Showing Spotlights 1689 - 1696 of 2382 in category All (newest first):
The hydrogen that will power tomorrow's cars is not a naturally occurring resource that can be tapped by drilling a hole in the ground. Hydrogen has to be produced, and that can be done using a variety of resources. The cleanest by far of course would be renewable energy electrolysis: using electricity to split water into hydrogen and oxygen; this electricity could be generated using renewable energy technologies such as wind, solar, geo- and hydrothermal power. As it stands, most of today's hydrogen production is 'dirty' - it is produced from methane in natural gas using high-temperature steam in what is called steam methane reforming. Many research groups around the world are working hard on developing cheap, clean and efficient technologies to produce hydrogen from water, particularly using sunlight (artificial photosynthesis). This would be the ultimate clean, renewable and abundant energy source. However, to become commercially viable, fuel cells have to overcome the barrier of high catalyst cost caused by the exclusive use of expensive platinum and platinum-based catalysts in the fuel-cell electrodes - the reason is that platinum is the most efficient electrocatalyst for accelerating chemical reactions in fuel cells. Scientists have found that platinum catalysts can be replaced with bacteria-produced hydrogenase enzymes that have nickel and iron in their active sites.
Dec 10th, 2008
The performance of devices like organic light emitting diodes (OLEDs), flexible solar cells, or plastic electronics is sensitive to moisture because water and oxygen molecules seep past the protective plastic layer over time and degrade the organic materials which form the core of these products. To protect these sensitive devices, barrier technologies have been developed that protect them from environmental degradation. State-of-the-art barrier materials employ metal oxide thin films, commonly from aluminum or silicon oxides, which provide excellent protection from atmospheric oxygen and water, but still suffer from problems. A new study demonstrates a nanocomposite material that can initiate self-healing upon the influx of water through pores and cracks by delivering titanium dioxide nanoparticles to the defective site, which ultimately slows the rate of moisture diffusion to the reactive electronic device.
Dec 9th, 2008
When it comes to nanotechnologies, Americans have a big problem: Nanotechnology and its capacity to alter the fundamentals of nature, it seems, are failing the moral litmus test of religion. Survey results from the United States and Europe reveal a sharp contrast in the perception that nanotechnology is morally acceptable. Those views, according to the report, correlate directly with aggregate levels of religious views in each country surveyed. In the United States and a few European countries where religion plays a larger role in everyday life, notably Italy, Austria and Ireland, nanotechnology and its potential to alter living organisms or even inspire synthetic life is perceived as less morally acceptable. In more secular European societies, such as those in France and Germany, individuals are much less likely to view nanotechnology through the prism of religion and find it ethically suspect.
Dec 8th, 2008
This week's successful international nanotechnology forum Rusnanotech in Moscow has put a spotlight on Russia's ambitions to catch up with the leading nanotechnology nations. While Russia has the money, the political will, and a well educated scientific base to be a leading player, it has completely missed the boat on developing its nanoscience programs and nanotechnology infrastructure. In terms of gross domestic product, Russia ranks as the eleventh largest economy in the world. But while many smaller countries such as Australia or South Korea, not to mention all of the bigger nations, have invested steadily and broadly in all areas of nanosciences and nanotechnologies for years now, Russia has had no coordinated science policy, no industrial policy, and no commercial industrial base to develop its nanotechnology capabilities. Until last year, that is. In April 2007, the Russian president signed off on a public policy paper that ordered a multi-billion dollar program to develop a world-class Russian nanotechnology industry by 2015.
Dec 5th, 2008
Scientists are intensely researching how animals like spiders and geckos generate the high adhesion force that allows them to cling to walls and walk on ceilings, feet over their head. While this research so far has focused on novel materials like carbon nanotubes to replicate spider feet and gecko toes, a key challenge for materials engineers is the scaling up of such materials from small animals to, say, spiderman gloves that support a fully grown human. Complementing the ongoing gecko biomimetic materials research, Nicola M. Pugno, an Associate Professor of Structural Mechanics at the Politecnico di Torino in Italy, has developed what he termed Adhesive Optimization Laws.
Dec 3rd, 2008
Miniaturizing traditional laboratory assays to automated lab-on-a-chip devices holds tremendous potential for enabling multiplex, efficient, cost-effective and accurate pathogen sensing systems for both security and medical applications. These sensors could be used to detect bacteria such as E. coli and Salmonella, but also other pathogens that could be used for bioterrorism. Traditional identification methods required time intensive cell culturing processes but novel pathogen sensors based on nanomaterials are promising vastly improved and speedy detection technologies. A recent example is a label-free sensor chip assembled from peptide nanotubes that enables the electrical detection of viruses with an extremely low detection limit. This could lead to compact super-sensitive pathogen detection chips for point of care applications that have a high tolerance against false-positive signals.
Dec 2nd, 2008
Advances in micro- and nanoscale engineering have led to various mobile devices that either can move on solids or swim in fluids. Researchers are applying various strategies to designing nanoscale propulsion systems by either using or copying biological systems such as the flagellar motors of bacteria or by employing various chemical reactions. Many of these approaches are fairly complex and not necessarily suited for large-scale deployment in practical applications. Scientists have theorized about simpler designs for mechanical swimmers that avoid the complexities of biological mechanisms and use very few degrees of freedom.
Researchers in Spain have now demonstrated the experimental realization of a simple device made by microscopic colloidal particles which can be externally controlled and propelled at low Reynolds number condition, i.e. when the viscosity of the fluid dominates over the inertia of the object. This is the same condition that governs the motion of bacteria such as E. Coli or other micro- or nanoscale objects that move in a fluid.
Dec 1st, 2008
Nanotechnology researchers are actively working on the beginnings of various nanorobotic systems that one day could lead to automated, assembly-line type nanofabrication processes. Last year we reported on a nanogripper, a kind of a robotic 'hand' some ten thousand times smaller than a human hand. This 'pick-and-place' device used a silicon gripper which was controlled by a nanorobotic arm and was capable of picking up a carbon nanofiber and fix it onto the tip of an atomic force microscope cantilever. One of the problems that is vexing researchers is that the nanoscale miniaturization of these grippers comes at the cost of reduced strength - the smaller the gripper, the weaker it becomes. Therefore what is needed is a gripper design that is strong enough yet sufficient flexible and small to handle tough materials like carbon nanotubes.
Nov 26th, 2008