Friday, May 28, 2010

This week in nanotechnology - May 28, 2010

Nanotechnology researchers build transistor with just seven atoms. Scientists have literally taken a leap into a new era of computing power by making the world's smallest precision-built transistor - a 'quantum dot' of just seven atoms in a single silicon crystal. Despite its incredibly tiny size - a mere four billionths of a meter long - the quantum dot is a functioning electronic device, the world's first created deliberately by placing individual atoms.

Creating catalysts that can operate efficiently and last a long time is a big barrier to taking fuel-cell technology from the lab bench to the assembly line. The precious metal platinum has been the choice for many researchers, but platinum has two major downsides: It is expensive, and it breaks down over time in fuel-cell reactions. In a new study, chemists have created a unique core and shell nanoparticle that uses far less platinum yet performs more efficiently and lasts longer than commercially available pure-platinum catalysts at the cathode end of fuel-cell reactions.

Graphane is the material of choice for physicists on the cutting edge of materials science. Researchers at Rice University have discovered the strategic extraction of hydrogen atoms from a two-dimensional sheet of graphane naturally opens up spaces of pure graphene that look - and act - like quantum dots. That opens up a new world of possibilities for an ever-shrinking class of nanoelectronics that depend on the highly controllable semiconducting properties of quantum dots, particularly in the realm of advanced optics.

microlens


Rice researchers created these fanciful images of electron densities from their graphane-embedded quantum dot calculations. The isosurfaces depict electrons in the valance band that, in reality, would be confined within the quantum dot, and demonstrate that very little charge would leak from the hydrogen-defined boundaries of such a dot.


Researchers have discovered thin films of nanotubes created with ink-jet printers offer a new way to make field-effect transistors (FET), the basic element in integrated circuits. While the technique doesn't exactly scale down to the levels required for modern microprocessors, it could be useful to inventors who wish to print transistors on materials of any kind, especially on flexible substrates.

Jeffrey Long’s lab will soon host a round-the-clock, robotically choreographed hunt for carbon-hungry materials.
The Berkeley Lab chemist leads a diverse team of scientists whose goal is to quickly discover materials that can efficiently strip carbon dioxide from a power plant’s exhaust, before it leaves the smokestack and contributes to climate change. They’re betting on a recently discovered class of materials called metal-organic frameworks that boast a record-shattering internal surface area. A sugar cube-sized piece, if unfolded and flattened, would more than blanket a football field. The crystalline material can also be tweaked to absorb specific molecules. The idea is to engineer this incredibly porous compound into a voracious sponge that gobbles up carbon dioxide.

Imagine creating novel devices with amazing and exotic optical properties not found in Nature - by simply evaporating a droplet of nanoparticles on a surface. By chemically building clusters of nanospheres from a liquid, a team of Harvard researchers, in collaboration with scientists at Rice University, the University of Texas at Austin, and the University of Houston, has developed just that.

Friday, May 21, 2010

This week in nanotechnology - May 21, 2010

UCLA researchers and their collaborators have developed a method that could open the door for investigations into the function of half of all proteins in the human body. The research team has demonstrated nanoscale control over molecules, allowing for the precise study of interactions between proteins and small molecules. Their new technique, in which molecules are used as bait to capture and study large biomolecules, could lead to a new generation of psychiatric medications.

A team of engineers has created the world's smallest pump. The minute device, similar in size to a human red blood cell, is powered by an electrode made from something that doesn't usually conduct electricity - glass.

At the scale of the very small, physics can get peculiar. A University of Michigan biomedical engineering professor has discovered a new instance of such a nanoscale phenomenon - one that could lead to faster, less expensive portable diagnostic devices and push back frontiers in building micro-mechanical and "lab on a chip" devices. The team was able to get an electric current to pass nondestructively through a sliver of glass, which isn't usually a conductor.

Researchers from Rensselaer Polytechnic Institute have developed a new nanotechnology-based “microlens” that uses gold to boost the strength of infrared imaging and could lead to a new generation of ultra-powerful satellite cameras and night-vision devices.

microlens


The device, pictured, leverages the unique properties of nanoscale gold to “squeeze” light into the tiny holes in its surface.


Nanoparticle 'sharkskin' for airplanes, ships and wind energy plants. To lower the fuel consumption of airplanes and ships, it is necessary to reduce their flow resistance, or drag. An innovative paint system makes this possible. This not only lowers costs, it also reduces CO2 emissions.

Physicists develop a nanowire quantum interface between light and atoms. The interface is based on an ultra-thin glass fiber and is suitable for the transmission of quantum information. This is an essential prerequisite for quantum communication which shall be used for secure data transmission via quantum cryptography.

Friday, May 14, 2010

This week in nanotechnology, May 14, 2010

Researchers at the University of Gothenburg, Sweden, have managed, with the help of an advanced X-ray flash, to photograph the movement of atoms during photosynthesis. Using the special X-ray camera, researchers can depict the position of atoms in a molecule and obtain a three-dimensional image of something that is smaller than a nanometer.

