Nanotube

Boron nitride nanotube (11)
Carbon nanotube (287)
Metallic nanotube (5)
Nanotube (302)
Nanotube transistor (7)
Semiconducting nanotubes (6)

Synopsis: Domenii: Nanotechnology: Nanotechnology generale: Nanostructures: Nanotube:

#Nanotubes: Can we make speakers as thin as paper? It's time for one of those imagined futures

a thin, transparent film made from microscopic tubes called carbon nanotubes (CNTS), aligned parallel to the plane of the film.

gasgetting CNT films to emit sound is not the same as producing good-quality sound over the whole frequency range of human hearing,

So while the CNT speakers might have valuable applications such as sonar#they work perfectly well underwater#it isn't yet clear

One of the ways in which#to improve sound output is to surround the CNT film with a gas that has a lower heat capacity than air,

All things considered, Barnard and colleagues conclude that a high power CNT loudspeaker is feasible, but it won't be simple.

The CNT films will need probably to be enclosed and immersed in xenon, for example, which would pose serious challenges for making robust"wearable#speakers.

So one way or another, these forms of nanocarbon look destined to make our isles full of noises.

is an array of multiwalled carbon nanotubes, which very efficiently absorbs the light energy and turns it to heat.

so that when it is heated by the attached layer of nanotubes, it lows ith light whose peak intensity is mostly above the bandgap of the adjacent PV,

and nanotubes By injecting carbon nanotubes into the bloodstream, scientists can use near-infrared lasers to see blood flow in a living animal brain.

The light causes the specially designed nanotubes to fluoresce at wavelengths of 1, 300-1, 400 nanometers;

The fluorescing nanotubes can then be detected to visualize the blood vesselsstructure. Amazingly, the technique allows scientists to view about three millimeters underneath the scalp

but those have focused mainly on the use of one or a bundle of nanotubes. The problem LÃNARD says is that terahertz radiation typically requires an antenna to achieve coupling into a single nanotube due to the relatively large size of terahertz waves.

The researchers however found a way to create a small detector that is visible to the naked eye.

The thin carbon nanotube film developed by Rice chemist Robert Hauge and graduate student Xiaowei He does not require an antenna

Carbon nanotube thin films are extremely good absorbers of electromagnetic light he explains. In the terahertz range the film a mix of metallic

and semiconducting nanotubes soaks up all of the incoming terahertz radiation. rying to do that with a different kind of material would be nearly impossible

Star and his team have developed similar chip/nanotube sensors that can be affixed to a toothbrush to detect bad breath (the presence of hydrogen sulfide)

#New nanothreads are like diamond necklaces Scientists say super-thin iamond nanothreadsould be stronger and stiffer than the strongest nanotubes

The tricky bit according to Rice university chemist Angel Martã is keeping the densely packed nanotubes apart before they re drawn together into a fiber.

Earlier research at Rice by chemist and chemical engineer Matteo Pasquali a coauthor of the new paper used an acid dissolution process to keep the nanotubes separated until they could be spun into fibers.

otherwise dampen the nanotubes ability to repel one another. Put enough nanotubes into such a solution and they re caught between the repellant forces

and an inability to move in a crowded environment Martã says. They re forced to align a defining property of liquid crystals

and tightly binds the nanotubes together says Martã an assistant professor of chemistry and bioengineering and of materials science and nanoengineering.

But to make macroscopic materials Martã s team needed to pack many more nanotubes into the solution than in previous experiments. s you start increasing the concentration the number of nanotubes in the liquid crystalline phase becomes more abundant than those in the isotropic (disordered) phase

The researchers discovered that 40 milligrams of nanotubes per milliliter gave them a thick gel after mixing at high speed

and filtering out whatever large clumps remained. t s like a centrifuge together with a rotary drummartã says of the mixing gear. t produces unconventional forces in the solution. eeding this dense nanotube gel through a narrow needle-like opening produced

and the team is investigating ways to improve their electrical properties through doping the nanotubes with iodide. he research is basically analogous to

but gave the process a spin with a different preparation so now we re the first to make neat fibers of pure carbon nanotube electrolytes.

because the setup is sealed. he nanotube electrolyte solution could be protected from oxygen and water which would have caused precipitation of the nanotubeshe says. t turns out that this is not a showstopper

because we want the nanotubes to precipitate and stick to each other as soon as they exit the sealed system through the needle.

and nanotubes Stanford university rightoriginal Studyposted by Bjorn Carey-Stanford on August 7 2014by injecting carbon nanotubes into the bloodstream scientists can use near-infrared lasers to see blood flow in a living animal s brain.

