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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS2013

Nanoscale Surface Plasmonics Sensor With Nanofluidic Control

Conventional quantitative protein assays of bodily fluids typically involve multiple steps to obtain desired measurements. Such methods are not well suited for fast and accurate assay measurements in austere environments such as spaceflight and in the aftermath of disasters. Consequently, there is a need for a protein assay technology capable of routinely monitoring proteins in austere environments. For example, there is an immediate need for a urine protein assay to assess astronaut renal health during spaceflight. The disclosed nanoscale surface plasmonics sensor provides a core detection method that can be integrated to a lab-on-chip device that satisfies the unmet need for such a protein assay technology. Assays based upon combinations of nanoholes, nanorings, and nanoslits with transmission surface plasmon resonance (SPR) are used for assays requiring extreme sensitivity, and are capable of detecting specific analytes at concentrations as low as picomole to femtomole level in well-controlled environments. The device operates in a transmission mode configuration in which light is directed at one planar surface of the array, which functions as an optical aperture. The incident light induces surface plasmon light transmission from the opposite surface of the array. The presence of a target analyte is detected by changes in the spectrum of light transmitted by the array when a target analyte induces a change in the refractive index of the fluid within the nanochannels. This occurs, for example, when a target analyte binds to a receptor fixed to the walls of the nanochannels in the array. Independent fluid handling capability for individual nanoarrays on a nanofluidic chip containing a plurality of nanochannel arrays allows each array to be used to sense a different target analyte and/or for paired arrays to analyze control and test samples simultaneously in parallel. The present invention incorporates transmission mode nanoplasmonics and nanofluidics into a single, microfluidically controlled device. The device comprises one or more arrays of aligned nanochannels that are in fluid communication with inflowing and outflowing fluid handling manifolds that control the flow of fluid through the arrays. The array acts as an aperture in a plasmonic sensor. Fluid, in the form of a liquid or a gas and comprising a sample for analysis, is moved from an inlet manifold through the nanochannel array, and out through an exit manifold. The fluid may also contain a reagent used to modify the interior surfaces of the nanochannels, and/or a reagent required for the detection of an analyte.

Wei, Jianjun↗
NASA NTRS2015

Nanoscale Test Strips for Multiplexed Blood Analysis

A critical component of the DNA Medicine Institute's Reusable Handheld Electrolyte and Lab Technology for Humans (rHEALTH) sensor are nanoscale test strips, or nanostrips, that enable multiplexed blood analysis. Nanostrips are conceptually similar to the standard urinalysis test strip, but the strips are shrunk down a billionfold to the microscale. Each nanostrip can have several sensor pads that fluoresce in response to different targets in a sample. The strips carry identification tags that permit differentiation of a specific panel from hundreds of other nanostrip panels during a single measurement session. In Phase I of the project, the company fabricated, tested, and demonstrated functional parathyroid hormone and vitamin D nanostrips for bone metabolism, and thrombin aptamer and immunoglobulin G antibody nanostrips. In Phase II, numerous nanostrips were developed to address key space flight-based medical needs: assessment of bone metabolism, immune response, cardiac status, liver metabolism, and lipid profiles. This unique approach holds genuine promise for space-based portable biodiagnostics and for point-of-care (POC) health monitoring and diagnostics here on Earth.

Chan, Eugene↗
NASA NTRS2016

Micro- and Nanoscale Capacitors that Incorporate an Array of Conductive Elements Having Elongated Bodies

Systems and methods in accordance with embodiments of the invention implement micro- and nanoscale capacitors that incorporate a conductive element that conforms to the shape of an array elongated bodies. In one embodiment, a capacitor that incorporates a conductive element that conforms to the shape of an array of elongated bodies includes: a first conductive element that conforms to the shape of an array of elongated bodies; a second conductive element that conforms to the shape of an array of elongated bodies; and a dielectric material disposed in between the first conductive element and the second conductive element, and thereby physically separates them.

