Friday, September 24, 2010

This week in nanotechnology - September 24, 2010

Is this the end of microplates? Novel nanoelectronic biosensing technology could facilitate new era of personalized medicine. The multi-welled microplate, long a standard tool in biomedical research and diagnostic laboratories, could become a thing of the past thanks to new electronic biosensing technology developed by a team of microelectronics engineers and biomedical scientists at the Georgia Institute of Technology.

The new electronic microplate is shown in front of the technology it aims to replace, the conventional microplate
The new electronic microplate is shown in front of the technology it aims to replace, the conventional microplate.

A nanoparticle-based catalyst developed at Rice University may give that tiger in your tank a little more roar. A new paper details a process that should help oil refineries make the process of manufacturing gasoline more efficient and better for the environment. The researchers found that sub-nanometer clusters of tungsten oxide lying on top of zirconium oxide are a highly efficient catalyst that turns straight-line molecules of n-pentane, one of many hydrocarbons in gasoline, into better-burning branched n-pentane.

A team of Yale physicists has used lasers to cool molecules down to temperatures near what's known as absolute zero, about -460 degrees Fahrenheit. Their new method for laser cooling is a significant step toward the ultimate goal of using individual molecules as information bits in quantum computing.

plasmons in a pair of gold nanotips concentrate light from a laser, amplifying it by a factor of 1,000
This artist's rendering shows how plasmons in a pair of gold nanotips concentrate light from a laser, amplifying it by a factor of 1,000.

Condensed matter physicists have found a way to make an optical antenna from two gold tips separated by a gap less than a nanometer wide, that gathers light from a laser. The tips grab the light and concentrate it down into a tiny space, leading to a thousand-fold increase in light intensity in the gap. Putting the nanotips so close together allows charge to flow via quantum tunneling as the electrons are pushed from one side to the other.

A novel nano-tomography method opens the door to computed tomography examinations of minute structures at nanometer resolutions. Three-dimensional detailed imaging of fragile bone structures becomes possible. This new technique will facilitate advances in both life sciences and materials sciences.
nano-tomography
Schematic of the new nano-CT method. The sample is scanned with an X-ray beam while the detector records a diffraction pattern for every beam position. The sample is then turned around its axis and scanned again, until a complete set of data is gathered for every angle. A high-resolution three-dimensional image of the sample is then computed from the hundreds of thousands of diffraction patterns by means of specially developed image reconstruction algorithms.

Researchers have come up with an intriguing new class of molecular probes for biomedical research called nanoLAMPs. Unlike most probes used in biomedicine or other types of research they don't require dyes or fluorescence but, like an ordinary house lamp, they do need a light switch in order to illuminate the molecular world. These nanoLAMPs, which stands for Nano-Layered Metal-dielectric Particles, can solve a problem in biomedical research: the inability to measure multiple molecules simultaneously with a high degree of accuracy and reliability.

Computers, light bulbs, and even people generate heat—energy that ends up being wasted. With a thermoelectric device, which converts heat to electricity and vice versa, you can harness that otherwise wasted energy. Researchers at Caltech have developed a new type of material - made out of silicon, the second most abundant element in Earth's crust - that could lead to more efficient thermoelectric devices.

Friday, September 17, 2010

This week in nanotechnology - September 17, 2010

Graphene may hold key to speeding up DNA sequencing. Researchers from Harvard University and MIT have demonstrated that graphene, a surprisingly robust planar sheet of carbon just one-atom thick, can act as an artificial membrane separating two liquid reservoirs. By drilling a tiny pore just a few-nanometers in diameter, called a nanopore, in the graphene membrane, they were able to measure exchange of ions through the pore and demonstrated that a long DNA molecule can be pulled through the graphene nanopore just as a thread is pulled through the eye of a needle.

artificial e-skin with nanowire active matrix circuitry covering a hand
An artist's illustration of an artificial e-skin with nanowire active matrix circuitry covering a hand. The fragile egg illustrates the functionality of the e-skin device for prosthetic and robotic applications.

