#NIST offers electronics industry two ways to snoop on self-organizing molecules A few short years ago,
the idea of a practical manufacturing process based on getting molecules to organize themselves in useful nanoscale shapes seemed...
working with IBM, demonstrated a new measurement technique*that uses low energy or"soft"X rays produced by the Advanced Light source at Lawrence Berkeley National Labs to probe the structure of the BCP film from multiple angles.
Because the film has a regular repeating structure, the scattering pattern can be interpreted, much as crystallographers do,
although the basic technique was developed using short wavelength"hard"X rays that have difficulty distinguishing two closely related polymers,
much better results can be obtained using longer wavelength X rays that are more sensitive to differences in the molecular structure.**
"Our business concept focuses on the design of processes with low energy, low toxicity, minimisation of waste and reduction of contaminating emissions",Víctor Puntes affirms."
#Atom-width graphene sensors could provide unprecedented insights into brain structure and function Understanding the anatomical structure
which use photons instead of electrons are opening new opportunities for visualizing neural network structure and exploring brain functions.
The graphene sensors are electrically conductive but only 4 atoms thick less than 1 nanometer and hundreds of times thinner than current contacts.
#See-through one-atom-thick carbon electrodes powerful tool to study brain disorders Researchers from the Perelman School of medicine and School of engineering at the University of Pennsylvania and The Children's Hospital of Philadelphia have used graphene
a two-dimensional form of carbon only one atom thick to fabricate a new type of microelectrode that solves a major problem for investigators looking to understand the intricate circuitry of the brain.
In the study Litt Kuzum and their colleagues performed calcium imaging of hippocampal slices in a rat model with both confocal and two-photon microscopy while also conducting electrophysiological recordings.
The simultaneous imaging and recording experiments involving calcium imaging with confocal and two photon microscopy was performed at Douglas Coulter's Lab at CHOP with Hajime Takano.
Lithium-ion batteries, though mature and widely utilized, have encountered the theoretical limit and therefore can not meet the urgent need for high energy density.
Lithium-sulfur batteries, owning a theoretical energy density of 2600 Wh kg-1, which are approximately 4 times as much as commercially used lithium-ion batteries,
are considered to be strong candidates. The abundance and environmentally friendly nature of the element sulfur as cathode material are factors in the huge potential of lithium-sulfur batteries.
"The areal capacity of commercially used lithium-ion batteries is about 4 mah cm-2,
high energy densities for future flexible electronic devices such as smart electronics and roll up displays. y
#New self-assembly method for fabricating graphene nanoribbons First characterized in 2004 graphene is a two-dimensional material with extraordinary properties.
Spintronics devices unlike conventional electronics use electrons'spins rather than their charge. But this top-down fabrication approach is not yet practical
In this bottom-up technique researchers use a copper substrate's unique properties to change the way the precursor molecules react to one another as they assemble into graphene nanoribbons.
Previous strategies in bottom-up molecular assemblies used inert substrates such as gold or silver to give molecules a lot of freedom to diffuse
But this also means that the way these molecules assemble is determined completely by the intermolecular forces and by the molecular chemistry.
or cathode and scratched the surface with sandpaper to form a light panel capable of producing a large stable and homogenous emission current with low energy consumption.
Under a strong electric field the cathode emits tight high-speed beams of electrons through its sharp nanotube tips a phenomenon called field emission.
The electrons then fly through the vacuum in the cavity and hit the phosphor screen into glowing.
Field emission electron sources catch scientists'attention due to its ability to provide intense electron beams that are about a thousand times denser than conventional thermionic cathode (like filaments in an incandescent light bulb.
and produce a much more directional and easily controllable stream of electrons. In recent years carbon nanotubes have emerged as a promising material of electron field emitters owing to their nanoscale needle shape and extraordinary properties of chemical stability thermal conductivity and mechanical strength.
Highly crystalline single-walled carbon nanotubes (HCSWCNT) have nearly zero defects in the carbon network on the surface Shimoi explained.
& Communication Technology were first in the world to demonstrate single-atom spin qubits in silicon reported in Nature in 2012 and 2013.
Now the team led by Dzurak has discovered a way to create an artificial atom qubit with a device remarkably similar to the silicon transistors used in consumer electronics known as MOSFETS.
Postdoctoral researcher Menno Veldhorst lead author on the paper reporting the artificial atom qubit says It is really amazing that we can make such an accurate qubit using pretty much the same devices as we have in our laptops and phones.
Meanwhile Morello's team has been pushing the natural phosphorus atom qubit to the extremes of performance.
