Carbon nanotube

Carbon nanotube (214)
Carbon nanotube transistor (19)
Multiwalled carbon nanotube (6)
Nanocarbon (11)
Walled carbon nanotube (23)

Synopsis: Domenii: Nanotechnology: Nanotechnology generale: Nanostructures: Nanotube: Carbon nanotube: Carbon nanotube:

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.

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

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.

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.

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.

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

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

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

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.

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.

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

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

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.

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

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

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

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,

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

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.

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

Adrian Bachtold, together with Marc Dykman (Michigan University), report on an experiment in which a carbon nanotube mechanical resonator exhibits quality factors of up to 5 million,

Nowadays, carbon nanotube mechanical resonators are in demand because of their extremely small size and their outstanding capability of sensing objects at the nanoscale.

Like a guitar string or a tightrope, a carbon nanotube resonator consists of a tiny, vibrating bridge-like (string) structure with typical dimensions of 1#m in length and 1nm in diameter.

A carbon nanotube is a cylindrical material that is a hexagonal or six-sided array of carbon atoms rolled up into a tube.

the Utah carbon nanotube technology has four advantages s

#A quantum leap in nanoparticle efficiency (Phys. org) New research has unlocked the secrets of efficiency in nanomaterials that is materials with very tiny particles

Breakthrough for carbon nanotube solar cell l

#See-through one-atom-thick carbon electrodes powerful tool to study brain disorders Researchers from the Perelman School of medicine and School of engineering at the University of Pennsylvania and The Children's Hospital of Philadelphia have used graphene

The Center for Neuroengineering and Therapeutics (CNT) under the leadership of senior author Brian Litt Phd has solved this problem with the development of a completely transparent graphene microelectrode that allows for simultaneous optical imaging

Kuzum emphasizes that the transparent graphene microelectrode technology was achieved through an interdisciplinary effort of CNT and the departments of Neuroscience Pediatrics and Materials science at Penn and the division of Neurology at CHOP.

Recently, scientists from Tsinghua University have created a freestanding carbon nanotube paper electrode with high sulfur loading for lithium-sulfur batteries.

"We select carbon nanotube (CNT) as the building block",Qiang told Phys. org, "CNTS are one of the most efficient and effective conductive fillers for electrode.

We selected short multi-walled CNTS (MWCNTS) with lengths of 10-50 m as the shortrange electrical conductive network to support sulfur,

as well as super long CNTS with lengths of 1000-2000 m from vertically aligned CNTS (VACNTS) as both long-range conductive networks and inter-penetrated binders for the hierarchical freestanding paper electrode.""

""We develop a bottom-up routine in which sulfur was dispersed firstly well into the MWCNT network to obtain MWCNT@S building blocks

and then MWCNT@S and VACNTS were assembled into macro-CNT-S films via the dispersion in ethanol followed by vacuum filtration",Zhe Yuan,

"Such sulfur electrodes with hierarchical CNT scaffolds can accommodate over 5 to 10 times the sulfur species compared with conventional electrodes on metal foil current collectors

"The areal capacity can be increased further to 15.1 mah cm-2 by stacking three CNT-S paper electrodes, with an areal sulfur loading of 17.3 mg cm-2 as the cathode in a Li

which is also favorable for graphene, CNT-graphene, CNTMETAL oxide based flexible electrodes, "Qiang said."

Electronics based on carbon especially carbon nanotubes (CNTS) are emerging as successors to silicon for making semiconductor materials.

#New nanomaterial introduced into electrical machines Lappeenranta University of Technology in Finland has constructed the world's first prototype electrical motor using carbon nanotube yarn in the motor windings.

carbon nanotube yarn. The presently most electrically conductive carbon nanotube yarn replaces usual copper wires in the windings.

The motor prototype is built by the LUT Electrical engineering group as a start towards lightweight efficient electric drives.

The best carbon nanotubes (CNTS) have demonstrated conductivities far beyond those of the best metals. Thus future windings made of CNTS may have a double conductivity compared with the present-day copper windings.

In order to make CNTS easy to manipulate they are spun to form multifiber yarn. If we keep the electrical machine design parameters unchanged and only replace copper with future carbon nanotube wires it is possible to reduce the Joule losses in the windings to half of the present-day machine losses.

