Nanotechnology

Nanotecgnology colaterale (31)
Nanotechnology generale (1069)
Nanotechnology tendinte (5)

Synopsis: Nanotechnology:

and other goods. The Flexpakrenew research team developed a number of new techniques that use renewable materials reinforced with nanoparticles and innovative coatings.

when added to a standard polymer-fullerene mixture. ullerene a small carbon molecule is one of the standard materials used in polymer solar cellslu says. asically in polymer solar cells we have a polymer as electron donor

and fullerene as electron acceptor to allow charge separation. n their work the researchers added another polymer into the device resulting in solar cells with two polymers and one fullerene.

when an optimal amount of PID2 was added the highest ever for solar cells made up of two types of polymers with fullerene

In order for a current to be generated by the solar cell electrons must be transferred from polymer to fullerene within the device.

But the difference between electron energy levels for the standard polymer-fullerene is large enough that electron transfer between them is difficult.

This shows that through nanoscale engineering of materials we can really make a difference in how we make fuels

and enable the economic production of gas resources with higher carbon dioxide content that would be too costly to recover using current carbon capture technologies says James Tour professor of mechanical engineering and nanoengineering and of computer science at Rice university.

#DNA motor uses arms to walk across a nanotube Purdue University rightoriginal Studyposted by Emil Venere-Purdue on December 19 2013engineers made a motor out of DNA

and then used it to move nanoparticles of cadmium disulfide along the length of a nanotube.

New findings were detailed in a paper published this month in the journal Nature Nanotechnology.

As it moves along a carbon-nanotube track it continuously harvests energy from strands of RNA molecules vital to a variety of roles in living cells

and viruses. ur motors extract chemical energy from RNA molecules decorated on the nanotubes and use that energy to fuel autonomous walking along the carbon nanotube trackchoi says.

The core is made of an enzyme that cleaves off part of a strand of RNA. After cleavage the upper DNA arm moves forward binding with the next strand of RNA

The process repeats until reaching the end of the nanotube track. The researchers combined two fluorescent imaging systems to document the motor s movement one in the visible spectrum and the other in the near-infrared range.

The nanoparticle is fluorescent in visible light and the nanotubes are fluorescent in the near-infrared.

The motor took about 20 hours to reach the end of the nanotube which was several microns long

but the process might be sped up by changing temperature and ph a measure of acidity.

#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

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.

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

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.

But the sensors aren just useful for explosives the researchers found that the coated nanotubes can also detect two pesticides that contain nitro-aromatic compounds.

and superhydrophobic (water hating) surfaces, on the nanoscale. Together these surfaces dramatically increased the efficiency of moisture condensation and

The best configuration, a honeycomb lattice with a 50 nanometer coat of alumina, is less dense than waterthat is,

#Graphene electrode promises stretchy circuits: Nature News A transparent, flexible electrode made from graphene could see a one-atom thick honeycomb of carbon first made just five years ago replace other high-tech materials used in displays.

It could even be used instead of silicon in electronics. Byung Hee Hong from Sungkyunkwan University in Suwon, Korea,

and his colleagues transferred a wafer-thin layer of graphene, etched into the shape needed to make an electrode, onto pieces of polymer.

The resulting films conduct electricity better than any other sample of graphene produced in the past. Until recently

high-quality graphene has been hard to make on a large scale. To produce their graphene, Hong and his colleagues used a technique that is well known in the semiconductor industry chemical vapour deposition.

This involves exposing a substrate to a number of chemicals, often at high temperatures. These chemicals then react on the surface to give a thin layer of the desired product.

The results in Hong's case were relatively large, high-quality films of graphene just a few atoms thick and several centimetres wide.

But by using a layer of nickel less than 300 nanometres thick and by cooling the sample quickly after the reaction the researchers could produce up to ten single-atom layers of carbon in graphene's signature honeycomb pattern.

Their work is published in Nature1. The samples aren't perfect each layer covers only around two-thirds of the sample

The graphene samples can be chemically etched into specific shapes. And when stamped onto the polymer,

Because the layers of graphene are so thin the resulting electrodes are transparent, and Hong says that makes the material ideal for use in applications such as portable displays.

