#Nanoscale light-emitting device has big profile University of Wisconsin-Madison engineers have created a nanoscale device that can emit light as powerfully as an object 10,000 times its size.
and his collaborators describe a nanoscale device that drastically surpasses previous technology in its ability to scatter light.
They showed how a single nanoresonator can manipulate light to cast a very large"reflection."
"The nanoresonator's capacity to absorb and emit light energy is such that it can make itself--and, in applications,
Given the nanoresonator's capacity to absorb large amounts of light energy, the technology also has potential in applications that harvest the sun's energy with high efficiency.
Because the nanoresonator has a large optical cross-section--that is, an ability to emit light that dramatically exceeds its physical size--it can shed a lot of heat energy,
#An easy, scalable and direct method for synthesizing graphene in silicon microelectronics: Korean researchers grow 4-inch diameter, high-quality, multi-layer graphene on desired silicon substrates,
an important step for harnessing graphene in commercial silicon microelectronics Abstract: In the last decade, graphene has been studied intensively for its unique optical, mechanical, electrical and structural properties.
The one-atom-thick carbon sheets could revolutionize the way electronic devices are manufactured and lead to faster transistors, cheaper solar cells, new types of sensors and more efficient bioelectric sensory devices.
As a potential contact electrode and interconnection material, wafer-scale graphene could be an essential component in microelectronic circuits,
but most graphene fabrication methods are not compatible with silicon microelectronics, thus blocking graphene's leap from potential wonder material to actual profit-maker.
Now researchers from Korea University in Seoul, have developed an easy and microelectronics-compatible method to grow graphene
and have synthesized successfully wafer-scale (four inches in diameter), high-quality, multi-layer graphene on silicon substrates.
The method is based on an ion implantation technique, a process in which ions are accelerated under an electrical field and smashed into a semiconductor.
The impacting ions change the physical, chemical or electrical properties of the semiconductor. In a paper published this week in the journal Applied Physics Letters, from AIP Publishing,
which takes graphene a step closer to commercial applications in silicon microelectronics.""For integrating graphene into advanced silicon microelectronics, large-area graphene free of wrinkles, tears and residues must be deposited on silicon wafers at low temperatures,
which cannot be achieved with conventional graphene synthesis techniques as they often require high temperatures, "said Jihyun Kim, the team leader and a professor in the Department of Chemical and Biological engineering at Korea University."
"Our work shows that the carbon ion implantation technique has great potential for the direct synthesis of wafer-scale graphene for integrated circuit technologies."
"Discovered just over a decade ago, graphene is considered now the thinnest, lightest and strongest material in the world.
Graphene is completely flexible and transparent while being inexpensive and nontoxic, and it can conduct electricity as well as copper,
carrying electrons with almost no resistance even at room temperature, a property known as ballistic transport. Graphene's unique optical, mechanical and electrical properties have lead to the one-atom-thick form of carbon being heralded as the next generation material for faster, smaller, cheaper and less power-hungry electronics."
"In silicon microelectronics, graphene is a potential contact electrode and an interconnection material linking semiconductor devices to form the desired electrical circuits,
"said Kim.""This renders high processing temperature undesirable, as temperature-induced damage, strains, metal spiking
"Thus, although the conventional graphene fabrication method of chemical vapor deposition is used widely for the large-area synthesis of graphene on copper and nickel films,
000 degrees Celsius and a subsequent transfer process of the graphene from the metallic film to the silicon."
"The transferred graphene on the target substrate often contains cracks, wrinkles and contaminants,"said Kim."
"Thus, we are motivated to develop a transfer-free method to directly synthesize high quality, multilayer graphene in silicon microelectronics."
The nickel layer, with high carbon solubility, is used as a catalyst for graphene synthesis. The process is followed then by high temperature activation annealing (about 600 to 900 degrees Celsius) to form a honeycomb lattice of carbon atoms, a typical microscopic structure of graphene.
