http://www.nanowerk.com/ Nanotechnology Spotlight from Nanowerk Copyright 2005-2009 Nanowerk LLC http://www.nanowerk.com/ http://www.nanowerk.com/images/logo10.gif michael@nanowerk.com (Michael Berger) en-us Fri, 06 Nov 2009 23:13:44 -0500 http://www.nanowerk.com/spotlight/spotid=13386.php For years now, nanotechnology researchers have been promising us carbon nanotubes as the basis for numerous breakthrough applications such as multifunctional high-strength fibres, coatings and transparent conducting films. Not to mention as a cure for cancer and a solution to the energy crisis. However, while the thermal, electrical and mechanical properties of carbon nanotubes (CNTs) are unique, materials engineers have been struggling to assemble CNTs into macroscopic structures that retain enough of the properties of the constituent nanotubes. CNTs are notoriously difficult to work with and, because researchers haven't found efficient ways yet to assemble them, the resulting materials demonstrate only a small fraction of the possible single-object properties of CNTs. So we are still waiting for those breakthrough applications. However, new research reported this week has now established an industrially relevant process for assembling carbon nanotubes that allows them to efficiently be made into fibers, coatings and films - the basic forms of material that can be used in engineering applications. http://www.nanowerk.com/spotlight/spotid=13386.php http://www.nanowerk.com/spotlight/spotid=13362.php Nanotechnology has brought a new area of finishing applications - nanofinishing - to the textile industry. Coating the surface of textiles and clothing with nanoparticles has become a common approach for the production of highly active surfaces to have UV blocking, antimicrobial, flame retardant, water repellant or self-cleaning properties. For centuries, silver has been used to prevent and treat a variety of diseases. Silver is known as one of the oldest antimicrobial agents and it has been used effectively against different bacteria, fungi and viruses. Researchers in Switzerland have now examined what happens to these silver nanoparticle-treated textiles during washing. The scientists studied release of nanoparticles in laundry water from nine different textiles, including different brands of commercially available anti-odor socks. http://www.nanowerk.com/spotlight/spotid=13362.php http://www.nanowerk.com/spotlight/spotid=13340.php The physical properties of nanostructures have been investigated extensively both theoretically and experimentally. Among these properties, melting temperature, superconductive temperature, Curie temperature and Debye temperature are key physical quantities since they are the characteristic temperatures of melting, superconduction, ferromagnetism and vibration, respectively: The melting temperature is the highest temperature where the solid phase exists under thermodynamical equilibrium. The superconductive temperature is the highest temperature for which the material looses all resistance to the flow of electricity and tend to expel any magnetic fields inside it. The Curie temperature is the highest temperature for which the ferromagnetic phase is stable. The Debye temperature is the temperature corresponding to the maximal energy which can excite lattice vibrations. http://www.nanowerk.com/spotlight/spotid=13340.php http://www.nanowerk.com/spotlight/spotid=13303.php In today's addition to our Application Note series we are looking at the future of electronics and the implications for research instrumentation. We are showing two examples of atomic force microscope (AFM) applications employed in this research. Current CMOS (complementary metal-oxide-semiconductor) technology used for making integrated circuits is constantly being scaled down. These devices will reach their ultimate physical limits in 10 to 15 years. As chip structures - which currently already have reached nanoscale dimensions - continue to shrink below the 20 nanometer mark, ever more complex challenges arise and scaling appears not to be economically feasible any more. And below 10 nm, the fundamental physical limits of CMOS technology will be reached. Researchers are therefore exploring novel concepts for future nanoelectronic devices. http://www.nanowerk.com/spotlight/spotid=13303.php http://www.nanowerk.com/spotlight/spotid=13288.php Traditional techniques in cell biology involve chemical or pharmaceutical treatments of entire cells; however, in many cases it would be advantageous to target a single organelle or other structure within a cell without damaging overall cell structure. If scientists could inject a drug into a chosen organelle within the cell, or even destroy, extract or isolate the whole organelle without significantly harming the cell itself, new insight could be