Materials & Coatings

Researchers Create Energy-Absorbing Material

Materials like solid gels and porous foams are used for padding and cushioning, but each has its own advantages and limitations.A team of engineers and scientists at Lawrence Livermore National Laboratory (LLNL) has found a way to design and fabricate, at the microscale, new cushioning materials with a broad range of programmable properties and behaviors that exceed the limitations of the material's composition, through additive manufacturing, also known as 3D printing. Livermore researchers, led by engineer Eric Duoss and scientist Tom Wilson, focused on creating a micro-architected cushion using a silicone-based ink that cures to form a rubber-like material after printing. During the printing process, the ink is deposited as a series of horizontally aligned filaments (which can be fine as a human hair) in a single layer. The second layer of filaments is then placed in the vertical direction. This process repeats itself until the desired height and pore structure is reached.The researchers envision using their novel energy-absorbing materials in many applications, including shoe and helmet inserts, protective materials for sensitive instrumentation, and in aerospace applications to combat the effects of temperature fluctuations and vibration.SourceAlso: Read more Materials tech briefs.

Posted in: News, Rapid Prototyping & Tooling

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NASA 3D Printing Technique Creates Metal Spacecraft Parts

Researchers at NASA's Jet Propulsion Laboratory are implementing a printing process that transitions from one metal or alloy to another in a single object. JPL scientists have been developing a technique to address this problem since 2010. An effort to improve the methods of combining parts made of different materials in NASA's Mars Science Laboratory mission inspired a project to 3D print components with multiple alloy compositions.

Posted in: News, Rapid Prototyping & Tooling, Metals

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Secret of Eumelanin’s Ability to Absorb Broad Spectrum of Light Uncovered

Melanin — and specifically, the form called eumelanin — is the primary pigment that gives humans the coloring of their skin, hair, and eyes. It protects the body from the hazards of ultraviolet and other radiation that can damage cells and lead to skin cancer. But the exact reason why the compound is so effective at blocking such a broad spectrum of sunlight has remained something of a mystery. Now, however, researchers at MIT and other institutions have solved that mystery, potentially opening the way for the development of synthetic materials that could have similar light-blocking properties.

Posted in: News, Solar Power, Composites, Optics, Photonics

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Engineers Hope to Create Electronics That Stretch at the Molecular Level

Nanoengineers at the University of California, San Diego are asking what might be possible if semiconductor materials were flexible and stretchable without sacrificing electronic function?

Posted in: News, Board-Level Electronics, Electronic Components, Electronics, Sensors

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High-Efficiency, Easy-to-Manufacture Engineered Nanomaterials for Thermoelectric Applications

Materials can be produced in thin/thick film form while maintaining film quality and stoichiometric balance. Marshall Space Flight Center, Alabama Stated generally, reducing the dimensionality of bulk-scale thermoelectric (TE) materials is theoretically and practically understood to be a viable route for maintaining/increasing phonon scattering, and maintaining/increasing electrical conductivity — necessary conditions for improving thermoelectric merit. Solution deposition of thin, anisotropic films of nanoscale particles of known TE materials is a route toward obtaining such low-dimensional materials with increased TE merit.

Posted in: Briefs

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Refractory Open-Cell Foam Fuel Matrix for High-Efficiency Nuclear Thermal Propulsion

A fuel form for fission applications is functional at extremely high temperatures with minimal erosion or fission product losses. Marshall Space Flight Center, Alabama A tricarbide foam fuel material has been developed that can operate at temperatures near 3,000 °C, without substantial hydrogen erosion, while providing highly efficient heat transfer to the coolant or propellant. A tricarbide foam fuel matrix of zirconium carbide (ZrC), niobium carbide (NbC), and uranium carbide (UC) has been successfully deposited and hydrogen tested. It shows that high-temperature, high-porosity foams can be produced that resist hydrogen corrosion and prevent the diffusion of fission products from the matrix. Chemical vapor deposition (CVD) technology was applied to nuclear materials systems that may be used in thermal propulsion and very high-temperature gas reactors.

Posted in: Briefs

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Hydrazine Absorbent/Detoxification Pad

This hydrazine-degrading pad has applications in hazardous-material emergency response situations. Lyndon B. Johnson Space Center, Houston, Texas A new chemistry was developed for existing hydrazine absorbent/detoxification pads. Enhancements include faster reaction rates, weight reduction, a color change that indicates spill occurrence, and another color change that indicates successful hydrazine degradation. The previous spill control pad, using copper oxide on the silica gel substrate as the reactant, affected only 50 percent degradation of hydrazine after 9 hours. The new prototypes have been found to degrade hydrazine from 95 to 99.9 percent in only 5 minutes, and to below detection limits within 90 minutes.

Posted in: Briefs, TSP

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