Kim explained that the activation annealing temperature could be lowered by performing the ion implantation at an elevated temperature.
multi-layer graphene by varying the ambient pressure, ambient gas, temperature and time during the treatment.
as the graphene layer thickness can be determined precisely by controlling the dose of carbon ion implantation.""Our synthesis method is controllable and scalable,
allowing us to obtain graphene as large as the size of the silicon wafer over 300 millimeters in diameter,
and to control the thickness of the graphene for manufacturing production n
#Self-Cleaning Woolen Fabrics Produced in Iran Woolen products are very good sources for the growth of bacteria and microorganisms due to their protein structure,
This objective was achieved by creating a homogenous coating made of a nanocomposite of zinc oxide/nitrogen silver (N-Ag/Zno) on the fabrics.
the processing of the woolen fabric samples by using optimum amount of honeycomb nanocomposite such as N-Ag/Zno improves the biological, mechanical and hydrophilicity of the fabrics.
Among the other advantages of the use of this nanocomposite in the production of fabrics, mention can be made of creating a delay in flammability,
Ultrasonic waves are also the cause of the homogenous distribution of simultaneous charges of silver and nitrogen on the surfaces of zinc oxide nanoparticles.
Finally, the abovementioned properties are created in the final product by processing of the woolen fabrics with the nanocomposite.
#Scientists print low cost radio frequency antenna with graphene ink (Nanowerk News) Scientists have moved graphene--the incredibly strong and conductive single-atom-thick sheet of carbon--a significant step along the path
Researchers from the University of Manchester, together with BGT Materials Limited, a graphene manufacturer in the United kingdom, have printed a radio frequency antenna using compressed graphene ink.
from AIP Publishing("Binder-free highly conductive graphene laminate for low cost printed radio frequency applications")."These scanning electron microscope images show the graphene ink after it was deposited
and dried (a) and after it was compressed (b). Compression makes the graphene nanoflakes more dense,
which improves the electrical conductivity of the laminate. Image: Xianjun Huang, et al.//University of Manchester) The study demonstrates that printable graphene is now ready for commercial use in low-cost radio frequency applications,
said Zhirun Hu, a researcher in the School of Electrical and Electronic engineering at the University of Manchester."
"The point is that graphene is no longer just a scientific wonder. It will bring many new applications to our daily life very soon,"added Kostya S. Novoselov, from the School of Physics and Astronomy at the University of Manchester, who coordinated the project.
Graphene Gets Inked Since graphene was isolated first and tested in 2004, researchers have striven to make practical use of its amazing electrical and mechanical properties.
One of the first commercial products manufactured from graphene was conductive ink, which can be used to print circuits and other electronic components.
Graphene ink is generally low cost and mechanically flexible advantages it has over other types of conductive ink,
such as solutions made from metal nanoparticles. To make the ink, graphene flakes are mixed with a solvent,
and sometimes a binder like ethyl cellulose is added to help the ink stick. Graphene ink with binders usually conducts electricity better than binder-free ink,
but only after the binder material, which is an insulator, is broken down in a high-heat process called annealing.
Annealing, however, limits the surfaces onto which graphene ink can be printed because the high temperatures destroy materials like paper or plastic.
The University of Manchester research team together with BGT Materials Limited, found a way to increase the conductivity of graphene ink without resorting to a binder.
They accomplished this by first printing and drying the ink, and then compressing it with a roller,
and the resulting"graphene laminate"was also almost two times more conductive than previous graphene ink made with a binder.
and More The researchers tested their compressed graphene laminate by printing a graphene antenna onto a piece of paper.
"Graphene based RFID tags can significantly reduce the cost thanks to a much simpler process and lower material cost,
The University of Manchester and BGT Materials Limited team has plans to further develop graphene enabled RFID tags,
Researchers measure graphene vibrations (Nanowerk News) An international research group led by scientists at the National Institute of Standards
and Technology's (NIST) Center for Nanoscale Science and Technology has developed a method for measuring crystal vibrations in graphene.
