Synopsis: Nanotechnology:

#At super high temps, white graphene stops rust Atomically thin sheets of hexagonal boron nitride (h-BN) have the handy benefit of protecting

They also grew h-BN on graphene and found they could transfer sheets of h-BN to copper

and materials science and of chemistry. t a few nanometers wide they'##re a totally noninvasive coating.

The findings are published in Nature Nanotechnology. Chemists and educators teach and use chemical reaction networks a century-old language of equations that describes how mixtures of chemicals behave.

The channel had earlier been patterned with precisely spaced nanoscale ridges. Infrared laser light shining on the pattern generates electrical fields that interact with the electrons in the channel to boost their energy.

and received funding support from the Defense Advanced Research Projects Agency Caltech s Kavli Nanoscience Institute and the Institute for Quantum Information and Matter an

#Does this carbon nanotube computer spell the end for silicon? Stanford university rightoriginal Studyposted by Tom Abate-Stanford on September 27 2013engineers have built a basic computer using carbon nanotubes a success that points to a potentially faster more efficient alternative to silicon chips.

The achievement is reported in an article on the cover of the journal Nature. eople have been talking about a new era of carbon nanotube electronics moving beyond siliconsays Subhasish Mitra an electrical engineer

and computer scientist at Stanford university who co-led the work. ut there have been few demonstrations of complete digital systems using this exciting technology.

Here is the proof. xperts say the achievement will galvanize efforts to find successors to silicon chips which could soon encounter physical limits that might prevent them from delivering smaller faster cheaper electronic devices. arbon nanotubes CNTS have long been considered as a potential successor to the silicon transistorsays Professor

But until now it hasn t been clear that CNTS a semiconductor material could fulfill those expectations. here is no question that this will get the attention of researchers in the semiconductor community

Mihail Roco a senior advisor for nanotechnology at the National Science Foundation called the work n important scientific breakthrough. t was roughly 15 years ago that carbon nanotubes were fashioned first into transistors the on-off switches

But a bedeviling array of imperfections in these carbon nanotubes has frustrated long efforts to build complex circuits using CNTS.

team has made to this worldwide effort. irst they put in place a process for fabricating CNT-based circuitsde Micheli says. econd they built a simple

but effective circuit that shows that computation is doable using CNTS. s Mitra says: t s not just about the CNT COMPUTER.

It s about a change in directions that shows you can build something real using nanotechnologies that move beyond silicon

and its cousins. uch concerns arise from the demands that designers place upon semiconductors and their fundamental workhorse unit those on-off switches known as transistors.

He called the Stanford work major benchmarkin moving CNTS toward practical use. CNTS are long chains of carbon atoms that are extremely efficient at conducting and controlling electricity.

They are so thinâ##thousands of CNTS could fit side by side in a human hairâ##that it takes very little energy to switch them off according to Wong a co-author of the paper. hink of it as stepping on a garden hosewong explains. he thinner the hose the easier it is to shut off the flow. n theory this combination

of efficient conductivity and low-power switching make carbon nanotubes excellent candidates to serve as electronic transistors. NTS could take us at least an order of magnitude in performance beyond where you can project silicon could take uswong said.

But inherent imperfections have stood in the way of putting this promising material to practical use.

First CNTS do not necessarily grow in neat parallel lines as chipmakers would like. Over time researchers have devised tricks to grow 99.5 percent of CNTS in straight lines.

But with billions of nanotubes on a chip even a tiny degree of misaligned tubes could cause errors

so that problem remained. A second type of imperfection has stymied also CNT technology. Depending on how the CNTS grow a fraction of these carbon nanotubes can end up behaving like metallic wires that always conduct electricity instead of acting like semiconductors that can be switched off.

Since mass production is the eventual goal researchers had to find ways to deal with misaligned

and/or metallic CNTS without having to hunt for them like needles in a haystack. e needed a way to design circuits without having to look for imperfections

or even know where they weremitra says. The Stanford paper describes a two-pronged approach that the authors call an mperfection-immune design. o eliminate the wire-like

or metallic nanotubes the Stanford team switched off all the good CNTS. Then they pumped the semiconductor circuit full of electricity.

All of that electricity concentrated in the metallic nanotubes which grew so hot that they burned up

This sophisticated technique eliminated the metallic CNTS in the circuit. Bypassing the misaligned nanotubes required even greater subtlety.

The Stanford researchers created a powerful algorithm that maps out a circuit layout that is guaranteed to work no matter

whether or where CNTS might be askew. his imperfections-immune design technique makes this discovery truly exemplarysays Sankar Basu a program director at the National Science Foundation.

