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Nanotechnology Spotlight

Behind the buzz and beyond the hype:
Our Nanowerk-exclusive feature articles

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Showing Spotlights 1433 - 1440 of 1672 in category All (newest first):


Nanotechnology food coming to a fridge near you

The potential benefits of Nanofoods - foods produced using nanotechnology - are astonishing. Advocates of the technology promise improved food processing, packaging and safety; enhanced flavor and nutrition; 'functional foods' where everyday foods carry medicines and supplements, and increased production and cost-effectiveness. In a world where thousands of people starve each day, increased production alone is enough to warrant worldwide support. For the past few years, the food industry has been investing millions of dollars in nanotechnology research and development. Some of the world's largest food manufacturers, including Nestle, Altria, H.J. Heinz and Unilever, are blazing the trail, while hundreds of smaller companies follow their lead. Yet, despite the potential benefits, compared with other nanotechnology arenas, nanofoods don't get a lot of publicity. The ongoing debate over nanofood safety and regulations has slowed the introduction of nanofood products, but research and development continue to thrive - though, interestingly, most of the larger companies are keeping their activities quiet (when you search for the term 'nano' or nanotechnology' on the websites of Kraft, Nestle, Heinz and Altria you get exactly zero results). Although the risks associated with nanotechnology in other areas, such as cosmetics and medicine, are equally blurry, it seems the difference is that the public is far less apt to jump on the nanotechnology bandwagon when it comes to their food supply.

Posted: Dec 28th, 2006

Real-time chemical warfare sensors built with nanotechnology

As their name suggests, nerve agents attack the nervous system of the human body. All such agents function the same way: by interrupting the breakdown of the neurotransmitters that signal muscles to contract, preventing them from relaxing. Nerve agents, depending on their purity, are clear and colorless or slightly colored liquids and may have no odor or a faint, sweetish smell. They evaporate at various rates and are denser than air, so they accumulate in low areas. Nerve agents include tabun(GA), sarin(GB), soman(GD), and VX. The military has a number of devices to detect nerve agent vapor and liquid. Current methods to detect nerve agents include surface acoustic wave (SAW) sensors, conducting polymer arrays, vector machines, and the most simple, color change paper sensors. Most of these systems have have certain limitations including low sensitivity and slow response times. By using readily synthesized network films of single-walled carbon nanotube bundles researchers have built a sensor capable of detecting G-series nerve agents such as Soman and Sarin (Sarin was used in the Tokyo subway terrorist attack in 1995). This research opens new opportunities in the design of real-time chemical warfare agent (CWA) sensors with independent response signatures.

Posted: Jan 29th, 2007

Metallic glass promises to become a useful material for nanotechnology fabrication

Micro-and/or nano-electromechanical systems (MEMS/NEMS) are the basis of future nanotechnology, because they combine miniature sensors and actuators with electronics. The selection of appropriate materials for MEMS/NEMS fabrication is based on the careful consideration of a material's properties with regard to its intended application. For example, many MEMS devices, such as pressure, chemical and bio sensors, rely on actuation of a membrane structure and require a high fracture toughness material for the enhanced durability and shock resistance. On the other hand, for fabrication of controlled nanostructures, the material should be machinable up to atomic level. Currently, the materials used for MEMS/NEMS fabrication are based on silicon or oxides, which are brittle and have size effects such as lattice defects, anisotropy, grains and grain boundaries. These effects are the limiting factors in the reduction of pattern size, especially when a dimension of the pattern approaches a few tenths of a nanometer. Researchers in Japan now have introduced zirconium-based glass thin films for the fabrication of 3D micro- and nanostructures. These materials exhibit excellent micro/nano-formability under very low stresses, and are expected to become one of the most useful materials for fabricating NEMS/MEMS devices.

Posted: Jan 26th, 2007

Investing in nanotechnology stocks - golden opportunity or bad idea?

There seem to be an increasing number of websites, articles and investment reports that push, some might say hype, nanotechnology stocks as the next stock market super growth area. On the other hand, some investors are wary of a nanotechnology boom, where too much money chases too few listed companies, turning into a bust. Hype usually involves a bit of underlying truth about a trend but says nothing about whether something is going to be a good investment. As the International Herald Tribune put it: "While nanotechnology is spurring a revolution in electronics and medicine, investors seeking to benefit may need a lot of luck, as they did during the Internet bubble of the 1990s." The current interest in nanotech stocks is driven by the many advances that nanoscience and nanotechnology promise. The commercial realization of most of these promises lies in the (some say near, some say distant) future; things like quantum computing, molecular electronics, or lab-on-a chip medicine. In its current state, nanotechnology to a large degree takes place in labs and there is only a trickle of products coming to the market. All of these products are incremental improvements of existing products - scratch-resistant paint, better engine oil, antimicrobial household products, smaller chips, improved cosmetics, etc. What we are seeing right now is the beginning of a large technological trend and a stock buyer has to understand the difference between the many promises of nano- technologies, the research taking place today, and the actual contribution of nanotechnologies to commercial products. Let's look at a few facts that might give some perspective on what investing in nanotechnology stocks today is about - how has the market performed so far? what exactly is a "nanotechnology stock"? and the issue with these trillion dollar market size forecasts.