Manohara, Harish↗
NASA NTRS2014

NASA GSFC Strategic Nanotechnology Interests: Symposium on High‐Rate Nanoscale Printing for Devices and Structures

The seminars invitees include representatives from industry, nonprofit research facility and universities. The presentation provides an overview of the NASAGSFC locations, technical capabilities and applied nanotechnology interests. Initially presented are advances by the broader technological communities on current miniaturized multiscale advanced manufacturing and 3D printing products on the micro and macro scale. Briefly assessed is the potential of moving toward the nanoscale for possible space flight applications and challenges. Lastly, highlighted are GSFCs current successes in nano-technology developments and targeted future applications.

APPLIED NANOTECHNOLOGY↗
NASA NTRS2015

A NASA First in Nano-Technology: Nanoscale Vacuum Tube for Radiation Immune Electronics

Vacuum provides the fastest electron speed, better than any semiconductor. Nevertheless vacuum tubes were bulky, fragile and consumed much power. Now nanotechnology has enabled fabrication of vacuum tubes at nanoscale in silicon chips. The speed, immunity to radiation and high temperature operation are expected to revolutionize space electronics.

Ingrid Desilestre↗
NASA NTRS2021

A Nanoscale Vacuum Field Emission Gated Diode with an Umbrella Cathode

A nanoscale field emission vacuum channel gated diode structure is proposed and a tungsten cathode with an umbrella-like geometry and sharp vertical edge is fabricated. The edge of the suspended cathode becomes the field emission surface. Unlike in the traditional transistor with the gate typically located between the source and the drain, the bottom silicon plate becomes the gate here and the anode terminal is located between the umbrella cathode and the gate. The fabricated devices show excellent diode characteristics and the gated diode structure is attractive for extremely low gate leakage.

Vacuum field emission diode↗
NASA NTRS2024

Nanoscale Mineralogy of Bennu Samples Returned by OSIRIS-REx

The OSIRIS-REx spacecraft returned regolith samples from asteroid Bennu and an initial sample was allocated for quick-look (QL) analyses. These QL particles were recovered from the avionics deck of the sample canister and were used to test the hypothesis that this dust is broadly representative of the bulk sample. The QL sample analyses showed that the materials are dominated by hydrated silicates, sulfides, magnetite, phosphates, and abundant organic matter, in addition to other minor/trace phases. Here we report our preliminary transmission electron microscope (TEM) observations for the nanoscale mineralogy of Bennu samples.

L P Keller↗
NASA NTRSDate not supplied

In-situ Nanoscale Ablation

An understanding of the ablation of carbon-based materials is crucial to modeling the behavior of atmospheric entry spacecrafts equipped with thermal protection systems (TPS).Carbon is the backbone of TPS systems such as PICA (phenolic-impregnated carbon ablator).Therefore in the present work we study ablation of highly oriented pyrolytic graphite (HOPG)in oxygen at temperatures up to 1000°C done within a gas reaction cell housed in a scanning transmission electron microscope (STEM). Observation of the HOPG oxidation on specimens sectioned parallel and normal to the carbon basal planes in the presence of oxygen are reported.Pitting caused by residual oxygen and/or platinum particles from the sectioning process was observed before oxygen gas flow was established at 750°C in the specimen sectioned with the carbon basal planes parallel to the beam direction. Introduction of oxygen flow caused rapid oxidation moving in a uniform front that completely consumed the HOPG in approximately 1.5minutes. The specimen sectioned with the carbon basal planes normal to the beam direction did not show the same pitting phenomenon but exhibited rapid oxidation at 1000°C that proceeded in a uniform front and completed in approximately 1 minute. All specimens tested had a husk resembling the original specimen shape left over after oxidation. It is concluded that this husk is most likely ash impurity from the HOPG or impurities from the sectioning process or E-chip. A residual gas analyszer (RGA) was successfully used to monitor gas flows during the experiments but was yet unsuccessful in monitoring oxidation gas products produced during the experiment.Future studies will optimize the RGA setup in order to maximize the potential for detecting these species. These in-situ studies successfully show how this highly ordered carbon ablates on a nano- and micro-scopic length scale and can be used to provide fundamental understanding of carbon ablation that can be used to design the next-generation of TPS systems.