Dr Juha Muhonen a postdoctoral researcher and lead author on the natural atom qubit paper notes:
The phosphorus atom contains in fact two qubits: the electron and the nucleus. With the nucleus in particular we have achieved accuracy close to 99.99%.
%That means only one error for every 10000 quantum operations. Dzurak explains that even though methods to correct errors do exist their effectiveness is guaranteed only
The high-accuracy operations for both natural and artificial atom qubits is achieved by placing each inside a thin layer of specially purified silicon containing only the silicon-28 isotope.
This isotope is perfectly nonmagnetic and unlike those in naturally occurring silicon does not disturb the quantum bit.
or millions of qubits and may integrate both natural and artificial atoms. Morello's research team also established a world-record coherence time for a single quantum bit held in solid state.
Pairing up single atoms in silicon for quantum computing More information: Storing quantum information for 30 seconds in a nanoelectronic device Nature Nanotechnology DOI:
For the very first time a general strategy to manufacture inorganic nanoparticles with user-specified 3d shapes has been achieved to produce particles as small as 25 nanometers or less with remarkable precision (less than 5 nanometers.
Just as any expanding material can be shaped inside a mold to take on a defined 3d form the Wyss team set out to grow inorganic particles within the confined hollow spaces of stiff DNA nanostructuresthe concept can be likened to the Japanese method of growing watermelons in glass cubes.
and height of the particle able to be controlled independently. Next researchers fabricated varied 3d polygonal shapes spheres and more ambitious structures such as a 3d Y-shaped nanoparticle and another structure comprising a cuboid shape sandwiched between two spheres proving that structurally-diverse
For particles that would better serve their purpose by being as electrically conducive as possible such as in very small nanocomputers
and functionality (controlled through surrounding molecules) of gold nanoparticles to see how these factors affect skin penetration.
When the nanoparticles are coated with cell penetrating peptides the penetration is enhanced further by up to ten times with many particles making their way into the deeper layers of the skin (such as the dermis.
and promises the ability to position functional biological molecules such as those involved in taste, smell,
In the study, the researchers used something called Atomic force microscopy (AFM), which is an imaging process that has a resolution down to only a fraction of a nanometer
However, instead of writing with fluid ink, we allow the lipid molecules the ink to dry on the tip first.
'which convert the detection of small molecules into electrical signals to stimulate our sense of smell. And many drugs work by targeting specific membrane proteins."
At the Vienna University of Technology (TU Wien) tiny particles have been coupled to a glass fibre. The particles emit light into the fibre in such a way that it does not travel in both directions,
as one would expect. Instead, the light can be directed either to the left or to the right.
This has become possible by employing a remarkable physical effect the spin-orbit coupling of light.
Gold nanoparticles on Glass fibres When a particle absorbs and emits light, this light is emitted not just into one direction."
"A particle in free space will always emit as much light into one particular direction as it emits into the opposite direction,
whether the light emitted by the particle travels left or right in the glass fibre. Bicycles and Airplane propellers This is only possible
because light has an intrinsic angular momentum, the spin. Similar to a pendulum which can swing in one particular plane
Its rotational axis corresponding to the spin points into the direction of propagation. But light moving through ultra-thin glass fibres has very special properties.
"Then, the direction of propagation is perpendicular to the spin, just like a bicycle, moving into a direction
The effect is called"spin-orbit-coupling of light"."Coupling Rotation and the Direction of Motion
When a particle that is coupled to the glass fibre is irradiated with a laser in such a way that it emits light of a particular sense of rotation,
the diameter of the gold particle is even four times less. Both the diameter of the fibre and the particle are even smaller than the wavelength of the emitted light."
"This new technology should be made easily available in commercial applications. Already now, the whole experiment fits into a shoebox,
which is known a'stealth'molecule that acts to camouflage the carrier preventing it from being detected
of microscopic cones that harness electrostatic forces to eject streams of ions. The technology has a range of promising applications:
array that generates 10 times the ion current per emitter that previous arrays did. Ion current is a measure of the charge carried by moving ions
which translates directly to the rate at which particles can be ejected. Higher currents thus promise more-efficient manufacturing and more-nimble satellites.
The same prototype also crams 1900 emitters onto a chip that's only a centimeter square quadrupling the array size and emitter density of even the best of its predecessors.
which droplets clumps of molecules rather than ions individual molecules begin streaming off of the emitters.
The ions ejected by Velsquez-Garca's prototype are produced from an ionic salt that's liquid at room temperature.
and ideally ejected one molecule at a time. When the ion current in an emitter gets high enough droplet formation is inevitable.
