. In a procedure that partly resembles the lost-wax casting process, a crucible made of a brittle material (ceramic, quartz, or glass) is covered with a layer of metal containing channels. The metal cover and the channels can serve any or all of several purposes, depending upon the application: Typically, the metal would serve at least partly to reinforce the crucible. The channels could be used as passages for narrow objects that could include thermocouples and heat-transfer strips. Alternatively or in addition, channels could be used as flow paths for liquid or gaseous coolants and could be positioned and oriented for position or direction-selective cooling. In some cases, the channels could be filled with known gases and sealed so that failure of the crucibles could be indicated by instruments that detect the gases.

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Solving Complex Engineering Challenges of Large Composite Aerostructures

Large-scale composite parts present unique design and manufacturing challenges in aerospace. Composites are becoming the material of choice for the manufacture of large, complex aerostructures. The aft section of the jumbo Airbus A380 and the wings of the military transport Airbus A400, for example, are all made of carbon-fiber composites. Boeing, for the first time, is building an all-composite airframe and wings for its groundbreaking 787 airliner. Because of these and other recent manufacturing achievements, there is little doubt that composite materials will be used extensively in many future aircraft programs — from wide-body jets and commercial airliners to regional, business, and “very light” airplanes.

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