High-performance electronic circuits made entirely from transparent materials could have countless applications, from head-up displays on car windscreens to transparent TV sets and smart windows in homes and offices. Researchers at the King Abdullah University of Science & Technology (KAUST) in Saudi Arabia have now found a way to make transparent transistors and other essential components of electronic circuitry using inexpensive and readily available materials with a simple fabrication technique. They report this work in a paper in Advanced Materials. Indium tin oxide (ITO) is the current material of choice for transparent electronics, with uses ranging from touch-sensitive smartphone screens to light-harvesting solar panels. Indium is in short supply, however, and as demand increases for ITO-containing devices, so does the price of indium. One promising low-cost ITO alternative is a transparent material known as aluminum-doped zinc oxide (AZO). "The elements that make up this material are more abundant than indium, making AZO a commercially sensible option," said Husam Alshareef, a professor in the KAUST Physical Science and Engineering Division, who led the research. "However, electronic devices made using AZO have traditionally shown inferior performance to devices made using ITO." To overcome this limitation, Alshareef and his research team took advantage of a high-precision technique called atomic layer deposition, which can build up circuits a single layer of atoms at a time. Using this technique, the researchers applied volatile vapors of aluminum and zinc in the form of trimethyl aluminum and diethyl zinc to a transparent substrate, where the aluminum and zinc adhere to the surface in a single layer before reacting in situ to form AZO. "Using atomic layer deposition to grow all active layers simplifies the circuit fabrication process and significantly improves circuit performance by controlling layer growth at the atomic scale," Alshareef explained. For many electronic devices, the key component is the thin-film transistor. When combined in great numbers, these devices allow computers to do calculations, drive displays and act as active sensors. Alshareef used a transparent material called hafnium oxide, sandwiched between layers of AZO, to form the highly-stable transistors used to fabricate the transparent circuits. "Our transistor properties are the best reported so far for fully transparent transistors using AZO contacts," said PhD student Zhenwei Wang, who carried out much of the experimental work. Another advantage of Alshareef's approach is that atomic layer deposition only requires a temperature of 160°C to form each layer. This is low enough for the transparent circuitry to be formed on flexible plastic substrates, as well as on rigid glass. This story is adapted from material from KAUST, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.
News Article | June 3, 2015
Eurofinsa: "La exclusión social de la infancia es un tema especialmente sensible" Lola Arias, directora de Comunicación y Responsabilidad Social Corporativa del Grupo Eurofinsa, explica en esta entrevista porque su compañía colabora con Grupo AMÁS. Lo hace desde julio de 2013. Lola Arias, directora de Comunicación y Responsabilidad Social Corporativa del Grupo Eurofinsa, explica en esta entrevista porque su compañía colabora con Grupo AMÁS. Lo hace desde julio 2013. ¿Cómo surgió la idea de colaborar con Grupo AMÁS? La responsabilidad e implicación con la que venimos desarrollando nuestra actividad en estos 37 años de actividad cristaliza ahora con nuestra incorporación al Pacto Mundial de Naciones Unidas. Dicha adhesión ha reforzado nuestra filosofía de trabajo y aporta valor añadido a la gestión y ejecución de nuestros proyectos que se relacionan directamente con el bienestar y la calidad de vida de las personas y, en consecuencia, confirmamos nuestro compromiso con el desarrollo local en todos los países donde estamos presentes. A través de los empleados conocimos la labor que el Grupo AMÁS está llevando a cabo en la Comunidad de Madrid. ¿Por qué habéis decidido colaborar con el centro de Atención Temprana? La exclusión social de la infancia es un tema especialmente sensible dentro de nuestra organización. Por ello, Eurofinsa decidió apostar por el proyecto que la Asociación AFANDEM realiza en la zona suroeste de la Comunidad. Nos parece impactante la calidad de los servicios y de los profesionales dentro de una modesta estructura que atiende anualmente a más de 300 niños con necesidades especiales. Desde nuestra posición, queremos aportar nuestro granito de arena para favorecer el mejor desarrollo posible de los niños y facilitar su integración social. Eurofinsa sólo presta apoyo a aquellas organizaciones que cuenten con una reputación intachable y que puedan garantizar la buena administración de los recursos asignados. Para nosotros es fundamental que la colaboración sea transparente y de confianza y que tengamos la garantía de que los recursos que destinamos estén bien empleados y sean sostenibles en el