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Showing posts from December, 2011

NEW YEAR GREETINGS

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Nanoall - Nanotechnology Blog wishes all readers Happy and Prosperous New Year 2012

Nanowire endoscope for cell

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Nanowire A nanowire is a nanostructure that has a thickness or diameter constrained to tens of nanometers or less and an unconstrained length in which quantum mechanical effects are important. Many different types of nanowires exist, including metallic (e.g., Ni, Pt, Au), semi conducting (e.g., Si, InP, GaN, etc.), and insulating (e.g., SiO2, TiO2). Molecular nanowires are composed of repeating molecular units either organic (e.g. DNA) or inorganic (e.g. Mo6S9-xIx). The nanowires could be used to link tiny components into extremely small circuits created out of chemical compounds. Nanowires probe Researchers at the Lawrence Berkeley National Lab in the US have made their device by attaching a tin oxide nanowire waveguide to the tapered end of an optical fibre. Light traveling along the fibre can be effectively coupled into the nanowire. This robust nanowire probe can be used as a non-invasive endoscope to image the inside of living cells. It can also be used to transport tiny "car

Nanobio materials in medical applications

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Nanotechnology plays an important role in biomedical and medical industry applications. Some of the applications are: tissue engineering, detection of protein, drug and gene delivery, probing of DNA structure, separation and purification of biological molecules and cells, etc. Nano particles are compatible in size to the protein dimensions making it appropriate for bio tagging or labeling. In addition, the biological tags, where the interaction with biological target happens by biological coating or layer of biopolymers and antibodies attached to nanoparticles. Nanomaterial is able to fluoresce or change optical properties. These behaviors result in biocompatible property for nanomaterials. Nano biomaterials are widely used in medicine and biological applications. Some recent developments for medicine applications are; tissue engineering, detection of protein and cancer therapy, medical imaging using quantum dots or chromophores synthesis for cancer diagnosis and drug delivery sy

Nanowires

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Nanowires A nanowire is a nanostructure and a solid, cylindrical wire with a diameter usually less than 100 nm or structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length where quantum mechanical effects are important. Types Many different types of nanowires exist, including metallic (e.g., Ni, Pt, Au), semi conducting (e.g., Si, InP, GaN, etc.), and insulating (e.g., SiO2, TiO2). Molecular nanowires are composed of repeating molecular units either organic (e.g. DNA) or inorganic (e.g. Mo6S9-xIx). The nanowires could be used to link tiny components into extremely small circuits. Classification Generally, nanowires are classified according to their structures: a) crystalline, those with structured alignments of polymer chains, b) polycrystalline, those with repeating chemical units for molecules, and c) nearly amorphous, those with random alignment of polymer chains. The varying shape is because the nanowire is only periodic alon

Measuring Nanoscale Temperature

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AFM tip Atomic force microscope cantilever tips with integrated heaters are widely used to characterize polymer films in electronics and optical devices, pharmaceuticals, paints, and coatings. These heated tips are also used in research labs to explore new ideas in nanolithography and data storage, and to study fundamentals of nanometer-scale heat flow. Until now, however, no one has used a heated nano-tip for electronic measurements. Nanoprobe “We have developed a new kind of electro-thermal nanoprobe,” according to William King, a College of Engineering Bliss Professor in the Department of Mechanical Science and Engineering at Illinois. “Our electro-thermal nanoprobe can independently control voltage and temperature at a nanometer-scale point contact. It can also measure the temperature-dependent voltage at a nanometer-scale point contact.” “Our goal is to perform electro-thermal measurements at the nanometer scale,” according to Patrick Fletcher, first author of the paper, “Thermoel

Nanopore

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DNA DNA is composed of four chemical bases: adenine, guanine, cytosine and thymine paired together in a complementary fashion and ordered in a species-specific sequence. The sequence represents a blueprint for the construction of the protein machinery to makes a cell work and store information. Sequencing of DNA involves cost and takes time because the procedure involves making multiple identical copies of the DNA and the chemistry involved. Sequencing DNA with a nanopore is a revolutionary concept that may enable sequencing a single molecule of DNA, eliminating the need for amplification and for reducing the cost. Nanopore A nanopore is a hole made in a nanometre-thick thin membrane of materials such as silicon or silicon nitride. Nanopore is comparable in size to a DNA molecule. Principle of DNA sequencing using nanopore When the hole is immersed in electrolyte and a voltage applied across the membrane, a current flows through it. In addition to electrolytic ions, highly charged DNA

