physicists have used graphene to build lightweight ultrasonic loudspeakers and microphones, enabling people to mimic bats
Graphene consists of carbon atoms laid out in a hexagonal, chicken-wire arrangement, which creates a tough,
"There's a lot of talk about using graphene in electronics and small nanoscale devices, but they're all a ways away,
because we've worked out how to make the graphene and mount it, and it's easy to scale up."
"Arrayarraytwo years ago, Zhou built loudspeakers using a sheet of graphene for the diaphragm, and since then has been developing the electronic circuitry to build a microphone with a similar graphene diaphragm.
One big advantage of graphene is that the atom-thick sheet is so lightweight that it responds well to the different frequencies of an electronic pulse, unlike today's piezoelectric microphones and speakers.
This comes in handy when using ultrasonic transmitters and receivers to transmit large amounts of information through many different frequency channels simultaneously,
"Graphene is a magical material; it hits all the sweet spots for a communications device, "he said.
The use of graphene allows the authors to obtain very flat frequency responses in a wide range of frequencies,
"Zettl noted that audiophiles would also appreciate the graphene loudspeakers and headphones, which have a flat response across the entire audible frequency range."
"But over the past decade the graphene community has come together to develop techniques to grow,
transport and mount graphene, so building a device like this is now very straightforward; the design is simple
termed phosphorene, in the same simple way as the Nobel-prize winning discovery of graphene. Unlike graphene, phosphorene is a semiconductor, like silicon,
which is the basis of current electronics technology.""Because phosphorene is so thin and light,
When the lubricant materials--graphene and diamond-like carbon (DLC)--slid against each other, the graphene began rolling up to form hollow cylindrical"scrolls"that helped to practically eliminate friction.
These so-called nanoscrolls represented a completely new mechanism for superlubricity a state in which friction essentially disappears."
The experimental setup consisted of small patches of graphene (a two-dimensional single-sheet form of pure carbon) sliding against a DLC-coated steel ball.
The graphene-DLC combination was registering a very low friction coefficient (a ratio that measures the force of friction between two surfaces),
This led to their discovery of the graphene nanoscrolls, which helped to fill in the blanks.
when the graphene patches were in an unscrolled state, "Deshmukh said. The computational scientists had an idea to overcome this issue.
The graphene patches spontaneously rolled around the nanodiamonds, which held the scrolls in place and resulted in sustained superlubricity.
The simulations showed that water suppresses the formation of scrolls by increasing the adhesion of graphene to the surface.
it would leave the graphene and nanodiamonds on one side of a moving part, and diamond-like carbon on the other side.
the graphene nanoscrolls could potentially work in humid environments as well.""Arraythe team's groundbreaking nanoscroll discovery would not have been possible without a supercomputer like Mira.
#Laser-induced graphene#super#for electronics Rice university scientists advanced their recent development of laser-induced graphene (LIG) by producing
since their work to make vertically aligned supercapacitors with laser-induced graphene on both sides of a polymer sheet.
But the graphene retains its ability to move electrons quickly and gives it the quick charge
or graphenes could stabilize the polysulphides by physically trapping them. But in an unexpected twist, they discovered metal oxides could be the key.
Looking at carbon-based graphene another atom-thick material with promise for chip development, researchers speculated that silicon atoms could be structured in a broadly similar way.
#Graphene displays clear prospects for flexible electronics Published in the scientific journal Nature Materials, University of Manchester and University of Sheffield researchers show that new 2d esigner materialscan be produced to create flexible, see-through and more efficient electronic devices.
The new research shows that graphene and related 2d materials could be utilised to create light emitting devices for the next-generation of mobile phones,
One-atom thick graphene was isolated first and explored in 2004 at The University of Manchester.
new possibilities for graphene based optoelectronics have now been realised. Freddie Withers, Royal Academy of Engineering Research Fellow at The University of Manchester, who led the production of the devices,
The new findings using a layer of one-atom-thick graphene deposited on top of a similar 2-D layer of a material called hexagonal boron nitride (hbn) are published in the journal Nano Letters.
The hybrid material blocks light when a particular voltage is applied to the graphene, while allowing a special kind of emission and propagation,
Light interaction with graphene produces particles called plasmons while light interacting with hbn produces phonons.
The properties of the graphene allow precise control over light, while hbn provides very strong confinement and guidance of the light.
says, his work represents significant progress on understanding tunable interactions of light in graphene-hbn.
