Materials & Coatings

Probabilistic Multi-Factor Interaction Model for Complex Material Behavior

Complex material behavior is represented by a single equation of product form.

Complex material behavior is represented by a single equation of product form to account for interaction among the various factors. The factors are selected by the physics of the problem and the environment that the model is to represent. For example, different factors will be required for each to represent temperature, moisture, erosion, corrosion, etc. It is important that the equation represent the physics of the behavior in its entirety accurately.

Posted in: Briefs, Materials, Mathematical models, Materials properties

Particle Distribution on Webs or Cloths

This technology provides the ability to uniformly distribute and attach particulate matter onto fibrous composite sheet or web materials.

This technology provides a methodology and products that are formed from fibrous substrates or film-like surfaces by uniform impregnation with a particulate that is subsequently firmly attached. The extremely uniform distribution of the particulate is accomplished by 1) electrically charging a fibrous matrix with individual exposed surfaces to create a uniform distribution of charged sites; 2) applying particulates to this matrix so that particulates adhere at the charged sites; and 3) the particulates are attached to the individual fibers within the substrate by firm non-transient bonding.

Posted in: Briefs, MDB, Briefs, Manufacturing & Prototyping, Coatings & Adhesives, Materials, Bio-Medical, Medical, Medical equipment and supplies, Fabrics, Fibers, Materials properties

Hollow Radiopaque Bioactive Microspheres Carry Drugs in Embolization Procedures

Combining embolization therapy with localized drug delivery, application of biomaterials is more effective.

The number of applications of synthetic biomaterials continues to expand. However, the imaging of injected biomaterials is important to control the treatment procedure in real time, to avoid complications, and to assess therapeutic success. Embolization is the obstruction of the blood flow in a vessel that can be an effective treatment for tumors in hepatocellular carcinoma or for uterine fibroids. By combining this embolization therapy with a localized drug delivery, the treatment can even be more effective. The material that is currently used is not radiopaque and can therefore cause difficulties for the interventional radiologist during placement of the embolic. Therefore, hollow, drug-carrying microspheres were made radiopaque.

Posted in: Briefs, MDB, Briefs, Coatings & Adhesives, Materials, Bio-Medical, Drug Delivery, Medical, Diseases, Biomaterials, Pharmaceuticals, Polymers

Liquid Cooling/Warming Garment

This lightweight garment can be used by firefighters, soldiers, and personnel working with hazardous materials.

The NASA liquid cooling/ventilating garment (LCVG) currently in use was developed over 40 years ago. With the commencement of a greater number of extra-vehicular activity (EVA) procedures with the construction of the International Space Station, problems of astronaut comfort, as well as the reduction of the consumption of energy, became more salient.

Posted in: Briefs, MDB, Briefs, Coatings & Adhesives, Materials, Bio-Medical, Medical, Patient Monitoring, Human factors, Spacesuits

Tissuelike 3D Assemblies of Human Broncho-Epithelial Cells

Experimental conditions are more realistic than those of 2D monolayer cell cultures.

Three-dimensional (3D) tissuelike assemblies (TLAs) of human bronchoepithelial (HBE) cells have been developed for use in in vitro research on infection of humans by respiratory viruses. The 2D monolayer HBE cell cultures heretofore used in such research lack the complex cell structures and interactions characteristic of in vivo tissues and, consequently, do not adequately emulate the infection dynamics of in-vivo microbial adhesion and invasion. In contrast, the 3D HBE TLAs are characterized by more-realistic reproductions of the geometrical and functional complexity, differentiation of cells, cell-to-cell interactions, and cell-to-matrix interactions characteristic of human respiratory epithelia. Hence, the 3D HBE TLAs are expected to make it possible to perform at least some of the research in vitro under more-realistic conditions, without need to infect human subjects.

Posted in: Briefs, MDB, TSP, Briefs, TSP, Coatings & Adhesives, Materials, Bio-Medical, Medical, Scale models, Anatomy, Biological sciences, Diseases, Test equipment and instrumentation

Magnetic Nanoparticles and Devices for Biomedical Uses

Potential applications include detecting selected biomolecules and treating some brain injuries.

A program comprising several collaborative research efforts has been dedicated to advancing the art of utilization of magnetic nanoparticles for biomedical purposes. The research has been performed by three teams, each focusing on different aspects of the art:

Posted in: Briefs, MDB, TSP, Briefs, TSP, Coatings & Adhesives, Materials, Bio-Medical, Medical, Sensors, Biological sciences, Medical equipment and supplies, Nervous system, Nanomaterials, Head injuries

Electroceramic Actuators for Operation at Low Temperatures

Relatively large strokes are produced at temperatures between 30 and 60 K.

Electrostrictive ceramic actuators that can function at low temperatures have been developed for controlling the shapes of mirrors in the Next Generation Space Telescope (NGST). On Earth, electrostrictive ceramic actuators may be useful for fine control of the positions of objects in cryogenic laboratory apparatuses and in industrial cryogenic (including superconducting) systems.

Posted in: Briefs, TSP, Materials, Optics, Sensors and actuators, Optics, Sensors and actuators, Ceramics

Improved Low-Temperature Performance of Li-Ion Cells Using New Electrolytes

This technology has utility in high-power batteries for electric vehicles.

As part of the continuing efforts to develop advanced electrolytes to improve the performance of lithiumion cells, especially at low temperatures, a number of electrolyte formulations have been developed that result in improved low-temperature performance (down to –60 °C) of 26650 A123Systems commercial lithium- ion cells. The cell type/design, in which the new technology has been demonstrated, has found wide application in the commercial sector (i.e., these cells are currently being used in commercial portable power tools). In addition, the technology is actively being considered for hybrid electric vehicle (HEV) and electric vehicle (EV) applications.

Posted in: Briefs, TSP, Materials, Battery cell chemistry, Lithium-ion batteries, Battery cell chemistry, Lithium-ion batteries, Electrolytes

Wider-Opening Dewar Flasks for Cryogenic Storage

Dewar flasks have been proposed as containers for relatively long-term (25 days) storage of perishable scientific samples or other perishable objects at a temperature of –175 °C. The refrigeration would be maintained through slow boiling of liquid nitrogen (LN2). For the purposes of the application for which these containers were proposed, (1) the neck openings of commercial off-the-shelf (COTS) Dewar flasks are too small for most NASA samples; (2) the round shapes of the COTS containers give rise to unacceptably low efficiency of packing in rectangular cargo compartments; and (3) the COTS containers include metal structures that are too thermally conductive, such that they cannot, without exceeding size and weight limits, hold enough LN2 for the required long-term-storage.

Posted in: Briefs, Materials, Performance upgrades, Containers, Storage, Refrigerants

Supercapacitor Electrolyte Solvents With Liquid Range Below –80 °C

New formulations extend operation into lower temperatures.

A previous NASA Tech Brief [“Low-Temperature Supercapacitors” (NPO-44386) NASA Tech Briefs, Vol. 32, No 7 (July 2008), page 32] detailed ongoing efforts to develop non-aqueous supercapacitor electrolytes capable of supporting operation at temperatures below commercially available cells (which are typically limited to charging and discharging at ≥40 °C). These electrolyte systems may enable energy storage and power delivery for systems operating in extreme environments, such as those encountered in the Polar regions on Earth or in the exploration of space. Supercapacitors using these electrolytes may also offer improved power delivery performance at moderately low temperatures (e.g., –40 to 0 °C) relative to currently available cells, offering improved cold-cranking and cold-weather acceleration capabilities for electrical or hybrid vehicles.

Posted in: Briefs, Materials

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