"We are planning to get an investment to build up mass-production facility of the large-scale graphene films,

His team is also looking at using the graphene electrodes in photovoltaic cells. Easing the pain

Geim had predicted that chemical vapour deposition would be the best technique for making high-quality graphene films3.

"Hong thinks that graphene's most promising application will be to replace the silicon-based materials used in semiconductor technologies.

But this would need technological breakthroughs such as the ability to grow larger-scale uniform monolayer graphene films

and to modify the conductivity of graphene nanostructures. Such applications could be some time off, says Geim."

However nanoparticles and other delivery methods now being developed for DNA and RNA could prove more effective in targeting other organs Sharp says.

Now, a team of MIT researchers wants to make plants even more useful by augmenting them with nanomaterials that could enhance their energy production

Using another type of carbon nanotube, they also modified plants to detect the gas nitric oxide. Together

these represent the first steps in launching a scientific field the researchers have dubbed lant nanobionics. lants are very attractive as a technology platform,

Supercharged photosynthesis The idea for nanobionic plants grew out of a project in Strano lab to build self-repairing solar cells modeled on plant cells.

the researchers embedded them with cerium oxide nanoparticles, also known as nanoceria. These particles are very strong antioxidants that scavenge oxygen radicals

photosynthetic activity measured by the rate of electron flow through the thylakoid membranes was 49 percent greater than that in isolated chloroplasts without embedded nanotubes.

and used a technique called vascular infusion to deliver nanoparticles into Arabidopsis thaliana, a small flowering plant.

the researchers applied a solution of nanoparticles to the underside of the leaf, where it penetrated tiny pores known as stomata,

the nanotubes moved into the chloroplast and boosted photosynthetic electron flow by about 30 percent.

What is the impact of nanoparticles on the production of chemical fuels like glucose? Giraldo says.

Strano lab has developed previously carbon nanotube sensors for many different chemicals, including hydrogen peroxide, the explosive TNT, and the nerve gas sarin.

When the target molecule binds to a polymer wrapped around the nanotube, it alters the tube fluorescence. e could someday use these carbon nanotubes to make sensors that detect in real time, at the single-particle level,

Giraldo says. his is a marvelous demonstration of how nanotechnology can be coupled with synthetic biology to modify

a professor of biomedical engineering at Boston University who was involved not in the research. he authors nicely show that self-assembling nanoparticles can be used to enhance the photosynthetic capacity of plants,

They are also working on incorporating electronic nanomaterials, such as graphene, into plants. ight now, almost no one is working in this emerging field,

and the chemical engineering nanotechnology community to work together in an area that has a large potential.

#New study shows how nanoparticles can clean up environmental pollutants Many human-made pollutants in the environment resist degradation through natural processes,

researchers from MIT and the Federal University of Goiás in Brazil demonstrate a novel method for using nanoparticles

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,

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,

#Nanoparticle network could bring fast-charging batteries (Phys. org) A new electrode design for lithium-ion batteries has been shown to potentially reduce the charging time from hours to minutes by replacing the conventional graphite electrode with a network of tin-oxide nanoparticles.

The anode consists of an ordered network of interconnected tin oxide nanoparticles that would be practical for commercial manufacture

When tin oxide nanoparticles are heated at 400 degrees Celsius they self-assemble into a network containing pores that allow the material to expand

Without the proper pore size and interconnection between individual tin oxide nanoparticles the battery fails. The research paper was authored by Etacheri;

They describe their nanowire mesh design in the journal ACS Nano. Peidong Yang Bin Liu and colleagues note that harnessing sunlight to split water

The researchers took a page from the paper industry using one of its processes to make a flat mesh out of light-absorbing semiconductor nanowires that

and the biochar nanoparticles can create an extremely large surface area which can then hold more charge.

The high-energy plasma can deposit highly transparent and conductive thin films create high quality semiconductors and pattern micro-or nanoscale devices thus making the display images brighter and clearer.

#Patent awarded for genetics-based nanotechnology against mosquitoes insect pests Kansas State university researchers have developed a patented method of keeping mosquitoes and other insect pests at bay.

U s. Patent 8841272 Double stranded-rna RNA-Based Nanoparticles for Insect Gene Silencing was awarded recently to the Kansas State university Research Foundation a nonprofit corporation responsible for managing technology transfer activities

nanoparticles comprised of a nontoxic biodegradable polymer matrix and insect derived double-stranded ribonucleic acid or dsrna.