The light causes the specially designed nanotubes to fluoresce at wavelengths of 1300-1400 nanometers;

The fluorescing nanotubes can then be detected to visualize the blood vessels structure. Amazingly the technique allows scientists to view about three millimeters underneath the scalp

The Research center for Exotic Nanocarbons in Japan and the Center for Nanoscale Science at Penn State supported the research u

HOW IT WORKS When the terahertz light hits the transducer, the nanotubes absorb it, turning it into heat.

#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.

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.

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.

but graphene nanoribbons (GNRS) unzipped from multiwalled carbon nanotubes in a chemical process invented by the Tour group in 2009 do the job nicely he says.

Volman suggests the material would make a compelling competitor to recently touted nanotube-based aerogels for deicing airplanes in the winter. e have the technology;

#Tiny Lego blocks build two-faced nanotubes University of Warwick rightoriginal Studyposted by Anna Blackaby-Warwick on November 14 2013using a process similar to molecular Lego scientists

and can be controlled with a much higher level of accuracy than natural channel proteins. hrough a process of molecular engineeringâ##a bit like molecular Legoâ##we have assembled the nanotubes from two types of building blocksâ##cyclic peptides

and polymers. anus nanotubes are a versatile platform for the design of exciting materials which have a wide range of application from membranesâ##for instance for the purification of waterâ##to therapeutic uses including the development of new drug systems. ource:

Tour s breakthrough nzippingtechnique for turning multiwalled carbon nanotubes into GNRS first revealed in Nature in 2009 has been licensed for industrial production. hese are being produced in bulk

#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

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

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.

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

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

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,

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.

Of course, duplicating synapse firings in nanotube circuits does not mean that scientists are ready to replace the human brain,

#Commercial nanotube transistors could be ready by 2020 Each chip on this wafer has 10,000 nanotube transistors on it.

who leads the company s nanotube project at the company s T. J. Watson research center in Yorktown Heights,

New york. Nanotubes are the only technology that looks capable of keeping the advance of computer power from slowing down,

In 1998, researchers at IBM made one of the first working carbon nanotube transistors. And now after more than a decade of research, IBM is the first major company to commit to getting the technology ready for commercialization.

Hannon led IBM s nanotube work before Haensch, who took over in 2011 after a career working on manufacturing conventional chips.

This is the point IBM hopes nanotubes can step in. The most recent report from the microchip industry group the ITRS says the so-called five-nanometernode is due in 2019.

000 nanotube transistors. Now it is working on a transistor design that could be built on the silicon wafers used in the industry today with minimal changes to existing design and manufacturing methods.

IBM s chosen design uses six nanotubes lined up in parallel to make a single transistor.

Each nanotube is 1. 4 nanometers wide about 30 nanometers long, and spaced roughly eight nanometers apart from its neighbors.

The IBM team has tested nanotube transistors with that design, but so far it hasn t found a way to position the nanotubes closely enough together,

because existing chip technology can t work at that scale. The favored solution is to chemically label the substrate

and nanotubes with compounds that would cause them to self-assemble into position. Those compounds could then be stripped away,

leaving the nanotubes arranged correctly and ready to have electrodes and other circuitry added to finish a chip.

Haensch s team buys nanotubes in bulk from industrial suppliers and filters out the tubes with the right properties for transistors using a modified version of a machine used to filter molecules such as proteins in the pharmaceutical industry.

It uses electric charge to separate semiconducting nanotubes useful for transistors from those that conduct electricity like metals

Last year researchers at Stanford created the first simple computer built using only nanotube transistors. But those components were bulky and slow compared to silicon transistors

says However, for now IBM s nanotube effort remains within its research labs, not its semiconductor business unit.

In particular, if the nanotube transistors are not ready soon after 2020 when the industry needs them,

If nanotubes don t make it, there s little else that shows much potential to take over from silicon transistors in that time frame.

Although IBM hasn worked t out how to make nanotube transistors small enough for mass production, Mirta says it has made concrete steps,

Baughman has made artificial muscles out of carbon nanotube yarns before but those are much more expensive and complicated to make.

