Keyword: Fabrication

Briefs: Manufacturing & Prototyping

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...

Briefs: Information Technology

A method of processing the digitized output of a charge-coupled device (CCD) image detector has been devised to enable reduction of the error in computed centroid of the image of a...

Briefs: Mechanical & Fluid Systems
Integral Flexure Mounts for Metal Mirrors for Cryogenic Use

Semi-kinematic, six-degree-of-freedom flexure mounts have been incorporated as integral parts of metal mirrors designed to be used under cryogenic conditions as parts of an astronomical instrument. The design of the mirrors and their integral flexure mounts can also be adapted to other...

Briefs: Mechanical & Fluid Systems

Shapes different from the traditional ones have been proposed for face worm gears and for conical and cylindrical worms that mesh with them. The proposed shapes are based on the concept of...

Application Briefs: Imaging

Micromachined deformable mirror (DM)
Boston Micromachines Corp.
Watertown, MA
617-926-4178
www.bostonmicromachines.com
Briefs: Electronics & Computers

Metal emitter structures in a class of developmental InP-based high-speed heterojunction bipolar transistors (HBTs) have been redesigned to have Tshaped cross sections. More precisely, the modified...

Briefs: Manufacturing & Prototyping
Simplified Fabrication of Helical Copper Antennas

A simplified technique has been devised for fabricating helical antennas for use in experiments on radio-frequency generation and acceleration of plasmas. These antennas are typically made of copper (for electrical conductivity) and must have a specific helical shape and precise diameter.

Briefs: Physical Sciences

An alternative design for dielectric optical microresonators and a relatively simple process to fabricate them have been proposed. The proposed microresonators would exploit the same...

Briefs: Physical Sciences

In one of several alternative approaches to the design and fabrication of a "whispering-gallery" optical microresonator of high resonance quality (high Q), the index of...

Briefs: Physical Sciences
Graded-Index “Whispering-Gallery” Optical Microresonators

Graded-index-of- refraction dielectric optical microresonators have been proposed as a superior alternative to prior dielectric optical microresonators, which include microspheres (described in several prior NASA Tech Briefs articles) and microtori wherein electromagnetic waves...

Briefs: Physical Sciences
Catalytic-Metal/ PdOₓ/SiC Schottky-Diode Gas Sensors

Miniaturized hydrogen- and hydrocarbon- gas sensors, heretofore often consisting of Schottky diodes based on catalytic metal in contact with SiC, can be improved by incorporating palladium oxide (PdOx, where 0≤x≤1) between the catalytic metal and the SiC.

Briefs: Materials

A methodology has been devised for designing cure cycles to be used in the fabrication of matrix/fiber composite parts (including laminated parts). As used here, “cure cycles”...

Briefs: Photonics/Optics

University of Texas at Austin and Omega Optics, Austin, Texas

For decades, silicon has not been considered a favorable material for manipulating light. Electrical Engineering...

Briefs: Photonics/Optics
Quantum-Dot Laser for Wavelengths of 1.8 to 2.3 μm

The figure depicts a proposed semiconductor laser, based on In(As)Sb quantum dots on a (001) InP substrate, that would operate in the wavelength range between 1.8 and 2.3 μm. InSb and InAsSb are the smallest-bandgap conventional III-V semiconductor materials, and the present proposal is an...

Briefs: Physical Sciences
Correction for Thermal EMFs in Thermocouple Feedthroughs

A straightforward measurement technique provides for correction of thermal-electromotive- force (thermal-EMF) errors introduced by temperature gradients along the pins of non-thermocouple- alloy hermetic feedthrough connectors for thermocouple extension wires that must pass through...

Briefs: Materials

Experiments have shown that it is feasible to use oxygen radicals (specifically, monatomic oxygen) from mild oxygen plasmas to remove organic contaminants and chemical fabrication...

Briefs: Software
Montage Version 3.0

The final version (3.0) of the Montage software has been released. To recapitulate from previous NASA Tech Briefs articles about Montage: This software generates custom, science-grade mosaics of astronomical images on demand from input files that comply with the Flexible Image Transport System (FITS) standard and contain...

Briefs: Manufacturing & Prototyping

Arrays of nanowires having controlled dimensions can now be fabricated on substrates, optionally as integral parts of multilayer structures, by means of a cost-effective, high-yield process...

Briefs: Test & Measurement
Dielectric Heaters for Testing Spacecraft Nuclear Reactors

Like the electrical-resistance heaters used heretofore for such testing, the dielectric heaters would be inserted in the reactors in place of nuclear fuel rods. A typical heater according to the proposal would consist of a rod of lossy dielectric material sized and shaped like a fuel rod...

Briefs: Electronics & Computers
Highly Efficient Multilayer Thermoelectric Devices

Multilayer thermoelectric devices now at the prototype stage of development exhibit a combination of desirable characteristics, including high figures of merit and high performance/cost ratios. These devices are capable of producing temperature differences of the order of 50 K in operation at or...

Briefs: Photonics/Optics
Electrically Tunable Terahertz Quantum-Cascade Lasers

Improved quantum-cascade lasers (QCLs) are being developed as electrically tunable sources of radiation in the far infrared spectral region, especially in the frequency range of 2 to 5 THz. (Heretofore, the wavelengths of QCLs have been adjusted by changing temperatures, but not by changing...

Briefs: Medical

A noninvasive, sensitive method of diagnosing certain pathological conditions of the human heart involves computational processing of digitized...

Briefs: Manufacturing & Prototyping
Manufacturing Precise, Lightweight Paraboloidal Mirrors

A process for fabricating a precise, diffraction- limited, ultralightweight, composite-material (matrix/fiber) paraboloidal telescope mirror has been devised. Unlike the traditional process of fabrication of heavier glass-based mirrors, this process involves a minimum of manual steps and...

Briefs: Manufacturing & Prototyping
Automated Solvent Seaming of Large Polyimide Membranes

A solvent-based welding process enables the joining of precise, cast polyimide membranes at their edges to form larger precise membranes. The process creates a homogeneous, optical - quality seam between abutting membranes, with no overlap and with only a very localized area of figure...

Briefs: Materials

A dry plasma process has been demonstrated to be useful for the selective modification of self-assembled monolayers (SAMs) of alkanethiolates. These SAMs are used, during the...

Briefs: Electronics & Computers

A proposed hybrid ultraviolet (UV) image sensor would comprise a planar membrane array of face-up AlGaN/GaN photodiodes integrated with a complementary metal oxide/semiconductor...

Briefs: Electronics & Computers
Some Improvements in H-PDLCs

Some improvements have been made in the formulation of holographically formed polymer-dispersed liquid crystals (H-PDLCs) and in the fabrication of devices made from these materials, with resulting improvements in performance. H-PDLCs are essentially volume Bragg gratings. Devices made from HPDLCs function as...

Briefs: Physical Sciences
The THz Hot-Electron Photon Counter Concept

A document proposes the development of hot-electron photon counters (HEPCs) for detecting terahertz photons in spaceborne far-infrared astronomical instruments. These would be superconducting-transition-edge devices: they would contain superconducting bridges that would have such low heat capacities...

Briefs: Physical Sciences

In their quest for the twin grails of high production volume and extreme precision in the manufacture of both spherical and aspherical optical surfaces,...