Understanding these vibrations is a critical step toward controlling future technologies based on graphene, a one-atom thick form of carbon.
Tunneling electrons from a scanning tunneling microscope tip excites phonons in graphene. The image shows the graphene lattice with blue arrows indicating the motion direction of that carbon atoms for one of the low energy phonon modes in graphene.
Image: Wyrick/NIST) They report their findings in the June 19, 2015, issue of Physical Review Letters("Strong Asymmetric Charge Carrier Dependence in Inelastic Electron Tunneling Spectroscopy of Graphene Phonons").
"Carbon atoms in graphene sheets are arranged in a regularly repeating honeycomb-like latticea two-dimensional crystal. Like other crystals,
when enough heat or other energy is applied, the forces that bond the atoms together cause the atoms to vibrate
NIST researchers used their STM to systematically alter the number of electrons moving through their graphene device.
The team was able to map all the graphene phonons this way, and their findings agreed well with their Georgia Tech collaborators'theoretical predictions.
when we switched the graphene charge carrier from holes to electronspositive to negative charges, "says Stroscio."
The high purity graphene device was fabricated by NIST researcher Y. Zhao in the Center for Nanoscale Science and Technology's Nanofab, a national user facility available to researchers from industry, academia and government t
#Nanogenerator harvests power from rolling tires A group of University of Wisconsin-Madison engineers and a collaborator from China have developed a nanogenerator that harvests energy from a car's rolling tire friction.
the nanogenerator ultimately could provide automobile manufacturers a new way to squeeze greater efficiency out of their vehicles.
which is the first of its kind, in a paper published May 6, 2015, in the journal Nano Energy("Single-electrode triboelectric nanogenerator for scavenging friction energy from rolling tires").
The nanogenerator relies on the triboelectric effect to harness energy from the changing electric potential between the pavement and a vehicle's wheels.
Wang says the nanogenerator provides an excellent way to take advantage of energy that is usually lost due to friction."
"The nanogenerator relies on an electrode integrated into a segment of the tire. When this part of the tire surface comes into contact with the ground,
#Nanotechnology transforms cotton fibers into modern marvel (Nanowerk News) Juan Hinestroza and his students live in a cotton-soft nano world,
who directs the Textiles Nanotechnology Laboratory at Cornell. In a nanoscale world and that is our world we can control cellulose-based materials one atom at a time.
The Hinestroza group has turned cotton fibers into electronic components such as transistors and thermistors so instead of adding electronics to fabrics,
Taking advantage of cottons irregular topography, Hinestroza and his students added conformal coatings of gold nanoparticles,
Synthesizing nanoparticles and attaching them to cotton not only creates color on fiber surfaces without the use of dyes,
can be manipulated at the nano level to build nanoscale cages that are the exact same size as the gas they are trying to capture.
#Environmentally friendly lignin nanoparticle'greens'silver nanobullet to battle bacteria North carolina State university researchers have developed an effective
and environmentally benign method to combat bacteria by engineering nanoscale particles that add the antimicrobial potency of silver to a core of lignin,
greener and safer nanotechnology and could lead to enhanced efficiency of antimicrobial products used in agriculture and personal care.
In a study published in Nature Nanotechnology("An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core),
"NC State engineer Orlin Velev and colleagues show that silver-ion infused lignin nanoparticles, which are coated with a charged polymer layer that helps them adhere to the target microbes,
As the nanoparticles wipe out the targeted bacteria, they become depleted of silver. The remaining particles degrade easily after disposal because of their biocompatible lignin core,
People have been interested in using silver nanoparticles for antimicrobial purposes, but there are lingering concerns about their environmental impact due to the long-term effects of the used metal nanoparticles released in the environment,
said Velev, INVISTA Professor of Chemical and Biomolecular engineering at NC State and the papers corresponding author.
The researchers used the nanoparticles to attack E coli a bacterium that causes food poisoning; Pseudomonas aeruginosa, a common disease-causing bacterium;
The nanoparticles were effective against all the bacteria. The method allows researchers the flexibility to change the nanoparticle recipe in order to target specific microbes.
