Showing Spotlights 1177 - 1184 of 2140 in category (newest first):
Electron pumps are devices that can transfer a certain number of electrons during each pumping cycle. Besides being of fundamental interest to physicists, single-electron pumps have a potential for practical application in metrology, acting as an accurate frequency-current converter. The general goal of this field is to build a current standard based on the electrical charge of a single electron in order to achieve high accuracy for current measurement. A device called single-electron transistor (SET) can confine charges down to single electron level and hence is applicable for quantized current generation. Attempts to generate quantized current in nanotubes have been made with various methods over the past few years, but were not very successful in obtaining a high degree of current quantization. A research team in Germany has now demonstrated the feasibility of using a single molecule - in this case, a single-walled carbon nanotube - for the generation of quantized electric current.
Sep 9th, 2010
Single-walled carbon nanotube (SWCNT) based thin film transistors (TFTs) could be at the core of next-generation flexible electronics - displays, electronic circuits, sensors, memory chips, and other applications that are transitioning from rigid substrates, such as silicon and glass, to flexible substrates. What's holding back commercial applications is that industrial-type manufacturing of large scale SWCNT-based nanoelectronic devices isn't practical yet because controlling the morphology of single-walled carbon nanotubes is still causing headaches for materials engineers. In an effort to develop a new and effective solution process of isolated SWCNTs, researchers in Japan have now demonstrated a novel solution process to fabricate high-performance TFTs of individual SWCNTs using DNA.
Sep 7th, 2010
Unlike most biological membranes, polymeric, nanometer-thin membranes are very stable and can withstand considerable pressure. This is an essential requirements for separation processes such as in water purification and desalination. Because their mechanical stability can be combined with flexibility and chemical functionality, polymer nanomembranes are also intensely researchers as materials for actuators and microsensors. They have also entered the biomedical field as artificial nacre and as a novel material used in surgery. Crosslinking of a spin-coated precursor solution, a common fabrication technique, reduces the interactions between the polymer chains and the environment and thus impairs the sensitivity and flexibility of the films. Researchers in Germany have now developed the first freestanding polymer brush, grafted from a crosslinked monolayer (nanosheet) that provides mechanical stability and structural integrity.
Sep 2nd, 2010
Australian researchers have introduced the Nanopatch - a new way of delivering vaccines to the skin and potentially a safer, cheaper alternative to traditional needle vaccines. The Nanopatch comprises arrays of densely packed projections with a defined geometry and distribution designed to physically target vaccines directly to thousands of epidermal and dermal antigen presenting cells. These miniaturized arrays are two orders of magnitude smaller than standard needles and are also much smaller than current microneedle arrays. The core idea is to achieve improved vaccine efficiency and effectiveness - over the needle and syringe - through precise targeting of vaccines to skin strata, achieved by device miniaturization utilizing micro- and nanotechnologies.
Aug 31st, 2010
Improvements in the design of medical equipment for better streamlined functionality and performance is influenced by a number of critical factors. The research, design, modeling, testing, prototyping, and FDA and EU approvals of new mechatronic devices, or the integration of changes to existing designs, usually represents a sizable capital investment of resources well before the equipment goes into serial production. Factored into the medical device's product development are considerations such as size of the equipment, speed of operation, heat generation, portability, handling of static or kinetic loads, power sources, measuring systems, vacuum and nonmagnetic requirements, sensors, machine controls, component part wear and diagnostics. A key impetus for medical and bioresearch companies to engage upon these involved product development cycles is the opportunity to capitalize on advances in technology for the manufacture of better operating, lower cost and more efficient equipment and devices.
Aug 27th, 2010
Various nanotechnologies are being researched for applications in water treatment because the removal of bacteria and other organisms from water is an extremely important process, not only for drinking and sanitation but also industrially as biofouling is a commonplace and serious problem. In what could be developed as a a cheap point-of-use water filter for deactivating pathogens in water, or as a new component to be integrated into existing filtration systems to kill microorganisms which cause biofouling in downstream filters, researchers have now demonstrated a textile based device for the high speed electrical sterilization of water. They came up with a new strategy for taking advantage of silver nanowires' and carbon nanotubes' unique ability to form complex multiscale coatings on cotton to produce an electrically conducting and high surface area device for the active, high-throughput inactivation of bacteria in water.
Aug 26th, 2010
Along with control of fire, iron smelting is one of the founding technological pillars of civilization. Industry has used the same basic process to make iron for over 3000 years. Yet, it is also one of the major global sources of greenhouse gas release. Iron, a basic commodity, is still produced by the greenhouse gas intensive reduction of iron oxide by carbon-coke and currently accounts for the release of one quarter of worldwide carbon dioxide emissions by industry. For instance, on average 1.9 tonnes of carbon dioxide are emitted for every tonne of steel produced. Due to a large share of coal in the energy mix of current production technology, the CO2 emissions are high. Through a new understanding of the chemistry of iron at high temperature, researchers have uncovered an effective new carbon-dioxide-free process to form iron.
Aug 25th, 2010
Most of today's lithium-ion batteries rely on anodes made from graphite, a form of carbon. There are several candidate electrodes to replace graphite as the anode for lithium-ion batteries. Such electrodes like silicon or tin have very high capacities but suffer from poor efficiency and cyclic stability as they experience large volume change and particle pulverization during repeated cycling. Silicon-based anodes, for instance, theoretically offer as much as a ten-fold capacity improvement over graphite, but silicon-based anodes have so far not been stable enough for practical use. Researchers have now used the macromolecular structure of self-assembled Tobacco mosaic virus as templates to fabricate stable three-dimensional current collectors for high power and high energy density Li-ion batteries.
Aug 24th, 2010