www.trndvby.com 2020

For the morphological control of nanostructures during bottom-up growth several techniques are used. GLAD Glancing angle deposition (GLAD) is a technique that uses a flow of atoms from gas phase to impinge on a substrate surface under an oblique angle. Physical vapor deposition under conditions of obliquely incident flux and limited atom diffusion results in a film with a columnar microstructure. These columns will be oriented toward the vapor source and substrate rotation can be used to sculpt the columns into various morphologies. Glancing angle deposition (GLAD) is an advanced bottom-up nanostructuring technique developed by Michael Brett’s group at the University of Alberta, Canada. GLAD provides precision engineering of nanostructures via control over macroscopic geometry during deposition. Deposition modulation allows for real-time fabrication of previously unachievable hybrid architectures during bottom-up growth. For example, with modulation of deposition rate and substrate ori

Scientists have manipulating materials such as nanoparticles, single molecules and atoms, in their natural environment by using new generation microscopes to explore the morphology of nanoscale objects. But there are still major hurdles to overcome in measuring the mechanical, chemical, electrical and thermal properties that make each object unique. Scientists working with biological complexes at the nanoscale use chemical labeling by incorporating a visible substance, such as fluorescent dye, into the target object to detect its presence and physical distribution often giving misleading results. Dielectrics Dielectric materials of nanoscale dimensions have aroused considerable interest. For examples in the semiconductor industry the thickness of gate oxide dielectric material is reaching nanoscale dimensions and the high energy density capacitor industry is currently considering dielectric composites with a polymer host matrix filled with inorganic dielectric nanoparticles or polariza

Gold nanoparticles Gold nanoparticles are promising molecular imaging agents; and conjugating such particles with cancer-seeking antibodies enables their direct targeting to tumors. The ability to quantitatively and noninvasively detect targeted nanoparticles in vivo could provide a promising cancer diagnostic tool. The method Researchers at the Engineering Faculty of Bar Ilan University in Israel have developed a tumor detection techniques based on diffusion reflectance (DR) measurements of injected gold nanorods (GNRs). The development is an inexpensive and easy-to-use method for analyzing tissue optical parameters by quantitatively measuring the in vivo concentration of GNRs which can indicate tumor size, the larger the GNR concentration the higher the EGFR amount in the cells as the EGFR concentration directly correlates with the carcinoma amount. Technique The DR technique involves measuring the reflected light intensity profile of an irradiated tissue at a range of source-detecto

Biosensor A biosensor is an analytical device for the detection of an analyte that combines a biological component with a physicochemical detector component. It has a sensitive biological element, transducer or the detector element and a reader device with the associated electronics. Few applications are in glucose monitoring in diabetes patients, environmental applications for the detection of pesticides and river water contaminants such as heavy metal ions, remote sensing of airborne bacteria such as in counter-bioterrorist activities, detection of pathogens, determining levels of toxic substances before and after bioremediation, detection and determining of organophosphate, routine analytical measurement of folic acid, biotin, vitamin B12 and pantothenic acid as an alternative to microbiological assay, determination of drug residues in food, such as antibiotics and growth promoters, particularly meat and honey, drug discovery and evaluation of biological activity of new compounds,

Researchers at the University of California have developed a technique to study in detail and monitor the behaviour of the biological molecules particularly protein which is useful for a host of applications in medicine. For investigating biomolecules implicated in various diseases, for developing novel drugs in the future, researchers are studying to understand complex biological molecules as to how they react with their environment. Proteins activity The enzyme is a very small molecule of size between 5 and 7 nm and is impossible to 'see' in any kind of optical microscope. Proteins fold along their long chains of amino acids and enzymes, in particular, change shape when they bind to substrates because these shape changes are crucial for how the molecule functions. The behaviour of proteins can be monitored to a certain extent, but there is no real way to track an individual protein over a long period of time. New technique The researchers have shown that they are able to obs

Physicists in Germany have developed a "nano-ear" of detecting sound on microscopic length scales. The technique was discovered in the 1980s and is used routinely in research labs around the world. It is particularly useful for manipulating biological objects, since the optical field used to make the trap is non-destructive. Working The researchers suspended gold nanoparticles in a drop of water. They trapped one sphere in a laser beam and then fired rapid pulses of light from a second laser at others a few micrometres away. The pulses heated the nanoparticles, which disturbed the water around them, generating pressure, or sound, waves. The device can optically trap gold nanoparticle and could be used to "listen" to biological micro-organisms as well as investigate the motion and vibrations in tiny machines. When laser light is focused at a point in space gold nanoparticles can be trapped in optical tweezers and an electric dipole moment is induced in the particle a

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

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

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