Friday, May 27, 2011

This week in nanotechnology - May 27, 2011

Electrical engineers at Duke University have determined that unique man-made materials should theoretically make it possible to improve the power transfer to small devices, such as laptops or cell phones, or ultimately to larger ones, such as cars or elevators, without wires. This advance is made possible by the recent ability to fabricate exotic composite materials known as metamaterials, which are not so much a single substance, but an entire man-made structure that can be engineered to exhibit properties not readily found in nature.

Being able to isolate individual molecules like DNA base pairs, which are just two nanometers across, is incredibly expensive and difficult to control. Now a team led by Yale University researchers has proven that isolating individual charged particles, like DNA molecules, is indeed possible using a method called "Paul trapping," which uses oscillating electric fields to confine the particles to a space only nanometers in size.
A single nanoparticle trapped between four microelectrodes
A single nanoparticle trapped between four microelectrodes


Physicist achieves measurement milestone down to the yoctonewton level. This is an incredibly small force - about a million million billion times smaller than the force exerted by a feather lying on a table. And the measurement is a thousand times more sensitive than anything previously possible.

A step closer to mass-manufacturing graphene for nanoelectronics: Researchers have developed a method for creating single-crystal arrays of graphene, an advance that opens up the possibility of a replacement for silicon in high-performance computers and electronics. The new findings represent an advance toward perfecting a method for manufacturing large quantities of single crystals of the material, similar to the production of silicon wafers.

At the forefront of nanotechnology, researchers design miniature machines to do big jobs, from treating diseases to harnessing sunlight for energy. But as they push the limits of this technology, devices are becoming so small and sensitive that the behavior of individual atoms starts to get in the way. Now Caltech researchers have, for the first time, measured and characterized these atomic fluctuations - which cause statistical noise - in a nanoscale device.

Friday, May 20, 2011

This week in nanotechnology - May 20, 2011

Victims of third-degree burns and other traumatic injuries endure pain, disfigurement, invasive surgeries and a long time waiting for skin to grow back. Improved tissue grafts designed by Cornell scientists that promote vascular growth could hasten healing, encourage healthy skin to invade the wounded area and reduce the need for surgeries.

Looking inside nanomaterials in three dimensions: Most solid materials are composed of millions of small crystals, packed together to form a fully dense solid. The orientations, shapes, sizes and relative arrangement of these crystals are important in determining many material properties. The newly developed technique allows 3D mapping of the crystal structure inside a material down to nanometer resolution, and can be carried out using a transmission electron microscope, an instrument found in many research laboratories.
3D mapping of the crystal structure inside a material down to nanometer resolution
3D mapping of the crystal structure inside a material down to nanometer resolution.


By combining high pressure with high temperature, Livermore researchers have created a nanocyrstalline diamond aerogel that could improve the optics for something as big as a telescope or as small as the lenses in eyeglasses.

A recent study at the National Institute of Standards and Technology (NIST) may have revealed the optimal characteristics for a new type of computer memory now under development. The work aims to optimize nanowire-based charge-trapping memory devices, potentially illuminating the path to creating portable computers and cell phones that can operate for days between charging sessions.

It sounds like hype from a late-night infomercial: It can twist and bend without breaking! And wait, there's more: It could someday help you fend off disease! Scientists from several institutions derived atomic-scale resolution structures of the cell's protein-making machine, the ribosome, at key stages of its job. Many antibiotics target the ribosomes of disease-causing microbes at precisely this stage. The high-resolution structures could allow scientists to develop antibiotics that better target this cellular Achilles' heel, perhaps leading to drugs that are less susceptible to resistance.

Friday, May 13, 2011

This week in nanotechnology - May 13, 2011

Scientists at the University of California, Berkeley, have demonstrated a new technology for graphene that could break the current speed limits in digital communications. The team built a tiny optical device that uses graphene, a one-atom-thick layer of crystallized carbon, to switch light on and off. This switching ability is the fundamental characteristic of a network modulator, which controls the speed at which data packets are transmitted.

What limits the behaviour of a carbon nanotube? This is a question that many scientists are trying to answer. Physicists at University of Gothenburg, Sweden, have now shown that electromechanical principles are valid also at the nanoscale. In this way, the unique properties of carbon nanotubes can be combined with classical physics – and this may prove useful in the quantum computers of the future.

MIT researchers have created a new detector so sensitive it can pick up a single molecule of an explosive such as TNT. To create the sensors, chemical engineers coated carbon nanotubes with protein fragments normally found in bee venom. This is the first time those proteins have been shown to react to explosives, specifically a class known as nitro-aromatic compounds that includes TNT.
Coated carbon nanotube sensors can detect single molecule of an explosive
The sensor uses carbon nanotubes covered in protein fragments to detect even a single molecule of an explosive, such as the TNT molecule shown here.


In a step toward engineering ever-smaller electronic devices, scientists at the Brookhaven National Laboratory have assembled nanoscale pairings of particles that show promise as miniaturized power sources. Composed of light-absorbing, colloidal quantum dots linked to carbon-based fullerene nanoparticles, these tiny two-particle systems can convert light to electricity in a precisely controlled way.

Friday, May 6, 2011

This week in nanotechnology - May 6, 2011

With the creation of a 3-D nanocone-based solar cell platform, a team led by Oak Ridge National Laboratory's Jun Xu has boosted the light-to-power conversion efficiency of photovoltaics by nearly 80 percent. The technology substantially overcomes the problem of poor transport of charges generated by solar photons. These charges – negative electrons and positive holes – typically become trapped by defects in bulk materials and their interfaces and degrade performance.

A data memory can hardly be any smaller: researchers have stored quantum information in a single atom. The researchers wrote the quantum state of single photons, i.e. particles of light, into a rubidium atom and read it out again after a certain storage time. This technique can be used in principle to design powerful quantum computers and to network them with each other across large distances.

MIT chemical engineers have designed a new type of drug-delivery nanoparticle that exploits a trait shared by almost all tumors: They are more acidic than healthy tissues. Such particles could target nearly any type of tumor, and can be designed to carry virtually any type of drug. Like most other drug-delivering nanoparticles, the new MIT particles are cloaked in a polymer layer that protects them from being degraded by the bloodstream. However, the team designed this outer layer to fall off after entering the slightly more acidic environment near a tumor.
cloaked nanoparticle
The outer layer of this nanoparticle (in yellow) falls off in an acidic environment.


An international team of plasmonics researchers has developed a novel type of nanoantennas that could one day lead to advances in security applications for the detection of drugs and explosives. Nanoantennas work in much the same way as regular antennas, except they collect light instead of radio waves and are millions of times smaller.

New research paves way for the nanoscale self-assembly of organic building blocks, a promising new route towards the next generation of ultra-small electronic devices. Ring-like molecules with unusual five-fold symmetry bind strongly to a copper surface, due to a substantial transfer of charge, but experience remarkably little difficulty in sideways diffusion, and exhibit surprisingly little interaction between neighbouring molecules. This unprecedented combination of features is ideal for the spontaneous creation of high-density stable thin films, comprising a pavement of these organic pentagonal tiles, with potential applications in computing, solar power and novel display technologies.