Researchers at Sandia National Laboratories, Livermore, California have succeeded in developing a device based on carbon nanotubes that can detect the entire visible spectrum of light and which may find potential uses in artificial retinas and other light gathering applications such as solar cells and miniature cameras for use in low light conditions. Earlier attempts at similar devices were only able to detect specific wavelengths.

The device utilizes carbon nanotubes decorated with three different types of chromophores, which are molecules that change shape in response to particular wavelengths of light… in the case of the Sandia research red, green and blue wavelengths. This change in shape alters the orientation of the chromophores in relation to the nanotube which, in turn, alters the conductivity of the nanotube to give a signal that can be measured. Because of their size, the nanotubes have intrinsically high resolution… around the diameter of each nanotube or 1nm.

The researchers believe that the process of manufacturing such devices could be scaled up and are also working on versions of the device that can detect infrared light, and which are more sensitive.

Source: MIT Technical Review

Posted: March 10th, 2009 under Advanced materials, Physics, Advanced medtech, Nanomedicine, Nanotechnology.
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A Cornell University research team has used light to hold and move DNA fragments more precisely and over longer distances previously possible. The technique involves condensing and streaming photons along a special type of waveguide with channels of 60nm to 120nm, far smaller than the wavelength of the infrared laser light, 1500nm, being channeled through them. The small size of the channel condenses the light energy to scales closer to those of the DNA molecules and enhances the ability of the photons to interact with them. Because the waveguide is also a nanochannel it can trap and transport the molecules.

The team, whose work was published in Nature on 1 January 2009, hope that it will be possible to refine and develop the technique to routinely trap and move DNA strands.

Source: Science Daily

Posted: January 5th, 2009 under Physics, Nanomedicine.
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It’s well-known that a gecko can cling to almost any surface, including smooth glass, due to the anatomy of its feet. Each toe is covered in microscopic hairs called setae which have yet smaller branches, called spatulae, at the tips. These present a large surface area to the substrate maximising the effect of van der Waals forces.

Researchers, led by Liming Dai at the University of Dayton in Ohio and Zhong Lin Wang at the Georgia Institute of Technology, have now made a material from carbon nanotubes that is up to 10 times stickier than gecko feet. They grew the carbon nanotubes on a silicon wafer to form a “forest” of vertical nanotube trunks with a canopy of tangled ends at the canopy level, mimicking the gecko’s spatulae and presenting a large surface area to any surface in contact. The new material is superior to some earlier competitors in that it can be easily loosened by varying the angle of pull.

Liming sees some potential applications for the sticky material… as carbon nanotubes are excellent conductors the material could replace solder in electronics in some situations or traditional adhesives in space where vacuum causes the adhesives to dry out and fail quickly.

Source: New Scientist

Posted: October 30th, 2008 under Advanced materials, Physics, Chemistry, Nanotechnology.
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Nanotechnology is producing a wealth of new products based on utilising features and characteristics at the nanoscale including microelectronics and micromachines with moving parts. One problem at such a tiny scale is how to switch them on and off or control them as needed.

In a new study, Dr Harold Zandvliet and colleagues at the University of Twente in the
Netherlands have developed a nanoscale mechanical device, grown on a wafer of germanium, that can respond to a tiny electrical current from the tip of a scanning tunneling microscope to make two atom pairs move like the flippers of a nanoscale pinball machine. The researchers state that understanding the mechanism can provide insights into the opportunities for future atomic-scale devices.

Paper published in Nano Letters

Source: Nanotechnology Now

Posted: October 30th, 2008 under Advanced materials, Physics, Chemistry, Advanced medtech, Nanotechnology.
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So-called “superbugs” like MRSA (methicillin-resistant Staphylococcus aureus) are becoming a huge burden on healthcare systems. In the UK alone, despite strenuous efforts to tackle the problem, there was still around 7000 cases during 2007 and a rise in cases during the last quarter of 2007 as compared with the previous quarter.

Vancomycin is one antibiotic that can still be used to fight MRSA and now researchers at the London Centre for Nanotechnology (LCN) at University College London are using nanotechnology to investigate how it works to provide insight into the possible development of other effective drugs. The team, led by Dr Rachel McKendry and Professor Gabriel Aeppli, used nanoscale silicon-based cantilever arrays to study the process that takes place when vancomycin binds to the surface of the bacteria. Comparing non-resistant and resistant strains, they found that the “superbugs” were resistant because of a simple mutation that deletes a single hydrogen bond from part of their cell wall resulting in a 1000-fold increase in difficulty for the vancomycin molecule to attach to the mucopeptide in the wall of the bacteria, thereby greatly reducing its effectiveness.

