White, Electrically Conductive, Radiation-Stable, Thermal Control Coating

Goddard Space Flight Center, Greenbelt, Maryland A highly reflective, white conductive coating system was developed using a layered approach with a combination of commercially available white conductive pigments within a conductive binder system. The top coating is a space-stable, radiation-resistant, highly reflective coating that has been tailored to provide optimum reflectance properties and meet vacuum thermal surface resistivities. The combined layer is a mixture of a highly reflective, electrically dissipative coating and a moderately reflective but highly conductive pigment in a conductive binder. A second, underlying layer of conductive white coating offers optimum adhesion to metal substrates and the topcoat. The system vacuum resistivity at room temperature is approximately 1 × 109 ohms/sq, and has a solar absorptance of less than 0.13 as measured on a Cary 5000 spectrophotometer.

Posted in: Briefs, TSP, Thermoelectrics, Coatings & Adhesives


Piezoelectric Actuated Inchworm Motor (PAIM)

This linear piezoelectric actuator can operate at temperatures of 77 K or below. NASA’s Jet Propulsion Laboratory, Pasadena, California Conventional piezoelectric materials, such as PZTs, have reasonably high electromechanical coupling over 70%, and excellent performance at room temperature. However, their coupling factor (converting electrical to mechanical energy and vice versa) drops substantially at cryogenic temperatures, as the extrinsic contributions (domain wall motions) are almost frozen out below 130 K.

Posted in: Briefs, TSP, Fluid Handling, Motors & Drives


Pumped Subsea Energy Storage

This technique would be applicable to offshore oil platforms and energy storage for public utilities. NASA’s Jet Propulsion Laboratory, Pasadena, California A local energy source is desired for near-shore and offshore applications. Gas generators, diesel generators, and long-length submerged power cables tend to be expensive. A proposed solution is to use offshore wind with some type of energy storage mechanism for up to 1 GW-h. Energy storage in batteries is too expensive and massive, and subsea compressed air energy storage (CAES) has not been proven for very deep depths. Furthermore, CAES involves very great temperature changes that result in large inefficiencies.

Posted in: Briefs, TSP, Energy Efficiency, Energy Storage, Solar Power, Wind Power


Design for Improving the Flatness of Solar Sails

An optically flat solar sail could be useful in optical communication and solar energy applications. NASA’s Jet Propulsion Laboratory, Pasadena, California This work describes a discontinuous or segmented mirror whose overall flatness is less dependent on the limited tension that can be supplied by the booms. A solar sail is a large, nominally flat sheet of extremely thin reflectorized film rigidly attached to a spacecraft, enabling propulsion via solar radiation pressure. Rip-stop fibers embedded in the backside of the film — with diameters ≈100× the thickness of the film — are commonly used to arrest tear propagation, which can easily occur in the handling and/or deployment of these gossamer-thin structures. Typically, the thin film or membrane that is the sail is systematically folded to enable both volumetrically compact transportation to space and mechanized deployment. It is the aggressive folding and creasing of the thin film that limits the ultimate flatness that can be achieved.

Posted in: Briefs, TSP, Solar Power


Negative Dielectric Constant Material Based on Ion-Conducting Materials

Langley Research Center, Hampton, Virginia Metamaterials, or artificial negative index materials (NIMs), have generated great attention due to their unique and exotic electromagnetic properties. A negative dielectric constant material, which is an essential key for creating the NIMs, was developed by doping ions into a polymer, a protonated poly(benzimidazole) (PBI).

Posted in: Briefs, TSP, Energy Storage, Sensors


Quantum Dot Light Enhancement Substrate

A cost-competitive solution for increasing the light extraction efficiency of organic light-emitting diodes (OLEDs) with efficient and stable color rendering index (CRI) for solid-state lighting (SSL) was developed and demonstrated. Solution-processable quantum dot (QD) films were integrated into OLED indium tin oxide (ITO)-glass substrates to generate tunable white emission from blue-emitting OLED devices.

Posted in: Briefs, Briefs, TSP, Energy Efficiency, OLEDs


Transparent Conducting Oxides and Undercoat Technologies for Economical OLED Lighting

Economics is a key factor for application of organic light emitting diodes (OLED) in general lighting relative to OLED flat panel displays that can handle high-cost materials such as indium tin oxide (ITO) or indium zinc oxide (IZO) as the transparent conducting oxide (TCO) on display glass. For OLED lighting to penetrate into general illumination, economics and sustainable materials are critical.

Posted in: Briefs, Briefs, TSP, Energy Efficiency