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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Triboelectric nanogenerator for harvesting broadband kinetic impact energy

A triboelectric generator includes a first triboelectric member, which includes a first conductive layer and an insulating triboelectric material layer disposed on the first conductive layer. The triboelectric material layer includes a first material having a first position on a triboelectric series. An elastic member, disposed against the triboelectric material layer of the triboelectric member and includes a second conductive material, has an elasticity that results in the elastic member being deformed when compressed and returning to an original non-deformed shape after being compressed. The second conductive material has a second position on the triboelectric series. A first load is coupled to the first conductive layer and with the second conductive material so that when a force compresses the elastic member charges will flow between the first conductive layer and the second conductive layer through the load.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Broadband and omnidirectional polymer antireflection coatings

A method for generating antireflective coatings for polymeric substrates using a deposition process and/or a dissolving process can provide a coating onto the outer surface of the substrate. Some embodiments can include a GLAD generated fluoropolymer coating or a co-evaporated fluoropolymer coating on a substrate that may achieve ultralow refractive index as well as improved adhesion and durability properties on polymeric substrates. In some embodiments, the deposition process is performed such that a fluoropolymer can be evaporated to form chain fragments of the fluoropolymer. The chain fragments diffused into the substrate can subsequently re-polymerize, interlocking with the polymer chains of the substrate. In some embodiments, the co-evaporation process can form a nanoporous polymer chain scaffold of the fluoropolymer, from which a sacrificial material can be dissolved out. The formed coating can be a multilayer or continuously-graded antireflective coating that has strong adhesion with the substrate.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Ultra-low reflectance broadband omni-directional anti-reflection coating

An anti-reflection coating has an average total reflectance of less than 10%, for example less than 5.9% such as from 4.9% to 5.9%, over a spectrum of wavelengths of 400-1100 nm and a range of angles of incidence of 0-90 degrees with respect to a surface normal of the anti-reflection coating. An anti-reflection coating has a total reflectance of less than 10%, for example less than 6% such as less than 4%, over an entire spectrum of wavelengths of 400-1600 nm and an entire range of angles of incidence of 0-70 degrees with respect to a surface normal of the anti-reflection coating.

Chhajed, Sameer↗
DOE OSTI2022

Broadband and omnidirectional polymer antireflection coatings

A method for generating antireflective coatings for polymeric substrates using a deposition process and/or a dissolving process can provide a coating onto the outer surface of the substrate. Some embodiments can include a GLAD generated fluoropolymer coating or a co-evaporated fluoropolymer coating on a substrate that may achieve ultralow refractive index as well as improved adhesion and durability properties on polymeric substrates. In some embodiments, the deposition process is performed such that a fluoropolymer can be evaporated to form chain fragments of the fluoropolymer. The chain fragments diffused into the substrate can subsequently re-polymerize, interlocking with the polymer chains of the substrate. In some embodiments, the co-evaporation process can form a nanoporous polymer chain scaffold of the fluoropolymer, from which a sacrificial material can be dissolved out. The formed coating can be a multilayer or continuously-graded antireflective coating that has strong adhesion with the substrate.

Wang, Baomin↗
DOE OSTI2022

Reflective metasurfaces for broadband terahertz linear-to-circular polarization conversion and circular dichroism spectroscopy

Metasurface polarization convertors permit conversion of an input linear polarization to right- or left-handed circular polarization based on the orientation of the input linear polarization, over a broad bandwidth and with high efficiency. The reflected circular polarizations can be used to evaluate samples for circular dichroism. A THz time-domain detection provides a time domain terahertz signal that is Fourier transformed to produce a THz circular dichroism spectrum.

Chen, Hou-Tong↗