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Nanotechnology Spotlight

Behind the buzz and beyond the hype:
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Showing Spotlights 1249 - 1256 of 1779 in category (newest first):

 

Producing isolated nanocrystalline diamond fibers at high growth rates

diamond-coated_nanowireDiamonds have been known in India for at least 3000 years and are thought to have been first recognized and mined there. The most familiar usage of diamonds today is as gemstones in jewelry but, apart from being a girl's best friend, it seems that diamonds, especially nanodiamonds, are quickly becoming a scientist's best friend as well. Diamonds are the hardest natural material - the word diamond comes from the Greek term adamas, which means 'invincible' - has the lowest coefficient of thermal conductivity, is electrically insulating, chemically inert, and optically transparent. In nanoparticulate form, diamonds possess an additional property that makes them so interesting for researchers: since they are carbon-based and non-toxic they are a suitable material for drug delivery, drug diagnostics and medical imaging applications. One of the challenges in fabricating nanodiamond coatings and composite materials is the difficulty of controlling the size, texture, and crystalline quality of the diamond particles. Now, researchers in Portugal have demonstrated for the first time the facile fabrication and the conformal coating of nanocrystalline diamond onto silica nanofibers by a two-step method: synthesis of templates on silicon wafer; and coating of the silica fibers with nanocrystalline diamond.

Posted: Apr 8th, 2008

Using nanotechnology to improve Li-ion battery performance

silicon_dioxide_nanospheresLithium-ion batteries seem to be everywhere these days. They power most of the electronic devices we carry around with us - cell phones, laptops, MP3 players, digital cameras and so on. They get their name from the lithium ion that moves from the anode to the cathode during discharge and from the cathode to the anode during recharging. Due to their good energy-to-weight ratios, lithium batteries are some of the most energetic rechargeable batteries available today. In terms of weight and size, batteries have become one of the limiting factors in the continuous process of developing smaller and higher performance electronic devices. To meet the demand for batteries having higher energy density and improved cycle characteristics, researchers have been making tremendous efforts to develop new electrode materials or design new structures of electrode materials. Demonstrating the benefits of directed nanostructure-design of electrode materials, Chinese scientists have prepared tin nanoparticles encapsulated in elastic hollow carbon spheres. This tin-based nanocomposite exhibits a very high specific capacity, excellent cycling performance, and therefore shows great potential as anode materials in lithium-ion batteries.

Posted: Apr 7th, 2008

A role for nanotechnology in capturing and storing greenhouse gases

cnt_capture_of_greenhouse_gasThe greenhouse effect is primarily a function of the concentration of water vapor, carbon dioxide, and other trace gases in the Earth's atmosphere that absorb the terrestrial radiation leaving the surface of the Earth. Changes in the atmospheric concentrations of these greenhouse gases can alter the balance of energy transfers between the atmosphere, space, land, and the oceans. The capture and storage of greenhouse gases could play a significant role in reducing the release of greenhouse gases into the atmosphere (read more about capture and storage of carbon dioxide here). Carbon dioxide (CO2) is the most important greenhouse gas and captures the limelight in most reports on global warming. While other greenhouse gases make up less of the atmosphere, they account for about 40 percent of the greenhouse gas radiation sent back to Earth. They can also be much more efficient at absorbing and re-emitting radiation than carbon dioxide, so they are small but important elements in the equation. In fact, molecule-for-molecule some gases containing lots of fluorine are 10,000 times stronger at absorbing radiation than carbon dioxide. A new systematic computational study shows an interesting approach of how nanotechnology, in this case the use of carbon nanotubes and other nanomaterials, could lead to effective filters for the capture and storage of greenhouse gases.

Posted: Apr 4th, 2008

Extremely sensitive protein detection with quantum dot self-assemblies

Quantum_Dot_SelfAssembly_for_Protein_DetectionIn proteomics research, the study of the structure and function of proteins, chemical as well as physical methods are used to detect proteins. Physical methods are mostly applied after chromatography. They are either based on spectroscopy like light absorption at certain wavelengths or mass determination of peptides and their fragments with mass spectrometry. Chemical methods are used after two-dimensional electrophoresis and employ staining with organic dyes, metal chelates, fluorescent dyes, complexing with silver, or pre-labeling with fluorophores. What these various methods have in common is that they are not very fast, can be expensive, sometimes don't offer the sensitivity required, and are not always easy to handle. Since protein detection can be a powerful tool for diagnosing, prognosing, and monitoring cancers and other medical conditions, researchers are working towards developing detection platforms that can multiple specific molecules from the complex mixture present in serum, and is rapid, sensitive, and simple to administer. Researchers now have demonstrated a simple and rapid way of detecting proteins of interest using nanoparticles. This single step reaction starts with nanoparticle-antibody conjugates that form large aggregates if the intended protein molecules are present in the solution. The large aggregates can be characterized individually by laser scattering and fluorescence.