Alexander Richter, the papers first author and an NC State Ph d. candidate who won a 2015 Lemelson-MIT prize,
#Nanoscale light-emitting device has big profile University of Wisconsin-Madison engineers have created a nanoscale device that can emit light as powerfully as an object 10,000 times its size.
In a paper published July 10 in the journal Physical Review Letters("Extraordinarily large optical cross section for localized single nanoresonator"),Zongfu Yu, an assistant professor of electrical and computer engineering,
and his collaborators describe a nanoscale device that drastically surpasses previous technology in its ability to scatter light.
They showed how a single nanoresonator can manipulate light to cast a very large"reflection."
"The nanoresonator's capacity to absorb and emit light energy is such that it can make itself--and, in applications,
Given the nanoresonator's capacity to absorb large amounts of light energy, the technology also has potential in applications that harvest the sun's energy with high efficiency.
Because the nanoresonator has a large optical cross-section--that is, an ability to emit light that dramatically exceeds its physical size--it can shed a lot of heat energy,
#An easy, scalable and direct method for synthesizing graphene in silicon microelectronics (Nanowerk News) In the last decade,
graphene has been studied intensively for its unique optical, mechanical, electrical and structural properties. The one-atom-thick carbon sheets could revolutionize the way electronic devices are manufactured
As a potential contact electrode and interconnection material, wafer-scale graphene could be an essential component in microelectronic circuits,
but most graphene fabrication methods are not compatible with silicon microelectronics, thus blocking graphene's leap from potential wonder material to actual profit-maker.
Now researchers from Korea University in Seoul, have developed an easy and microelectronics-compatible method to grow graphene
and have synthesized successfully wafer-scale (four inches in diameter), high-quality, multi-layer graphene on silicon substrates.
The method is based on an ion implantation technique, a process in which ions are accelerated under an electrical field and smashed into a semiconductor.
In a paper published this week in the journal Applied Physics Letters("Wafer-scale synthesis of multi-layer graphene by high-temperature carbon ion implantation"),from AIP Publishing
which takes graphene a step closer to commercial applications in silicon microelectronics. Wafer-scale (4 inch in diameter) synthesis of multi-layer graphene using high-temperature carbon ion implantation on nickel/Sio2/silicon.
Image: J. Kim/Korea University, Korea)" For integrating graphene into advanced silicon microelectronics, large-area graphene free of wrinkles, tears and residues must be deposited on silicon wafers at low temperatures,
which cannot be achieved with conventional graphene synthesis techniques as they often require high temperatures, "said Jihyun Kim, the team leader and a professor in the Department of Chemical and Biological engineering at Korea University."
"Our work shows that the carbon ion implantation technique has great potential for the direct synthesis of wafer-scale graphene for integrated circuit technologies."
"Discovered just over a decade ago, graphene is considered now the thinnest, lightest and strongest material in the world.
Graphene is completely flexible and transparent while being inexpensive and nontoxic, and it can conduct electricity as well as copper,
carrying electrons with almost no resistance even at room temperature, a property known as ballistic transport. Graphene's unique optical, mechanical and electrical properties have lead to the one-atom-thick form of carbon being heralded as the next generation material for faster, smaller, cheaper and less power-hungry electronics."
"In silicon microelectronics, graphene is a potential contact electrode and an interconnection material linking semiconductor devices to form the desired electrical circuits,
"said Kim.""This renders high processing temperature undesirable, as temperature-induced damage, strains, metal spiking
"Thus, although the conventional graphene fabrication method of chemical vapor deposition is used widely for the large-area synthesis of graphene on copper and nickel films,
000 degrees Celsius and a subsequent transfer process of the graphene from the metallic film to the silicon."
"The transferred graphene on the target substrate often contains cracks, wrinkles and contaminants,"said Kim."
"Thus, we are motivated to develop a transfer-free method to directly synthesize high quality, multilayer graphene in silicon microelectronics."
