Manufacturing & Prototyping

Silicon/Carbon Nanotube Photocathode for Splitting Water

The combination of materials is expected to increase the efficiency of the redox reaction. A proof-of-concept device is being developed (see figure) for hydrogen gas production based on water-splitting redox reactions facilitated by cobalt tetra-aryl porphyrins (Co[TArP]) catalysts stacked on carbon nanotubes (CNTs) that are grown on n-doped silicon substrates. The operational principle of the proposed device is based on conversion of photoelectron energy from sunlight into chemical energy, which at a later point, can be turned into electrical and mechanical power.

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Circularly Polarized Microwave Antenna Element With Very Low Off-Axis Cross-Polarization

The goal of this work was to improve offaxis cross-polarization performance and ease of assembly of a circularly polarized microwave antenna element. To ease assembly, the initial design requirement of Hexweb support for the internal circuit part, as well as the radiating disks, was eliminated.

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Flash Cracking Reactor for Waste Plastic Processing

Conversion of waste plastic to energy is a growing problem that is especially acute in space exploration applications. Moreover, utilization of heavy hydrocarbon resources (wastes, waxes, etc.) as fuels and chemicals will be a growing need in the future. Existing technologies require a trade-off between product selectivity and feedstock conversion. The objective of this work was to maintain high plastic-to-fuel conversion without sacrificing the liquid yield. The developed technology accomplishes this goal with a combined understanding of thermodynamics, reaction rates, and mass transport to achieve high feed conversion without sacrificing product selectivity.

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Ultra-Low Heat- Leak, High- Temperature Superconducting Current Leads for Space Applications

NASA Goddard Space Flight Center has a need for current leads used in an adiabatic demagnetization refrigerator (ADR) for space applications. These leads must comply with stringent requirements such as a heat leak of approximately 100 μW or less while conducting up to 10 A of electric current, from more than 90 K down to 10 K. Additionally, a length constraint of < 300 mm length and < 50 mm diameter is to be maintained.

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Castable Amorphous Metal Mirrors and Mirror Assemblies

Commercial applications include optics for spacecraft and satellites, mirror components for telescopes, and mirrors for lasers, sensing, and solar energy collection. The use of mirror assemblies is commonplace in the aerospace industry, as most satellites and spacecraft contain optics. The fabrication of these mirrors is extremely complex due to the nature of their intended use, which includes telescope lenses, camera optics, or laser mirrors. Some of the common requirements of spacecraft mirrors are that they have the correct optical curvature to some defined tolerance, they have low surface roughness, they have high reflectivity, and they are rigid (either against thermal expansion or flexing).

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High-Reliability Waveguide Vacuum/Pressure Window

This design is suitable for commercial, military, and space applications requiring a helium-leaktight vacuum pressure window. The NASA Deep Space Network (DSN) uses commercial waveguide windows on the output waveguide of Ka-band (32 GHz) low-noise amplifiers. Mechanical failure of these windows resulted in an unacceptable loss in tracking time.

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Methods of Fabricating Scintillators With Radioisotopes for Beta Battery Applications

Applications for these power sources are implantable medical devices, power supplies for remote monitoring, and “trickle chargers” for consumer applications. Technology has been developed for a class of self-contained, long-duration power sources called beta batteries, which harvest the energy contained in the radioactive emissions from beta decay isotopes. The new battery is a significant improvement over the conventional phosphor/ solar cell concept for converting this energy in three ways. First, the thin phosphor is replaced with a thick scintillator that is transparent to its own emissions. By using a scintillator sufficiently thick to completely stop all the beta particles, efficiency is greatly improved. Second, since the energy of the beta particles is absorbed in the scintillator, the semiconductor photodetector is shielded from radiation damage that presently limits the performance and lifetime of traditional phosphor converters. Finally, instead of a thin film of beta-emitting material, the isotopes are incorporated into the entire volume of the thick scintillator crystal allowing more activity to be included in the converter without self-absorption.

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