Posted: Apr 3rd, 2008

Using molecules as processable semiconductors

printed_electronicsThe most common type of modern transistor, and the type of transistor used in integrated circuits, is called a field-effect transistor (FET). The FET is so named because it relies on an electric field to control the shape and hence the conductivity of a 'channel' (the charge carrier) in a semiconductor material. This field causes a second electrical current to flow across the semiconductor, identical to the first weak signal, but stronger. Since the invention of the first transistor in 1947, the vast majority of electronic devices have been based on inorganic semiconductors, which in most cases has been silicon. Due to the demand for lightweight, flexible opto-electronic devices such as displays, solar cells and lasers, organic materials have become an important new class of semiconductor as they combine the virtues of plastics, which can be easily shaped, with those of semiconductors which are the basis of all microelectronics. Organic field-effect transistors (OFETs) have been mainly based on two types of semiconductors: conjugated polymers and small conjugated molecules. A recent review, published in Chemical Society Reviews, provides a general introduction about the current standing in the area of OFETs focusing on the new processable small molecules that have been recently reported for their use as organic semiconductors.

Posted: Apr 2nd, 2008

Newly formed Nanotechnology Protection Agency (NPA) to regulate molecular assemblers

nanofactoryThe newly created U.S. Nanotechnology Protection Agency (NPA) announced today, April 1, 2008, that, effective immediately, all laboratories and production facilities for molecular assemblers (commonly called nanobots) need a special license and have to follow strict guidelines in all research and production facilities that deal with nanoassemblers. At the same time, the NPA declared gray goo a hazardous substance. While the NPA regulations will have an immediate economic impact on many nanotechnology companies, most have been preparing for this dreaded day. However, public and media reactions seem to indicate that the public and many organizations were taken completely by surprise.

Posted: Apr 1st, 2008

Ivy's gripping nanotechnology secrete

ivyYou probably have seen quite a number of research reports on the amazing climbing abilities of geckos. Here at Nanowerk, we ran several Spotlights on this topic, for instance on mimicking gecko toe structures to fabricate super-strong dry adhesives. One demonstration of so-called 'gecko tape' has already been used in building Stickybot, a quadruped robot capable of climbing smooth vertical surfaces, such as glass, acrylic and whiteboard. In addition to the animal kingdom, scientists have started looking at plants to identify biological climbing mechanisms that could be exploited for engineering applications. One obvious candidate is ivy, a climbing woody plant. Researchers now have found that ivy secretes nanoparticles which allow the plant to affix to a surface and play an important role in the plant's climbing capability. This ivy secretion mechanism may inspire new, 'green' methods for synthesizing nanoparticles biologically or new approaches to adhesion mechanisms for mechanical devices.

Posted: Mar 31st, 2008

Nanotechnology manufacturing key to industrialized countries' future competitiveness

nanomanufacturingAn Interagency Working Group on Manufacturing Research and Development established by the National Science and Technology Council has identified three technology areas as key research and development priorities for future manufacturing: Manufacturing for Hydrogen Technologies; Nanomanufacturing; and Intelligent and Integrated Manufacturing. The Working Group summarized their findings in a new report titled 'Manufacturing the Future.' Although this report is specific to the U.S., most of its general conclusions and recommendations apply to most other industrialized nations and their industrial nanotechnology efforts as well. Nanotechnology is viewed throughout the world as a critical driver of future economic growth and as a means to addressing some of humanity's most vexing challenges. Because of its broad range of prospective uses, nanotechnology has the potential to impact virtually every industry, from aerospace and energy to healthcare and agriculture. Nanomanufacturing integrates science and engineering knowledge and develops new processes and systems to assure quality nanomaterials, to control the assembly of molecular-scale elements, and to predictably incorporate nanoscale elements into nano-, micro-, and macroscale products utilizing new design methods and tools. Efforts in this area are directed toward enabling the mass production of reliable and affordable nanoscale materials, structures, devices, and systems. Nanomanufacturing includes the integration of ultra-miniaturized top-down processes and evolving bottom-up or self-assembly processes.

Posted: Mar 28th, 2008