It is the first time that a single detector has been able to monitor the spectral range from visible light to infrared radiation and right through to terahertz radiation.
this comparatively simple and inexpensive construct can cover the enormous spectral range from visible light all the way to terahertz radiation."
"In contrast to other semiconductors like silicon or gallium arsenide, graphene can pick up light with a very large range of photon energies and convert it into electric signals.
"explained Dr. Stephan Winnerl, physicist at the Institute of Ion beam Physics and Materials Research at the HZDR.
thereby transferring the energy of the photons to the electrons in the graphene. These"hot electrons"increase the electrical resistance of the detector
and generate rapid electric signals. The detector can register incident light in just 40 picoseconds these are billionths of a second.
Then there is also an antenna which acts like a funnel and captures long-wave infrared and terahertz radiation.
This optical universal detector is already being used at the HZDR for the exact synchronization of the two free-electron lasers at the ELBE Center for High-power Radiation Sources with other lasers.
obviating the need for the expensive and time-consuming nitrogen or helium cooling processes with other detectors c
The particles, described today in Nature Communications, are enhanced an version of a naturally occurring, weakly magnetic protein called ferritin. erritin,
This eliminates the need to tag cells with synthetic particles and allows the particles to sense other molecules inside cells.
The paper lead author is former MIT graduate student Yuri Matsumoto. Other authors are graduate student Ritchie Chen and Polina Anikeeva, an assistant professor of materials science and engineering.
Magnetic pull Previous research has yielded synthetic magnetic particles for imaging or tracking cells, but it can be difficult to deliver these particles into the target cells.
In the new study, Jasanoff and colleagues set out to create magnetic particles that are encoded genetically.
With this approach the researchers deliver a gene for a magnetic protein into the target cells,
which carries a supply of iron atoms that every cell needs as components of metabolic enzymes.
) Plasmonic devices harness clouds of electrons called surface plasmons to manipulate and control light. Potential applications for the nanotweezer include improved-sensitivity nanoscale sensors
The nanotweezer might be used to create devices containing nanodiamond particles or other nanoscale light-emitting structures that can be used to enhance the production of single photons, workhorses of quantum information processing,
which could bring superior computers, cryptography and communications technologies. Conventional computers use electrons to process information.
However, the performance might be ramped up considerably by employing the unique quantum properties of electrons
and photons, said Vladimir M. Shalaev, co-director of a new Purdue Quantum Center, scientific director of nanophotonics at the Birck Nanotechnology Center and a distinguished professor of electrical and computer engineering."
"The nanotweezer system has been shown to cause convection in fluid on-demand, resulting in micrometer-per-second nanoparticle transport by harnessing a single plasmonic nanoantenna,
which cannot result in a net transport of suspended particles. However, the Purdue researchers have overcome this limitation,
increasing the velocity of particle transport by 100 times by applying an alternating current electric field in conjunction with heating the plasmonic nanoantenna using a laser to induce a force far stronger than otherwise possible."
The interesting thing about this system is that not only can we trap particles but also do useful tasks
If I bring a particle to the hotspot then I can do measurements, and sensing is enhanced
""Then, once we turn off the electric field the laser holds the particles in place, so it can operate in two modes.
The laser traps the particles, making it possible to precisely position them. The technique was demonstrated with polystyrene particles i
#An important step in artificial intelligence: Researchers in UCSB's Department of Electrical and Computer engineering are seeking to make computer brains smarter by making them more like our own Abstract:
which rely on the drift and diffusion of electrons and their holes through semiconducting material, memristor operation is based on ionic movement,
The ionic memory mechanism brings several advantages over purely electron-based memories, which makes it very attractive for artificial neural network implementation,
"Ions are also much heavier than electrons and do not tunnel easily, which permits aggressive scaling of memristors without sacrificing analog properties."
Measurement of a single nuclear spin in biological samples May 11th, 2015graphene holds key to unlocking creation of wearable electronic devices May 11th, 2015new Method to Produce Dual Zinc oxide Nanorings May 11th
Measurement of a single nuclear spin in biological samples May 11th, 2015graphene holds key to unlocking creation of wearable electronic devices May 11th, 2015new Method to Produce Dual Zinc oxide Nanorings May 11th
Measurement of a single nuclear spin in biological samples May 11th, 2015graphene holds key to unlocking creation of wearable electronic devices May 11th, 2015new Method to Produce Dual Zinc oxide Nanorings May 11th
Measurement of a single nuclear spin in biological samples May 11th, 2015graphene holds key to unlocking creation of wearable electronic devices May 11th, 2015new Method to Produce Dual Zinc oxide Nanorings May 11th
Measurement of a single nuclear spin in biological samples May 11th, 2015graphene holds key to unlocking creation of wearable electronic devices May 11th,
She uses a chemical vapour coating technique (sprayed ion-layer gas reaction/Spray-ILGAR) that was developed
and reveals large photoelectrocatalytic activity of about 690 hydrogen molecules produced per second and per active center at the surface under illumination.