Their CNT COMPUTER performed tasks such as counting and number sorting. It runs a basic operating system that allows it to swap between these processes.

In a demonstration of its potential the researchers also showed that the CNT COMPUTER could run MIPS a commercial instruction set developed in the early 1980s by then Stanford engineering professor and now university President John Hennessy.

Though it could take years to mature the Stanford approach points toward the possibility of industrial-scale production of carbon nanotube semiconductors according to Naresh Shanbhag a professor at the University of Illinois at Urbana-Champaign

and director of SONIC a consortium of next-generation chip design research. he Wong/Mitra paper demonstrates the promise of CNTS in designing complex computing systemsshanbhag says adding that this will motivate researchers elsewhere toward greater efforts in chip design

beyond silicon. hese are initial necessary steps in taking carbon nanotubes from the chemistry lab to a real environmentsays Supratik Guha director of physical sciences for IBM s Thomas J. Watson Research center

and a world leader in CNT research. The National Science Foundation SONIC the Stanford Graduate Fellowship and the Hertz Foundation Fellowship funded the work.

Using a scanning electron microscope the Stanford team captured images of these microbes attaching milky tendrils to the carbon filaments. ou can see that the microbes make nanowires to dump off their excess electronscriddle says.

#Ink-jet printing creates soft nanostructures A new way to make nanostructures combines advanced ink-jet printing technology with block copolymers that spontaneously form ultra-fine structures.

Researchers were able to increase the resolution of their intricate structure fabrication from approximately 200 nanometers to approximately 15 nanometers.

A nanometer is a billionth of a meter the width of a double-stranded DNA molecule.

The ability to fabricate nanostructures out of polymers DNA proteins and other oftmaterials has the potential to enable new classes of electronics diagnostic devices and chemical sensors.

Recently developed ultra high-resolution ink jet printing techniques have some potential with demonstrated resolution down to 100-200 nanometers

but there are significant challenges in achieving true nanoscale dimension. ur work demonstrates that processes of polymer self-assembly can provide a way around this limitationsays John Rogers professor of materials science and engineering at University of Illinois at Urbana-Champaign.

and a co-author of the paper in Nature Nanotechnology. his concept turned out to be really usefulrogers says.

For the new paper this was done at imec in Belgium an independent nanoelectronics research center. The resolution of the chemical pattern nears the current limit of traditional photolithography notes Lance Williamson a graduate student in molecular engineering at University of Chicago

And because e-jet can naturally handle fluid inks it is suited exceptionally well for patterning solution suspensions of nanotubes nanocrystals nanowires

and other types of nanomaterials. he most interesting aspect of this work is the ability to combine top down techniques of jet printing with â##bottom upâ##processes of self-assembly in a way that opens up new capabilities

in lithographyâ##applicable to soft and hard materials alikerogers says. he opportunities are in forming patterned structures of nanomaterials to enable their integration into real devices.

Scientists at Cornell and Germany s University of Ulm had been making graphene a two-dimensional sheet of carbon atoms in a chicken wire crystal formation on copper foils in a quartz furnace.

They noticed some uckon the graphene and upon further inspection found it to be composed of the elements of everyday glass silicon and oxygen.

This produced the glass layer on the would-be pure graphene. The work that describes direct imaging of this thin glass was published first in January 2012 in Nano Letters

The nanoscale building blocks display remarkable strength and resistance to failure despite being more than 85 percent air.

of which are measured on the scale of billionths of meters or nanometers. Julia R. Greer professor of materials science and mechanics at the California Institute of technology (Caltech) says the work was inspired by earlier work to fabricate extremely lightweight microtrusses. e designed architectures with building blocks that are less than five microns

long meaning that they are not resolvable by the human eye. onstructing these architectures out of materials with nanometer dimensions has enabled us to decouple the materials strength from their density

which are very stiff yet extremely lightweight. t the nanometer scale solids have been shown to exhibit mechanical properties that differ substantially from those displayed by the same materials at larger scales.

