Showing Spotlights 945 - 952 of 2333 in category All (newest first):
In nature, numerous inorganic materials are synthesized by living organisms. These bioinorganic materials can be extremely complex both in structure and function, and also exhibit exquisite hierarchical ordering from the nanometer to macroscopic length scales. The possibility of using such microorganisms and plants in the deliberate synthesis of nanomaterials is a recent phenomenon and scientists are now exploring the use of biological organisms and materials to literally grow nanomaterials. In a novel approach, researchers have now synthesized nanoparticles in hair. The purpose was to try to describe some of the chemical reactions occurring inside the hair shaft, in the so-called amorphous matrix surrounding intermediate filaments made of keratin proteins. This matrix can be seen as a set of nanoreactors.
Nov 20th, 2012
Optical tweezers offer researchers the chance to perform precise force sensing in a fluid environment. This could help to give clarity to some of the picoNewton forces that govern fundamental processes in the cell. However, currently the use of tweezers to probe biological, samples requires either direct irradiation with a laser, or the use of a tool or proxy to exert or sense very small forces. There are many instances when exposing samples to high intensity laser light is less than ideal - typically this is within a biological context. Researchers have now have shown that optical tweezers can be combined with naturally derived algae to create a stable nanoscale optical force sensor. This may enable other groups to utilize this technique to probe key force interactions that occur at the lowest end of the nanoscale force regime.
Nov 15th, 2012
One of the key issues in the development of novel nanomedicines is the ability to track nanoscale drug carriers inside the body to evaluate where they go and how they get there. Virtually all previous preclinical studies in this area of research rely on 2D Fluorescence Reflectance Imaging (FRI). Given the limitation of 2D FRI in not being able to detect the fluorescence in deep-seated organs and tissues, 3D Fluorescence Molecular Tomography (3D FMT) emerged as an alternative. However, the lack of anatomical information was an important barrier hindering the routine use of standard 3D FMT for in vivo imaging of nanomedicines. Researchers have now developed a hybrid CT-FMT-based imaging protocol to enable more meaningful and more quantitative in vivo analyses.
Nov 13th, 2012
Within graphene research, transmission electron microscopy (TEM) has proven to be an extremely useful and versatile characterization tool. However, the electron beam can interact with the sample leading to its modification during the process. This may be an undesirable effect and measures to avoid this do exist. In other cases, however, electron beam-sample interactions can be useful for nanoengineering or nanomanufacturing. It is therefore crucially important to understand how a material responds to the electron beam and the environment inside a TEM. In new work, researchers have now demonstrated that damage-free sculpting of graphene with condensed electron beams is feasible.
Nov 12th, 2012
Power dissipation is the limiting factor to the continued scaling of size and speed of conventional silicon technology used for fabrication of integrated circuits and computer chips. For each switch of a transistor, an amount of energy needs to be dissipated that is proportional to the number of electrons and temperature. This condition is of a fundamental nature, resulting from the laws of thermodynamics.However, the assumption underlying this fundamental limit is that the electrons or spins act as an ensemble of independent particles. If instead, the electrons are in a collective state, then the minimum dissipation limit for one switching cycle can be greatly reduced. This fact provides a strong motivation to exploit collective states as alternative variables for information processing.
Nov 8th, 2012
Protection against nerve agents - such as tabun, sarin, soman, VX, and others - is a major terrorism concern of security experts. Current methods to detect nerve agents include surface acoustic wave sensors; conducting polymer arrays; vector machines; and the most simple: color change paper sensors. Most of these systems have have certain limitations including low sensitivity and slow response times. Nanoporous material can remove highly toxic nerve agent vapors by physical adsorption. Unfortunately, the broad range of toxic agents, environmental conditions and types of carbonaceous material simply does not allow laboratory testing of every possible combination. New research is now shedding new light on the selection of an optimal nanomaterial for capturing highly volatile nerve agents.
Nov 7th, 2012
Recent developments in nanotechnology have enabled significant improvement in the field of anti-counterfeiting measures. One company for instance is working on fluorescent nanostructures to improve banknote security; another one has developed DNA tags for deposition on nanoelectronics wafers and computer chips to ensure the integrity and security of processed wafers. DNA-based protection technologies are especially suitable for anti-counterfeiting measures.The DNA molecules are added a products raw material during the production process. Only 1 ppm (one part per million) is required to uniquely mark the material The DNA molecular structure can then be read as a mathematical code based on the four DNA molecules. So a DNA code, in contrast to the binary code used in IT security, is a combination of the letters A, C, G and T. A 10-digit code could look like this: C-G-A-C-T-T-G-A-C-A.
Nov 6th, 2012
The refractive index is the property of a material that changes the speed of light and describes how light propagates through the material. The refractive index is an important property of solar cells - the higher it is, the more incident light gets reflected and is not converted to a photocurrent. Solar cell manufacturers have developed various kinds of antireflection coatings to reduce the unwanted reflective losses. The purpose of these optical thin-films is to minimize the differences in the refractive indices between the ambient medium and the solar cells. For both solar cells and LEDs, coating with nanoparticles can enhance the performance without harming the electrical properties of the devices, as can occur with etching or lithographic processing. In new work, researchers have now have not only demonstrated this advantageous feature but also provided a strategy for optimizing the types and sizes of nanoparticles for use in both solar cells and LEDs.
Nov 5th, 2012