Nasa Tech Briefs

Preparation of Metal Nanowire Decorated Carbon Allotropes

This technology produces materials for a variety of applications in electronics, communications, catalysis, and optics.NASA's Langley Research Center has created a new class of materials based on depositing nanometer-sized metal particles onto carbon allotropes. The method is scalable and relatively simple, and allows for control over the size and distribution of the metal particles in the substrate, adjusting the surface area to optimize specific thermal or electrical properties of the material. One promising nanocomposite material created consists of multi-walled carbon nanotubes (MWCNTs) decorated with metal particles dispersed in a polymer matrix. Ribbons, tubes, and moldings of the nanocomposite were found to have novel intrinsic electrical characteristics that enable tunable dielectric constants with low loss factors. The decoupling and independent control of the two fundamental parameters offer a class of materials with the potential for finely tailored electronic properties. The novel methods enable materials that show promise for a variety of applications in electronics, communications, catalysis, and optics.

Posted in: Briefs, Materials, Product development, Fabrication, Composite materials, Metals, Nanomaterials

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Controlled Deposition and Alignment of Carbon Nanotubes

CNTs are manipulated into specific orientations to create small, powerful, and flexible sensors.NASA Langley Research Center researchers are experts at producing carbon nanotube (CNT)-based sensors for structural health monitoring (SHM). The sensors can be embedded in structures of all geometries to monitor conditions both inside and at the surface of the structure to continuously sense changes. Having accumulated a body of knowledge on how to deposit and align CNTs, NASA is adept at manipulating the CNTs into specific orientations to create small, powerful, and flexible sensors. One of the sensors created by NASA is a highly flexible sensor for crack growth detection and strain field mapping that features a very dense and highly ordered array of single-walled CNTs. NASA is seeking companies that are interested in licensing technology or engaging NASA in joint research in the area of CNT sensors.

Posted in: Briefs, Sensors, On-board diagnostics, On-board diagnostics (OBD), Sensors and actuators, Product development, Fabrication, Nanotechnology

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Melt Infiltration of SiC/SiC Preforms Using Cr-Si Alloys

These composites can be used in aircraft engine turbine blades, vanes, combustor lines, and shrouds.The goal of this work was to develop engineered matrix SiC/SiC ceramic composites with crack blunting and self-healing capabilities for 1588 to 1755 K applications. The work optimized the temperature and time conditions for melt-infiltrating SiC/SiC preforms with chromium silicide alloys, and established that these alloys do not react with the coatings on the SiC fibers. Traditional ways of fabricating SiC fiber-based ceramic matrix composites (CMCs) use silicon to melt-infiltrate the CMC preforms, where the Si is often converted to SiC by reaction with carbon. The traditional SiC matrices have poor high-temperature creep properties due to the presence of residual silicon. They also have low fracture toughness and a low matrix cracking stress.

Posted in: Briefs, Manufacturing & Prototyping, Product development, Ceramics, Coatings, colorants, and finishes, Composite materials, Silicon alloys, Smart materials

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Automating Optimization and Design Tasks Across Disciplines

A multidisciplinary design analysis and optimization (MDAO) solution leverages existing analysis codes to streamline optimization tasks early in the design process.When tackling modern engineering projects, designers must consider not only engineering parameters, but also such key factors as cost, safety, and environmental impact. To exploit the interactions of these various elements, designers must consider them simultaneously. Unfortunately, doing so significantly increases project complexity.

Posted in: Briefs, Software, Design processes, Optimization, Systems engineering, Automation

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A Modular Apparatus and Method for Attaching Multiple Devices

This technology improves the real-time monitoring of high-temperature or other harsh environments.Scientists at NASA's Glenn Research Center have received several patents for fabrication methods that speed the production of silicon carbide (SiC) sensors and electronics, reduce fabrication costs, and enable advanced semiconductor functionality at temperatures greater than 600 °C. Glenn has developed a method for fabricating ultra-thin SiC microstructures using a dopant selective reactive ion etching (DSRIE) technique that can create extremely thin diaphragms (approximately 2 microns), increasing sensor sensitivity and resolution. In addition, Glenn has developed a modular protective packaging that allows SiC-based electronic devices to survive and operate reliably at very high temperatures. These innovations improve the real-time monitoring of high-temperature harsh environments, such as jet and rocket engines, allowing faster response times and more accurate readings.

Posted in: Briefs, Electronics & Computers, Electronic equipment, Sensors and actuators, Fabrication, Silicon alloys, Protective structures

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Method of Making a Composite Panel Having Subsonic Transverse Wave Speed Characteristics

Applications include internal aircraft structures, buildings, and enclosures for machines.NASA's Langley Research Center has developed an enhanced design for a composite panel with a recessed core. NASA designed it to decrease the radiation efficiency and increase the transmission loss while maintaining load-bearing capability so it could be used in applications such as aircraft floors. Similar to traditional composite panels, the innovation possesses low weight characteristics, but in addition, it can be used in load-bearing applications. The invention was developed for NASA's Quiet Aircraft Technology Program. The superior design of the composite panel can be used in a wide variety of commercial applications wherever honeycomb is needed and improved acoustics are desired. NASA has patented and tested the novel design, and is interested in attracting development partners and potential licensees for the recessed core composite panel design.

Posted in: Briefs, Manufacturing & Prototyping, Aircraft structures, Design processes, Flooring, Composite materials

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Aviation Environmental Design Tool (AEDT)

The Federal Aviation Administration's Aviation Environmental Design Tool (AEDT) is a software system that dynamically models aircraft performance in space and time to estimate fuel consumption, emissions, noise, and air quality assessments. Full-flight gate-to-gate analyses are possible for study sizes ranging from a single flight at an airport, to scenarios at the regional, national, and global levels.

Posted in: Briefs, Software, Mathematical models, Computer software and hardware, Environmental testing, Aircraft operations

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