tiempo. Junto al desafío permanente de competir en el mercado global, nos guiamos por la convicción de que nuestras actividades estén alineadas con la sostenibilidad económica, social y medioambiental. Por ello, además de desarrollar una gestión empresarial responsable y comprometida, promocionamos aquellos proyectos sociales en los que la compañía proporcione un valor añadido y que estén dentro de la dinámica de los proyectos que hacemos alrededor del mundo. Nuestro objetivo es implicar y beneficiar al máximo a las comunidades locales. ¿Cómo animarías a otras a organizaciones a colaborar? Les animaría a que involucraran a sus empleados en sus decisiones y a que escogieran aquellos proyectos relacionados con su negocio que es donde más pueden ayudar y que mejor saben hacer. ¿Qué papel deben jugar entidades cómo la vuestra para mejorar la sociedad? Más allá del beneficio económico, las empresas tienen un papel esencial para encontrar el equilibrio necesario entre el crecimiento económico, la protección del medio ambiente y el desarrollo de una sociedad más justa. Además, las empresas no son entes sino que están compuestas de personas a las que se les debería involucrar directamente en acciones concretas, tales como donaciones conjuntas, voluntariado, apoyo a la participación individual en proyectos, participación en eventos y campañas a favor de causas sociales, etc.
A new chemical route for potential antimalarial compounds has been pioneered by chemists at KAUST. It offers hope for improved treatment of malaria, a disease that kills more than a million people each year. "The parasites that cause the disease continuously evolve and become resistant to existing drugs, so we need to constantly design and synthesize new drugs to treat malaria," noted Xinbo Wang, a chemist in Associate Professor Zhiping Lai's group in the KAUST Physical Science and Engineering Division. The work could also lead to the development of new drugs against bacterial infections, cancer and other diseases. A chemical structure called the alpha-amino peroxide group, which is found in existing anti-malarial compounds, is a good basis for building potential new drugs. However, there are significant problems with existing methods for making such compounds because they require difficult chemical conditions. Lai and his colleagues devised a simple and efficient procedure1 and showed that the alpha-amino peroxide group can be combined with an "indole" chemical grouping to make the "N-(alpha-peroxy)-indole" structure. "There are lots of reports on the synthesis of indole or peroxide-containing compounds, but there are no general methodologies for combining the two functional groups in one molecule that had been previously reported," stated Wang. The KAUST team took things a step further by adding a carbazole group. The indole, carbazole and peroxide groups occur separately in many antimalarial, antibacterial and anti-tumor compounds. "Merging these functional groups in one molecular structure may offer great potential for the discovery of new types of drugs," Wang said. The reactions proceed in "one-pot, open atmosphere" conditions, meaning everything occurs in one vessel without complicated intermediate steps. The vessel is also open to the air rather than protected by unreactive gases, as is required for many similar chemical processes. "Our procedure could be easily handled and scaled-up to allow the construction of a new library of molecules for drug screening," he noted. Upscaling is the challenge that the KAUST researchers plan to turn to next to make a wide variety of compounds that can be tested for useful biological activity against a variety of diseases, and especially against malaria. In developing their new chemical procedures, the researchers drew inspiration from a chemical reaction used by another research project at KAUST. "Our story proves the importance of a multidisciplinary research environment, which we consider is the treasure of KAUST," Lai said. "Here, experts from different fields work closely together." More information: Wang, X., Pan, Y., Huang, K.-W. & Lai, Z.; One-pot synthesis of N‑(α-peroxy)indole/carbazole via chemoselective three-component condensation reaction in open atmosphere; Organic Letters 17, 5630 - 5633 (2015);
"This novel, low-cost prototype was developed for less than $1 million, which is one-tenth the cost of other comparable balloon-borne observatories," said Principal Investigator Dr. Craig DeForest, a principal scientist in SwRI's Space Science and Engineering Division. "Funded by NASA's Game-Changing Technologies program, SSIPP is a reusable, optical table-based platform. This novel approach breaks down barriers to science by allowing low-cost solar research." SSIPP collects solar data using infrared, ultraviolet, or visible light instruments on an optical table, similar to those used in ground-based observatories but from a near-space environment. This arcsecond-class observatory provides optical precision equivalent to imaging a dime from a mile away. Originally conceived to fly aboard a