gained into the inner workings of the cell. In recent years, techniques have been developed which allow the manipulation of the individual nanoscale structures within biological cells. This manipulation, or 'nanosurgery', has the potential to provide new insight into the internal structure and dynamics of cells. Nanosurgical methods have been developed to target the cell's internal organelles, the cell membrane, and the structural protein filaments within the cell. http://www.nanowerk.com/spotlight/spotid=13288.php http://www.nanowerk.com/spotlight/spotid=13248.php Due to their unique structural and electrical properties, carbon nanotubes have been extensively investigated as promising catalyst supports to improve the efficiency of direct ethanol/methanol fuel cells. CNTs have a significantly higher electronic conductivity and an extremely higher specific surface area in comparison with the most widely-used Vulcan XC-72R carbon support. Several approaches, such as electrochemical reduction, electroless deposition, spontaneous reduction, sonochemical technique, microwave-heated polyol process, and nanoparticle decoration on chemically oxidized nanotube sidewalls, have been reported to form CNT-supported platinum catalysts. Some remarkable progress has been made in synthesis techniques; however, pioneering breakthroughs have not been made yet in terms of cost-effectiveness catalyst activity, durability, and chemical-electrochemical stability. Nanotechnology researchers in the U.S. have now discovered that platinum nanoparticles selectively grow on carbon nanotubes in accordance with single-stranded DNA locations. http://www.nanowerk.com/spotlight/spotid=13248.php http://www.nanowerk.com/spotlight/spotid=13226.php 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. http://www.nanowerk.com/spotlight/spotid=13226.php http://www.nanowerk.com/spotlight/spotid=13206.php A couple of years ago we reported on applications of nanotechnology-based processes to the restoration and preservation of priceless artwork. Researchers have shown that nanodispersions of solids, micelle solutions, gels and microemulsions offer new reliable ways to restore and preserve works of art by merging together the main features and properties of soft-matter and hard-matter systems, allowing the synthesis of systems specifically tailored for the works of art to fight the deterioration processes which threaten many priceless masterpieces. Researchers at the University of Florence, who have been leading efforts to apply nanoparticle-based cleaning agents for artwork, have now further developed their work by exploring the design of novel systems containing low amounts of volatile oils as low-impact cleaning tools for the removal of aged polymeric coatings from the surface of paintings. http://www.nanowerk.com/spotlight/spotid=13206.php http://www.nanowerk.com/spotlight/spotid=13201.php Eric Drexler replies to yesterday's Spotlight on Feynman and nanotechnology. 'Neither Feynman nor the vision of molecular manufacturing created the fields that have joined to become 'nanotechnology', nor did they provide the concrete scientific opportunities and technological applications that drive it forward. However, what set nanotechnology on its path to prominence was not a sudden realization by the public and politicians that new molecules and nanostructures have a host of applications in materials, sensors, and so on. It was, and is, the promise of revolutionary advances in atomically precise manufacturing, advances that will build on the technology platform now emerging from nanotechnology research.' http://www.nanowerk.com/spotlight/spotid=13201.php http://www.nanowerk.com/spotlight/spotid=13169.php In December 2009 we will receive a series of reminders of the fiftieth anniversary of Richard Feynman's noted talk, 'There's Plenty of Room at the Bottom'. As commentaries appear in scientific journals, the nanotechnology community will have multiple opportunities to think about the role of Feynman's talk in the history of nanotechnology. Feynman's 1959 talk has been widely hailed as the origin of nanotechnology. It is a comprehensive vision of controlling matter at the nanoscale, including controlling individual atoms. However, at this point, there are two very different views of the role of Feynman's talk in the history of nanotechnology: 1. Everybody knows that Feynman's 'Plenty of Room' is the origin of nanotech. 