Engineers make artificial skin out of nanowires. Engineers at UC Berkeley, have developed a pressure-sensitive electronic material from semiconductor nanowires that could one day give new meaning to the term "thin-skinned." A touch-sensitive artificial skin would help overcome a key challenge in robotics: adapting the amount of force needed to hold and manipulate a wide range of objects.

Using carbon nanotubes, MIT chemical engineers have found a way to concentrate solar energy 100 times more than a regular photovoltaic cell. Such nanotubes could form antennas that capture and focus light energy, potentially allowing much smaller and more powerful solar arrays.

Molecular machines can be found everywhere in nature, for example, transporting proteins through cells and aiding metabolism. To develop artificial molecular machines, scientists need to understand the rules that govern mechanics at the molecular or nanometer scale. To address this challenge, a research team at UC Riverside studied a class of molecular machines that 'walk' across a flat metal surface. They considered both bipedal machines that walk on two 'legs' and quadrupedal ones that walk on four.

aregions on a cathode surface display varying electrochemical behaviors when probed with ESM
This 1 micron x 1 micron composite image demonstrates how regions on a cathode surface display varying electrochemical behaviors when probed with ESM.

As industries and consumers increasingly seek improved battery power sources, cutting-edge microscopy performed at the Department of Energy's Oak Ridge National Laboratory is providing an unprecedented perspective on how lithium-ion batteries function. They have developed a new type of scanning probe microscopy called electrochemical strain microscopy (ESM) to examine the movement of lithium ions through a battery's cathode material.

A Florida State University engineering professor's innovative research with nanomaterials could one day lead to a new generation of hydrogen fuel cells that are less expensive, smaller, lighter and more durable. Working with carbon nanotubes, he has designed a membrane that could reduce the need for expensive platinum components in hydrogen fuel cells.

quantum tornado
A flat wave (left) meets the specially shaped grid screen, which converts the electron beam into right-rotating and left-rotating vortex beams (top and bottom), and a middle beam that does not rotate. Similar to in a tornado, the rotation of the electron current is low internally.

Manipulating materials with rotating quantum particles: a team from the University of Antwerp and TU Vienna has succeeded in producing what are known as vortex beams - rotating electron beams, which make it possible to investigate the magnetic properties of materials. In the future, it may even be possible to manipulate the tiniest components in a targeted manner and set them in rotation.

Researchers at Oregon State University have reported the successful loading of biological molecules onto "nanosprings" - a type of nanostructure that has gained significant interest in recent years for its ability to maximize surface area in microreactors. Nanosprings are a little like a miniature version of an old-fashioned, curled-up phone cord. They make a great support on which to place reactive catalysts, and there are a variety of potential applications.

The ability of phase-change materials to readily and swiftly transition between different phases has made them valuable as a low-power source of non-volatile or "flash" memory and data storage. Now an entire new class of phase-change materials has been discovered that could be applied to phase change random access memory (PCM) technologies and possibly optical data storage as well. The new phase-change materials – nanocrystal alloys of a metal and semiconductor – are called "BEANs," for binary eutectic-alloy nanostructures.

Friday, September 10, 2010

This week in nanotechnology - September 10, 2010

Researchers create new self-assembling photovoltaic technology that repairs itself. Plants are good at doing what scientists and engineers have been struggling to do for decades: converting sunlight into stored energy, and doing so reliably day after day, year after year. Now some MIT scientists have succeeded in mimicking a key aspect of that process. Plants constantly break down their light-capturing molecules and reassemble them from scratch, so the basic structures that capture the sun's energy are, in effect, always brand new.

Researchers from ETH Zurich's Institute for Field Theory and High Frequency Electronics have developed new surfaces for radar absorption. Thanks to this multifaceted application, window panes could even double up as solar panels in future. The researchers have devised a new method to produce surfaces that can absorb radar radiation over an extremely broad range.
new metamaterials are particularly efficient at absorbing radar radiation through a recurring pattern of copper plates and holes.

The new metamaterials are particularly efficient at absorbing radar radiation through a recurring pattern of copper plates and holes.