Posted: Jan 25th, 2007

Size-based sorting and manipulation of nanoparticles becomes possible

The precise positioning of nanoparticles on surfaces is key to most nano- technology applications especially molecular electronics. However, for automated patterning of particles, existing methods are either slow (e.g., dip-pen lithography) or require prefabricated patterns (e.g., by electrostatic positioning or by successive self-assembly, transfer, and integration). Moreover, the sorting of differently sized particles, organelles, and cells in microfluidic networks is important for many biological and medical applications. Purely size-based sorting would offer the greatest control, but an automated method so far does not exist. Researchers in Switzerland now have discovered that acoustic streaming leads to sorting of particles dependent on their size. Nanoparticles aggregate at the antinodes and micrometer-sized particles aggregate on the nodes of oscillation patterns on micro- machined cantilevers. These surprising results open new possibilities for the sorting of nanoparticles.

Posted: Jan 24th, 2007

Self-heating nanoparticles as tumor-destroying hyperthermia agents

Hyperthermia therapy, a form of cancer treatment with elevated temperature in the range of 41-45C, has been recently paid considerable attention because it is expected to significantly reduce clinical side effects compared to chemotherapy and radiotherapy and can be effectively used for killing localized or deeply seated cancer tumors. Accordingly, various forms of hyperthermia have been intensively developed for the past few decades to provide cancer clinics with more effective and advanced cancer therapy techniques. However, in spite of the enormous efforts, all the hyperthermia techniques introduced so far were found to be not effective for completely treating cancer tumors. The low heating temperature owing to the heat loss through a relatively big space gap formed between targeted cells and hyperthermia agents caused by the hard to control agent transport, as well as killing healthy cells attributed to the difficulties of cell differentiations by hyperthermia agents, are considered as the main responsibilities for the undesirable achievements. In a possible breakthrough, researchers in Singapore now report the very promising and successful self-heating temperature rising characteristics of NiFe2O4 nanoparticles. Different from conventional magnetic hyperthermia, in-vivo magnetic nanoparticle hyperthermia is expected to be one of the best solutions for killing tumor cells which are deeply seated and localized inside the human body.

Posted: Jan 23rd, 2007

Nanowire growth through ion beams

Nanowires are expected to play an important role in the emerging fields of nanoelectronics and nanooptics. In particular, the permanently growing complexity of integrated circuit designs requires a further reduction of the size of IC components that nanowires could facilitate. Nanowires are also a possible candidate for future functional nanostructures in plasmonic devices, i.e. for information (light) propagation and manipulation below the optical diffraction limit. For these purposes, cobalt disilicide (CoSi2) is a very promising contact material due to its extremely useful properties such as low resistance, its metallic behavior, its low lattice mismatch to Si of only -1.2%. the plasmon wavelength of 1.2 micrometer, and its compatibility with modern silicon technology. Many efforts have been made to fabricate silicide nanowires employing the bottom-up approach without elaborate microlithography. Researchers in Germany now have demonstrated a promising technique that allows the defect-induced formation and placing of cobalt disilicide nanowires by focused ion beam synthesis in silicon directly where it is needed.

Posted: Jan 22nd, 2007

Nanotechnology risks: Clear indications that carbon-based nanomaterials are toxic

The discovery of numerous nanomaterials has added a new dimension to the rapid development of nanotechnology. Consequently, the professional and public exposure to nanomaterials is supposed to increase dramatically in the coming years. Especially, carbon-based nanomaterials (CBNs) are currently considered to be one of the key elements in nanotechnology. Their potential applications range from biomedicine through nanoelectronics to mechanical engineering. Thus, it is primordial to know the health hazards related to their exposure. As the public calls for safety studies get louder more and more researchers begin to study the potential toxicity of nanomaterials. Especially carbon-based nanomaterials, due to their numerous and wide-ranging applications and increasing real life usage, get nanotoxicological attention. Scientists in Switzerland studied the toxicity of carbon- based nanomaterials (nanotubes, nanofibers and nanowires) as a function of their aspect ratio and surface chemistry. Their work clearly indicates that these materials are toxic while the hazardous effect is size-dependent.

Posted: Jan 19th, 2007