But earlier emitter arrays those built both by Velsquez-Garca's group and by others fell well short of that threshold.
Increasing an array's ion current is a matter of regulating the flow of the ionic salt up the emitters'sides.
But in the new work they instead used carbon nanotubes atom-thick sheets of carbon rolled into cylinders grown on the slopes of the emitters like trees on a mountainside.
and height of the nanotubes the researchers were able to achieve a fluid flow that enabled an operating ion current at very near the theoretical limit.
which is broken into particles by chemical reactions with both the substrate and the environment. Then they expose the array to a plasma rich in carbon.
The nanotubes grow up under the catalyst particles which sit atop them until the catalyst degrades.
Typically the interest of this type of emitter is to be able to emit a beam of ions
Using their nanotube forest they're able to get the devices to operate in pure ion mode
The reason you'd like to be in ion mode is to have the most efficient conversion of the mass of the propellant into the momentum of the spacecraft t
and build new materials at the level of individual atoms More information: Nijland M. George A. Thomas S. Houwman E. P. Xia J. Blank D. H. A. Rijnders G. Koster G. and ten Elshof
so that doctors and researchers can track the particles. Finally they need to perform their function at the right moment ideally in response to a stimulus. The Nanoparticles By design Unit at the Okinawa Institute of Science
and Technology Graduate University is trying to develop new particles with unprecedented properties that still meet these requirements.
and particles in the air and enzymes molecules and antibodies in the body that could indicate diabetes cancer and other diseases.
It's been a challenge to sense very small particles or very low concentrations of a substance.
They found that the particles which have no electric charge or surface molecules that would attract the attention of circulating immune cells were able to enter the mice's lymph nodes.
But once inside the lymph nodes'core the special kind of macrophage engulfed the particles. When molecules for signaling killer T cells were put inside the nanoparticles they hindered tumor growth far better than existing vaccines.
Explore further: Hitchhiking vaccines boost immunity More information: Nanogel-Based Immunologically Stealth Vaccine Targets Macrophages in the Medulla of Lymph node
and Induces Potent Antitumor Immunity ACS Nano 2014 8 (9) pp 9209#9218. DOI: 10.1021/nn502975r Because existing therapeutic cancer vaccines provide only a limited clinical benefit a different vaccination strategy is necessary to improve vaccine efficacy.
The results indicate little risk to humans ingesting the particles through drinking water say scientists at Duke's Center for the Environmental Implications of Nanotechnology (CEINT.
if the nanoparticles provide Trojan horse piggyback rides to other harmful molecules. The results appear online in the journal Environmental science:
These nanoparticles are really good at latching onto other molecules including many known organic contaminants said Ferguson.
For example, they reported the world's first"domain wall gate"at last year's International Electron Devices Meeting.
Extremely low energy consumption is one of their most promising characteristics. They also can operate at room temperature
and resist radiation. The potential to pack more gates onto a chip is especially important.
Charge transport anisotropy is a phenomenon where electrons flow faster along a particular crystallographic direction due to close molecule-molecule interactions.
Briseno says The biggest challenge in producing this architecture was finding the appropriate substrate that would enable the molecules to stack vertically.
Dr. Tal Dvir and his graduate student Michal Shevach of TAU's Department of Biotechnology, Department of Materials science and engineering,
However, due to residual remnants of antigens such as sugar or other molecules, the human patients'immune cells are likely to attack the animal matrix.
#Nanotube cathode beats large pricey laser Scientists are a step closer to building an intense electron beam source without a laser.
Using the High-Brightness Electron Source Lab at DOE's Fermi National Accelerator Laboratory a team led by scientist Luigi Faillace of Radiabeam Technologies is testing a carbon nanotube cathode about the size of a nickel
and national security since an electron beam is a critical component in generating X-rays. While carbon nanotube cathodes have been studied extensively in academia Fermilab is the first facility to test the technology within a full-scale setting.
and expertise for handling intense electron beams one of relatively few labs that can support this project.
When a strong electric field is applied it pulls streams of electrons off the surface of the cathode creating the electron beam.
Traditionally accelerator scientists use lasers to strike cathodes in order to eject electrons through photoemission. The electric and magnetic fields of the particle accelerator then organize the electrons into a beam.
The tested nanotube cathode requires no laser: it only needs the electric field already generated by an accelerator to siphon the electrons off a process dubbed field emission n
#Nanoengineering enhances charge transport promises more efficient future solar cells Solar cells based on semiconducting composite plastics and carbon nanotubes is one of the most promising novel technology for producing inexpensive printed solar cells.
