Tech Briefs

Novel Chemistry for Deposition of MgF2 Thin Films

NASA’s Jet Propulsion Laboratory, Pasadena, California Magnesium fluoride (MgF2) thin films are useful for many different optics applications. In particular, they are useful for ultraviolet anti-reflective and protective coatings. However, in the far UV, one needs a very small, controllable amount of material to get the best optical performance. That is difficult to achieve with conventional methods. Atomic layer deposition (ALD) is an ideal UV-compatible thin-film deposition technique due to its ability to deposit uniform, pin-hole free films with angstrom-level thickness control. Therefore, it is an ideal technique to use to deposit protective thin films in the 2-nm thickness range. However, conventional ALD-MgF2 reactions are very unpredictable due to the low reactivity and volatility of the precursors.

Posted in: Manufacturing & Prototyping, Briefs

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The Flexibility of ITO Films in Electronic Coating Applications

Indium-tin oxide (ITO) is used in nearly all flat panel displays, laptop screens, and mobile phones, in addition to solar panels and “smart” windows. Indium Corporation, Utica, New York ITO is a doped metal oxide semiconductor that combines two properties that usually are mutually exclusive in most materials: optical transparency and electrical conductivity. It is critical to understand the importance of this combination of optical transparency and electrical conductivity. A flat panel display cannot work without both properties. Yet the very nature of electrical conductivity normally excludes optical transparency. Doped metal oxide semiconductors conduct electricity in a different manner than metals, and hence, are not doomed to be opaque.

Posted in: Materials, Briefs

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Electride Mediated Surface Enhanced Raman Spectroscopy

NASA’s Jet Propulsion Laboratory, Pasadena, California A new sensor substrate supports Surface Enhanced Raman Spectroscopy. A ceramic electride is demonstrated to provide surface enhanced Raman scattering. This provides a sensitive method for monitoring the chemistry and electronic environment at the electride surface. The electride, an ionic crystal in which the electrons serve as anions, is a conductive calcium aluminate with a mayenite structure. The textured electride surface is found to strongly enhance the Raman scattering of an organic analyte at 532-nm and 785-nm excitation wavelengths. This provides a sensitive method for monitoring the chemistry and electronic environment at the electride surface.

Posted in: Materials, Briefs

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Patterned Carbon Nanotube Arrays for Displays

Applications include aviation/avionics, HD displays, lightweight displays for mobile devices, and virtual reality and games. Ames Research Center, Moffett Field, California Multi-colored electronic displays that are dynamically reconfigurable require substantial electrical power and are limited in the amount of fine detail provided by the physical size of the light sources. For example, where phosphor elements are used, as in a television screen or computer monitor, the pixel size is generally no smaller than about 0.1 mm. This limits the resolution available, where much finer work is desired.

Posted in: Materials, Briefs

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Pneumatic Sample Acquisition and Transfer System

This system can be used to collect samples from such hazardous areas as nuclear, extremely hot, and toxic environments. NASA’s Jet Propulsion Laboratory, Pasadena, California Sampling, sample handling, and sample transfer to lander platforms of in situ exploration missions involve great technical challenges. These challenges are even harder to address when the planetary bodies have extreme environments. For example, Venus has an ambient temperature of around 460 °C, and atmospheric pressure that is over 90 times the atmosphere of Earth.

Posted in: Mechanics, Mechanical Components, Briefs

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Brine Residual in Containment

This system can be used in water recovery from industrial waste streams that may contain toxic compounds. Lyndon B. Johnson Space Center, Houston, Texas Improvements in brine water recovery are critical to advancing NASA’s goals for human exploration of space. Water recovery systems must minimize the need for new supplies of clean water by closing the water loop. To accomplish this, water losses must be minimized or eliminated. A major loss of water is the brine produced by the primary water processor. For current technologies, this loss can be up to 15%.

Posted in: Mechanics, Mechanical Components, Briefs

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Locking Orifice Retaining Nut

Lyndon B. Johnson Space Center, Houston, Texas Fluid flow systems often require orifices to control pressure drop or flow rate. These orifices are often retained in bolted housings that require seals and introduce potential leak points into the system.

Posted in: Mechanics, Mechanical Components, Briefs

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