Carbon nanotube wires are significantly lighter than copper and also environmentally friendlier. Therefore replacing copper with nanotube wires should significantly reduce the CO2 EMISSIONS related to the manufacturing

and operating of electrical machines. Furthermore the machine dimensions and masses could be reduced. The motors could also be operated in significantly higher temperatures than the present ones says Professor Juha Pyrh nen who has led the design of the prototype at LUT.

No definite upper limit for the conductivity Traditionally the windings in electrical machines are made of copper which has the second best conductivity of metals at room temperature.

The carbon nanotube yarn does not have a definite upper limit for conductivity (e g. values of 100 MS/m have already been measured.

The prototype motor uses carbon nanotube yarns spun and converted into an isolated tape by a Japanese-Dutch company Teijin Aramid

We expect that in the future the conductivity of carbon nanotube yarns could be even three times the practical conductivity of copper in electrical machines.

Using the High-Brightness Electron Source Lab at DOE's Fermi National Accelerator Laboratory a team led by scientist Luigi Faillace of Radiabeam Technologies is testing a carbon nanotube cathode about the size of a nickel

While carbon nanotube cathodes have been studied extensively in academia Fermilab is the first facility to test the technology within a full-scale setting.

Biocompatible Carbon nanotube#Chitosan Cardiac Scaffold Matching the Electrical conductivity of the Heart. Seokwon Pok Flavia Vitale Shannon L. Eichmann Omar M. Benavides Matteo Pasquali and Jeffrey G Jacot ACS Nano Just Accepted Manuscript DOI:

#Aligned carbon nanotube/graphene sandwiches By in situ nitrogen doping and structural hybridization of carbon nanotubes (CNTS) and graphene via a two-step chemical vapor deposition (CVD) scientists have fabricated nitrogen-doped aligned carbon nanotube/graphene (N-ACNT/G) sandwiches

with three-dimensional (3d) electron transfer pathways interconnected ion diffusion channels and enhanced interfacial affinity and activity.

CNTS and graphene the most highlighted sp2-bonded carbon nanomaterials over the past decades have attracted enormous attention in the area of energy storage heterogeneous catalysis healthcare environmental protection as well as nanocomposites

The combination of CNTS and graphene into 3d hybrid composites can usually mitigate the self-aggregation

Up to now several strategies have been explored to fabricate such CNTS/graphene hybrids including post-organization methods and in situ growth while integration of high-quality CNTS and graphene without barrier layers is still difficult.

A team from Tsinghua University (China) led by Prof. Qiang Zhang and Fei Wei have fabricated now successfully sandwich-like N-ACNT/G hybrids via a two-step catalytic growth on bifunctional natural materials.

Aligned CNTS were intercalated firstly into the interlayer spaces of the layered catalyst embedded with metal nanoparticles (NPS) through a low-temperature (L-T) CVD

and graphene was deposited sequentially onto the surface of lamellar flakes at the bottom of aligned CNTS through a high-temperature (H-T) CVD.

After catalyst removal alternative aligned CNTS and graphene were connected vertically to each other in long-range periodicity thereby forming a sandwich-like structure.

The key issue for the fabrication of the novel N-ACNT/G architecture is that the high-quality aligned CNTS

Org''Thereby the seamless connection of high-quality aligned CNTS and graphene provided 3d electron transfer pathways and interconnected ion diffusion channels.

which was about 65%higher than that of sole aligned CNTS. Even at a high current density of 5. 0 C a reversible capacity of ca. 770 mah g-1 can be achieved.

Zhang elaborated The seamless junction of CVD-grown aligned CNTS and graphene provides rapid electron transfer and mechanical robustness.

Tang C Zhang Q Zhao MQ Huang JQ Cheng XB Tian GL Peng HJ Wei F. Nitrogen-Doped Aligned Carbon nanotube

The manufacture of`super-black`carbon nanotube-based materials has required traditionally high temperatures preventing their direct application to sensitive electronics or materials with relatively low melting points.

"the main hurdle (of carbon-based electronics) is our current inability to produce large amounts of identical nanostructureshere is no reliable way to directly produce a single CNT type such as will be needed in a large integrated system."

researchers from the USC Viterbi School of engineering describe how they have overcome a major issue in carbon nanotube technology by developing a flexible,

energy-efficient hybrid circuit combining carbon nanotube thin film transistors with other thin film transistors. This hybrid could take the place of silicon as the traditional transistor material used in electronic chips,

and Jialu Zhang developed this energy-efficient circuit by integrating carbon nanotube (CNT) thin film transistors (TFT) with thin film transistors comprised of indium, gallium and zinc oxide (IGZO)."

