Not surprisingly, it has been scientists in The Netherlands - a country that has long been conducting large-scale and long-term field studies on the benefits of certain plants to mental and physical health (scientists refer to this effort as the 'great coffee house smoke screen studies') - that have come up with a nanotechnology discovery that could well revolutionize many consumer products from food to toys. In a report released today, April 1, the Dutch scientists report that a nanoparticulate substance found in Cannabis sativa, also know as marijuana, has an amazing ability to kill fat cells in the human body. Hoping to ride an early wave of commercialization, the Dutch research group has already filed for patent protection and registered the trademark 'Royal Spliffmeister Edition' for a range of planned products.
The emerging field of transparent and flexible electronics not only holds the promise of a new class of device components that would be more environmentally benign than current electronics; being able to print transparent circuits on low-cost and flexible plastic substrates also opens up the possibility of a wide range of new applications, ranging from windshield displays and flexible solar cells to clear toys and artificial skins and even sensor implants. Three broad application areas for this technology are taking shape: transparent displays; flexible displays; and transparent/flexible electronics. Traditional materials used for transparent electronics include indium tin oxide films and indium oxide nanowires. In their search for materials that can offer even higher mobility and therefore even better performance, researchers have turned to single-walled carbon nanotubes .New work at the University of Southern California has now demonstrated the great potential of massively aligned single-walled carbon nanotubes for high-performance transparent electronics.
Forget boxy loudspeakers. Researchers have now found that just a piece of carbon nanotube thin film could be a practical magnet-free loudspeaker simply by applying an audio frequency current through it. These loudspeakers - which are only tens of nanometers thick, transparent, flexible, and stretchable - can be tailored into many shapes and mounted on a variety of insulating surfaces, such as room walls, ceilings, pillars, windows, flags, and clothes without area limitations. The scientists demonstrated that their CNT loudspeakers can generate sound with wide frequency range, high sound pressure level, and low total harmonic distortion. Another advantage compared to conventional loudspeakers is that the CNT loudspeakers don't vibrate and are damage tolerant. They will work even if part of the thin film is torn or damaged.
The controversy over the use of nanoparticles in everyday products, such as cosmetics, has been going on for a while now. At best, the evidence is inconclusive - it's too early to say whether there is a risk or not. The cosmetics industry of course argues that their nanoparticle-containing products are perfectly safe because no problem has been reported so far. Consumer, health and environmental groups beg to differ and claim that there is a potential risk because we just don't know enough about this issue and that we rather should err on the side of caution. The fact is, as a recent report by the European Commission's Health and Consumer Protectorate states, that at present there is inadequate information on hazard identification, exposure assessment, uptake, the role of physico-chemical parameters of nanoparticles determining absorption and transport across membranes in the gut and lungs, the role of physico-chemical parameters of nanoparticles in systemic circulation determining biokinetics and accumulation in secondary target organs, possible health effects, and translocation of nanoparticles via the placenta to the foetus. The EU report concludes that conventional risk assessment methodologies may be adequate for products that contain soluble and/or biodegradable nanoparticles but not for insoluble and/or biopersistent nanoparticles.
Lithium-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.
Our title today poses a loaded question. The cosmetics industry of course would argue that their products are already safe, whether they use nanoparticulate ingredients or not. On the other hand, there are research reports that show that nanoparticles could cause DNA damage and could accumulate in organs (with unknown consequences). It has not conclusively been proven, or disproven, that nanoparticles in cosmetics applied to the (healthy) skin are able to penetrate the skin and get into the body. Sunscreens are a good example for the pro and contra discussion about nanoparticles in cosmetics. Most people use sunscreen for two reasons: to avoid getting sunburn and to avoid getting skin cancer. If applied frequently and thoroughly, sunscreens do prevent sunburn. However, no one has ever determined that sunscreens actually prevent skin cancer. Another, mostly aesthetic, limitation with sunscreens is that they don't rub into the skin very easily. You rub, and rub, and rub, but still your skin has that pasty, white appearance. That's due to the two most common active ingredients in sunscreens - zinc oxide (ZnO) and titanium dioxide (TiO2). These inorganic materials are used in sunscreen in order to reflect UV radiation and reduce the amount of organic materials necessary to achieve a specific SPF (sun protection factor) value, but the drawback is they leave that unsightly white film. To resolve this problem, manufacturers have started using nanoparticles in place of the bulk forms of zinc oxide and titanium dioxide because the smaller particle size reduces the visibility of the cream. This could potentially mean solving one problem by creating another because TiO2 nanoparticles - a major component of photovoltaic cells - emit photoelectrons when exposed to UV light. These electrons, in turn, induce the formation of peroxides, free radicals and other reactive oxygen species (ROS) which interact with lipids and DNA, causing damage which may lead to a host of medical problems. Researchers have now found clear evidence that titanium dioxide nanoparticles catalyze DNA damage. Fortunately, they also came up with a solution - by coating them - that would allow these nanoparticles to be used with less risk in cosmetics.
Liquid crystal displays (LCD) have become an integral part of our everyday life. LCDs are everywhere, on your digital watches, cameras, iPods, laptop computers, television screens or car navigation displays. LCDs get their name from the special liquid crystal solution that is contained between two thin glass plates inside the display. Recent research findings suggest that embedding doped metal nanoparticles (MNP) in liquid crystal materials increases the performance of certain display devices. So far, however, the main problem with this approach has been that the inclusion of nanoparticles destabilizes the LC material. Researchers have now succeeded in synthesizing metal nanoparticle embedded stable liquid crystals in a single step, without using any external reducing and stabilizing agents. As a bottom-up strategy, this work is a further step towards synthesizing three-dimensional macro structures using small nanoparticles as building blocks, and an elegant method in fabricating soft organic architectures; particularly when it is combined with electronic, magnetic or photonic properties of inorganic materials.
Imagine a toothpaste that not only seeks out but actually repairs damage to tooth enamel. For those who dread their annual visit to the dentist, this may sound like science fiction. For people in Japan, it is a reality. Using nanoparticles, Japan's Sangi Company, Ltd., has sold more than 50 million tubes - and continues to expand its line of products containing nanoparticles. Scientists have learned to synthesize hydroxyapatite, a key component of tooth enamel, as nanosized crystals. When nano-hydroxyapatite is used in toothpaste, it forms a protective film on tooth enamel, and even restores the surface in damaged areas. Availability of similar products that claim to actually repair cavities is just around the corner. Unlikely as it seems at first blush, the $200 billion global cosmetics industry is one of the major players in the emerging field of nanotechnology. According to the Centre for the Study of Environmental Change at Lancaster University in Britain, the cosmetics industry already holds the largest number of patents for nanoparticles - and be it toothpaste, sunscreen, shampoo, hair conditioner, lipstick, eye shadow, after shave, moisturizer or deodorant, the industry is leading the way.