The nickel layer, with high carbon solubility, is used as a catalyst for graphene synthesis. The process is followed then by high temperature activation annealing (about 600 to 900 degrees Celsius) to form a honeycomb lattice of carbon atoms, a typical microscopic structure of graphene.
Kim explained that the activation annealing temperature could be lowered by performing the ion implantation at an elevated temperature.
multi-layer graphene by varying the ambient pressure, ambient gas, temperature and time during the treatment.
as the graphene layer thickness can be determined precisely by controlling the dose of carbon ion implantation.""Our synthesis method is controllable and scalable,
allowing us to obtain graphene as large as the size of the silicon wafer over 300 millimeters in diameter,
and to control the thickness of the graphene for manufacturing production n
#New study shows how nanoparticles can clean up environmental pollutants Many human-made pollutants in the environment resist degradation through natural processes,
and disrupt hormonal and other systems in mammals and other animals. Removing these toxic materials
In a new paper published this week in Nature Communications("Nanoparticles with photoinduced precipitation for the extraction of pollutants from water and soil),
"researchers from MIT and the Federal University of Goiás in Brazil demonstrate a novel method for using nanoparticles
Nanoparticles that lose their stability upon irradiation with light have been designed to extract endocrine disruptors, pesticides,
The system exploits the large surface-to-volume ratio of nanoparticles, while the photoinduced precipitation ensures nanomaterials are released not in the environment.
Ferdinand Brandl and Nicolas Bertrand, the two lead authors, are former postdocs in the laboratory of Robert Langer, the David H. Koch Institute Professor at MIT Koch Institute
They initially sought to develop nanoparticles that could be used to deliver drugs to cancer cells. Brandl had synthesized previously polymers that could be cleaved apart by exposure to UV LIGHT.
Nanoparticles made from these polymers have a hydrophobic core and a hydrophilic shell. Due to molecular-scale forces
in a solution hydrophobic pollutant molecules move toward the hydrophobic nanoparticles, and adsorb onto their surface,
If left alone, these nanomaterials would remain suspended and dispersed evenly in water. But when exposed to UV LIGHT,
The fundamental breakthrough, according to the researchers, was confirming that small molecules do indeed adsorb passively onto the surface of nanoparticles. o the best of our knowledge,
it is the first time that the interactions of small molecules with preformed nanoparticles can be measured directly,
we showed in a system that the adsorption of small molecules on the surface of the nanoparticles can be used for extraction of any kind,
as another example of a persistent pollutant that could potentially be remediated using these nanomaterials. nd for analytical applications where you don need as much volume to purify or concentrate,
The study also suggests the broader potential for adapting nanoscale drug-delivery techniques developed for use in environmental remediation. hat we can apply some of the highly sophisticated,
and an expert in nanoengineering for health care and medical applications. hen you think about field deployment,
#Making polymer nanostructures from a greenhouse gas (Nanowerk News) A future where power plants feed their carbon dioxide directly into an adjacent production facility instead of spewing it up a chimney
In the journal Angewandte Chemie("Construction of Versatile and Functional Nanostructures Derived from CO2-based Polycarbonates),
and can aggregate into nanoparticles or micelles. Versatile nanostructures made from CO2 based polycarbonates. Wiley-VCH) CO2 and epoxides (highly reactive compounds with a three-membered ring made of two carbon atoms
and one oxygen atom) can be polymerized to form polycarbonates in reactions that use special catalysts.
#Boron Turns Graphene into Blue light Emitter FRANKFURT, Germany, July 14, 2015 Chemists at Goethe University Frankfurt have developed a new class of organic luminescent materials through the targeted introduction of boron
atoms into graphene. The compounds exhibit an intense blue fluorescence and, consequently, are of interest for use as organic LEDS (OLEDS).
Within graphene, benzene rings are fused to form a honeycomb structure. Sections of this structure, referred to as nanographenes or polycyclic aromatic hydrocarbons (PAHS), play an integral role in organic electronics.