Nanoscale Ablation↗
NASA NTRS1995

High-Performance electronics at ultra-low power consumption for space applications: From superconductor to nanoscale semiconductor technology

A detailed review of Sandia's work in ultralow power dissipation electronics for space flight applications, including superconductive electronics, new advances in quantum well structures, and ultra-high purity 3-5 materials, and recent advances in micro-electro-optical-mechanical systems (MEMS) is presented. The superconductive electronics and micromechanical devices are well suited for application in micro-robotics, micro-rocket engines, and advanced sensors.

Duncan, Robert V.↗
NASA NTRS2000

Monitoring Astronaut Health at the Nanoscale Cellular Level Through the Eye

A user friendly goggles-like head-mounted device equipped with a suite of instruments for several non-invasive and quantitative medical evaluation of the eye, skin, and brain is desired for monitoring the health of astronauts during space travel and exploration of neighboring and distant planets. Real-time non-invasive evaluation of the different structures within the above organs can provide indices of the health of not just these organs, but the entire body. The techniques such as dynamic light scattering (for the early detection of uveitis, cholesterol levels, cataract, changes in the vitreous and possibly Alzheimer's disease), corneal autofluorescence (to assess extracellular matrix biology e.g., in diabetes), optical activity measurements (of anterior ocular fluid to evaluate blood-glucose levels), laser Doppler velocimetry (to assess retinal, optic nerve, and choroidal blood flow), reflectometry/oximetry (for assessing ocular and central nervous system oxygen metabolism), optical coherence tomography (to determine retinal tissue microstructure) and possibly scanning laser technology (for intraocular tissue imaging and scanning) will he integrated into this compact device. Skin sensors will also be mounted on the portion of the device in contact with the periocular region. This will enable monitoring of body temperature, EEG, and electrolyte status. This device will monitor astronaut health during long-duration space travel by detecting aberrations from pre-established "nonns", enabling prompt diagnosis and possibly the initiation of early preventative/curative therapy. The non-invasive nature of the device technologies permits frequent repetition of tests, enabling real-time complete crew health monitoring. This device may ultimately be useful in tele-medicine to bring modern healthcare to under-served areas on Earth as well as in so-called "advanced" care settings (e.g. diabetes in the USA).

Ansari, Rafat R.↗
NASA NTRS2001

Quantum Mechanical Study of Nanoscale MOSFET

The steady state characteristics of MOSFETS that are of practical Interest are the drive current, off-current, dope of drain current versus drain voltage, and threshold voltage. In this section, we show that quantum mechanical simulations yield significantly different results from drift-diffusion based methods. These differences arise because of the following quantum mechanical features: (I) polysilicon gate depletion in a manner opposite to the classical case (II) dependence of the resonant levels in the channel on the gate voltage, (III) tunneling of charge across the gate oxide and from source to drain, (IV) quasi-ballistic flow of electrons. Conclusions dI/dV versus V does not increase in a manner commensurate with the increase in number of subbands. - The increase in dI/dV with bias is much smaller then the increase in the number of subbands - a consequence of bragg reflection. Our calculations show an increase in transmission with length of contact, as seen in experiments. It is desirable for molecular electronics applications to have a small contact area, yet large coupling. In this case, the circumferential dependence of the nanotube wave function dictates: - Transmission in armchair tubes saturates around unity - Transmission in zigzag tubes saturates at two.

