Check ’em out:
Red, green and blue OLEDs with an active surface area of 2×2 millimeters, being tested for performance. Credit: Deutscher Zukunftpreis/Ansgar Pudenz.
Researchers at Germany’s Fraunhofer Institute have developed an alternative to silicon semiconductors using an organic material, a type of dye commonly used in the production of road signs. Such materials have the advantage that they can be applied as a coating on flexible films and other substrates. This gives rise to new possibilities, such as displays that can be rolled up and carried in a vest pocket or switchable window panes that light up at night to illuminate rooms while hardly consuming any electricity. However, organic dyes are poor electrical conductors. But, their less-than-satisfactory conductivity can be increased by doping, and after years of experiments, researchers have succeeded in creating materials with an electrical conductivity a million and more times greater than the original dyes, with a doping ratio of no more than one percent.
Minerals and metals scarcity in manufacturing: the ticking timebomb (pdf)
Executives of leading global manufacturing companies believe that the impact of minerals and metals scarcity will increase strongly in the next five years. However, there are large variations in the likely impact on different sectors and regions and their state of preparedness. Economic and political dimensions are generally more important than the physical dimension of scarcity. Collaboration within the supply chain and new business models will be fundamental to the ability to respond appropriately to the risks and opportunities posed by the scarcity of minerals and metals. The December 2011 report is published by PricewaterhouseCoopers Accountants (PwC).
Towards artificial photosynthesis for solar hydrogen generation
Traditionally, photo-electrochemical cell electrodes are made of semiconducting materials such as metal oxides, some of which are also known for their photocatalytic properties. For quite some time, researchers at Empa’s Laboratory for High Performance Ceramics have been investigating nanoparticles of these materials, for instance titanium dioxide, for the neutralization of organic pollutants in air and water. Collaborating with colleagues at the University of Basel and at Argonne National Laboratory, they have now succeeded in making a nano-bio PEC electrode, consisting of iron oxide conjugated with a protein from blue-green algae (also known as cyanobacteria), which is twice as efficient in water splitting as iron oxide alone (see paper in Advanced Functional Materials, “Functionalization of Nanostructured Hematite Thin-Film Electrodes with the Light-Harvesting Membrane Protein C-Phycocyanin Yields an Enhanced Photocurrent”).
Class project turns recycled car parts into sandals and possibly jobs
Junkyard car seatbelts and abandoned tires come together in a sustainable sandal that could one day put Detroit homeless people to work manufacturing them. University of Michigan students created Treads Motor City Sandals in a unique class that requires aspiring designers, engineers and business professionals to work together to make a marketable product. Treads is one of six eco-friendly mini business ideas that students developed for consideration for addition to a portfolio of micro enterprises.
Diamonds and dust for better cement
Over 17 billion tons of Portland cement are consumed each year. Portland cement provides the essential binder for strong, versatile concrete; its basic materials are found in many places around the globe; and, at about $100 a ton, it’s relatively cheap. Making it, however, releases massive amounts of carbon dioxide, accounting for more than five percent of the total CO2 emissions from human activity. Recently, researchers at Lawrence Berkeley National Lab gradually squeezed specks of fine dust of the mineral tobermorite in a diamond anvil cell until they achieved pressures like those 100 miles below the surface of Earth. This was the first experiment to determine tobermorite’s bulk modulus from diffraction patterns obtained by sending a bright beam of x-rays through the sample, revealing how its structure changed as the pressure increased. The results will appear in Cement and Concrete Research and are now available online to subscribers.