Precise targeting biological molecules, such as cancer cells, for treatment is a challenge, due to their sheer size.
which is the basis for controlling electrons in computers, phones, medical equipment and other electronics. Yoke Khin Yap, a professor of physics at Michigan Technological University, has worked with a research team that created these digital switches by combining graphene and boron nitride nanotubes.
Nanoscale Tweaks Graphene is a molecule-thick sheet of carbon atoms; the nanotubes are made like straws of boron and nitrogen.
or differences in how much energy it takes to excite an electron in the material.""When we put them together,
you form a band gap mismatch--that creates a so-called'potential barrier'that stops electrons.""The band gap mismatch results from the materials'structure:
caused by the difference in electron movement as currents move next to and past the hairlike boron nitride nanotubes.
"Imagine the electrons are like cars driving across a smooth track, "Yap says.""They circle around and around,
With their aligned atoms, the graphene-nanotube digital switches could avoid the issues of electron scattering."
"You want to control the direction of the electrons, "Yap explains, comparing the challenge to a pinball machine that traps,
slows down and redirects electrons.""This is difficult in high speed environments, and the electron scattering reduces the number and speed of electrons."
"Much like an arcade enthusiast, Yap says he and his team will continue trying to find ways to outsmart
or change the pinball setup of graphene to minimize electron scattering. And one day, all their tweaks could make for faster computers--and digital pinball games--for the rest of us s
The team managed to synthesize a thin film made of densely packed aluminum oxide nanorods blended with molecules of a thrombolytic enzyme (urokinase-type plasminogen activator.
For example, particles organized in long-ranged structures by external fields can be bound permanently into stiff chains through electrostatic or Van der waals attraction,
much like sand particles mixed with the right amount of water can form sandcastles.""Because oil and water don't mix,
the oil wets the particles and creates capillary bridges between them so that the particles stick together on contact,
"said Orlin Velev, INVISTA Professor of Chemical and Biomolecular engineering at NC State and the corresponding author of the paper."
and an external magnetic field is applied to the particles.""In other words, this material is temperature responsive, and these soft and flexible structures can be pulled apart
Control voltages that shift oxygen ions and vacancies switch the bits between ones and zeroes.
the researchers found the tantalum oxide gradually loses oxygen ions, changing from an oxygen-rich, nanoporous semiconductor at the top to oxygen-poor at the bottom.
First, the control voltage mediates how electrons pass through a boundary that can flip from an ohmic (current flows in both directions) to a Schottky (current flows one way) contact and back.
These are"holes"in atomic arrays where oxygen ions should exist, but don't. The voltage-controlled movement of oxygen vacancies shifts the boundary from the tantalum/tantalum oxide interface to the tantalum oxide/graphene interface."
Third, the flow of current draws oxygen ions from the tantalum oxide nanopores and stabilizes them.
These negatively charged ions produce an electric field that effectively serves as a diode to hinder error-causing crosstalk.
The modular aspect of the system makes it possible to accommodate various radiation sources such as tunable lasers and non-coherent monochromatic or polychromatic sources s
a semiconducting layer made of silicon and germanium.""had used we an unknown sample for the demonstration,
The principle was tested at the HZDR on a typical laboratory laser as well as on the free-electron laser FELBE.
Graphene, an atom-thick material with extraordinary properties, is a promising candidate for the next generation of dramatically faster, more energy-efficient electronics.
Now, University of Wisconsin-Madison engineers have discovered a way to grow graphene nanoribbons with desirable semiconducting properties directly on a conventional germanium semiconductor wafer.
"Graphene nanoribbons that can be grown directly on the surface of a semiconductor like germanium are more compatible with planar processing that's used in the semiconductor industry,
Graphene, a sheet of carbon atoms that is only one atom in thickness, conducts electricity and dissipates heat much more efficiently than silicon,
straight edges directly on germanium wafers using a process called chemical vapor deposition. In this process, the researchers start with methane,
which adsorbs to the germanium surface and decomposes to form various hydrocarbons. These hydrocarbons react with each other on the surface,
the graphene crystals naturally grow into long nanoribbons on a specific crystal facet of germanium. By simply controlling the growth rate and growth time,
when graphene grows on germanium, it naturally forms nanoribbons with these very smooth, armchair edges,
or growing, at seemingly random spots on the germanium and are oriented in two different directions on the surface.