Svizhenko, Alexei↗
NASA NTRS1998

Nanoscale Etching and Indentation of Silicon Surfaces with Carbon Nanotubes

The possibility of nanolithography of silicon and germanium surfaces with bare carbon nanotube tips of scanning probe microscopy devices is considered with large scale classical molecular dynamics (MD) simulations employing Tersoff's reactive many-body potential for heteroatomic C/Si/Ge system. Lithography plays a key role in semiconductor manufacturing, and it is expected that future molecular and quantum electronic devices will be fabricated with nanolithographic and nanodeposition techniques. Carbon nanotubes, rolled up sheets of graphene made of carbon, are excellent candidates for use in nanolithography because they are extremely strong along axial direction and yet extremely elastic along radial direction. In the simulations, the interaction of a carbon nanotube tip with silicon surfaces is explored in two regimes. In the first scenario, the nanotubes barely touch the surface, while in the second they are pushed into the surface to make "nano holes". The first - gentle scenario mimics the nanotube-surface chemical reaction induced by the vertical mechanical manipulation of the nanotube. The second -digging - scenario intends to study the indentation profiles. The following results are reported in the two cases. In the first regime, depending on the surface impact site, two major outcomes outcomes are the selective removal of either a single surface atom or a surface dimer off the silicon surface. In the second regime, the indentation of a silicon substrate by the nanotube is observed. Upon the nanotube withdrawal, several surface silicon atoms are adsorbed at the tip of the nanotube causing significant rearrangements of atoms comprising the surface layer of the silicon substrate. The results are explained in terms of relative strength of C-C, C-Si, and Si-Si bonds. The proposed method is very robust and does not require applied voltage between the nanotube tips and the surface. The implications of the reported controllable etching and hole-creating for nanolithography on silicon are discussed in detail.

Dzegilenko, Fedor N.↗
NASA NTRS2003

Nanoscale Liquid Jets Shape New Line of Business

Just as a pistol shrimp stuns its prey by quickly closing its oversized claw to shoot out a shock-inducing, high-velocity jet of water, NanoMatrix, Inc., is sending shockwaves throughout the nanotechnology world with a revolutionary, small-scale fabrication process that uses powerful liquid jets to cut and shape objects. Emanuel Barros, a former project engineer at NASA s Ames Research Center, set out to form the Santa Cruz, California-based NanoMatrix firm and materialize the micro/nano cutting process partially inspired by the water-spewing crustacean. Early on in his 6-year NASA career, Barros led the development of re-flown flight hardware for an award-winning Spacelab project called NeuroLab. This project, the sixteenth and final Spacelab mission, focused on a series of experiments to determine the effects of microgravity on the development of the mammalian nervous system.

Source record↗
NASA NTRS2003

Detection of Strand Cleavage And Oxidation Damage Using Model DNA Molecules Captured in a Nanoscale Pore

We use a biological nano-scale pore to distinguish among individual DNA hairpins that differ by a single site of oxidation or a nick in the sugar-phosphate backbone. In earlier work we showed that the protein ion channel alpha-hemolysin can be used as a detector to distinguish single-stranded from double-stranded DNA, single base pair and single nucleotide differences. This resolution is in part a result of sensitivity to structural changes that influence the molecular dynamics of nucleotides within DNA. The strand cleavage products we examined here included a 5-base-pair (5-bp) hairpin with a 5-prime five-nucleotide overhang, and a complementary five-nucleotide oligomer. These produced predictable shoulder-spike and rapid near-full blockade signatures, respectively. When combined, strand annealing was monitored in real time. The residual current level dropped to a lower discrete level in the shoulder-spike blockade signatures, and the duration lengthened. However, these blockade signatures had a shorter duration than the unmodified l0bp hairpin. To test the pore sensitivity to nucleotide oxidation, we examined a 9-bp hairpin with a terminal 8-oxo-deoxyguanosine (8-oxo-dG), or a penultimate 8-oxo-dG. Each produced blockade signatures that differed from the otherwise identical control 9bp hairpins. This study showed that DNA structure is modified sufficiently by strand cleavage or oxidation damage at a single site to alter in a predictable manner the ionic current blockade signatures produced. This technique improves the ability to assess damage to DNA, and can provide a simple means to help characterize the risks of radiation exposure. It may also provide a method to test radiation protection.

