Friday, November 26, 2010

This week in nanotechnology - November 26, 2010

A breakthrough in a University of Cincinnati engineering lab that could clear the way for a low-cost, even disposable, e-reader is gaining considerable attention. The researchers demonstrated that paper could be used as a flexible host material for an electrowetting device.

Methane-powered laptops may be closer than you think. Making fuel cells practical and affordable will not happen overnight. It may, however, not take much longer. With advances in nanostructured devices, lower operating temperatures, and the use of an abundant fuel source and cheaper materials, a group of researchers at the Harvard School of Engineering and Applied Sciences (SEAS) are increasingly optimistic about the commercial viability of the technology.

Oxygen rich graphene support could lead to durable fuel cell catalysts. In the search for efficient, durable and commercially viable fuel cells, scientists have discovered a new catalyst-support combination that could make fuel cells more efficient and more resistant to carbon monoxide poisoning.
Platinum nanocatalysts

Platinum nanocatalysts supported on lightly reduced graphene oxide could make fuel cells more stable and resistant to carbon monoxide poisoning.

Emerging applications of carbon nanotubes: Researchers at MIT have published an overview of a variety of applications that are based on the unique properties of pristine as well as functionalized carbon nanotubes.

Success in developing groundbreaking electrolyte materials for solid oxide fuel cells: The Fuel Cell Nano-Materials Group at the International Center for Materials Nanoarchitectonics in Japan has successfully developed two types of novel materials which satisfy all the three requirements for electrolyte: ion conductivity, chemical stability and sinterability, at high levels.

Ultrathin alternative to silicon for future electronics: Integrating ultra-thin layers of the semiconductor indium arsenide onto a silicon substrate leads to a nanoscale transistor with excellent electronic properties. A member of the III–V family of semiconductors, indium arsenide offers several advantages as an alternative to silicon including superior electron mobility and velocity, which makes it an oustanding candidate for future high-speed, low-power electronic devices.

Researchers are creating a system that harvests heat from an engine's exhaust to generate electricity, reducing a car's fuel consumption. Current thermoelectric technology cannot withstand the temperatures inside catalytic converters, where gases are about 1,000 degrees Celsius, he said. However, researchers also are working on new thermoelectrics capable of withstanding such high temperatures, a step that would enable greater fuel savings.

New YouTube videos explain graphene for the baffled. Two two short videos explain graphene and its amazing properties. The videos show how amazingly graphene can be produced using just a pencil and some sticky tape.

Friday, November 19, 2010

This week in nanotechnology - November 19, 2010

Engineers from Harvard University have designed and demonstrated ice-free nanostructured materials that literally repel water droplets before they even have the chance to freeze. The finding could lead to a new way to keep airplane wings, buildings, powerlines, and even entire highways free of ice during the worst winter weather. Moreover, integrating anti-ice technology right into a material is more efficient and sustainable than conventional solutions like chemical sprays, salt, and heating.

Sunlight represents the cleanest, greenest and far and away most abundant of all energy sources, and yet its potential remains woefully under-utilized. High costs have been a major deterrant to the large-scale applications of silicon-based solar cells. Nanopillars – densely packed nanoscale arrays of optically active semiconductors – have shown potential for providing a next generation of relatively cheap and scalable solar cells, but have been hampered by efficiency issues. The nanopillar story, however, has taken a new twist and the future for these materials now looks brighter than ever.

Nanotech teabag filter cleans water: Instead of being filled with black or green tea, the bag contains active carbon granules and is made from nanofibers treated with biocide, which kills bacteria rather than simply filtering them from the water.
teabag water filter

Each disposable filter can purify one liter of water.

Gene therapy holds the promise for curing a variety of diseases, including cancer, and nanoparticles have been recognized as promising vehicles for effective and safe delivery of genes into specific type of cells or tissues. However, the existing process available for producing and examining nanoparticles for this purpose is limited due to the use of conventional synthetic approaches that are cumbersome and time-consuming. UCLA researchers have now found a faster way to produce efficient nano-vehicles for gene delivery.

As electronics become smaller and smaller the need to understand nanoscale phenomena becomes greater and greater. Because materials exhibit different properties at the nanoscale than they do at larger scales, new techniques are required to understand and to exploit these new phenomena. A team of researchers led by Paul Weiss, UCLA's Fred Kavli Chair in NanoSystems Sciences, has developed a tool to study nanoscale interactions. Their device is a dual scanning tunneling and microwave-frequency probe that is capable of measuring the interactions between single molecules and the surfaces to which the molecules are attached.

Cancer scientists believe nanoparticles could accurately target tumors, avoiding side effects. Several nanoparticle drugs are now in clinical trials, and many more are being developed in research labs. These particles hold great potential to improve the performance of existing cancer drugs.

Friday, November 12, 2010

This week in nanotechnology - November 12, 2010

Low-cost, hybrid thermoelectrics: Historically, high-efficiency thermoelectrics have required high-cost, materials-intensive processing. By engineering a hybrid of soft and hard materials using straightforward flask chemistry in water, researchers at the Berkeley Lab have now developed a route that provides respectable efficiency with a low cost to production.

