Materials & Coatings

Digital Microfluidics Sample Analyzer

Combined innovations enable portable analyzers for medical diagnostics, bioterrorism pathogen detection, and food supply analysis.

Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations.

Posted in: Briefs, MDB, Briefs, Coatings & Adhesives, Materials, Bio-Medical, Diagnostics, Medical, Patient Monitoring, Software, Microelectromechanical devices, Sensors and actuators, Diagnosis, Medical equipment and supplies, Product development, Test equipment and instrumentation

Low-Outgassing Adhesives

Applications include solar panels, LEDs, and medical devices.

Products and manufacturing processes can be sensitive to outgassed chemical compounds, resulting in the use of adhesives, encapsulants, and sealants that have been specially formulated for low-outgassing performance. The most stringent outgassing requirements are best met by products formulated to pass an industry-standard outgassing test known as ASTM E595-07. Low-outgassing adhesives don’t typically require any sacrifice in other mechanical or physical properties. What sets low-outgassing products apart from their generic counterparts is that the low-outgassing grades have passed the ASTM test.

Posted in: Briefs, Materials, Adhesives and sealants, Chemicals, Gases, Materials properties

Functionalization of Single-Wall Carbon Nanotubes by Photo-Oxidation

A new technique for carbon nanotube oxidation was developed based upon the photo-oxidation of organic compounds. The resulting method is more benign than conventional oxidation approaches and produces single-wall carbon nanotubes (SWCNTs) with higher levels of oxidation.

Posted in: Briefs, TSP, Materials, Chemicals, Nanotechnology, Oxygen

Magnesium Diboride Current Leads

The superconductor can be applied to cryogenic wiring.

A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Discovered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A.

Posted in: Briefs, Materials, Electric cables, Thermal management, Fabrication, Conductivity, Magnesium, Electric motors

Polyimide Aerogels With Three-Dimensional Cross-Linked Structure

These aerogels are suited for use as insulation as well as adsorbent beds for chemical separators, and as platforms for solid-state sensors.

Polyimide aerogels with three-dimensional cross-linked structure are made using linear oligomeric segments of polyimide, and linked with one of the following into a 3D structure: trifunctional aliphatic or aromatic amines, latent reactive end caps such as nadic anhydride or phenylethynylphenyl amine, and silica or silsesquioxane cage structures decorated with amine. Drying the gels supercritically maintains the solid structure of the gel, creating a polyimide aerogel with improved mechanical properties over linear polyimide aerogels.

Posted in: Briefs, TSP, Materials, Insulation, Materials properties, Nanotechnology, Polymers

Alumina Paste Layer as a Sublimation Suppression Barrier for Yb₁₄MnSb₁₁

This material can be applied to any thermoelectric couples requiring sublimation suppression.

Sublimation is a major cause of degradation of thermoelectric power generation systems. Most thermoelectric materials tend to have peak values at the temperature where sublimation occurs. A sublimation barrier is needed that is stable at operating temperatures, inert against thermoelectric materials, and able to withstand thermal cycling stress.

Posted in: Briefs, TSP, Materials, Nuclear energy, Thermal management, Aluminum alloys, Insulation

Silica/Polymer and Silica/Polymer/Fiber Composite Aerogels

These materials resist compression better than pure silica aerogels do.

Aerogels that consist, variously, of neat silica/polymer alloys and silica/polymer alloy matrices reinforced with fibers have been developed as materials for flexible thermal-insulation blankets. In comparison with prior aerogel blankets, these aerogel blankets are more durable and less dusty. These blankets are also better able to resist and recover from compression — an important advantage in that maintenance of thickness is essential to maintenance of high thermal-insulation performance. These blankets are especially suitable as core materials for vacuum-insulated panels and vacuum-insulated boxes of advanced, nearly seamless design. (Inasmuch as heat leakage at seams is much greater than heat leakage elsewhere through such structures, advanced designs for high insulation performance should provide for minimization of the sizes and numbers of seams.)

Posted in: Briefs, TSP, Materials, Composite materials, Fabrics, Fibers, Insulation, Polymers, Silicon alloys

High-Temperature Solid Lubricant Coating

NASA PS400 is a solid lubricant coating invented for high-temperature tribological applications. This plasma-sprayed coating is a variant of the previously patented PS304 coating, and has been formulated to provide higher density, smoother surface finish, and better dimensional stability.

Posted in: Briefs, TSP, Materials, Lubricants, Coatings, colorants, and finishes, Composite materials, Materials properties, Tribology

Exfoliated Graphite Nano-Reinforcements With Surface Modifications to Improve Dispersability

Exfoliated graphite nanoflakes are a potential low-cost source of nano-reinforcement for making polymer composites with unique properties. The chemical nature of the graphitic surface leads to a low-surface energy as produced. This makes the nanoflakes difficult to disperse in polymer resins and makes it difficult to make high-quality composites. To improve nanoflake dispersability in various polymers, two surface treatments were selected to modify the chemical structure of the graphite nanoflakes.

Posted in: Briefs, TSP, Materials, Fabrication, Composite materials, Graphite, Nanomaterials, Resins

MicroGel® for Passivation of Pigment Degradation

MicroGel® is a unique, highly porous xero-gel silica formed using sol-gel techniques. The starting materials used are designed per guidance from molecular dynamic calculations, and are made up of mixed alkali silicates rather than normally used single alkali silicates that are gelled with appropriate mineral acid at controlled temperature and time.

Posted in: Briefs, TSP, Materials, Fabrication, Composite materials, Materials properties, Silicon alloys

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