Nanoblade for hydrogen storage

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Hydrides for storage Hydrogen Storage is the bottleneck for on-board vehicle applications. Magnesium hydride is one of the most promising candidates for solid-state hydrogen storage due to its light weight, low cost and highly reversible hydrogen storage capacity of 7.6 mass% in MgH2. The high thermodynamic stability and sluggish reaction kinetics limit its practical applications. But making magnesium into nanostructures along with appropriate transition metal catalyst addition could solve the problems. Nanoblade Researchers at the University of Georgia, US, have designed and fabricated a vanadium-decorated magnesium nanoblade array structure by coating a thin layer of vanadium onto the two sides of individual magnesium nanoblades. The structures were made using a dynamic shadowing growth (DSG) technique, which is based on a physical vapor deposition method and combines oblique angle deposition (OAD) with substrate manipulation and source control. Performance The nanoblades are extreme

Golden nanocups for focusing light

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Scientists have used metallic nanoparticles to manipulate light in more effective ways than conventional optical materials to tap extra energy from the sunlight. Metamaterials Metamaterials have an edge over naturally occurring materials because they can cause dramatic physical effect with the interaction of light. These materials have very fine structures with features smaller than the wavelength of light which can pass on unique and fascinating optical behaviors. Nanocups The material having very tiny, cup-shaped particles called nanocups can collect light from any direction and emits it in a single direction. Rice University researchers have used cup-shaped gold nanostructures which behave like three-dimensional nano-antennas to bend light in a more manipulative manner. The gold nanocups interrelate with light in two major ways: axially, the up-down direction, or transverse, the left-right track. The transverse mode is by far the more powerful of the two. When the nanocups are illum

Frequency doubling with nanocups

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Researchers at Rice University in Houston, Texas have discovered a new type of material for converting red light into blue light. Harmonic generation Second harmonic generation (SHG) also called frequency doubling is a nonlinear optical process, in which photons interacting with a nonlinear material are effectively "combined" to form new photons with twice the energy, and therefore twice the frequency and half the wavelength of the initial photons. The principle is that in quantum mechanics, the recolliding electron is represented as a de Broglie wave. This wave shifts over the molecular or atomic orbital, from which it was originally ionized. During this shifts, interferences occur, that modulate the amplitude and phase of the harmonic radiation. Nanocups Nanocups are three-dimensional artificially designed plasmonic nanostructures. Second harmonic generation is an important nonlinear optical process that has been used since the 1960s for making new light sources, optical cr

Making Plasmonics with Silver Polyhedral Nanocrystals

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Plasmonics Nanoscale fabrication (such as focused ion beam lithography techniques) allow one to make new materials with increasing sophistication and freedom of design, but controlling light at the nanoscale remains a challenge. Traditionally light can only be controlled on length scales down to a little below the wavelength of light, a few hundred nanometers, hence the usual resolution limit of optical microscopes and telescopes. Plasmonics is the phenomenon by which a beam of light is confined in ultra-cramped spaces allowing it to be manipulated as desired. Plamonics is thought to embody the strongest points of both optical and electronic data transfer, allowing the fast transmission of information over very small wires. Plasmonics, sometimes called "light on a wire," would allow the transmission of data at optical frequencies along the surface of a tiny metal wire, despite the fact that the data travels in the form of electron density distributions rather than photons. Pl

Nanoparticle Electrode for Storage Batteries

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For making wind and solar power usable on a grand scale there is a need for an efficient, durable, high-power, rechargeable battery to store large quantities of excess power generated. Conventionally lithium ion batteries are used in most applications. Lithium ion batteries The conventional lithium ion batteries have a high energy density so that they can hold a lot of charge for their size, making them great for portable electronics such as laptop computers. But energy density is not very important as for as storage on the power grid is concerned while cost is a greater concern. Some of the components in lithium ion batteries are so expensive that the batteries on a scale for use in the power grid will ever be economical. Also lithium ion battery can handle only about 400 charge/discharge cycles before it deteriorates too much to be of practical use. Battery electrode An electrode in an electrochemical cell is referred to as either an anode or a cathode (words that were by Faraday).

Potential Uses of Nanotechnology

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See the video on potential uses of nanotechnology

Nanotechnology for never weting fabrics - video

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See the super power of nanotechnology in this video.

superhydrophobic spray-on nanocoating

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See a video on NeverWet, a silicon-based spray-on coating that repels water and heavy oils.