Andre Geim, who along with his colleague  Kostya Novoselov won the 2010 Nobel Prize for graphene, has now modified it to make fluorographene – a one-molecule-thick material chemically similar to Teflon. The team hope that fluorographene, which is a flat, crystal version of Teflon and is mechanically as strong as graphene, could be used as a thinner, lighter version of Teflon, but could also be in electronics, such as for new types of LED devices.

In other graphene news, Empa researchers have fabricated graphene-like materials using a surface chemical route and clarified in detail the corresponding reaction pathway. Understanding chemical reactions in detail helps to control them and enables to tailor graphene products.
graphene

The scanning tunnelling microscope images shows nanographene molecules and the two stabilized intermediate products on a copper surface. The molecular models show a nanographene (at the bottom right) as well as the two intermediate products (above and left). In reality the diameter of the molecule is approximately one nanometer.

Scientists at the Institute of Bioengineering and Nanotechnology in Singapore have devised a new environmentally friendly technique to transform carbon dioxide, an abundant and renewable carbon source, into highly functionalized propiolic acids, which are basic building blocks for the synthesis of a wide range of pharmaceuticals such as cholesterol-reducing drugs and peptidomimetic and other small molecule inhibitors that may be used, for example, to kill cancer cells.

Nanogenerators grow strong enough to power small conventional electronics: The nanogenerators devised in the laboratory of Zhong Lin Wang at Georgia Tech rely on the piezoelectric effect seen in crystalline materials such as zinc oxide, in which an electric charge potential is created when structures made from the material are flexed or compressed. By capturing and combining the charges from millions of these nanoscale zinc oxide wires, Wang and his research team can produce as much as three volts – and up to 300 nanoamps.

Quantum computers should be much easier to build than previously thought, because they can still work with a large number of faulty or even missing components. This surprising discovery brings scientists one step closer to designing and building real-life quantum computing systems – devices that could have enormous potential across a wide range of fields, from drug design, electronics, and even code-breaking.

A greener way to grow carbon nanotubes: It turns out that one process commonly used to produce carbon nanotubes may release several hundred tons of chemicals, including greenhouse gases and hazardous air pollutants, into the air each year. MIT researchers report that in experiments, removing one step in that process — a step that involves heating carbon-based gases and adding key reactive "ingredients" — reduced emissions of harmful by-products at least tenfold and, in some cases, by a factor of 100. It also cut the amount of energy used in the process by half.

Friday, November 5, 2010

This week in nanotechnology - November 5, 2010

Researchers at Oregon State University have solved a quest in fundamental material science that has eluded scientists since the 1960s, and could form the basis of a new approach to electronics. The discovery outlines the creation for the first time of a high-performance "metal-insulator-metal" diode. These diodes can be used to perform some of the same functions as silicon-based materials, but in a fundamentally different way.

A team of researchers at the University of Warwick has found molecular hooks on the surface of Graphene Oxide that will potentially provide massive benefits to researchers using transmission electron microscopes. They could even be used in building molecular scale mechanisms.

Scientists at Brookhaven National Laboratory and Los Alamos National Laboratory have fabricated transparent thin films capable of absorbing light and generating electric charge over a relatively large area. The material - which consists of a semiconducting polymer doped with carbon-rich fullerenes - could be used to develop transparent solar panels or even windows that absorb solar energy to generate electricity. Under carefully controlled conditions, the material self-assembles to form a reproducible pattern of micron-size hexagon-shaped cells over a relatively large area (up to several millimeters).
conjugated polymer honeycombTop: Scanning electron microscopy image and zoom of conjugated polymer (PPV) honeycomb. Bottom (left-to-right): Confocal fluorescence lifetime images of conjugated honeycomb, of polymer/fullerene honeycomb double layer and of polymer/fullerene honeycomb blend. Efficient charge transfer within the whole framework is observed in the case of polymer/fullerene honeycomb blend as a dramatic reduction in the fluorescence lifetime.

Radically simple technique developed to grow conducting polymer thin films: Oil and water don't mix, but add in some nanofibers and all bets are off. A team of UCLA chemists and engineers has developed a new method for coating large surfaces with nanofiber thin films that are both transparent and electrically conductive. Their method involves the vigorous agitation of water, dense oil and polymer nanofibers. After this solution is sufficiently agitated it spreads over virtually any surface, creating a film.

Engineers have discovered a new method to speed the production rate of nanoparticles by 500 times, an advance that could play an important role in making nanotechnology products more commercially practical. The approach uses an arrayed microchannel reactor and a "laminated architecture" in which many sheets, each with thousands of microchannels in them, are stacked in parallel to provide a high volume of production and excellent control of the processes involved.

Remember the Star Wars scene in which R2D2 projects a three-dimensional image of a troubled Princess Leia delivering a call for help to Luke Skywalker and his allies? What used to be science fiction is now close to becoming reality thanks to a breakthrough in 3D holographic imaging technology developed at the University of Arizona College of Optical Sciences.