Our electronic whiskers consist of high-aspect-ratio elastic fibers coated with conductive composite films of nanotubes and nanoparticles.

The nanotubes provide both flexibility allowing the whiskers to bend when they experience pressure and conductivity allowing them to transmit data on the environmental factors they experience.

and height of the nanotubes the researchers were able to achieve a fluid flow that enabled an operating ion current at very near the theoretical limit.

To control the nanotubes growth the researchers first cover the emitter array with an ultrathin catalyst film

The nanotubes grow up under the catalyst particles which sit atop them until the catalyst degrades.

Using their nanotube forest they re able to get the devices to operate in pure ion mode

Grossman team tried attaching the molecules to carbon nanotubes (CNTS), but t incredibly hard to get these molecules packed onto a CNT in that kind of close packing,

Kucharski says. But then they found a big surprise: Even though the best they could achieve was a packing density less than half of

called azobenzene, protrude from the sides of the CNTS like the teeth of a comb.

they were interleaved with azobenzene molecules attached to adjacent CNTS. The net result: The molecules were actually much closer to each other than expected.

The interactions between azobenzene molecules on neighboring CNTS make the material work, Kucharski says. While previous modeling showed that the packing of azobenzenes on the same CNT would provide only a 30 percent increase in energy storage,

the experiments observed a 200 percent increase. New simulations confirmed that the effects of the packing between neighboring CNTS,

as opposed to on a single CNT, explain the significantly larger enhancements. This realization, Grossman says,

opens up a wide range of possible materials for optimizing heat storage. Instead of searching for specific photoswitching molecules

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

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.

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

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,

In the past, researchers have exploited this phenomenon to create sensors by coating the nanotubes with molecules, such as natural antibodies, that bind to a particular target.

the carbon nanotube fluorescence brightens or dims. The MIT team found that they could create novel sensors by coating the nanotubes with specifically designed amphiphilic polymers polymers that are drawn to both oil and water, like soap.

This approach offers a huge array of recognition sites specific to different targets, and could be used to create sensors to monitor diseases such as cancer, inflammation,

or diabetes in living systems. his new technique gives us an unprecedented ability to recognize any target molecule by screening nanotube-polymer complexes to create synthetic analogs to antibody function,

Their approach takes advantage of a phenomenon that occurs when certain types of polymers bind to a carbon nanotube.

These loops form a new layer surrounding the nanotube, known as a corona. The MIT researchers found that the loops within the corona are arranged very precisely along the tube,

and alter the carbon nanotube fluorescence. Molecular interactions What is unique about this approach, the researchers say,

and the polymer before it attaches to the nanotube. he idea is that a chemist could not look at the polymer

It has to adsorb onto the nanotube and then, by having certain sections of the polymer exposed,

The researchers used an automated, robot-assisted trial and error procedure to test about 30 polymer-coated nanotubes against three dozen possible targets, yielding three hits.

They are now working on a way to predict such polymer-nanotube interactions based on the structure of the corona layers,

using data generated from a new type of microscope that Landry built to image the interactions between the carbon nanotube coronas

Overall, niobium-based supercapacitors can store up to five times as much power in a given volume as carbon nanotube versions.

#Carbon nanotube finding could lead to flexible electronics with longer battery life University of Wisconsin-Madison materials engineers have made a significant leap toward creating higher-performance electronics with improved battery lifend the ability

the team has reported the highest-performing carbon nanotube transistors ever demonstrated. In addition to paving the way for improved consumer electronics,

000 times better and a conductance that's 100 times better than previous state-of-the-art carbon nanotube transistors."

because metallic nanotube impurities act like copper wires and"short"the device. Researchers have struggled also to control the placement and alignment of nanotubes.

Until now these two challenges have limited the development of high-performance carbon nanotube transistors. Building on more than two decades of carbon nanotube research in the field,

the UW-Madison team drew on cutting-edge technologies that use polymers to selectively sort out the semiconducting nanotubes,

achieving a solution of ultra-high-purity semiconducting carbon nanotubes. Previous techniques to align the nanotubes resulted in less than-desirable packing density,

or how close the nanotubes are to one another when they are assembled in a film. However, the UW-Madison researchers pioneered a new technique,

called floating evaporative self-assembly, or FESA, which they described earlier in 2014 in the ACS journal Langmuir.

