Manufacturing & Prototyping

All-Organic Electroactive Device Fabricated with Single- Wall Carbon Nanotube Film Electrode

These devices have applications as electromechanical sensors, sonar, medical and optical devices, artificial muscles, and noise control. Langley Research Center, Hampton, Virginia A novel, all-organic electroactive device system has been fabricated with a single-wall carbon nanotube (SWCNT) film used as an alternative electrode. This system was fabricated with LaRC-Electro Active Polymer (LaRC-EAP) active layer and the SWCNT films by pressing at 600, 3,000, and 6,000 psi (≈4.1, 20.7, and 41.4 MPa, respectively). Silicone elastomer plates (3-mm thick) were used on the press plate surfaces for better contact adhesion between the SWCNT film and the actuating layer. This polymeric electroactive device layered with the SWCNT-FE (SWCNT-Film Electrode) can serve as an actuator. The density (or modulus) of the SWCNT-FE can be controlled by adjusting the fabrication pressure. It is anticipated that less dense SWCNT-FE can provide less constrain displacement of the polymeric actuating layer by matching the modulus.

Posted in: Briefs, TSP

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Process to Fabricate Specific Sized Monodisperse Polystyrene Microparticles

Langley Research Center, Hampton, Virginia A new method was developed to prepare monodisperse nano to microparticles of polystyrene ranging from 0.5 to 2.5 microns in relatively large-quantity batches (2 L, 10% by weight in water). Current commercial sources are very expensive and can typically only be acquired on a relatively small scale. Monodisperse polystyrene in this size range is an important component of laser velocimetry measurements in wind tunnels, but has many other potential uses. Polystyrene microparticles have uses in paints/coatings, adhesives, bio/immunoassays, reaction catalysts, and chromatography materials. The main benefits of this technology are low cost, scalability, and selectable size.

Posted in: Briefs, TSP

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Lunar Cold Trap Contamination by Landing Vehicles

Software and methods are developed to assess the magnitude and distribution of lunar surface contamination caused by the engine exhaust of a landing vehicle. John F. Kennedy Space Center, Florida The emerging interest in lunar mining poses a threat of contamination to pristine craters at the lunar poles, which act as cold traps for water, and may harbor other valuable minerals. Lunar Prospector type missions will be looking for volatile (molecular) compounds that may be masked by the exhaust gases from landing vehicle engines. The possible self-contamination of the landing site could negate the scientific value of the soil samples taken in the vicinity of the landing site. Self-contamination may also lead to false-positive readings of resources available on the lunar surface. This innovation addresses the software and methods needed to assess the magnitude and distribution of lunar surface contamination caused by the engine exhaust of landing vehicles on known or planned descent trajectories.

Posted in: Briefs, TSP

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Process for Coating Substrates With Catalytic Materials

This process can remove volatile organic compounds from indoor air in planes, automobiles, homes, and industrial plants. Langley Research Center, Hampton, Virginia This invention relates to the process of coating substrates with one or more components to form a catalyst; specifically, the process of layering one or more catalytic components onto a honeycomb monolith to form a carbon monoxide oxidation that combines CO and O2 to form CO2, or alternatively, a volatile organic compound oxidation catalyst that combines the compound and O2 to form CO2 and H2O.

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Multimode, Fiber-Coupled, Tungsten Silicide, Superconducting Nanowire Single-Photon Detector Array

Amorphous WSi allows a much greater active area due to lower incidence of nanowire constrictions. NASA’s Jet Propulsion Laboratory, Pasadena, California The superconducting nanowire single-photon detector (SNSPD) arrays created in this innovation were fabricated using a WSi nanowire process. A gold mirror layer is deposited on an oxidized silicon wafer, and amorphous-state WSi is sputtered from a compound target at a thickness of 5 nm. The WSi nanowire is embedded at the center of a three-layer vertical optical cavity consisting of two silica layers and a titanium oxide anti-reflective coating. The layer thicknesses were chosen, on the basis of simulations and measured material parameters, to optimize efficiency at the target communication wavelength of 1,550 nm, and to minimize the polarization dependence of the detector response.

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New Compounds Developed to Manufacture Tunable OLED Devices

Researchers have developed new organic compounds characterized by higher modularity, stability, and efficiency that could be applicable for use in electronics or lighting. A proof-of-concept project has begun to verify that the compounds have the photoluminescence and electrochemical properties required for the manufacture of tunable organic LEDs (OLEDs) that can emit in the blue portion of the visible spectrum, thus applying lower voltages and achieving greater efficiency and longer life.

Posted in: News, Energy Efficiency, OLEDs

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Researchers Measure Stress in 3D-Printed Metal Parts

Lawrence Livermore National Laboratory researchers have developed an efficient method to measure residual stress in metal parts produced by powder-bed fusion additive manufacturing (AM).The 3D-printing process produces metal parts layer by layer using a high-energy laser beam to fuse metal powder particles. When each layer is complete, the build platform moves downward by the thickness of one layer, and a new powder layer is spread on the previous layer.While the method produces quality parts and components, residual stress is a major problem during the fabrication process. Large temperature changes near the last melt spot, and the repetition of this process, result in localized expansion and contraction.An LLNL research team, led by engineer Amanda Wu, has developed an accurate residual stress measurement method that combines traditional stress-relieving methods (destructive analysis) with modern technology: digital image correlation (DIC). The process provides fast and accurate measurements of surface-level residual stresses in AM parts.The team used DIC to produce a set of quantified residual stress data for AM, exploring laser parameters. DIC is a cost-effective, image analysis method in which a dual camera setup is used to photograph an AM part once before it’s removed from the build plate for analysis and once after. The part is imaged, removed, and then re-imaged to measure the external residual stress.SourceAlso: Learn about Design and Analysis of Metal-to-Composite Nozzle Extension Joints.

Posted in: News, Cameras, Rapid Prototyping & Tooling, Metals, Lasers & Laser Systems, Photonics, Measuring Instruments

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