For example Greer s group has shown previously that at the nanoscale some metals are about 50 times stronger than usual

and removed the polymer core leaving a ceramic nanolattice. The lattice is constructed of hollow struts with walls no thicker than 75 nanometers. e are now able to design exactly the structure that we want to replicate

and then process it in such a way that it s made out of almost any material class we d likeâ##for example metals ceramics

and the Kavli Nanoscience Institute at Caltech provided support and infrastructure. Source: Caltechyou are free to share this article under the Creative Commons Attribution-Noderivs 3. 0 Unported license t

the researchers sandwiched it between layers of reduced graphene oxide and two current collectors to form a supercapacitor.

researchers use nanoplasmonicsevices that use short electromagnetic waves to modulate light on the nanometer scale, where conventional optics do not work.

you really need to precisely control light in nanoscale, and that where this work can be a very important component,

and the Penn State Center for Nanoscale Science funded this study. Source: Penn Stat i

#The National Science Foundation the Gordon and Betty Moore Foundation the Air force Office of Scientific research and the Kavli Nanoscience Institute at Caltech supported the work.

#Compact graphene device could shrink supercapacitors Monash University rightoriginal Studyposted by Emily Walker-Monash on August 5 2013monash U. AUS)# A new strategy to engineer graphene-based supercapacitors could make them viable

Graphene which is formed when graphite is broken down into layers one atom thick is very strong chemically stable and an excellent conductor of electricity.

To make their uniquely compact electrode Li s team exploited an adaptive graphene gel film they had developed previously.

They used liquid electrolytes#generally the conductor in traditional supercapacitors#to control the spacing between graphene sheets on the subnanometer scale.

maintaining the minute space between the graphene sheets and conducting electricity. Unlike in traditional#hard#porous carbon where space is wasted with unnecessarily large pores density is maximized without compromising porosity in Li s electrode.

#We have created a macroscopic graphene material that is a step beyond what has been achieved previously. It is almost at the stage of moving from the lab to commercial development#Li says.

##Solar steam kills germs while off the grid RICE (US) A new sterilization system uses nanomaterials to convert 80 percent of the energy in sunlight into heat,

Solar steam efficiency comes from light-harvesting nanoparticles that were created at LANP by Rice graduate student Oara Neumann,

Neumann created a version of nanoshells that converts a broad spectrum of sunlightncluding both visible and invisible bandwidthsirectly into heat.

#Graphene#s jagged edge can easily slice cells Brown University right Original Study Posted by Kevin Stacey-Brown on July 10 2013brown (US) the jagged edges of tiny graphene sheets

After the membrane is pierced an entire graphene sheet can be pulled inside the cell where it may disrupt normal function.

The new insight may be helpful in finding ways to minimize the potential toxicity of graphene says Agnes Kane chair of the pathology and laboratory medicine department at Brown and one of the study s authors.

Is nanotech toxic? Discovered about a decade ago graphene is a sheet of carbon just one atom thick.

It is incredibly strong despite being so thin and has remarkable electronic mechanical and photonic properties.

and material scientists at Brown aimed at understanding the toxic potential of a wide variety of nanomaterials.

Their work on graphene started with some seemingly contradictory findings. Oddly shaped flakes Preliminary research by Kane s biology group had shown that graphene sheets can indeed enter cells

but it wasn clear how they got there. Huajian Gao professor of engineering tried to explain those results using powerful computer simulations

His models which simulate interactions between graphene and cell membranes at the molecular level suggested that it would be quite rare for a microsheet to pierce a cell.

The problem turned out to be that those initial simulations assumed a perfectly square piece of graphene.

In reality graphene sheets are rarely so pristine. When graphene is exfoliated or peeled away from thicker chunks of graphite the sheets come off in oddly shaped flakes with jagged protrusions called asperities.

When Gao reran his simulations with asperities included the sheets were able to pierce the membrane much more easily.

She placed human lung skin and immune cells in Petri dishes along with graphene microsheets. Electron microscope images confirmed that graphene entered the cells starting at rough edges and corners.

The experiments showed that even fairly large graphene sheets of up to 10 micrometers could be internalized completely by a cell.

The engineers and the material scientists can analyze and describe these materials in great detail Kane says.

what happens once a graphene sheet gets inside the cell. But Kane says this initial study provides an important start in understanding the potential for graphene toxicity.

This is about the safe design of nanomaterials she says. Theye man-made materials so we should be able to be clever

and make them safer. Other contributors to the study were Brown graduate students Yinfeng Li (now a professor at Shanghai Jiao Tong University) Hongyan Yuan and Megan Creighton.

#Graphene ribbons improve lithium ion batteries Anodes for lithium ion batteries built with ribbons of graphene perform better, tests show.

Rice university chemist James Tour and colleagues, who developed a method for unzipping nanotubes into graphene nanoribbons (GNRS),

figured out how to make graphene nanoribbons in bulk and are moving toward commercial applications. One area ripe for improvement is the humble battery.