This hybridization of carbon nanotube thin films and IGZO thin films was achieved by combining their types, p-type and n-type, respectively,

Zhou likened the coupling of carbon nanotube TFTS and IGZO TFTS to the Chinese philosophy of yin and yang."

With this development, Zhou and his team have circumvented the difficulty of creating n-type carbon nanotube TFTS

and p-type IGZO TFTS by creating a hybrid integration of p-type carbon nanotube TFTS and n-type IGZO TFTS and demonstrating a large-scale integration of circuits.

Up to this point, all carbon nanotube-based transistors had a maximum number of 200 transistors.""We believe this is a technological breakthrough,

"The next step for Zhou and his team will be to build more complicated circuits using a CNT

"Zhou and Chen believe that carbon nanotube technology, including this new CNT-IGZO hybrid, will be commercialized in the next 5-10 years."

"I believe that this is just the beginning of creating hybrid integrated solutions, "said Zhou.""We will see a lot of interesting work coming up. g

#Charging portable electronics in 10 minutes Researchers at the University of California Riverside Bourns College of Engineering have developed a three-dimensional silicon-decorated cone-shaped carbon nanotube cluster architecture for lithium ion battery anodes that could enable charging of portable

In a paper Silicon Decorated Cone Shaped Carbon nanotube Clusters for Lithium ion battery Anode recently published in the journal Small UC Riverside researchers developed a novel structure of three-dimensional silicon decorated cone-shaped

carbon nanotube clusters architecture via chemical vapor deposition and inductively coupled plasma treatment. Lithium ion batteries based on this novel architecture demonstrate a high reversible capacity and excellent cycling stability.

and scaffolds with the required shapes and sizes. he carbon nanotubes (or CNT) were added to the bioprintable material mixture to create a hree-dimensional electrical conducting network all through the volume of the scaffold,

CNTS are basically one-atom-thick graphene sheets rolled up onto themselves in order to form very long filaments with diameters of only a few nanometers. n this sense,

by adding conducting CNTS into the bioprinted polymer and mineral prosthetic bone implant, you can stimulate the regrowth of the actual bone cells.

Perhaps one of the most curious aspects is that bioprinting CNTS created no additional difficulties,

the addition of the CNTS was performed and reaching a proper dispersion took a bit of stirring time. ercedes

which is sufficient for ejecting electrons out of the carbon nanotube antennas upon the absorption of visible light Light in the form of oscillating waves interacts with nanotubes after going through the calcium-aluminum electrode.

Carbon nanotubes (CNTS) have electrical properties similar to those of conventional silicon transistors. In a head-to-head competition between a silicon transistor and a CNT transistor,"hands down, the CNT would win,

"Shulaker told Live Science.""It would be a better transistor; it can go faster; it uses less energy."

while most CNTS have the properties of a semiconductor (like silicon), a few act just like an ordinary conducting metal,

As a remedy, Shulaker and his colleagues essentially"turn off"all the semiconducting CNTS, leaving huge jolts of current to circulate through the remaining conducting nanotubes.

We have fabricated also Li-ion batteries based on structurally resilient carbon nanotube-based electrodes that have survived thousands of flexing cycles.

The sensor is similar to other carbon nanotube devices that Swager's lab has developed in recent years,

it increases the electrical resistance of the carbon nanotube, which can be measured easily.""We use these porphyrins to fabricate a very simple device where we apply a potential across the device

#Taking aircraft manufacturing out of the oven Aerospace engineers at MIT have developed now a carbon nanotube (CNT) film that can heat

"Wardle says the carbon nanotube film is also incredibly lightweight: After it has fused the underlying polymer layers,

Carbon nanotube deicerswardle and his colleagues have experimented with CNT films in recent years, mainly for deicing airplane wings.

If the CNT film could generate heat, why not use it to make the composite itself?

The researchers manufactured a CNT film about the size of a Post-it note, and placed the film over a square of Cycom 5320-1. They connected electrodes to the film,

or cross-link, the polymer and carbon fiber layers, finding that the CNT film used one-hundredth the electricity required for traditional oven-based methods to cure the composite.