Toxicity and cancer-cell resistance can also compromise the effectiveness of radiation and chemotherapy that's often used as a follow-up to surgery.
Now, researchers from the University of Bristol in the UK and Nippon Telegraph and Telephone (NTT) in Japan, have pulled off the same feat for light in the quantum world by developing an optical chip that can process photons in an infinite number
which are typically extremely demanding due to the notoriously fragile nature of quantum systems. This result shows a step change for experiments with photons,
and what the future looks like for quantum technologies. Dr Anthony Laing, who led the project,
Now anybody can run their own experiments with photons, much like they operate any other piece of software on a computer.
We have fabricated also Li-ion batteries based on structurally resilient carbon nanotube-based electrodes that have survived thousands of flexing cycles.
a Lawrence Berkeley National Laboratory (Berkeley Lab) researcher has invented a new technology to image single molecules with unprecedented spectral and spatial resolution,
Because SR-STORM gives full spectral and spatial information for each molecule, the technology opens the door to high-resolution imaging of multiple components and local chemical environments, such as ph variations, inside a cell.
The research was reported in the journal Nature Methods in a paper titled,"Ultrahigh-throughput single-molecule spectroscopy and spectrally resolved super-resolution microscopy"
and spectrum of each individual molecule, plotting its super-resolved spatial position in two dimensions and coloring each molecule according to its spectral position,
"This is a new type of imaging, combining single-molecule spectral measurement with super-resolution microscopy."
able to deliver spatial and spectral information for millions of single molecules in about five minutes,
compared to several minutes for a single frame of image comprising tens of molecules using conventional scanning-based techniques.
Xu built on work he did as a postdoctoral researcher at Harvard with Xiaowei Zhuang, who invented STORM, a super-resolution microscopy method based on single-molecule imaging and photoswitching.
which is useful for scientists to understand the behavior of individual molecules, as well as to enable high-quality multicolor imaging of multiple targets."
but dispersed the single-molecule image collected by one objective lens into spectrum while keeping the other image for single-molecule localization,
"Now we are simultaneously accumulating the spectrum of the single molecules and also their position,
"Next they dyed the sample with 14 different dyes in a narrow emission window and excited and photoswitched the molecules with one laser.
they found that the spectra of the individual molecules were surprisingly different and thus readily identifiable."
they were able to easily distinguish molecules of different dyes based on their spectral mean alone,
The photoanode uses sunlight to oxidize water molecules, generating protons and electrons as well as oxygen gas.
The photocathode recombines the protons and electrons to form hydrogen gas. A key part of the JCAP design is the plastic membrane,
which keeps the oxygen and hydrogen gases separate. If the two gases are allowed to mix
and electrons to pass through. The new complete solar fuel generation system developed by Lewis and colleagues uses such a 62.5-nanometer-thick Tio2 layer to effectively prevent corrosion
This catalyst is among the most active known catalysts for splitting water molecules into oxygen
protons, and electrons and is a key to the high efficiency displayed by the device.
while still allowing the ions to flow seamlessly to complete the electrical circuit in the cell.
#Building the electron superhighway: Vermont scientists invent new approach in quest for organic solar panels and flexible electronics University of Vermont scientists have invented a new way to create
what they are calling an electron superhighway in an organic semiconductor that promises to allow electrons to flow faster
But the basic science of how to get electrons to move quickly and easily in these organic materials remains murky.
what they are calling"an electron superhighway"in one of these materials--a low-cost blue dye called phthalocyanine--that promises to allow electrons to flow faster and farther in organic semiconductors.
"Roughly speaking, an exciton is displaced a electron bound together with the hole it left behind.
the UVM team was able to observe nanoscale defects and boundaries in the crystal grains in the thin films of phthalocyanine--roadblocks in the electron highway."
"We have discovered that we have hills that electrons have to go over and potholes that they need to avoid,
The new technique allows the scientists a deeper understanding of how the arrangement of molecules
"The molecules are stacked like dishes in a dish rack, "Furis explains, "these stacked molecules--this dish rack--is the electron superhighway."
"Though excitons are charged neutrally --and can't be pushed by voltage like the electrons flowing in a light bulb--they can, in a sense, bounce from one of these tightly stacked molecules to the next.