Graphene absorbs infrared light

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Graphene can absorb more than 2% of incident visible light, but researchers at IBM have discovered that graphene can absorb up to 40% of light in the far infrared and microwave frequency ranges. The finding confirms that the material could be ideal for terahertz applications. Graphene Graphene is a 2D sheet of carbon just one atom thick with unique electronic and mechanical properties. Graphene has a number of technological applications and can even replace silicon in the electronic industry. This is because electrons travel through graphene at extremely high speeds with no rest mass. It can also absorb light over a very wide range of wavelengths, ranging from the visible to the infrared. This is unlike III-V semiconductors that do not work over such a wide range. Infrared light The infrared part of the electromagnetic spectrum is important for optical telecommunications, for example, and the terahertz range in areas like biological imaging, materials analysis and security screening. C

Nanocages to treat tumour

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Researchers at Washington University in St Louis have used photo acoustic tomography, a non-invasive imaging technique to understand the transport kinetics of gold nanocages in the lymphatic system. The technique could be used to design new tools for cancer therapy. Gold nanocages Gold nanocages were invented by Younan Xia and colleagues at Washington University. These nanostructures have hollow interiors having diameter typically between 30–100 nm and ultra thin porous walls. The structures can be designed to absorb strongly and scatter light in the near-infrared (IR) region of 700–900 nm in the electromagnetic spectrum. Conventional methods Tumors spread by invading adjacent issue and cancerous cells propagate throughout the lymphatic system and then into the blood stream. The closest lymph node that drains from a tumor is called the sentinel lymph node (SLN) and this is most likely the area from which metastasis starts. Conventional methods based on injecting organic dyes and hazar

Nanoscale modeling

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MIT simulation tools This set of simulation tools has been developed to provide students with the fundamentals of computational problem-solving techniques that are used to understand and predict properties of nanoscale systems. Emphasis is placed on how to use simulations effectively, intelligently, and cohesively to predict properties that occur at the nanoscale for real systems. The course is designed to present a broad overview of computational nanoscience and is therefore suitable for both experimental and theoretical researchers. These tools have been updated throughout spring term of 2011. The simulations are run by the tool are: Averages and Error Bars, Molecular Dynamics (Lennard-Jones), Molecular Dynamics (Carbon Nanostructures), Monte Carlo (Hard Sphere), Monte Carlo (Ising Model), Quantum Chemistry (GAMESS), Quantum Chemistry (Quantum Espresso), Density Functional Theory (Siesta), and Quantum Monte Carlo (QWalk). Purdue University modeling kit for quantum dot devices Quantu

Nanoparticle tattoo to monitor health

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Diabetes is a common disease with all age group, and despite decades of medical advancement, measuring accurately the glucose level in the human body is still a problem because it involves the daily task of pricking their fingers to check glucose levels. Sensing system MIT researchers have reported about a sensing system that consists of a “tattoo” of nanoparticles injected below the skin to detect glucose. The device can be worn over the tattoo to clearly display glucose level. The tattoo material consists of carbon nanotubes which are injected under the skin. Nanotubes are wrapped in glucose-responsive polymers and when the polymers encounter blood sugar, they cause the nanotubes to flash light. The sensor recognizes this flashed light with near-infrared detection. Nanotubes are unique resilient to light exposure and hence the device can provide constant information on blood glucose level without damaging the particles. Nanoparticle solution Adding functionality to body art, research

Functionalized biocompatible CNTs

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Researchers at Stanford University have developed a technique to prepare conductive single-walled carbon nanotube films for biotechnology applications by depositing them on substrates coated with poly-L-lysine. Poly-L-Lysine Poly-L-Lysine is a synthetic amino acid chain that is positively charged and widely used as a coating to enhance cell attachment and adhesion to both plastic ware and glass surfaces. Poly-L-Lysine is normally used to cover tissue culture plates to help biological cells better stick to the plates. The molecular weight of Poly-L-Lysine can vary significantly with lower molecular weight (30,000 Da) being less viscous and higher molecular weight (>300,000 Da) having more binding sites per molecule. Poly-L-Lysine is used to coat tissue culture plastic ware for enhanced cell attachment and adhesion. Coated surfaces will often improve cell attachment in reduced or serum-free conditions. SWCNT SWNTs on the market, regardless of which manufacturer produces them have 90%

Bangalore Nano Science Meet

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Banglore Nano Science Meet 2011 will start from 7 December 2011 in the IT city Banglore. The International conference will end on 9 December 2011. This is fourth edition of Bangalore Nano Science Meet. Prof. C.N.R. Rao, Chairman of Scientific Advisory Council to the Prime Minister of India, at the curtain raiser of the Bangalore Nano Science Meet on Friday said that at the age of 78, he works harder than techies in their 40s. Prof. C.N.R Rao stated that the 4th Edition of Bangalore Nano Science Meet will have pre-conference turtorials for students and young researches on nano medicine and biotechnology, advance nano materials, nano in energy and environment, nano electronics and Microsystems. Nano For Young is a programme put together by Prof. C.N.R. Rao and his team including Ajay K. Sood of Indian Institute of Science, Bangalore and Umesh Waghmare of Jawaharlal Nehtru Centre for Advanced Studies and Research where insightful discourses into nano research will be given by subject expe