commercial suborbital rocket, SSIPP has now been adapted for balloon flight. Collecting data from the edge of space—around 20 miles above the Earth's surface—avoids image distortions caused by looking through the atmosphere. "SSIPP could support the development of a range of new instruments for the near-space environment at relatively low cost," DeForest said. "Using a standard optical table platform increases flexibility, allowing scientists to try new things and develop new technologies without designing a custom observatory." During the demonstration, scientists will spend two hours commissioning the observatory and searching for visible signatures of "high-frequency" solar soundwaves, which are actually some eight octaves below the deepest audible notes. By contrast, the most studied sound waves in the Sun (the solar "P-modes" used to probe the solar interior) are five octaves deeper still. The surface of the Sun is covered with granular convection cells analogous to a pot of water at a rolling boil. Continuously, every 5 minutes, a million of these cells erupt, creating sound waves at a range of frequencies. SSIPP will image the solar atmosphere to understand their heat and noise properties. The comparatively high frequency of the "solar ultrasound" waves makes them undetectable by ground-based observatories. "The transfer of heat to the surface of our star is a violent and tremendously loud process," DeForest said. "Soundwaves heat the solar atmosphere to extremely high temperatures, but it's a poorly understood process. Existing measurements of the solar infrasound cannot account for all the energy required." SSIPP will launch aboard a World View stratospheric balloon, funded by NASA's Flight Opportunities Program under the Space Technology Mission Directorate. The program is managed by NASA's Armstrong Flight Research Center in Edwards, California. Explore further: SwRI to build miniature solar observatory for manned suborbital flight
Home > Press > Faster, finer filtration: The right blend of polymers enables rapid and molecule-selective filtering of tiny particles from water Abstract: A method of fabricating polymer membranes with nanometer-scale holes that overcomes some practical challenges has been demonstrated by KAUST researchers. Porous membranes can filter pollutants from a liquid, and the smaller the holes, the finer the particles the membrane can remove. The KAUST team developed a block copolymer membrane with pores as small as 1.5 nanometers but with increased water flux, the volume processed per hour by a membrane of a certain area. A nanofilter needs to be efficient at rejecting specific molecules, be producible on a large scale, filter liquid quickly and be resistant to fouling or the build-up of removed micropollutants on the surface. Block copolymers have emerged as a viable material for this application. Their characteristics allow them to self-assemble into regular patterns that enable the creation of nanoporous materials with pores as small as 10 nanometers. However, reducing the size further to three nanometers has only been possible by post-treating the membrane (depositing gold, for example2). Moreover, smaller holes usually reduce the water flux. Klaus-Viktor Peinemann from the KAUST Advanced Membranes & Porous Materials Center and Suzana Nunes from the KAUST Biological and Environmental Science and Engineering Division formed a multidisciplinary team to find a solution. "We mixed two block copolymers in a casting solution, tuning the process by choosing the right copolymer systems, solvents, casting conditions," explained Haizhou Yu, a postdoctoral fellow in Peinemann's group. This approach is an improvement on alternatives because it doesn't require material post-treatment. Peinemann and colleagues blended polystyrene-b-poly(acrylic acid) and polystyrene-b-poly(4-vinylpyridine) in a ratio of six to one. This created a sponge-like layer with a 60 nanometer film on top. Material analysis showed that nanoscale pores formed spontaneously without the need for direct patterning1. The researchers used their nanofiltration material to filter the biological molecule protoporphyrin IX from water. The filter simultaneously allowed another molecule, lysine, to pass through, demonstrating its molecular selectivity. The researchers were able to filter 540 liters per hour for every square meter of membrane, which is approximately 10 times faster than commercial nanofiltration membranes. The groups teamed up with Victor Calo from the University's Physical Science and Engineering Division to develop computer models to understand the mechanism of pore formation. They showed that the simultaneous decrease in pore size and increase in flux was possible because, while the pores are smaller, the pore density in the block copolymer is higher. "In the future, we hope to optimize membranes for protein separation and other applications by changing the copolymer composition, synthesizing new polymers and mixing with additives," said Nunes. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.