Quite a lot of nanotechnology research and manufacturing efforts go into synthesizing metal-based nanoparticles. Unfortunately, some of the nanoparticle manufacturing processes themselves as well as the final nanoparticle materials may be of potential concern for environmental regulators and for researchers attempting to address nanomaterial toxicity. As an alternative to using these potentially hazardous metal-based nanoparticles, some researchers are suggesting the use of naturally occurring nanoparticles. However, this area has not yet been well explored with regard to natural nanoparticles' diverse properties and potential applications. Researchers have now made the discovery that naturally occurring nanoparticles have unique optical properties. In addition, they are less toxic and biodegradable than their synthesized, metal-based counterparts. This discovery makes it likely that scientists will be able to find more biocompatible nanoparticles to replace metal-based nanoparticles, predominantly for biomedical applications.
With all the buzz that is being created by portable e-book readers, it's worth taking a look at one of the advanced display technologies - also often referred to as electronic paper - that make these devices happen. Unlike a conventional flat panel display, which uses a power-consuming backlight to illuminate its pixels, electronic paper reflects light like ordinary paper and is capable of holding text and images indefinitely without drawing electricity, while allowing the image to be changed later. Because they can be produced on thin, flexible substrates an due to their paper-like appearance, electrophoretic displays are considered prime examples of the electronic paper category. Electrophoretic displays already are in commercial use, for instance in the Kindle or in the Sony Reader, but so far the displays are mostly black and white. There are still cost and quality issues with color displays. New work by researchers in South Korea shows that organic ink nanoparticles could provide an improved electronic ink fabrication technology resulting in e-paper with high brightness, good contrast ratio, and lower manufacturing cost.
One important aspect of clothing comfort is thermo-physiological comfort. By adjusting the transport of heat and moisture through a fabric, thermo-physiological comfort can keep people comfortable with regard to temperature and moisture. Some hydrophobic fabrics have deficiencies in this area. Take wool. Wool is one of the best insulating fibers known to man - while at the same time being light and soft. The quality that distinguishes wool fibers is the presence of a fatty, water-repellent outer layer that surrounds each fiber. Therefore, the water absorption and sweat venting properties of wool fiber are not very good, which affects the wearing comfort of wool textiles. The wool hydrophobic surface layer is also a barrier to anticrease finishing, dyeing, and grafting of hydrophilic agents, which is an issue in trying to add smart functionalities to wool fabrics.
Researchers have now developed a simple method for fabricating environmentally stable superhydrophilic wool fabrics. They applied silica sols to natural wool fibers to form an ultrathin layer on the surface of the fibers.
OLEDs - organic light-emitting diodes - are full of promise for a range of practical applications. With more efficient and cheaper OLED technologies it becomes possible to make ultraflat, very bright and power-saving OLED televisions, windows that could be used as light source at night, and large-scale organic solar cells. One of the drawbacks of this technology, apart from its currently high manufacturing cost, are problems with the OLED fabrication process where issues such as material damage, yield, and thickness uniformity haven't been completely solved yet. Researchers in Japan have now proposed a nanoparticle-based deposition method that might be able to overcome these fabrication problems.
Most products today are defined as 'nanotechnology product' because they contain nanoparticles in some form or other. For instance, many antimicrobial coatings contain silver in nanoscale form; food products and cosmetics contain nanoparticles; drug formulations are made with nanoscale ingredients; and some products are partially made with composite materials containing nanomaterials (e.g. carbon nanotubes or carbon nanofibers) to mechanically strengthen the material. Two researchers from the Norwegian National Institute for Consumer Research (SIFO), Harald Throne-Holst and Pal Strandbakken, argue that consumer rights in the nanotechnology age are not self-evident but rather have to be strengthened, partly redefined and certainly revived in order to empower and protect consumers.
From an energy savings point of view, the use of smart windows - electrically switchable glass which controls the amount of light passing through when voltage is applied - can save costs for heating, air-conditioning and lighting and avoid the cost of installing and maintaining motorized light screens or blinds or curtains. A disadvantage is of course the fact that the smart windows themselves need to draw energy in order to do their job. Now, researchers have developed a self-powered, fast-switching smart window that doubles as a solar cell, using sun light to power its chromic behavior and making the case for energy savings even more compelling. By employing a patterned tungsten oxide/platinum electrochromic electrode and a dye-sensitized titanium dioxide nanoparticle photoanode, the self-powered photovoltachromic cell (PVCC) which exhibits distinct electrochromic characteristics of a fast switching rate and tunable transmittance under illumination. The novel device has both photoelectrochromic and photovoltaic characteristics.
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.