A North Carolina State University researcher and colleagues have figured out a way to make an aluminum alloy, or a mixture of aluminum and other elements, just as strong as steel. The aluminum alloys have unique structural elements that, when combined to form a hierarchical structure at several nanoscale levels, make them super-strong and ductile.

Scientists have discovered that electrons in graphene can split up into an unexpected and tantalizing set of energy levels when exposed to extremely low temperatures and extremely high magnetic fields. The new research raises several intriguing questions about the fundamental physics of this exciting material and reveals new effects that may make graphene even more powerful than previously expected for practical applications.

For the first time, a team of MIT chemical engineers has observed single ions marching through a tiny carbon-nanotube channel. Such channels could be used as extremely sensitive detectors or as part of a new water-desalination system. They could also allow scientists to study chemical reactions at the single-molecule level.

Friday, September 3, 2010

This week in nanotechnology - September 3, 2010

Sugar, salt, alcohol and a little serendipity led a Northwestern University research team to discover a new class of nanostructures that could be used for gas storage and food and medical technologies. And the compounds are edible. The porous crystals are the first known all-natural metal-organic frameworks (MOFs) that are simple to make. Most other MOFs are made from petroleum-based ingredients, but the Northwestern MOFs you can pop into your mouth and eat, and the researchers have.

Silicon oxide nanoelectronics circuits break barrier. Scientists at Rice University have created the first two-terminal memory chips that use only silicon, one of the most common substances on the planet, in a way that should be easily adaptable to nanoelectronic manufacturing techniques and promises to extend the limits of miniaturization subject to Moore's Law.

Playing snooker with atoms. Scientists speak of sputtering when energy-rich ions hit a solid object and cause atoms to be released from its surface. The phenomenon can be exploited to apply microscopically thin coatings to glass surfaces. A research team has developed a special sputtering technique that greatly increases the efficiency of the coating process.

One of the most difficult aspects of working at the nanoscale is actually seeing the object being worked on. Biological structures like viruses, which are smaller than the wavelength of light, are invisible to standard optical microscopes and difficult to capture in their native form with other imaging techniques. A multidisciplinary research group at UCLA has now teamed up to not only visualize a virus but to use the results to adapt the virus so that it can deliver medication instead of disease.

To watch a magician transform a vase of flowers into a rabbit, it's best to have a front-row seat. Likewise, for chemical transformations in solution, the best view belongs to the molecular spectators closest to the action. Those special molecules comprise the "first solvation shell," and although it has been known for decades that they can sense and dictate the fate of nearly every chemical reaction, it has been virtually impossible to watch them respond. University of Michigan researchers Kevin Kubarych and Carlos Baiz, however, recently achieved the feat.
An optical microscopy image of seven color filters illuminated by white microscope light

The molecules shown here in yellow are first-hand observers to an ultrafast chemical reaction. As the reaction proceeds, the vibrational frequencies of the yellow molecules change. By "listening" to changes in these vibrational frequencies, researchers could observe the chemical reaction underway. The rainbow colors indicate how the "notes" of the yellow molecules change in response to the reaction.

Physicists at the National Institute of Standards and Technology have used a small crystal of ions (electrically charged atoms) to detect forces at the scale of yoctonewtons - that's 0.000000000000000000000001 Newtons. The ion sensor works by examining how an applied force affects ion motion, based on changes in laser light reflected off the ions.

Researchers at Georgia Tech have developed a new class of electronic logic device in which current is switched by an electric field generated by the application of mechanical strain to zinc oxide nanowires. The devices, which include transistors and diodes, could be used in nanometer-scale robotics, nano-electromechanical systems (NEMS), micro-electromechanical systems (MEMS) and microfluidic devices. The mechanical action used to initiate the strain could be as simple as pushing a button, or be created by the flow of a liquid, stretching of muscles or the movement of a robotic component.

Researchers at Caltech have devised a new technique - using a sheet of carbon just one atom thick - to visualize the structure of molecules. The technique, which was used to obtain the first direct images of how water coats surfaces at room temperature, can also be used to image a potentially unlimited number of other molecules, including antibodies and other biomolecules.