After testing a series of unsuccessful genetic techniques the team turned to a nanoparticle-based approach.

Once ingested the nanoparticles act as a Trojan horse releasing the loosely bound dsrna into the insect gut.

which the nanoparticle-based method was developed the technology can be applied to other insect pests Zhu said.

When you make baits containing gene-specific nanoparticles you may be able to kill the insects through the RNAI pathway.

#'Endless possibilities'for bionanotechnology Scientists from the University of Leeds have taken a crucial step forward in bionanotechnology,

Importantly, the new technique can use these lipid membranes to'draw'akin to using them like a biological ink with a resolution of 6 nanometres (6 billionths of a meter),

which is an imaging process that has a resolution down to only a fraction of a nanometer

in order to create nanostructures and to'draw'substances onto nano-sized regions. The latter is called'nanolithography 'and was used the technique by Professor Evans and his team in this research.

The ability to controllably'write 'and'position'lipid membrane fragments with such high precision was achieved by Mr George Heath,

#Scientists grow a new challenger to graphene A team of researchers from the University of Southampton's Optoelectronics Research Centre (ORC) has developed a new way to fabricate a potential challenger to graphene.

Graphene a single layer of carbon atoms in a honeycomb lattice is increasingly being used in new electronic and mechanical applications such as transistors switches

Now ORC researchers have developed molybdenum di-sulphide (Mos2) a similar material to graphene that shares many of its properties including extraordinary electronic conduction

This new class of thin metal/sulphide materials known as transition metal di-chalcogenides (TMDCS) has become an exciting complimentary material to graphene.

However unlike graphene TMDCS can also emit light allowing applications such as photodetectors and light emitting devices to be manufactured.

and related materials rather than just microscopic flakes as previously was the case greatly expands their promise for nanoelectronic and optoelectronic applications.

Dr Huang and his team published their findings in the latest issue of the journal Nanoscale.

and a two-dimensional graphene platform to boost production of the hard-to-make element. The research also unveiled a previously unknown property of graphene.

The two-dimensional chain of carbon atoms not only gives and receives electrons, but can also transfer them into another substance.

"said Elena Rozhkova, chemist at Argonne's Center for Nanoscale Materials, a DOE Office of Science (Office of Basic energy Sciences) User Facility."

in short, a material like graphene. Graphene is a super strong, super light, near totally transparent sheet of carbon atoms and one of the best conductors of electricity ever discovered.

Graphene owes its amazing properties to being two-dimensional.""Graphene not only has all these amazing properties,

but it is also ultra-thin and biologically inert,"said Rozhkova.""Its very presence allowed the other components to self-assemble around it,

which totally changes how the electrons move throughout our system.""Rozhkova's mini-hydrogen generator works like this:

both the br protein and the graphene platform absorb visible light. Electrons from this reaction are transmitted to the titanium dioxide on

These protons make their way to the platinum nanoparticles which sit on top of the titanium dioxide. Hydrogen is produced by the interaction of the protons

and time-resolved spectroscopy at the Center for Nanoscale Materials verified the movements of the electrons within the system,

Tests also revealed a new quirk of graphene behavior.""The majority of the research out there states that graphene principally conducts

and accepts electrons, "said Argonne postdoctoral researcher Peng Wang.""Our exploration using EPR allowed us to prove, experimentally,

that graphene also injects electrons into other materials.""Rozhkova's hydrogen generator proves that nanotechnology,

merged with biology, can create new sources of clean energy. Her team's discovery may provide future consumers a biologically-inspired alternative to gasoline."

"This research,"Photoinduced Electron Transfer pathways in Hydrogen-Evolving Reduced graphene oxide-Boosted Hybrid Nano-Bio Catalyst,

Using the special properties of graphene a two-dimensional form of carbon that is only one atom thick a prototype detector is able to see an extraordinarily broad band of wavelengths.

A research paper about the new detector was published Sunday September 07 2014 in Nature Nanotechnology.

and colleagues at the U s. Naval Research Lab and Monash University Australia gets around these problems by using graphene a single layer of interconnected carbon atoms.

