Other materials science stories that may be of interestPublished on June 5th, 2012 | By: Peter Wray
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As Janine Schneider walks through the materials testing facility, her eyes light up; it is clear that she is comfortable between the long rows of test equipment. She knew she wanted to work here the moment she entered the premises of the DLR Institute of Materials Research in Cologne for the first time, during a trip there as a student. It was not so long ago. Janine Schneider was 20 years old when she first visited the Institute. Today, just eight years later, she is head of mechanical materials testing at the German Aerospace Center in Cologne. In the testing facility at the Institute of Materials Research, technicians, scientists and engineers subject samples to loads to determine the physical properties of various materials. “We break samples and, with the scientists, analyse why and how they broke,” is Schneider’s somewhat casual explanation of her team’s work. This enables the scientists to work out how the material behaves in tests that simulate operating conditions (testing of actual large structures under real working conditions is carried out by aircraft manufacturers, IMA Dresden or IABG).
Researchers are edging toward the creation of new optical technologies using “nanostructured metamaterials” capable of ultra-efficient transmission of light, with potential applications including advanced solar cells and quantum computing. The metamaterial—layers of silver and titanium oxide and tiny components called quantum dots—dramatically changes the properties of light. The light becomes “hyperbolic,” which increases the output of light from the quantum dots. Such materials could find applications in solar cells, light emitting diodes and quantum information processing far more powerful than today’s computers. Such metamaterials could make it possible to use single photons—the tiny particles that make up light-for switching and routing in future computers. While using photons would dramatically speed up computers and telecommunications, conventional photonic devices cannot be miniaturized because the wavelength of light is too large to fit in tiny components needed for integrated circuits.
Scientists have created and imaged the smallest possible five-ringed structure—about 100,000 times thinner than a human hair. A collaboration among the Royal Society of Chemistry, the University of Warwick, and IBM Research-Zurich has allowed the scientists to bring a single molecule to life in a picture, using a combination of clever synthetic chemistry and state-of-the-art imaging techniques. The scientists decided to make and visualize olympicene, whose five-ringed structure was entered two years ago on ChemSpider, the RSC’s free online chemical database of over 26 million records. David Fox and Anish Mistry, chemists at the University of Warwick, used some clever synthetic organic chemistry-the modern molecule designer’s toolbox-to build olympicene. “Alongside the scientific challenge involved in creating olympicene in a laboratory, there’s some serious practical reasons for working with molecules like this,” says Fox. “The compound is related to single-layer graphite, also known as graphene, and is one of a number of related compounds which potentially have interesting electronic and optical properties. For example these types of molecules may offer great potential for the next generation of solar cells and high-tech lighting sources such as LEDs.”
A new type of scanning probe microscopy can see nanoscale processes in real time, such as neurotransmitter release, alloy corrosion and photocatalysis. Researchers at Warwick University, alongside colleges in Japan, developed the method—coined voltage-switching electrochemical microscopy (VSM-SECM)—which can simultaneously provide information on the physical topography of surfaces, as well as localised functional activity. The new technique builds on the principles of scanning probe microscopy. With electrochemical microscopy the substrate surface of interest is placed in a chemical solution and the tip is lowered extremely close to it until a faradaic current formed. This gives flux information about the processes and reactions occurring, to which the tip is pre-tuned for particular molecular species. The tip then moves to the next ‘pixel’ point building an overall image. The tips are controlled by piezoelectric actuators in the Z axis, which can infer the topographical height of surface features based on the degree of deformation in the material and therefore current change. The Warwick team’s innovation was to develop a voltage-switching tip, which essentially allows functional and topographical information to be sampled simultaneously. The team also developed a novel pyrolytic carbon nanoelectrode for the tip that can be produced as small as 6 nanometers using a CO laser fabrication process.
NexTech Materials, Ltd. has received a contract from the Office of Naval Research for a Future Naval Capability (FNC) project aimed at design, development and demonstration of a compact energy system for unmanned underwater vehicles (UUVs). In this project, NexTech and its team will complete a comprehensive design of an energy-dense power system for a 21-inch diameter UUV. This system will be based on solid oxide fuel cell power generation using liquid hydrocarbon fuel (JP-10) and liquid oxygen reactants. The project provides follow-on funding for three years of previous development work under an SBIR project (Phases I and 2) funded by the Office of Naval Research. The starting point system design was established during this project, including a CAD model of the system and an analysis of system energy density over a range of conditions. In addition, a breadboard SOFC system was built and tested at the 1-kW scale.
Transparent armor solutions, based on polycrystalline, transparent ceramics such as ALON offer a factor of two improvement in areal density and thickness over conventional glass armor. ALON Transparent Armor also provides significant advantages for Night Vision Goggles (NVG) and situational awareness. Furthermore, ALON’s ease of manufacture makes it compatible with the very large scale, low cost manufacturing required to meet the growing demand for high performance applications. Surmet’s vertically integrated manufacturing capability begins with the synthesis of its own ALON powder from affordable precursor materials which are abundantly available in the USA. The combination of a dependable supply of low cost, ultra high purity powder, a robust and reproducible process for ALON blanks, and an established capability to fabricate these blanks into finished windows allows ALONTransparent Armor to be seriously considered for many current and future applications.
The Department of Energy will host the SunShot Initiative summit and technology forum <> June 13-14 at the Hyatt Regency in Denver, Colo. The SunShot Initiative seeks to achieve grid-parity solar energy within the decade. Through the Grand Challenge series, the DOE is launching a broad-based effort to address the scientific, technological and market barriers to achieving breakthroughs in national energy challenges. The Department is convening the best and brightest minds across government, industry and academia to strengthen US leadership in the global clean energy race, increase American economic prosperity and capture the new markets and jobs of the 21st century. The event will include plenary sessions featuring DOE Secretary Steven Chu and other industry leaders; group discussions focusing on the future priorities and transformational ideas needed to achieve the SunShot goal of cost-competitive solar by the end of the decade; a technology forum featuring exhibits from a wide range of SunShot partners and grant recipients, as well as DOE national labs.
Researchers at Oregon State University have discovered a new type of blue pigment that could help boost the energy efficiency of buildings. Discovered unexpectedly three years ago, the “cool blue” pigment has unusually high infrared heat reflectivity which it is hoped can be channeled into commercial products in the near future. “This pigment has infrared heat reflectivity of about 40 percent, which is significantly higher than most blue pigments now being used,” said Mas Subramanian, an OSU professor of chemistry who discovered the compound. The chance discovery occurred during unrelated research into the electrical properties of manganese compounds. When heated to 2,000°F the compounds changed to a “beautiful blue,” researchers later determined that this was due to what’s described as the trigonal bipyramidal crystalline structure of some of these compounds. This became the starting point for the development of the pigment, which also has the advantage of being durable and environmentally-benign. The compound, which has now received patent approval, is also being investigated for various commercial application according to OSU and research into its molecular structure and reflective properties is ongoing. The initial blue color in the pigment came from the manganese used in the compound. The scientists have now discovered that the same structure will produce other colors simply by substituting different elements. The broader potential for these pigments, researchers say, is the ability to tweak essentially the same chemical structure in slightly different ways to create a whole range of new colors in pigments that may be safer to produce, more durable and more environmentally benign than many of those that now exist.
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