Tech Briefs

Software for Secondary-School Learning About Robotics

The ROVer Ranch is an interactive computer program designed to help secondary-school students learn about space-program robotics and related basic scientific concepts by involving the students in simplified design and programming tasks that exercise skills in mathematics and science.

Posted in: Briefs

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Surface Bacterial-Spore Assay Using Tb3+/DPA Luminescence

A total spore count could be obtained in minutes. Equipment and a method for rapidly assaying solid surfaces for contamination by bacterial spores are undergoing development. The method would yield a total (nonviable plus viable) spore count of a surface within minutes and a viable-spore count in about one hour. In this method, spores would be collected from a surface by use of a transparent polymeric tape coated on one side with a polymeric adhesive that would be permeated with one or more reagent(s) for detection of spores by use of visible luminescence. The sticky side of the tape would be pressed against a surface to be assayed, then the tape with captured spores would be placed in a reader that illuminates the sample with ultraviolet light and counts the green luminescence spots under a microscope to quantify the number of bacterial spores per unit area. The visible luminescence spots seen through the microscope would be counted to determine the concentration of spores on the surface.

Posted in: Bio-Medical, Briefs, TSP

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Instrumented Spindle Improves Manufacturing of Optical Materials

Sensors and data acquisition system provide real-time visibility of grinding system operation. Lion Precision and Professional Instruments, St. Paul, Minnesota High-performance materials such as ceramics, optics, and alloy steels are manufactured using abrasive grinding technology. Until now, the grinding wheel and process conditions have been difficult to measure in production.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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Flexible Laser Design Targets Low-Volume Material Processing Needs

A flexible approach to diode-pumped laser design combines customized performance with cost-effective manufacturing. Coherent, Inc., Santa Clara, California Q-switched, diode-pumped solid-state lasers with an end-pumped cavity design are now widely used in micromachining, materials processing, marking, and related applications. They are used to process a broad range of materials including metals, glass, plastics, and semiconductors. But this application diversity creates a concomitant need for laser diversity. Namely, while each application requires superior reliability and performance, the definition of “superior performance” is very application-specific. For example, some metal ablation applications may benefit from a long laser pulse, whereas semiconductor scribing needs a short pulse and a very high pulse repetition rate.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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Aligning Optical Fibers by Means of Actuated MEMS Wedges

Wedges would be fabricated using gray-scale exposure of photoresist. Goddard Space Flight Center, Greenbelt, Maryland Microelectromechanical systems (MEMS) of a proposed type would be designed and fabricated to effect lateral and vertical alignment of optical fibers with respect to optical, electro-optical, optoelectronic, and/or photonic devices on integrated circuit chips and similar monolithic device structures. A MEMS device of this type would consist of a pair of oppositely sloped alignment wedges attached to linear actuators that would translate the wedges in the plane of a substrate, causing an optical fiber in contact with the sloping wedge surfaces to undergo various displacements parallel and perpendicular to the plane. In making it possible to accurately align optical fibers individually during the packaging stages of fabrication of the affected devices, this MEMS device would also make it possible to relax tolerances in other stages of fabrication, thereby potentially reducing costs and increasing yields.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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Optical Characterization of Molecular Contaminant Films

A theoretical model is correlated with measured spectral transmittances and VUV exposures of spacecraft optics. Lyndon B. Johnson Space Center, Houston, Texas A semi-empirical method of optical characterization of thin contaminant films on surfaces of optical components has been conceived. The method was originally intended for application to films that become photochemically deposited on such optical components as science windows, lenses, prisms, thin-film radiators, and glass solar-cell covers aboard spacecraft and satellites in orbit. The method should also be applicable, with suitable modifications, to thin optical films (whether deposited deliberately or formed as contaminants) on optical components used on Earth in the computer microchip laser communications and thin-film industries.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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Reactive Additives for Phenylethynyl-Containing Resins

Processability is improved. Phenylethynyl containing reactive additive (PERA) compounds and mixtures have been found to be useful for improving the processability of oligomers, polymers, cooligomers, and copolymers that contain phenylethynyl groups. The additives can be incorporated in different forms:

Posted in: Briefs

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