Wardle says the results pushed the group to test the CNT film further: As different composites require different temperatures in order to fuse,

whether the CNT film could, quite literally, take the heat.""At some point, heaters fry out,

"Gregory Odegard, a professor of computational mechanics at Michigan Technological University, says the group's carbon nanotube film may go toward improving the quality and efficiency of fabrication processes for large composites, such as wings on commercial aircraft.

more conductive carbon nanotube films"It's a simple process and can create a lightweight CNT film,

or'bucky paper,'that is a meter wide and twice as strong as previous such films--it's even stronger than CNT FIBERS,

The researchers begin by growing the CNTS on a conventional substrate in a closely packed array.

The CNTS are tangled together, so when researchers pull on one end of the array the CNTS form a continuous ribbon that is only nanometers thick.

This ribbon is attached to a spool which begins winding the ribbon up. As the spool pulls, the CNT ribbon is dragged between two surgical blades.

While the blades appear straight to the naked eye, they actually have micrometer-scale fissures on their cutting edge.

These fissures create a kind of"microcomb"that pulls the CNTS into alignment--just as a regular comb sorts through tangled hair.

When the ribbon of aligned CNTS is being wound onto the spool, the researchers apply an alcohol solution.

This pulls the CNTS closer together, strengthening the bonds between CNTS. The CNT ribbon wraps around itself as it winds around the spool

creating a layered film of pure CNTS. Researchers can control the thickness of the film by controlling the number of layers.

The CNT films made using the microcombing technique had more than twice the tensile strength of the uncombed CNT films--greater than 3 gigapascals for the microcombed material,

versus less than 1. 5 gigapascals for the uncombed material. The microcombed CNT film also had 80 percent higher electrical conductivity than the uncombed film."

"This is a significant advance, but we want to find ways to make CNT alignment even straighter,

"Zhu says.""It's still not perfect.""In addition, the technique would theoretically be easy to scale up for large-scale production.

The pressure sensors are made of a carbon nanotube-elastomer composite shaped into tiny pyramidal structures that are coated onto a surface.

#icrocombingcreates Stronger, More Conductive Carbon nanotube Films Researchers from North carolina State university and China Suzhou Institute of Nanoscience and Nano-Biotics have developed an inexpensive technique called icrocombingto align carbon nanotubes (CNTS),

pure CNT films that are stronger than any previous such films. The technique also improves the electrical conductivity that makes these films attractive for use in electronic

and aerospace applications. t a simple process and can create a lightweight CNT film, or ucky paper, that is a meter wide and twice as strong as previous such films it even stronger than CNT FIBERS,

The researchers begin by growing the CNTS on a conventional substrate in a closely packed array.

The CNTS are tangled together, so when researchers pull on one end of the array the CNTS form a continuous ribbon that is only nanometers thick.

This ribbon is attached to a spool, which begins winding the ribbon up. As the spool pulls, the CNT ribbon is dragged between two surgical blades.

While the blades appear straight to the naked eye they actually have micrometer-scale fissures on their cutting edge.

These fissures create a kind of icrocombthat pulls the CNTS into alignment just as a regular comb sorts through tangled hair.

When the ribbon of aligned CNTS is being wound onto the spool, the researchers apply an alcohol solution.

This pulls the CNTS closer together, strengthening the bonds between CNTS. The CNT ribbon wraps around itself as it winds around the spool,

creating a layered film of pure CNTS. Researchers can control the thickness of the film by controlling the number of layers.

The CNT films made using the microcombing technique had more than twice the tensile strength of the uncombed CNT films greater than 3 gigapascals for the microcombed material

versus less than 1. 5 gigapascals for the uncombed material. The microcombed CNT film also had 80 percent higher electrical conductivity than the uncombed film. his is a significant advance,

but we want to find ways to make CNT alignment even straighter, Zhu says. t still not perfect. n addition,

the technique would theoretically be easy to scale up for large-scale production. We like to find an industry partner to help us scale this up

enough to drive electrons out of the carbon nanotube antennas when they are excited by light. In operation, oscillating waves of light pass through the transparent calcium-aluminum electrode

Electronics based on carbon especially carbon nanotubes (CNTS) are emerging as successors to silicon for making semiconductor materials.

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