Further revealing the secrets behind photosynthesis, researchers in the U.S. have recorded the first observation and characterization of a critical physical phenomenon behind photosynthesis known as quantum entanglement. This is the first study to show that entanglement, perhaps the most distinctive property of quantum mechanical systems, is present across an entire light harvesting complex.

In a single day, a solitary grad student at a lab bench can produce more simple logic circuits than the world's entire output of silicon chips in a month. So says a Duke University engineer, who believes that the next generation of these logic circuits at the heart of computers will be produced inexpensively in almost limitless quantities. The secret is that instead of silicon chips serving as the platform for electric circuits, computer engineers will take advantage of the unique properties of DNA. DNA-based, waffle-like nanostructures will efficiently self-assemble, and when different light-sensitive molecules are added to the mixture, the waffles exhibit unique and "programmable" properties.

Self-assembling, waffle-like nanostructures


Self-assembling, waffle-like nanostructures.


MIT researchers find a way to calculate the effects of Casimir forces. Discovered in 1948, Casimir forces are complicated quantum forces that affect only objects that are very, very close together. They’re so subtle that for most of the 60-odd years since their discovery, engineers have safely ignored them. Now, the MIT team have developed a powerful new tool for calculating the effects of Casimir forces, with ramifications for both basic physics and the design of microelectromechanical systems (MEMS).

Nanotechnology sensor detects type 1 diabetes in breath. Acetone is also found in a healthy person’s breath, but the concentration is only about 900 ppb (particles per billion); in people suffering from type 1 diabetes, however, the concentration is double that; and in the case of a ketoacidosis it can be even higher. That’s why the sensor developed at ETH Zurich works so well: it can detect as few as 20 ppb of acetone and even works at extremely high humidity levels of over 90 percent - like in the human breath.

Physicists at McGill University have developed a system for measuring the energy involved in adding electrons to semi-conductor nanocrystals, also known as quantum dots - a technology that may revolutionize computing and other areas of science. The team has developed a cantilever force sensor that enables individual electrons to be removed and added to a quantum dot and the energy involved in the operation to be measured.

Researchers from Columbia University, Arizona State University, the University of Michigan and the California Institute of Technology (Caltech) have created and programmed robots the size of single molecule that can move independently across a nano-scale track. This development marks an important advancement in the nascent fields of molecular computing and robotics, and could someday lead to molecular robots that can fix individual cells or assemble nanotechnology products.

Friday, May 7, 2010

This week in nanotechnology - May 7, 2010

A team of scientists at UC Santa Barbara that helped pioneer research into the quantum properties of a small defect found in diamonds has now used cutting-edge computational techniques to produce a road map for studying defects in alternative materials. Their new research may enable new applications for semiconductors – materials that are the foundation of today's information technology. In particular, they may help identify alternative materials to use for building a potential quantum computer.

UCLA researchers report that they have imaged a virus structure at a resolution high enough to effectively "see" atoms, the first published instance of imaging biological complexes at such a resolution. The research team used cryo-electron microscopy to image the structure at 3.3 angstroms. An angstrom is the smallest recognized division of a chemical element and is about the distance between the two hydrogen atoms in a water molecule.

Depiction and manipulation the spin direction of individual atoms. An international team of researchers has built a chain of cobalt atoms and analysed its magnetic properties. Surprisingly, the spin sensitive measurements (”Spins“ = magnetic moments of electrons) show that the observed form of atoms depends on its magnetic orientation.

Lateral manipulation of a chain of six cobalt atoms


Lateral manipulation of a chain of six cobalt atoms.


Electrical currents are invisible to the naked eye – at least they are when they flow through metal cables. In nerve cells, however, scientists are able to make electrical signals visible. Scientists have successfully used a specialized fluorescent protein to visualize electrical activity in neurons of living mice. They are now able to apply the method to watch activity in nerve cells during animal behavior.

Quantum dots may be small. But they usually don’t let anyone push them around. Now, however, researchers have devised a self-adjusting remote-control system that can place a dot 6 nanometers long to within 45 nm of any desired location. That’s the equivalent of picking up golf balls around a living room and putting them on a coffee table – automatically, from 100 miles away.

New metamaterial device may lead to see-through cameras and scanners. Devices that can mimic Superman's X-ray vision and see through clothing, walls or human flesh are the stuff of comic book fantasy, but a group of scientists at Boston University has taken a step toward making such futuristic devices a reality. The team has developed a new way to detect and control terahertz (THz) radiation using optics and materials science. This type of radiation is made up of electromagnetic waves that can pass through materials safely. Their work may pave the way for safer medical and security scanners, new communication devices, and more sensitive chemical detectors.

Nanotechnology probe taps into algae cell and saps electrical energy. An intriguing novel approach to extract the energy from the photosynthetic conversion process has been demonstrated by researchers at Stanford and Yonsei Universities. They have inserted ultrasharp gold nanoelectrodes into living algae cells and extracted electrons, thereby harnessing an – albeit very tiny – electrical current. This is electricity production that doesn't release carbon into the atmosphere.