Manufacturing & Prototyping

Micro-Propulsion Devices Made of Low-Temperature Co-Fired Ceramics

In the satellite industry, the trend is towards decreasing the size of satellites and clustering of small satellites. Technological advancements in microelectronics have made it more economical to launch a cluster of satellites with a single vehicle rather than the traditional one satellite per vehicle. A small satellite cannot carry a large quantity of fuel or batteries for power so it will require an alternative propulsion system for station-keeping and orbital corrections. The current micro-propulsion alternatives include miniaturized versions of Hall Effect thrusters, plasma thrusters, and chemical devices. These devices are commonly fabricated as microelectromechanical system (MEMS) devices using silicon.

Posted in: Briefs, Manufacturing & Prototyping, Downsizing, Microelectricmechanical device, Product development, Ceramics, Silicon alloys, Satellites
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Microfabrication and Testing of a Thermoelectric Device for Generating Mobile Electrical Power

Several attractive features of thermo-electric (TE) technology include no moving parts, light weight, modularity, covertness, silence, high power density, low amortized cost, and long service life with no required maintenance. Many of the potential uses for mounted/ dismounted power, such as recharging batteries, are therefore ideal for TE technologies. However, these applications will require more interconnected, smaller-scale modular devices than are currently available. Most commercial off-the-shelf (COTS) TE devices are optimized for cooling, not for generating power, so new device structures with materials and geometries better optimized for power generation are needed for broader use of TE technologies.

Posted in: Briefs, Manufacturing & Prototyping, Architecture, Fabrication, Electro-thermal engines, Test procedures
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Manufacturing Cylindrical Parts Using Deep Draw Technology

In applications where product performance is mission critical, commercial, military, and aerospace companies require technology to manufacture deep- drawn cylindrical product components. Conventional production alternatives such as impact, spinning, and supplemental annealing processes often do not deliver reliable results for certain applications.

Posted in: Briefs, Manufacturing & Prototyping, Molding, Production engineering, Parts
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Fabricating Biologically Inspired Artificial Haircell Sensors

As electronics packaging and equipment have decreased in size and weight, so have the potential dimensions of unmanned aircraft. Specifically, a classification of micro air vehicles (MAVs) has emerged that limits the scale of the aircraft to approximately 6" (15 cm). A project is underway aimed at developing artificial haircell flow sensors following biological inspiration of insect flow sensors, and demonstrate the potential of these sensors for controlling the flight of MAVs.

Posted in: Briefs, Manufacturing & Prototyping, Downsizing, Sensors and actuators, Biological sciences, Unmanned aerial vehicles
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Improvements in Manufacturing BMI/Fiber Composites Using AFP

A program now in progress is dedicated to making improvements in automated fiber placement (AFP) for the manufacture of advanced composite-material (matrix/fiber) structural components — especially skin and shell components for aircraft. [In AFP, a composite-material part is formed by laying down fiber tow or tape pre-impregnated with a matrix resin (“prepreg”) onto a mandrel that defines the shape of the part.] Improvements are sought for the following reasons:

Posted in: Briefs, Manufacturing & Prototyping
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Patterning of Polycrystalline Bi2Te3 Thin Films on Silicon

Experiments in patterning of thin films of polycrystalline bismuth telluride (Bi2Te3) on silicon substrates have been performed. Bi2Te3 is representative of a family of thermoelectric materials that are well suited for use in extracting electric energy from thermal gradients associated with flows of waste heat at temperatures in the approximate range of 0 to 150°C. Techniques and processes for fabricating macroscopic thermoelectric devices from bulk thermoelectric materials are mature and well known, but the same cannot yet be said concerning the fabrication of microscopic thermoelectric devices. The experiments reported here were performed as part of a continuing effort to develop capabilities for fabrication (including mass production) of microscopic thermoelectric devices, with a view toward eventually enabling the incorporation of them as integral parts of micro-electromechanical systems (MEMS) that could also include heat exchangers, sensors, actuators, and/or flow channels. Thus, the development of microscopic thermoelectric devices could benefit from the established industrial infrastructure for manufacturing MEMS and other silicon-based microsystems.

Posted in: Briefs, Manufacturing & Prototyping
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Progress Toward Carbon-Nanotube Arrays for Probing Cells

Progress has been reported in research oriented toward the goal of fabricating arrays of interconnected single-walled carbon nanotubes (SWNTs) that could serve as probes for measuring localized events within living cells. As used here, "interconnected" signifies mechanically and electrically connected to patterned metal films (interconnections) that lead to contact pads, which, in turn, enable electrical connection to external electronic instrumentation. This research poses a high economic risk because it entails pushing several technological disciplines beyond their present limits. There is no previously reported combination of fabrication techniques and processes for producing carbon nanotubes that have the required properties at the required positions and orientations on patterned metal films.

Posted in: Briefs, Manufacturing & Prototyping, Architecture, Sensors and actuators, Biological sciences, Fabrication, Metals, Nanomaterials
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Inexpensive Free-Form Fabrication of Titanium-Alloy Parts

A continuing effort to devise relatively inexpensive means of manufacturing titanium-alloy parts has been focused on a free-form fabrication approach. As used here, “free-form fabrication” refers generally to any or all of a number of methods and processes denoted, variously, as rapid prototyping or three-dimensional (3D) printing.

Posted in: Briefs, Manufacturing & Prototyping
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Advances in Fabrication of Nanoscale Devices

Some advances have recently been made on several fronts in a continuing effort to develop of means of fabricating electronic and magnetic devices having dimensions of the order of tens to hundreds of nanometers. This effort is a collaboration of members, from three universities, whose interests, expertise, and facilities span synthesis of materials, nanoscale characterization, nanoscale lithography, and non-lithographic processing of nanostructures.

Posted in: Briefs, Manufacturing & Prototyping
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Experiments in Vacuum Brazing of Titanium

An experimental study of vacuum brazing of titanium and of the effects of changes in brazing alloys and brazing process conditions has been performed. [As used here, “titanium” signifies both commercially pure titanium and an alloy nominally consisting of 90 weight percent of titanium, 6 weight percent of aluminum, and 4 weight percent of vanadium (commonly abbreviated “Ti-6Al-V”).] The knowledge gained in this study is intended to contribute to development of capabilities for fabricating titanium structures in circumstances in which welding — heretofore the typical method of joining titanium — cannot be performed because access is limited or adjacent nonmetallic components would be harmed. There is a particular need for such knowledge to enable fabrication of lightweight, durable titanium- based structures for armored vehicles. Examples of such structures include standard lightweight plate structures, titanium components encapsulating ceramics, and panels that comprise pyramidal frame cores sandwiched between face sheets.

Posted in: Briefs, Manufacturing & Prototyping
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