2. The emergence of nanotech had little to do with Feynman's talk. http://www.nanowerk.com/spotlight/spotid=13169.php http://www.nanowerk.com/spotlight/spotid=13150.php Nanotechnologies are opening vast new opportunities for scientists, engineers and entrepreneurs to participate in solving some of the major problems facing mankind today. But the road from idea to commercially viable product or process is long. Especially when it comes to nanotech innovations, the research and development phase tends to be relatively lengthy. To help potential nanotechnology start-up founders with shaping their plans, Nanowerk, the leading nanotechnology information service, and Nanostart, the world's leading nanotechnology venture capital company, have teamed up to provide this useful guide which particularly addresses the funding aspects of nanotechnology start-ups, along with answers to some of the most commonly asked questions. http://www.nanowerk.com/spotlight/spotid=13150.php http://www.nanowerk.com/spotlight/spotid=13101.php Detection at the earliest stage provides the greatest chance of survival for cancer patients. Cancer has a logarithmic growth rate and doctors typically don't see 80% of the life of a tumor. Detection can be done using a number of techniques including standard immunoassays and biopsies. Nanotechnology offers new detection approaches such as targeted contrast agents, nanoscale cantilevers coated with antibodies against tumor markers, and magnetic nanoparticles coated with DNA labeling. But the problem is daunting because there are over 50 common types of cancer and in practice it is difficult to ask people to come to the clinic on a regular basis for cancer screening. Researchers have now proposed a new method for the detection of cancer cells based on measurement of the physical adhesion of silica beads to malignant versus normal cells cultured from human cervix. http://www.nanowerk.com/spotlight/spotid=13101.php http://www.nanowerk.com/spotlight/spotid=13072.php Spider silk is a fascinating biopolymer that is stronger than steel and more elastic than rubber. Most of the world's 40,000 species of spiders produce a silken thread that possesses a unique combination of mechanical properties: strength (its tensile strength is about five times as strong a steel of the same density), extensibility (up to 30%) and toughness (its ability to absorb a large amount of energy without breaking). Researchers are experimenting with spider silk to design better adhesives; advanced materials that are both stretchy and strong; and to get clues for protein engineering. Yet the impressive performance of spider silk is not limited solely to tensile mechanics. Researchers have now shown that silk also exhibits powerful cyclic contractions that are precisely controlled by changes in humidity, allowing it to act as a high performance mimic of biological muscles. http://www.nanowerk.com/spotlight/spotid=13072.php http://www.nanowerk.com/spotlight/spotid=13042.php In animal cells, the well known cytoskeletal proteins actin microfilaments and microtubules are accompanied by a third filament system that in humans consist of a family of more than 70 proteins. These fibrous proteins are absent from both plants and fungi, and have been linked to serious human diseases including cancer, muscle dystrophies and rapid aging disease. Their name, intermediate filament, was coined back in 1978 because their diameters - about 10 nanometers - appeared to be intermediate in size between those of microtubules and microfilaments. Their atomistic-level molecular structure remains elusive, and as a consequence, the understanding of the biological role in physiological and disease states is still in its infancy. Researchers now report a breakthrough in explaining the structural and mechanistic origin of the unique mechanical properties of intermediate filaments. By combining atomistic and molecular modeling with experimental studies, the researchers report a multi-scale analysis that showed that the mechanical properties of intermediate filaments are controlled by their characteristic hierarchical makeup. http://www.nanowerk.com/spotlight/spotid=13042.php http://www.nanowerk.com/spotlight/spotid=13027.php Surface-plasmon resonance is a quantum-electromagnetic phenomenon arising from the interaction of light with free electrons at the planar interface of a metal and a (nonconducting) dielectric material. This resonance arises when the energy carried by photons in the dielectric material is transferred to collective excitations (called plasmons) of free electrons in the metal at that interface. As the free electrons in the metal are coupled to the photons in the polarizable dielectric material, the quantum is called a surface plasmon-polariton (SPP). Typically, a SPP wave is launched on a metal-dielectric interface at one particular frequency. That wave has a certain polarization state. Researchers have now shown theoretically and experimentally that by modifying the dielectric material, novel surface-plasmon-polariton wave behavior can be created with the result that the same interface can independently guide more than one SPP wave. http://www.nanowerk.com/spotlight/spotid=13027.php