In the new experiments, the Rice lab mixed graphene nanoribbons and tin oxide particles about 10 nanometers wide in a slurry with a cellulose gum binder and a bit of water, spread it on a current collector

but also help deliver lithium ions to the nanoparticles. Major hurdle Lab tests showed initial charge capacities of more than 1

Tour says. raphene nanoribbons make a terrific framework that keeps the tin oxide nanoparticles dispersed and keeps them from fragmenting during cycling,

he adds. ince the tin oxide particles are only a few nanometers in size and permitted to remain that way by being dispersed on GNR surfaces,

the volume changes in the nanoparticles are not dramatic. NRS also provide a lightweight, conductive framework, with their high aspect ratios and extreme thinness.

Lin says the lab plans to build batteries with other metallic nanoparticles to test their cycling and storage capacities.

##Quilted graphene is also super strong COLUMBIA U. US) Graphene, even if stitched together from many small crystalline grains,

Graphene consists of a single atomic layer of carbon, arranged in a honeycomb lattice. ur first Science paper,

in 2008, studied the strength graphene can achieve if it has no defectsts intrinsic strength,

pristine graphene exists only in very small areas. Large-area sheets required for applications must contain many small grains connected at grain boundaries,

reports on the strength of large-area graphene films grown using chemical vapor deposition (CVD), and wee excited to say that graphene is back and stronger than ever.

The study verifies that commonly used methods for postprocessing CVD-grown graphene weaken grain boundaries

resulting in the extremely low strength seen in previous studies. The team developed a new process that prevents any damage of graphene during transfer. e substituted a different etchant

and were able to create test samples without harming the graphene, notes the paper lead author, Gwan-Hyoung Lee,

a postdoctoral fellow in the Hone lab. ur findings clearly correct the mistaken consensus that grain boundaries of graphene are weak.

This is great news because graphene offers such a plethora of opportunities both for fundamental scientific research and industrial applications.

In its perfect crystalline form, graphene (a one-atom-thick carbon layer) is the strongest material ever measured

as the team reported in 2008o strong that, as Hone observes, t would take an elephant, balanced on a pencil,

to break through a sheet of graphene the thickness of Saran wrap. For the first study, the team obtained small, structurally perfect flakes of graphene by mechanical exfoliation,

or mechanical peeling, from a crystal of graphite. But exfoliation is a time-consuming process that will never be practical for any of the many potential applications of graphene that require industrial mass production. httpv://www. youtube. com/watch?

v=VSPWRC6RCVY Why so weak? Currently, scientists can grow sheets of graphene as large as a television screen by using chemical vapor deposition (CVD), in

which single layers of graphene are grown on copper substrates in a high-temperature furnace. One of the first applications of graphene may be as a conducting layer in flexible displays. ut CVD graphene is titchedtogether from many small crystalline grainsike a quiltt grain boundaries that contain defects

in the atomic structure, Kysar explains. hese grain boundaries can severely limit the strength of large-area graphene

if they break much more easily than the perfect crystal lattice, and so there has been intense interest in understanding how strong they can be.

The team wanted to discover what was making CVD graphene so weak. In studying the processing techniques used to create their samples for testing,

they found that the chemical most commonly used to remove the copper substrate also causes damage to the graphene,

severely degrading its strength. Their experiments demonstrated that CVD graphene with large grains is exactly as strong as exfoliated graphene,

showing that its crystal lattice is just as perfect. And, more surprisingly, their experiments also showed that CVD graphene with small grains

even when tested right at a grain boundary, is about 90 percent as strong as the ideal crystal. his is an exciting result for the future of graphene,

because it provides experimental evidence that the exceptional strength it possesses at the atomic scale can persist all the way up to samples inches

Strong, large-area graphene can be used for a wide variety of applications such as flexible electronics and strengthening componentsotentially,

a science fiction idea of a space elevator that could connect an orbiting satellite to Earth by a long cord that might consist of sheets of CVD graphene,

since graphene (and its cousin material, carbon nanotubes) is the only material with the high strength-to-weight ratio required for this kind of hypothetical application.

The team is excited also about studying 2d materials like graphene. ery little is known about the effects of grain boundaries in 2d materials

This is due to all the atoms in graphene being surface atoms, so surface damage that would normally not degrade the strength of 3d materials can completely destroy the strength of 2d materials. owever with appropriate processing that avoids surface damage,

especially graphene, can be nearly as strong as the perfect, defect-free structure. The Air force Office of Scientific research and the National Science Foundation supported the research c

#Our nanotechnology produces entanglements that are millions of times more dense than woven products such as fabrics

#Bendy nanosensors detect infrared light University of Pennsylvania rightoriginal Studyposted by Evan Lerner-Pennsylvania on May 22 2013u.

