What is Nanoelectronic?
Nanoelectronic is concerned with understanding and exploiting the properties of devices, which have dimensions at the nanometre scale.
Microelectronics will gradually evolve into nano-electronic. In fact, this has already happened as can be seen from the smallest feature size of present integrated circuits, which is below of one micrometer. It is currently believed that optical lithography can be used for ground rules down to 150 nm and might even be used for the 100 nm generation and below. This would imply an increasing process and mask complexity, and consequently, increasing the cost.
Molecular-scale electronic has been widely touted as “the next step” in electronic miniaturization, with theory and research suggesting that single molecules may have the capability to take the place of today’s much larger electronic components.
Therefore, what are the advantages of scaling down of devices?
Flat Panel Displays – Beyond Plasma
The term set-top box will become something of a misnomer in the near future, as most displays will become too thin to allow a box to placed on top of them. As the price of plasma & LCD displays has plummeted and their image quality has improved, they are popping up in homes everywhere.
Although they are the darlings of the media and the generic for flat panel display in the minds of many, plasmas are about to be in a serious fight with other technologies for the flat panel crown.
LCD displays, seen on the desktop for years as computer monitors, and commonplace in smaller flat panel TVs, are finally increasing in size to the point they are becoming a rival to plasmas in the 42″ – 50” size range. Picture quality is similar to plasmas; however LCDs are immune to the burn-in that can affect plasma displays. This burn-in occurs when plasma units are used to display static images such as video game screens and stock or sports tickers.
Plasmas generally have an edge in the ability to produce deeper blacks and more saturated colors than LCDs. Plasmas are also better at producing full motion video than LCDs because of the response time of the LCD panels, although this difference is disappearing. (more…)
What is Nanotube?
They were discovered in 1991 by the Japanese electron microscopist Simio Iijima who was studying the material deposited on the cathode during the arc-evaporation synthesis of fullerenes. Carbon nanotubes are fullerene-related structures which consist of graphene[1] cylinders closed at either end with caps containing pentagonal rings. Examples of Nanotubes are Single-layer nanotubes and nanotube “ropes” and nanohorns. Carbon nanotubes, therefore, are rolled-up sheets of graphite – i.e. the same material that is used in pencils. A sheet of graphite is composed of carbon atoms arranged in a flat hexagonal pattern similar to chicken wire mesh.
Nanoelectronic has witnessed a shift towards molecular systems in recent years. Though the term molecular electronic is rather an old one, it is only recently that single molecules have become the focus of interest, as nanoelectronic start to surface. This was triggered by research on carbon nanotubes. But before the carbon nanotubes entered the scene, molecular electronic was the science of organic polymers, their synthesis, processing and doping. With carbon nanotubes, we finally have a model system at hand that is equally of interest for chemists, material scientists and physicists. However, carbon nanotubes are supramolecular objects for a chemist; they are one-dimensional solids for a physicist. In the future, more of this supramolecular structure will be studied on a single molecule level.
Theorists have shown that nanotubes can be conducting or insulating depending on their structure. Therefore, this may lead to applications in nanoelectronic.
Wires are not possible for use in nanoelectronic, because they are susceptible to thinning and breakage. Despite recent interest in carbon nanotubes, they have variable electronic properties, depending on their orientation, reducing their functionality as electrical conductors.
One problem that plagues researchers looking to fashion circuit components from nanotubes is separating metallic tubes from the ones that are semi-conducting. Common synthesis procedures produce spaghetti-like mixtures of nanotube ropes that are unusable for semiconductor applications because they contain both types of tubes.
Nanotubes can be metals or semiconductors, and because of their strong chemical bonds and satisfied valences[2], the materials boast high thermal, mechanical, and chemical stability. In addition, carbon nanotubes can be efficient conductors as a result of their tiny diameters, long lengths, and defect-free structures that make them ideal one-dimensional systems.
Theoretical models have predicted that nanotubes could behave as ideal one-dimensional “quantum wires” with either semi conducting or metallic behaviours. Study of Transmission Electron Micrograph (TEM) images, however, has indicated that the nanotubes also incorporate kinks and defects into their walls
Progress in nanotubes synthesis has now yielded single-walled nanotubes (SWNTs) with well-defined diameters, bringing the experimental situation much closer to that of the theoretical models. Recent measurements indicate that these materials do behave like one-dimensional wires. The SWNTs should also be more sensitive to defects, to the extent that defects may dominate the transport characteristics. In this work, an STM tip was used as a sliding electrical contact to probe the length-dependence of SWNT conductance. Although atomic defects were not directly imaged, sharp conductance transitions and hetero-junction behaviours in the nanotube conductance are suggestive of the signatures of nanotube defects.
Altawell.
[1] Graphene: A sheet similar in appearance to “chicken wire mesh” made up from carbon atoms.
[2] Valence: The number of chemical bonds an atom can form.
[3] STM: Scanning Tunneling Microscope.
Article Source: EzineArticles.com/?expert=Najib_Altawell
NanoTube Cancer Weapons
Nano Technology may in fact hold the keys to fighting many different types of cancer in the human bio-system. The technologies are so promising we may see survival rates skyrocket, thus everyone can live strong in the upcoming decade. Nano Tubes use in fighting cancer is indeed, a unique process; it works by inserting tiny microscopic carbon synthetic rods into the body to deliver the cancer treatment to the exact spot needed. By directly aiming the rods into the cancer cells, the healthy tissue is saved.
This research is quite promising and is being researched by Stanford University. Chemotherapy seems to becoming a thing of the past. That is the theory that nuking the body and seeing which dies first; the cancer or the person. Even when the human survives it is left with huge amounts of destroyed tissue, which was not cancerous. When you see a person who is using chemotherapy to treat the cancer you see their hair fallout, but that is only one of many dire and serious side effects.
These nanotubes are so small they are the width of a DNA strand. The nano tubes will be heated up using near infrared light in a laser beam, which takes about two-minutes. The cancerous cells are quickly destroyed. This research is only in the preliminary stages but should be solved within the coming decade.
The nano tubes will be coated with a vitamin called folate, which is found in cancerous cells, but does not normally bind with healthy cells. Once these tubes touch the cancerous area they quickly bind and then are electrified with near infrared laser light, killing the cells. Nano Tube technologies are quickly coming of age and once they are available this process should be relatively easy to use. One cancer already targeted is Lymphoma and tests of the process are being done on mice with good results. There are other cancers it might work on well to and have been suggested. For instance Ovarian Cancers, Cervical Cancer and others; Nano Technology and biomedical processes are coming of age as we speak.
“Lance Winslow” – Online Think Tank forum board. If you have innovative thoughts and unique perspectives, come think with Lance; http://www.WorldThinkTank.net/. Lance is an online writer in retirement.
Article Source: EzineArticles.com/?expert=Lance_Winslow
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