By utilizing the special properties of graphene the research team has been able to increase the speed

Graphene a sheet of pure carbon only one atom thick is suited uniquely to use in a terahertz detector

because when light is absorbed by the electrons suspended in the honeycomb lattice of the graphene they do not lose their heat to the lattice

Light is absorbed by the electrons in graphene which heat up but don't lose their energy easily.

These heated electrons escape the graphene through electrical leads much like steam escaping a tea kettle.

Sensitive Room-temperature Terahertz Detection via Photothermoelectric Effect in Graphene Xinghan Cai et al. Nature Nanotechnology dx. doi. org/10.1038/nnano. 2014.18

#Team develops ultra sensitive biosensor from molybdenite semiconductor Move over graphene. An atomically thin two-dimensional ultrasensitive semiconductor material for biosensing developed by researchers at UC Santa barbara promises to push the boundaries of biosensing technology in many fields from health care to environmental protection to forensic industries.

Based on molybdenum disulfide or molybdenite (Mos2) the biosensor materialsed commonly as a dry lubricanturpasses graphene's already high sensitivity offers better scalability

and lends itself to high-volume manufacturing. Results of the researchers'study have been published in ACS Nano.

While graphene has attracted wide interest as a biosensor due to its two-dimensional nature that allows excellent electrostatic control of the transistor channel by the gate

and high surface-to-volume ratio the sensitivity of a graphene field-effect transistor (FET) biosensor is restricted fundamentally by the zero band gap of graphene that results in increased leakage current leading to reduced sensitivity explained Banerjee

who is also the director of the Nanoelectronics Research Lab at UCSB. Graphene has been used among other things to design FETSEVICES that regulate the flow of electrons through a channel via a vertical electric field directed into the channel by a terminal called a gate.

In digital electronics these transistors control the flow of electricity throughout an integrated circuit and allow for amplification and switching.

Graphene has received wide interest in the biosensing field and has been used to line the channel and act as a sensing element

despite graphene's excellent characteristics its performance is limited by its zero band gap. Electrons travel freely across a graphene FETENCE it cannot be switched offhich in this case results in current leakages and higher potential for inaccuracies.

Much research in the graphene community has been devoted to compensating for this deficiency either by patterning graphene to make nanoribbons

or by introducing defects in the graphene layerr using bilayer graphene stacked in a certain pattern that allows band gap opening upon application of a vertical electric fieldor better control and detection of current.

Enter Mos2 a material already making waves in the semiconductor world for the similarities it shares with graphene including its atomically thin hexagonal structure and planar nature as well as

what it can do that graphene can't: act like a semiconductor. Monolayer or few-layer Mos2 have a key advantage over graphene for designing an FET biosensor:

They have a relatively large and uniform band gap (1. 2-1. 8 ev depending on the number of layers) that significantly reduces the leakage current

and increases the abruptness of the turn-on behavior of the FETS thereby increasing the sensitivity of the biosensor said Banerjee.

Additionally according to Deblina Sarkar a Phd student in Banerjee's lab and the lead author of the article two-dimensional Mos2 is relatively simple to manufacture.

While one-dimensional materials such as carbon nanotubes and nanowires also allow excellent electrostatics and at the same time possess band gap they are not suitable for low-cost mass production due to their process complexities she said.

At present the scientific community worldwide is actively seeking practical applications of 2d semiconductor materials such as Mos2 nanosheets.

Professor Banerjee and his team have identified a breakthrough application of these nanomaterials and provided new impetus for the development of low-power

New rapid synthesis developed for bilayer graphene and high-performance transistors More information: ACS Nano pubs. acs. org/doi/abs/10.1021/nn500914 i

a new class of nanoscale materials made in sheets only three atoms thick. The University of Washington researchers have demonstrated that two of these single-layer semiconductor materials can be connected in an atomically seamless fashion known as a heterojunction.

or monolayer, materials molybdenum diselenide and tungsten diselenide that have very similar structures, which was key to creating the composite two-dimensional semiconductor.

"The researchers have demonstrated already that the junction interacts with light much more strongly than the rest of the monolayer,

"By focusing on the nanoelectronic connections between cells, we can do things no one has done before,

By using nanoelectronics, it could become possible for scientists to peer for the first time inside cells, see what's going wrong in real time

His team has made ultrathin nanowires that can monitor and influence what goes on inside cells.

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