Special Coverage


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: Materials, Briefs, TSP


Nanotechnology Approach to Lightweight, Multifunctional Polyethylene Composite Materials

Potential uses include personal armor, implantable prosthetics, and cut-resistant fabrics such as gloves worn by chefs and scuba divers. Langley Research Center, Hampton, Virginia Of several ideas being pursued by NASA for the reduction of radiation dosage to astronauts, the use of ultra-high-molecular-weight polyethylene (UHMWPE)-based composite materials for both radiation shielding and micrometeorite shielding appears to be particularly appealing. UHMWPE has long been understood to provide superior radiation shielding following encounters with energetic nucleons due to its high hydrogen content. Meanwhile, impacts of micrometeorites with UHMWPE tend to vaporize it, rather than causing spallation of the shield material, which then creates additional potentially damaging micrometeorites. Less widely appreciated is the high specific strength of UHMWPE and UHMWPE fibers, which provide structural integrity to the composite. Amongst thermoplastics, UHMWPE has the highest impact strength and is also highly resistant to abrasion. Despite this highly appealing combination of properties, UHMWPE’s key mechanical properties can be improved by forming composites with other nanostructured materials, leading to further performance increases and weight reductions. Such composites will increase the ability of UHMWPE structures to withstand micrometeorite impacts and maintain the structural integrity of a pressurized environment.

Posted in: Materials, Briefs


Electrostrictive Polymers

These lightweight and durable materials enable sensing and actuation devices. Langley Research Center, Hampton, Virginia A new class of electroactive polymeric blend materials has been created that offers both sensing and actuation dual functionality. The blend is comprised of two components where one has sensing capability, and the other has actuating capability. These innovative materials provide significant field-induced strain, high mechanical output force, and exceptional strain energy density. These electrostrictive polymers are conformable, lightweight, and durable. The processing system to fabricate these polymers is simple and can be manipulated to control and optimize the materials’ mechanical and electrical properties.

Posted in: Materials, Briefs


Researchers Build 'Invisible' Materials with Light

Metamaterials have a wide range of potential applications, including sensing and improving military stealth technology. Before cloaking devices can become reality on a larger scale, however, researchers must determine how to make the right materials at the nanoscale. Using light is now shown to be an enormous help in such nano-construction. A new technique uses light like a needle to thread long chains of particles. The development could help bring sci-fi concepts, such as cloaking devices, one step closer to reality.The technique developed by the University of Cambridge team involves using unfocused laser light as billions of needles, stitching gold nanoparticles together into long strings, directly in water for the first time. The strings can then be stacked into layers one on top of the other, similar to Lego bricks. The method makes it possible to produce materials in much higher quantities than can be made through current techniques. SourceAlso: See other Sensors tech briefs.

Posted in: Photonics, Lasers & Laser Systems, Materials, Sensors, Nanotechnology, Defense, News


Spongelike Structure Converts Solar Energy into Steam

A new material structure developed at MIT generates steam by soaking up the sun.The structure — a layer of graphite flakes and an underlying carbon foam — is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam. The brighter the light, the more steam is generated.The new material is able to convert 85 percent of incoming solar energy into steam — a significant improvement over recent approaches to solar-powered steam generation.“Steam is important for desalination, hygiene systems, and sterilization,” says Hadi Ghasemi, a postdoc in MIT’s Department of Mechanical Engineering, who led the development of the structure. “Especially in remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful.”SourceAlso: See other Energy tech briefs.

Posted in: Materials, Solar Power, Energy Harvesting, Energy, News


Engineers Use Resin Inks, 3D Printing to Build Lightweight Cellular Composites

Like other manufactured products that use sandwich panel construction to achieve a combination of light weight and strength, turbine blades contain carefully arrayed strips of balsa wood from Ecuador, which provides 95 percent of the world’s supply.As turbine makers produce ever-larger blades—the longest now measure 75 meters, almost matching the wingspan of an Airbus A380 jetliner—they must be engineered to operate virtually maintenance-free for decades. In order to meet more demanding specifications for precision, weight, and quality consistency, manufacturers are searching for new sandwich construction material options.Now, using a cocktail of fiber-reinforced epoxy-based thermosetting resins and 3D extrusion printing techniques, materials scientists at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering have developed lightweight cellular composite materials.The work could have applications in many fields, including the automotive industry where lighter materials hold the key to achieving aggressive government-mandated fuel economy standards. SourceAlso: See more Materials tech briefs.

Posted in: Manufacturing & Prototyping, Rapid Prototyping & Tooling, Materials, Composites, Aerospace, Aviation, News


Nano-Pixels Promise Flexible, High-Res Displays

A new discovery will make it possible to create pixels just a few hundred nanometers across. The "nano-pixels" could pave the way for extremely high-resolution and low-energy thin, flexible displays for applications such as 'smart' glasses, synthetic retinas, and foldable screens.Oxford University scientists explored the link between the electrical and optical properties of phase change materials (materials that can change from an amorphous to a crystalline state). By sandwiching a seven=nanometer-thick layer of a phase change material (GST) between two layers of a transparent electrode, the team found that they could use a tiny current to 'draw' images within the sandwich "stack."Initially still images were created using an atomic force microscope, but the researchers went on to demonstrate that such tiny "stacks" can be turned into prototype pixel-like devices. These 'nano-pixels' – just 300 by 300 nanometers in size – can be electrically switched 'on and off' at will, creating the colored dots that would form the building blocks of an extremely high-resolution display technology.SourceAlso: Learn about Slot-Sampled Optical PPM Demodulation.

Posted in: Electronics & Computers, Board-Level Electronics, Electronics, Imaging, Displays/Monitors/HMIs, Materials, Semiconductors & ICs, Nanotechnology, News