Physicists at Umeå University have discovered that one can reduce the number of carbon nanotubes in the device by more than 100 times
The microscopic lithium-ion batteries are created by taking a silicon wire a few micrometers long and covering it in successive layers of different materials.
With STEM electrons illuminate the battery which scatters them at a wide range of angles.
To see as much detail as possible the team decided to use a set of electron detectors to collect electrons in a wide range of scattering angles an arrangement that gave them plenty of structural information to assemble a clear picture of the battery's interior down to the nanoscale level.
Miniature all-solid-state heterostructure nanowire Li-ion batteries as a tool for engineering and structural diagnostics of nanoscale electrochemical processes.
#Harnessing an unusual'valley'quantum property of electrons Yoshihiro Iwasa and colleagues from the RIKEN Center for Emergent Matter Science the University of Tokyo and Hiroshima University have discovered that ultrathin films of a semiconducting material have properties that form the basis for a new kind of low-power electronics
and process information using the electrical charge of an electron. The use of charge however requires physically moving electrons from one point to another
which can consume a great deal of energy particularly in computing applications. Researchers are therefore searching for ways to harness other properties of electrons such as the'spin'of an electron as data carriers in the hope that this will lead to devices that consume less power.
Valleytronics is based on the quantum behavior of electrons in terms of a material's electronic band structure.
Semiconductors and insulators derive their electrical properties from a gap between the highest band occupied by electrons known as the valence band
and the lowest unoccupied band or'conduction band'in the band structure explains Iwasa. If there are two
Using this valley property of electrons to encode information without physically moving electrons is the central tenet of valleytronics.
Iwasa and his co-workers combined theoretical calculations with an experimental spin -and angle-resolved photoelectron spectroscopy technique to identify such valleys in the band structure of an ultrathin layer of molybdenum disulfide just a few atoms thick.
Molybdenum disulfide is a member of a family of materials known as transition metal dichalcogenides which are currently the focus of intense research because of the unusual electronic properties they display
Instead the atoms in each molybdenum disulfide layer in the films created by Iwasa's team were shifted slightly from those in the two-dimensional level beneath (Fig. 1). This breaking of the film's symmetry meant that the researchers were also able to harness the spin of electrons.
and spin degrees of freedom says Iwasa. The researchers hope to demonstrate valleytronics prototypes based on molybdenum disulfide
When semiconducting materials are subjected to an input of a specific energy bound electrons can be moved to higher energy conducting states.
Goncharov's team focused on the novel application of very high pressure which can cause a compound to undergo electronic changes that can alter the electron-carrier properties of materials.
They discovered the band gap that the electrons need to leap across to also widened although not as much as in the case of the zincblende crystal nanowires.
the smallest known reference material ever created for validating measurements of these man-made, ultrafine particles between 1 and 100 nanometers (billionths of a meter) in size.
Particle size and chemical composition are determined by dynamic light scattering, analytical centrifugation, electron microscopy and inductively coupled plasma mass spectrometry (ICP-MS),
Notably electrons in quantum dot structures are confined inside nanometer sized three dimension boxes. Novel applications of'quantum dots'including lasers biological markers qubits for quantum computing
But this was done using a chemical process for example using osmosis. Researchers at the Nijmegen Institute for Molecules
They have stretched the walls of the vesicles by aligning the molecules in the wall using the strong magnets of the High Field magnet Laboratory (HFML.
They will also experiment with different types of wall molecules. Wilson:''The current bubbles are not suitable for use in the human body
so we are looking for molecules which are. We also hope to find materials for which the same effect occurs in a lower magnetic field-that of an MRI.
Now researchers at A*STAR have used a process known as friction stir processing (see image) to produce an evenly distributed mix of nanosized aluminum oxide (Al2o3) particles in aluminum.
It also reduced the amount of airborne particles produced during powder placement and friction stir processing explains Guo.
smaller aluminum matrix grains can flow past each other more smoothly than larger particles enhancing the strength of the material.
Effects of nano-Al2o3 particle addition on grain structure evolution and mechanical behaviour of friction-stir-processed Al.
#Researchers uncover properties in nanocomposite oxide ceramics for reactor fuel Nanocomposite oxide ceramics have potential uses as ferroelectrics fast ion conductors
and radiation properties of the material as a whole said Pratik Dholabhai principal Los alamos National Laboratory researcher on the project.
It is in the chemical makeup of these interfaces where we can improve features such as tolerance against radiation damage and fast ion conduction.