This allows organic thin films to carry energy along this molecular highway with relative ease,
#First realization of an electric circuit with a magnetic insulator using spin waves In our current electronic equipment,
information is transported via the motion of electrons. In this scheme, the charge of the electron is used to transmit a signal.
In a magnetic insulator, a spin wave is used instead. Spin is a magnetic property of an electron.
A spin wave is caused by a perturbation of the local magnetisation direction in a magnetic material.
Such a perturbation is caused by an electron with an opposite spin, relative to the magnetisation.
Spin waves transmit these perturbations in the material. This research demonstrates for the first time that it is possible to transmit electric signals in an insulating material.
Strong perturbation So far electrical circuits based on spin waves have not been realised, since it turned out to be impossible to introduce a perturbation in the system large enough to create spin waves.
FOM workgroup leader prof. dr. Bart van Wees and his Phd student Ludo Cornelissen, both from the University of Groningen and FOM workgroup leader dr. Rembert
Duine from Utrecht University have succeeded to use spin waves in an electric circuit by carefully designing the device geometry.
This allows them to make use of the spin waves that are already present in the material due to thermal fluctuations
which requires a much smaller disturbance of the system and hence enables the spin waves to be used in an electric circuit.
The spin wave circuit that the researchers built, consists of a 200 nanometre thin layer of yttrium iron garnet (a mineral and magnetic insulator, YIG in short), with a conducting platinum strip on top of that on both sides.
An electron can flow through the platinum, but not in the YIG since it is an insulator.
However, if the electron collides on the interface between YIG and platinum, this influences the magnetisation at the YIG surface and the electron spin is transferred.
This causes a local magnetisation direction generating a spin wave in the YIG. Spin wave detection The spin waves that the researchers send into the YIG are detected by the platinum strip on the other side of the YIG.
The detection process is exactly opposite to the spin wave injection: a spin wave collides at the interface between YIG and platinum,
and transfers its spin to an electron in the platinum. This influences the motion of the electron, resulting in an electric current that the researchers can measure.
The researchers already studied the combination of platinum and YIG in previous research. From this research it was found that
when spin is transferred from platinum to YIG, this also implies the transfer of heat across the interface.
This enables the heating or cooling of the platinum-YIG interface, depending on the relative orientation of the electron spins in the platinum and the magnetisation in the YIG G
#Researchers develop'instruction manual'for futuristic metallic glass: Research paves the way for alloys that are 3x stronger than steel yet bend like gum Abstract:
Creating futuristic, next generation materials called'metallic glass'that are ultra-strong and ultra-flexible will become easier and cheaper,
based on UNSW Australia research that can predict for the first time which combinations of metals will best form these useful materials.
Just like something from science fiction-think of the Liquid-Metal Man robot assassin (T-1000) in the Terminator films-these materials behave more like glass or plastic than metal.
While still being metals, they become as malleable as chewing gum when heated and can be moulded easily
with their atoms arranged in a highly organised and regular manner. Metallic glass alloys, however, have disordered a highly structure,
with the atoms arranged in a non-regular way.""There are many types of metallic glass, with the most popular ones based on zirconium, palladium, magnesium, titanium or copper.
The nanoparticles can be packed with many small drug molecules that diffuse out of the polymer core and through the platelet membrane onto their targets.
and some of those photons interfere with one another and find their way onto a detector,
a computer then reconstructs the path those photons must have taken, which generates an image of the target material--all without the lens that's required in conventional microscopy."
"Without a lens, the quality of the images primarily depends on the radiation source. Traditionally, researchers use big, powerful X-ray beams like the one at the SLAC National Accelerator Laboratory in Menlo Park, California, USA.
Over the last ten years, researchers have developed smaller, cheaper machines that pump out coherent, laser-like beams in the laboratory setting.
The table-top machines are unable to produce as many photons as the big expensive ones
hardly any photons will bounce off the target at large enough angles to reach the detector.
Without enough photons, the image quality is reduced. Zürch and a team of researchers from Jena University used a special, custom-built ultrafast laser that fires extreme ultraviolet photons a hundred times faster than conventional table-top machines.
With more photons, at a wavelength of 33 nanometers, the researchers were able to make an image with a resolution of 26 nanometers--almost the theoretical limit."