Dr McKendry believes that the knowledge of both the binding mechanism and the related mechanical influences on the bacterial cell structure will provide useful insight into the development of more powerful and effective future antibiotics.

Read the original article from the London Centre for Nanotechnology .

Posted: October 23rd, 2008 under Physics, Nanomedicine, Nanotechnology.
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The world’s most powerful microscope, a Transmission Electron Aberration-corrected Microscope known as TEAM 0.5, has been installed at the US Department of Energy’s National Center for Electron Microscopy at the Lawrence Bereley National Laboratory. TEAM 0.5 is capable of resolving images down to 0.5Å (ångström) or 0.05nm or, described in different terms, less than the diameter of a single hydrogen atom. The construction of TEAM 0.5 by a US-European team has only been made possible by advances in a number of other areas such as ultra-stable electronics, very bright electron sources and greatly improved aberration correctors.

The microscope itself, together with its sister microscope TEAM 1 that will additionally correct for chromatic aberration, will be housed in the multistory silo that used to accomodate the historic high-voltage electron microscope and the atomic resolution microscope, once the world’s most powerful instruments. Because the aberration correction allows high resolution to be maintained at lower beam energies, the microscope will be useful for studies where the sample is easily damaged, more example in biological or medical research. Imaging using tomographic techniques that allow 3D imaging, is also possible.

Read the full story at Innovations Report.

Posted: January 24th, 2008 under Physics, Nanotechnology.
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New research, published in Nature Nanotechnology, has shown that cell functions can be controlled using physical, rather than chemical, means. The research team, led by Professor Donald Ingber of Harvard Medical School and the Harvard Insitute for Biologically Inspired Engineering, attached nanoparticles with iron oxide cores to immune-system cells using biomolecules that bind to receptors on the immune cells. In the presence of a weak magnetic field, the nanoparticles became magnetic charged and drew the immune cells together in clusters, causing them to take up calcium. In-vivo, this would be part of a chain of reactions leading to the cells releasing histamine. When the magnetic field was released, uptake of calcium ceased.

According to Professor Ingber, this calcium uptake function is a result of proximity rather than chemistry.The research herald interesting possibilities for drug design and delivery as many drugs rely on the activation of cell receptors. Ingber himself sees a number of potential applications including magnetic pacemakers working through direct action on cells rather than by means of electrodes. Other researchers see possibilities also in controlling man-machine interface systems in the longer term while, in the shorter term, it may give important insights into the mechanisms of cell signaling.

More information available at MIT Technology Review.

Posted: January 21st, 2008 under Physics, Nanomedicine, Nanotechnology.
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Intel has launched its new 45nm feature chip, named Penryn. Using a new hafnium-based gate, the processors incorporate 420 million transistors on each dual-core chip and 840 million on each quad-core chip. The scale is such that 30 million of the transistors would fit on the head of a pin.

Hafnium is a so-called high-K material and has a greater ability to store electrical charge than a similar design using silicon dioxide, thereby overcoming current leakage problems that would otherwise reduce the effectiveness of the chip.

Several manufacturers have already announced that they will use the new Penryn processors in top-of-the-line personal computers.

As previously reported on Ten to the Minus Nine, Intel’s next generation chips, planned for 2009, will incorporate features down to 32nm and will also be based on a hafnium high-K insulator.

More details at the BBC News Technology website.

Posted: November 12th, 2007 under Physics, Nanotechnology.
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New developments in “spintronics” (also  called spin-based electronics or magnetoelectronics) which exploits the quantum spin states of electrons as well as there charge state may soon render current hard drives look massive according to Albert Fert, co-winner of the 2007 Nobel Prize for Physics. Fert is a co-discoverer of giant magnetoresistance which heralded the birth of spintronics.

Many believe that spintronic devices represent a future multi-billion industry and could lead to the development of quantum-based microchips. So-called magnetic random access memory  (MRAM) described by Fert and colleagues could lead to a new era of computing where computer chips and disk drives could be collapsed into one device with massively increased processing power and storage capacity, and access times for reading/writing of information down to five nanoseconds.

The development of such devices is part of an ongoing revolution enabled by nanoscale innovations in materials, moving from silicon to metals and other materials within the transistor gate and “bottom-up” assembled nanotubes and nanowires in electronic circuits.

Further information at the Physorg website.

Posted: November 5th, 2007 under Physics, Nanotechnology.
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