In that technique, researchers exploited a self-assembly phenomenon triggered by rapidly evaporating a carbon nanotube solution.

The team's most recent advance also brings the field closer to realizing carbon nanotube transistors as a feasible replacement for silicon transistors in computer chips and in high-frequency communication devices,

which are rapidly approaching their physical scaling and performance limits.""This is not an incremental improvement in performance,

"With these results, we've really made a leap in carbon nanotube transistors. Our carbon nanotube transistors are an order of magnitude better in conductance than the best thin film transistor technologies currently being used commercially

while still switching on and off like a transistor is supposed to function.""The researchers have patented their technology through the Wisconsin Alumni Research Foundation

and T cells found that carbon nanotubes (CNTS) triggered a chain reaction in the complement system which is part of the innate immune system

The interaction between CNTS and C1q (a starter-protein for complement) was anti-inflammatory. This suggests that either coating nanoparticles

if the binding between complement proteins and CNTS was direct or indirect. However changing the surfaces of CNTS affected how likely the complement system was to be activated and in what way.

Using the data from this study carbon nanoparticles coated with genetically-engineered proteins are being used to target glioblastoma the most aggressive form of brain tumour.

#Scientists use'smallest possible diamonds'to form ultra-thin nanothreads For the first time scientists have discovered how to produce ultra-thin diamond nanothreads that promise extraordinary properties including strength and stiffness greater than that of today's strongest nanotubes

Scientists create multifunctional nanotubes using nontoxic materials A doctoral student in materials science at Technische Universitat Darmstadt is making multifunctional nanotubes of goldith the help of Vitamin c and other harmless substances.

The doctoral student in the research group of Professor Wolfgang Ensinger in the Department of Material Analysis is working on making nanotubes of gold.

The metal on the walls of the channels adopts the shape of nanotubes; the film is dissolved then.

The gold nanotubes are thus several hundred times finer than a human hair. Their wall thickness depends both on the duration of precipitation and on the gold concentration of the original solution.

the result is-depending on the experimental conditions-a collection of individual nanotubes or an array of hundreds of thousands of interconnected tubes.

"With 1 gram of gold, we could make a nanotube for literally every person on earth."

Ensinger's team has tested already successfully one use of the gold nanotubes: they are suitable for building sensors to measure hydrogen peroxide.

The gold nanotubes conduct electricity especially well due to their one-dimensional structure. In addition, they are relatively long

For example, they are thinking about also using the nanotubes to measure blood sugar.""A subcutaneous sensor could save diabetes patients from having to constantly prick their fingers"thinks Ensinger.

#Nanotubes may restore sight to blind retinas The aging process affects everything from cardiovascular function to memory to sexuality.

or older who have damage to a specific part of the retina will stand to benefit from the nanotube device

We hope our carbon nanotube and semiconductor nanorod film will serve as a compact replacement for damaged retinas.

#Graphene/nanotube hybrid benefits flexible solar cells Rice university scientists have invented a novel cathode that may make cheap, flexible dye-sensitized solar cells practical.

from nanotubes that are bonded seamlessly to graphene and replaces the expensive and brittle platinum-based materials often used in earlier versions.

In his process, the nanotubes remained attached to the surface substrate but pushed the catalyst up as they grew.

The graphene/nanotube hybrid came along two years ago. Dubbed"James'bond"in honor of its inventor, Rice chemist James Tour, the hybrid features a seamless transition from graphene to nanotube.

The graphene base is grown via chemical vapor deposition and a catalyst is arranged in a pattern on top.

which lifts off and allows the new nanotubes to grow. When the nanotubes stop growing,

the remaining catalyst (the"carpet")acts as a cap and keeps the nanotubes from tangling.

The hybrid material solves two issues that have held back commercial application of dye-sensitized solar cells,

First, the graphene and nanotubes are grown directly onto the nickel substrate that serves as an electrode,

With no interruption in the atomic bonds between nanotubes and graphene, the material's entire area, inside and out, becomes one large surface.

Lou's lab built and tested solar cells with nanotube forests of varying lengths The shortest,

Other nanotube samples were grown for an hour and measured about 100-150 microns. When combined with an iodide salt-based electrolyte and an anode of flexible indium tin oxide,

Tests found that solar cells made from the longest nanotubes produced the best results and topped out at nearly 18 milliamps of current per square centimeter

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