PENN (US)# Engineers have used a pattern of nanoantennas to develop a new way of turning infrared light into mechanical action

At the core of the device is a nanoscale structure#about a tenth of a millimeter wide

The new device is an improvement in this regard due to the inclusion of#slot#nanoantennas cavities that are etched into the gold layer at intervals that correspond to wavelengths of mid-infrared light.#

and by patterning it with these nanoscale antennas the conversion efficiency of the detector improves 10 times.#

#The inclusion of nanoantennas provides the device with an additional advantage: the ability to tailor

The National Science Foundation Penn s Materials Research Science and Engineering Center Penn s Nano/Bio Interface Center and the Penn Regional Nanotechnology Facility

Exposure to high radiation alone produces significant damage at the nanoscale, so scientists at Los alamos National Laboratory, New mexico, have been working on a mechanism that allows nanocrystalline materials to heal themselves after suffering radiation-induced damage.

This gives hope for materials that will improve the reliability, safety and lifespan of nuclear energy systems.

The nanocrystalline materials the scientists have been working on are created those from nanosized particles, in this case from copper.

Nanocrystalline materials comprise a mixture of grains and the interface between those grains, called grain boundaries.

Nanocrystalline materials contain a large amount of grain boundaries which are thought to be able to absorb

But until conducting recent computer simulations, scientists lacked the ability to predict the performance of nanocrystalline materials in extreme environments.

the researchers describe a newly discovered oading-unloadingphenomenon at grain boundaries in nanocrystalline materials, which allows for effective self-healing of radiation-induced defects.

each sensor utilizes an array of tens of thousands of carbon nanotubes, which have had copper atoms attached to them.

While electrons ordinarily flow freely through the nanotubes, any ethylene molecules present in the vicinity will bond with the copper atoms,

which absorb ethylene and concentrate it near the nanotubes. By measuring how much the electron flow has been slowed,

It's these approximately 100-nanometers-wide slits that allow the device to differentiate between colors with plasmons waves of electrons that flow across metal surfaces) excited by light of a specific wavelength.

#Scientists find that exposure to nanoparticles could impact cardiovascular health Due to its huge potential in applications ranging from cheaper vaccinations to energy-storing car panels there's plenty of excitement surrounding the emergence of nanotechnology.

But a team of scientists are urging caution with a study conducted at the Technion-Israel Institute of technology suggesting that exposure to silicon-based nanoparticles may play a role in the development of cardiovascular disease.

exposing them to nanoparticles made from silicon dioxide. The team was seeking to explore the effects that the nanoparticles have on the development of atherosclerosis a condition that leads to the hardening of the arteries and cardiovascular events such as heart attack and stroke.

What the researchers found was a negative relationship between the silicon-based nanoparticles and macrophages a type of white blood cell that destroys damaged or dead cells.

The toxicity of the nanoparticles causes the macrophages to transform into foam cells or lipids leading to the development of lesions and hastening the onset of atherosclerosis.

This exposure may be especially chronic for those employed in research laboratories and in high tech industry where workers handle manufacture use

and dispose of nanoparticles says the study's lead author Professor Michael Aviram. Products that use silica-based nanoparticles for biomedical uses such as various chips drug or gene delivery and tracking imaging ultrasound therapy and diagnostics may also pose an increased cardiovascular

risk for consumers as well. This study isn't the first time concerns have been raised about the dangers of nanotechnology.

Operating at a scale of 1-100 nanometers (a nanometer is one billionth of a meter) the chemical reactions

when dealing with nanotechnology can be somewhat unpredictable. Previous research has turned up some unsettling results including that silver nanoparticles can materially alter a person's immunity and that titanium dioxide nanoparticles cause systemic genetic damage in mice.

The researchers warn that adopting a cautious approach is critical in the near-term with nanotechnology-based consumer products on the rise a world market they estimate will hit US$3 trillion by 2020.

This reality leads to increased human exposure and interaction of silica-based nanoparticles with biological systems write the researchers.

Because our research demonstrates a clear cardiovascular health risk associated with this trend steps need to be taken to help ensure that potential health

and environmental hazards are being addressed at the same time as the nanotechnology is being developed. The research was published in the journal Environmental Toxicology y

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