Within the study, boron atoms specifically replaced the two meso carbon atoms within the PAH, which resulted in its ability to transform a near-infrared dye into a blue luminophore.
The boron-containing nanographenes have an impact on two key properties of an OLED luminophore
"For a long time, efforts were focused largely on affecting the properties of nanographenes by chemically manipulating their edges,
Hertz and Wagner anticipate that such materials like the graphene flakes they developed will be particularly suitable for use in portable electronic devices,
#Here's how to make carbon nanoparticles with honey and a microwave Carbon nanoparticles can be incredibly useful in the treatment of many types of disease,
as they can evade our natural immune defences and deliver medicine to wherever it's most needed in the body.
but so far creating these nanoparticles has been a long and expensive process. Now researchers at the University of Illinois in the US have found a much easier way to create a certain type of nanoparticle:
using a process that involves plain old honey and a microwave. The resulting particles are less than 8 nanometres thick (a human hair is around 80,000-100,000 nanometres)
so your body's immune system won't try and interfere with them as they deliver their medicine."
but that is nanoparticles with high luminescence. This is one of the simplest systems that we can think of.
the microwave-produced nanoparticles are effective in delivering the drugs where they're needed, and vibrational spectroscopic techniques were used to monitor how the polymers gradually released their payload.
Different polymer coatings were tested too as the team works towards getting these'homemade'carbon nanoparticles ready for clinical use."
#Nanowire clothing could keep people warm without heating everything else To stay warm when temperatures drop outside,
But scientists have developed now a novel nanowire coating for clothes that can both generate heat
the special nanowire cloth trapped body heat far more effectively. Because the coatings are made out of conductive materials,
Use of nanotechnology in cosmetics and pharmaceuticals A Faculty of science Universiti Putra Malaysia (UPM) lecturer Professor Dr Mahiran Basri not only succeeded in producing new useful substances made of oils
This organic synthesis uses enzymes and it is produced through nanotechnology. Our focus is to process new substances derived from oils
and antiaging substances through the use of nanotechnology those substances can easily absorb through the skin.
'Thus we created drugs through nanotechnology and that way we hope they are more effective she said.
which increasingly benefits both micro-and nanoelectronics. The integration of optical components is advanced already well in many areas.
However in spite of intensive research a laser source that is compatible with the manufacturing of chips is not yet achievable according to the head of Semiconductor Nanoelectronics (PGI-9). The basis of chip manufacturing is silicon an element of main group IV of the periodic table.
That way we were able to demonstrate that the germanium-tin compound can amplify optical signals as well as generate laser light reports Dr. Hans Sigg from the Laboratory for Micro and Nanotechnology.
transparent nanomaterial made from wood. Compared to other polymers like plastics, the wood nanomaterial is biocompatible
and has relatively low thermal expansion coefficient, which means the material won't change shape as the temperature changes.
#Nanoscale light-emitting device has big profile University of Wisconsin-Madison engineers have created a nanoscale device that can emit light as powerfully as an object 10,000 times its size.
and his collaborators describe a nanoscale device that drastically surpasses previous technology in its ability to scatter light.
They showed how a single nanoresonator can manipulate light to cast a very large"reflection."
"The nanoresonator's capacity to absorb and emit light energy is such that it can make itself--and, in applications,
Given the nanoresonator's capacity to absorb large amounts of light energy, the technology also has potential in applications that harvest the sun's energy with high efficiency.
Because the nanoresonator has a large optical cross-section--that is, an ability to emit light that dramatically exceeds its physical size--it can shed a lot of heat energy,
so Bailie did it manually. e used a sheet of plastic with silver nanowires on it, he said. hen we built a tool that uses pressure to transfer the nanowires onto the perovskite cell, kind of like a temporary tattoo.
You just need to rub it to transfer the film. Remarkable efficiency For the experiment, the Stanford team stacked a perovskite solar cell with an efficiency of a 12.7 percent on top of a low-quality silicon cell with an efficiency of just 11.4 percent. y combining two cells
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011