"Nobody has achieved such a high resolution with respect to the wavelength in the extreme ultraviolet before, "Zürch said.
and cools it in a way that allows it to convert more photons into electricity. The work by Shanhui Fan, a professor of electrical engineering at Stanford, research associate Aaswath P. Raman and doctoral candidate Linxiao Zhu is described in the current issue of Proceedings of the National Academy
the less efficient they become at converting the photons in light into useful electricity. The Stanford solution is based on a thin,
but captures and emits thermal radiation, or heat, from infrared rays.""Solar arrays must face the sun to function,
DNA sequencing is a technique that can determine exact sequence of a DNA molecule. One of the most critical biological and medical tools available today, it lies at the core of genome analysis. Reading the exact make-up of genes,
Reading too fast DNA is a long molecule made up of four repeating different building-blocks.
DNA is a fairly sticky molecule and Mos2 is considerably less adhesive than graphene. The team then created a nanopore on membrane, almost 3 nm wide.
The next step was to dissolve DNA in a thick liquid that contained charged ions and whose molecular structure can be tuned fine to change its thickness, or"viscosity gradient".
By combining ionic liquids with nanopores on molybdenum disulfide thin films, they hope to create a cheaper DNA sequencing platform with a better output.
i e. depending on the arrangement of the atoms in the material. This changeability-between crystalline (regular) and amorphous (irregular) states-allowed the team to store many bits in a single integrated nanoscale optical phase-change cell l
leading to inexpensive devices that could detect dozens of disease markers in less than 5 minutes Chemists used DNA molecules to developed rapid,
when atoms are brought too close together-to detect a wide array of protein markers that are linked to various diseases.
because the optimum conditions for applying nanocomposite coating through electrophoretic method on metals are obtained at low particle size distributions s
#A new single-molecule tool to observe enzymes at work A team of scientists at the University of Washington
and the biotechnology company Illumina have created an innovative tool to directly detect the delicate, single-molecule interactions between DNA and enzymatic proteins.
"There are other single-molecule tools around, but our new tool is said far more sensitive senior author and UW physics professor Jens Gundlach."
they developed this tool--the single-molecule picometer-resolution nanopore tweezers, or SPRNT--while working on a related project.
Our genes are long stretches of DNA molecules, which are made up of combinations of four chemical DNA"letters."
"Generally, most existing techniques to look at single-molecule movements--such as optical tweezers--have a resolution, at best,
however, require averaging over a large number of molecules and thus structural details of an individual biomolecule are lost often.
The work demonstrates the potential of low energy electron holography as a non-destructive, single-particle imaging technique for structural biology.
The researchers describe their work in a paper published this week on the cover of the journal Applied Physics Letters, from AIP Publishing."
"We've shown that by means of low energy holography, it is possible to image individual tobacco mosaic virions deposited on ultraclean freestanding graphene,
"The virions are imaged with one nanometer resolution exhibiting details of the helical structure of the virus. Our technique would be the first non-destructive imaging tool for structural biology at the truly single molecule level."
and chemically refines molecules that have some complementarity in shape and charge to some part of another molecule--such as the binding site of a human protein involved in some physiological process that goes awry in a given disease.
Better knowledge about the individual structures of those target proteins can help scientists develop more effective drugs.
Low energy electron holography is a technique of using an electron wave to form holograms. Similar to light optical holography
"The low energy electron holography has two major advantages over conventional microscopy. First, the technique doesn't employ any lenses,
Second, low energy electrons are harmless to biomolecules, "Longchamp said. In many conventional techniques such as transmission electron microscopy, the possible resolution is limited by high-energy electrons'radiation damage to biological samples.
Individual biomolecules are destroyed long before an image of high enough quality can be acquired. In other words, the low permissible electron dose in conventional microscopies is not sufficient to obtain high-resolution images from a single biomolecule.
However in low energy electron holography, the employed electron doses can be much higher--even after exposing fragile molecules like DNA or proteins to a electron dose more than five orders of magnitude higher
than the critical dose in transmission electron microscopy, no radiation damage could be observed. Sufficient electron dose in low energy electron holography makes imaging individual biomolecules at a nanometer resolution possible.
In Longchamp's experiment, the tobacco mosaic virions were deposited on a freestanding, ultraclean graphene, an atomically thin layer of carbon atoms arranged in a honeycomb lattice.
The graphene substrate is similar to a glass slide in optical microscopy which is conductive, robust and transparent for low energy electrons.
To obtain the high-resolution hologram, an atomically sharp, tungsten tip acts as a source of a divergent beam of highly coherent electrons.
When the beam hits the sample, part of the beam is scattered and the other part is affected not.
"This is the first time to directly observe the helical structure of the unstained tobacco mosaic virus at a single-particle level,
"Since low energy electron holography is a method very sensitive to mechanical disturbance, the current nanometer resolution could be improved to angstrom (one ten billionth of a meter)
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