Using simulations that explicitly account for the position of each atom within the material the Los alamos research team examined the interface between Srtio3
and radiation damage resistance of oxide nanocomposites by controlling the termination chemistry at the interface.
since 2001 and our technology has achieved now the fabrication of large area(>1000 mm2) ultra-thin films only a few atoms thick.
they have amplified the interaction of light with DNA to the extent that they can now track interactions between individual DNA molecule segments.
Their optical biosensor for single unlabelled molecules could also be a breakthrough in the development of biochips:
In cells, nanomachines such as ribosomes and DNA polymerases stitch individual molecules together to form complex biological structures such as proteins and DNA molecules, the repositories of genetic information.
Although it is possible to investigate the interaction of individual molecules with enzymes or ribosomes,
the molecules often have to be labelled, for example with fluorescent markers, in order to observe them. However, such labelling is only possible with certain molecules,
and it can interfere with the function of the biological nanomachines. Although light can be used to detect unlabelled biomolecules,
the approach cannot be used to detect single DNA molecules, as the interaction of light waves with the molecule is too weak.
A team of physicists headed by Frank Vollmer of the Laboratory for Nanophotonics and Biosensors at the Max Planck Institute for the Science of Light has succeeded now in amplifying the interaction of light with DNA molecules to the extent that their photonic biosensor can be used to observe single unlabelled molecules and their interactions.
A microsphere becomes an optical whispering gallery To achieve this, the physicists use glass beads around 60 micrometres in diameter, about the thickness of a human hair,
The microsphere and nanowire amplify the interaction between light and molecules. With the help of a prism, the researchers shine laser light into the microsphere.
If a molecule is fixed to the surface of the glass bead, the light beam travels past it more than a hundred thousand times.
an interaction occurs between it and the molecule. This interaction is amplified greatly due to the frequent contact between the light and the molecule.
However the interaction is still too weak to register single molecules. Vollmer and his colleagues therefore fix a nanowire to the surface of the glass bead.
The light whizzing past generates plasmons: collective oscillations of electrons.""The plasmons pull the light wave a little further out of the glass microsphere,
"Vollmer explains. This amplifies the field strength of the light wave by a factor of more than a thousand.
"Based on the duration and frequency of the measured interactions, it is then possible to detect specific unlabelled DNA molecules."
Even in nature, the bonds formed between molecules and nanomachines are fleeting. Thanks to the new method, it is now possible to explore such natural kinetics in greater detail,
and transport fundamental particles of light called photons. The tiny device is just. 7 micrometers by 50 micrometer (about. 00007 by. 005 centimeters) and works almost like a seesaw.
These cavities capture photons that streamed from a nearby source. Even though the particles of light have no mass the captured photons were able to play seesaw
because they generated optical force. Researchers compared the optical forces generated by the photons captured in the cavities on the two sides of the seesaw by observing how the seesaw moved up and down.
In this way the researchers weighed the photons. Their device is sensitive enough to measure the force generated by a single photon
which corresponds to about one-third of a thousand-trillionth of a pound or one-seventh of a thousand-trillionth of a kilogram.
Professor Li and his research team also used the seesaw to experimentally demonstrate for the first time the mechanical control of transporting light.
When we filled the cavity on the left side with photons and leave the cavity on the right side empty the force generated by the photons started to oscillate the seesaw.
When the oscillation was strong enough the photons can spill over along the beam from the filled cavity to the empty cavity during each cycle Li said.
We call the phenomenon'photon shuttling.''The stronger the oscillation the more photons are shuttled to the other side.
Currently the team has been able to transport approximately 1000 photons in a cycle. For comparison a 10w light bulb emits 1020 photons every second.
The team's ultimate goal is to transport only one photon in a cycle so that the quantum physics of light can be revealed and harnessed.
The ability to mechanically control photon movement as opposed to controlling them with expensive and cumbersome optoelectronic devices could represent a significant advance in technology said Huan Li the lead author of the paper.
The research could be used to develop an extremely sensitive micromechanical way to measure acceleration of a car
or a runner or could be used as part of a gyroscope for navigation Li said.
In the future the researchers plan to build sophisticated photon shuttles with more traps on either side of the seesaw device that could shuttle photons over greater distances and at faster speeds.
They expect that such devices could play a role in developing microelectronic circuits that would use light instead of electrons to carry data
which would make them faster and consume less power than traditional integrated circuits. Explore further: Breakthrough in light sources for new quantum technology More information:
Optomechanical photon shuttling between photonic cavities Nature Nanotechnology (2014) DOI: 10.1038/nnano. 2014.20 0
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