Vercoutere, W.↗
NASA NTRS2004

Combining Hard with Soft Materials in Nanoscale Under High-Pressure High-Temperature Conditions

Nano-composites with a primary nanocrystalline ceramic matrix and a secondary nanocrystalline material (metal or semiconductor) were synthesized by infiltration of an appropriate liquid into ceramic compacts under pressures of up to 8 GPa and temperatures of up to 2000 K. The purpose of our work is to obtain nanocomposites which constitute homoger?ous mixtures of two phases, both forming nano- grains of about 10 nm in size. The high pressure is used to bring the porosity of the compacted powders down to the nano-scale and force a given liquid into the nano-sized pores. The advantage of the infiltration technique is that, in a single, continuous process, we start with a nanocrystalline powder, compress it to form the matrix of the composite, and crystallize and/or synthesize a second nanomaterial in the matrix pores. The key limitation of this technology is, that the pores in the matrix need to stay open during the entire process of infiltration. Thus the initial powder should form a rigid skeleton, otherwise the so-called self-stop process can limit cr block a further flow of the liquid phase and hinder the process of the composite formation. Therefore powders of only very hard ceramic materials like diamond, Sic, or Alz03, which can withstand a substantial external load without undesired deformation, can be used as the primary phase. With this technique, using diamond and S i c ceramic powders infiltrated by liquid metals (AI, Zn, Sn, Ag, Au) and semiconductors (Si, Ge, GaAs, CdTe), we obtained nano-composites with the grain size in the range of 10 - 30 nm. Our work addresses the key problem in manufacturing bulk nanocrystalline materials, i.e. preservation of nano-scale during the fabrication process. In this paper we discuss basic technical and methodological problems associated with nano-infiltration based on the results obtained for Zn-Sic composites.

Palosz, B.↗
NASA NTRS2004

[Using Molecular Simulations to Understand Complex Nanoscale Dynamic Phenomena in Polymer Solutions]

The first half of the project concentrated on molecular simulation studies of the translocation of model molecules for single-stranded DNA through a nanosized pore. This has resulted in the publication, Translocation of a polymer chain across a nanopore: A Brownian dynamics simulation study, by Pu Tian and Grant D. Smith, JOURNAL OF CHEMICAL PHYSICS VOLUME 119, NUMBER 21 1 DECEMBER 2003, which is attached to this report. In this work we carried out Brownian dynamics simulation studies of the translocation of single polymer chains across a nanosized pore under the driving of an applied field (chemical potential gradient) designed to mimic an electrostatic field. The translocation process can be either dominated by the entropic barrier resulted from restricted motion of flexible polymer chains or by applied forces (or chemical gradient). We focused on the latter case in our studies. Calculation of radius of gyration of the translocating chain at the two opposite sides of the wall shows that the polymer chains are not in equilibrium during the translocation process. Despite this fact, our results show that the one-dimensional diffusion and the nucleation model provide an excellent description of the dependence of average translocation time on the chemical potential gradients, the polymer chain length and the solvent viscosity. In good agreement with experimental results and theoretical predictions, the translocation time distribution of our simple model shows strong non-Gaussian characteristics. It is observed that even for this simple tube-like pore geometry, more than one peak of translocation time distribution can be generated for proper pore diameter and applied field strengths. Both repulsive Weeks-Chandler-Anderson and attractive Lennard-Jones polymer-nanopore interaction were studied. Attraction facilitates the translocation process by shortening the total translocation time and dramatically improve the capturing of polymer chain. The width of the translocation time distribution was found to decrease with increasing temperature, increasing field strength, and decreasing pore diameter.

Smith, Grant↗