Showing Spotlights 993 - 1000 of 2140 in category (newest first):
Until more information becomes available on the mechanisms underlying nanomaterial toxicity, it is uncertain what measurement technique should be used to monitor exposures in the workplace. Many of the sampling techniques that are available for measuring airborne nano aerosols vary in complexity but can provide useful information for evaluating occupational exposures with respect to particle size, mass, surface area, number concentration, and composition. Unfortunately, relatively few of these techniques are readily applicable to routine exposure monitoring. That's why researchers have now developed a unique new sampler design that collects nanoparticles separately from larger particles in a way that mimics the respiratory system.
Aug 4th, 2011
Exotic artificial composite materials called metamaterials can be engineered with certain electromagnetic properties that allows them to act as invisibility cloaks. These materials bend all light or other electromagnetic waves around an object hidden inside a metamaterial cloak, to emerge on the other side as if they had passed through an empty volume of space. Researchers have already been experimenting with cloaking devices for various, usually longer wavelengths such as microwave or infrared waves. Recently, even graphene has been added to the family of cloaking materials. Now, for the first time, a team of scientists at UC Berkeley have devised an invisibility cloak material that hides objects from detection using light that is visible to humans.
Aug 3rd, 2011
Structural color - where the color results from interferences, not pigments - is a natural fit for new display technologies and writing substrates since it can provide vivid colors in environments of high intensity light (e.g. sunlight) without the need for additional illuminating power. Most existing display technologies such as LCDs and LEDs require power to actively project colors and often suffer from performance degradations in these reflective environments. Recognizing this, researchers have developed a number of techniques for dynamically and spatially modulating the colors reflected off of photonic crystal-like substrates. In new work, researchers have demonstrated an electrical-power-free infusion technique that allows them to draw multi-color images on colloidal photonic crystal substrates using transparent imaging oils.
Aug 2nd, 2011
Using single molecules as electronic components like diodes, switches or transistors is the ultimate goal for future electronic nanotechnology devices. In order to explore the electronic properties of a single molecule, researchers have to make electrical contact between electrodes and molecules - and this has proven to be a big challenge. Though many efforts have been made to realize single-molecule electronics, it is still impossible to fabricate a practical single-molecule integrated circuit. One of the problems is the lack of viable methods for wiring each functional molecule. Researchers have now demonstrated a novel method for controlling single molecule chemical reactions - a kind of 'chemical soldering'.
Jul 28th, 2011
Single-molecule magnets (SMM) are fascinating nanoscale structures with unique functional properties showing promise for high-density electronic data storage devices, solid state quantum computers, spintronic devices such as spin valves, and other advanced technological applications. Despite a flurry of research in this area - since an individual magnetic molecule represents the ultimate size limit to storing and processing information - the main challenge related to harnessing properties of SMM remained unsolved. A new study by a group of European researchers reports the successful encapsulation of single-molecule magnets in carbon nanotubes, yielding a new type of hybrid nanostructure that combines all the key single-molecule magnet properties of the guest molecules with the functional properties of the host CNT.
Jul 27th, 2011
To build microprocessors with more than one billion transistors, manufacturers still use the same technique - photolithography, the high-tech, nanoscale version of printing technology - that they have been using for the past 50 years. State-of-the-art photolithography processes use 193 nm light to produce diffraction-limited features as small as 32 nm. Going beyond 32 nm, the cost and complexity rises significantly, posing massive technological and economic challenges for chip manufacturers. This provides plenty of incentives for researchers to explore alternative manufacturing technologies for chipmakers. One novel approach is based on the use of DNA nanostructures to pattern a silicon wafer.
Jul 26th, 2011
Surface energy is ubiquitous in nature and it plays an important role in many scientific areas such as for instance surface physics, biophysics, surface chemistry, or catalysis. Prior to the area of nanotechnology it has been impractical to consider utilizing surface energy as an energy source because there are few molecules or atoms involved in the surface interaction and the density of surface energy is low. Now, however, due to the lower power consumption requirements of nanoscale devices and the higher specific surface area for nanomaterials it appears attractive to use surface energy at the nanoscale. In new work, researchers have investigated how the flow of water over surfaces coated with graphene could generate small amounts of electricity.
Jul 25th, 2011
Integrating biological molecules or even complex molecular machines with man-made nanoelectronic devices is one of the ultimate goals of bionanotechnology. Already there is a growing community of researchers interested in this area of bio/nano integration where biological components are interfaced with inorganic nanomaterials to create new devices and systems that combine the desirable properties of each system. One particular nanomaterial used in this kind of research are carbon nanotubes (CNTs). Scientists now report the integration of a CNT transistor with olfactory receptor proteins. The ultimate goal of this type of research is to transfer the sensing properties of biological molecular systems to artificial electronic devices.
Jul 21st, 2011