The work is retty criticalfor providing the understanding needed to develop optoelectronic or photonic devices based on graphene and hbn,
#How to make continuous rolls of graphene Graphene is a material with a host of potential applications,
MIT mechanical engineering Associate professor A. John Hart, the paper senior author, says the new roll-to-roll manufacturing process described by his team addresses the fact that for many proposed applications of graphene
Making such quantities of graphene would represent a big leap from present approaches where researchers struggle to produce small quantities of graphene often pulling these sheets from a lump of graphite using adhesive tape,
or producing a film the size of a postage stamp using a laboratory furnace. But the new method promises to enable continuous production,
That could finally unleash applications for graphene, which has unique electronic and optical properties and is one of the strongest materials known.
and elsewhere to make graphene using a small vacuum chamber into which a vapor containing carbon reacts on a horizontal substrate,
where the graphene is formed on the ribbon. The chamber is heated to approximately 1, 000 degrees Celsius to perform the reaction.
high-quality single layer of graphene is created. When rolled 20 times faster, it still produces a coating,
but the graphene is of lower quality, with more defects. Some potential applications, such as filtration membranes
may require very high-quality graphene, but other applications, such as thin-film heaters may work well enough with lower-quality sheets,
So far, the new system produces graphene that is ot quite equal to the best that can be done by batch processing,
such as between higher production rate and graphene quality. Then, he says, he next step is to understand how to push the limits,
Hart says that while this study focuses on graphene, the machine could be adapted to continuously manufacture other two-dimensional materials,
which his group is also studying. his is high-quality research that represents significant progress on the path to scalable production methods for large-area graphene,
It has the potential to lead to significantly lower production costs for graphene, if it can be scaled to larger copper-foil widths. d
#Breakthrough in graphene production could trigger revolution in artificial skin development A pioneering new technique to produce high-quality,
low cost graphene could pave the way for the development of the first truly flexible lectronic skin that could be used in robots.
Researchers from the University of Exeter have discovered an innovative new method to produce the wonder material Graphene significantly cheaper,
from Exeter Engineering department, believes the new discovery could pave the way for graphene-driven industrial revolutionto take place.
he vision for a raphene-driven industrial revolutionis motivating intensive research on the synthesis of high quality and low cost graphene.
Currently, industrial graphene is produced using a technique called Chemical Vapour Deposition (CVD. Although there have been significant advances in recent years in this technique,
which grows graphene in an industrial cold wall CVD system, a state-of-the-art piece of equipment recently developed by UK graphene company Moorfield.
This so-called nanocvd system is based on a concept already used for other manufacturing purposes in the semiconductor industry.
This shows to the semiconductor industry for the very first time a way to potentially mass produce graphene with present facilities rather than requiring them to build new manufacturing plants.
This new technique grows graphene 100 times faster than conventional methods reduces costs by 99
and look forward to seeing where it can take the graphene industry in the future. Professor Seigo Tarucha from the University of Tokyo, coordinator of the Global Center of Excellence for Physics at Tokyo university and director of the Quantum Functional System Research Group at Riken Center
he ability to manufacture high quality, large area graphene (at a low cost) is essential for advancing this exciting material from pure science and proof-of-concept into the realm of conventional and quantum electronic applications.
we are using Exeter CVD grown graphene instead of the exfoliated material in our graphene-based devices, whenever possible.
The research team used this new technique to create the first graphene-based transparent and flexible touch sensor.
and energy harvesting devices could be transformed by the unique properties of graphene. The extremely cost efficient procedure that we have developed for preparing graphene is of vital importance for the quick industrial exploitation of graphene.
At just one atom thick, graphene is the thinnest substance capable of conducting electricity. It is very flexible
and is one of the strongest known materials. The race has been on for scientists and engineers to adapt graphene for flexible electronics.
Professor Saverio Russo, co-author and also from the University of Exeter added: his breakthrough will nurture the birth of new generations of flexible electronics and offers exciting new opportunities for the realization of graphene-based disruptive technologies.
Source: University of Exete s
#Electrical engineers Break Power and Distance Barriers for Fiber optic communication Electrical engineers have broken key barriers that limit the distance information can travel in fiber optic cables
and detected using ferromagnetic metal contacts with a tunnel barrier consisting of single layer graphene between the metal and silicon NW.
The ferromagnetic metal/graphene tunnel barrier contacts used to inject and detect spin appear as blue,
The use of graphene as the tunnel barrier provides a low-resistance area product contact
and used a graphene tunnel barrier contact that produces excellent spin injection and also satisfies several key technical criteria:
Using intrinsic 2d layers such as graphene or hexagonal boron nitride as tunnel contacts on nanowires offers many advantages over conventional materials deposited by vapor deposition (such as Al2o3
The use of multilayer rather than single layer graphene in such structures may provide much higher values of the tunnel spin polarization because of band structure derived spin filtering effects predicted for selected ferromagnetic metal/multi
#Graphene flexes its electronic muscles Flexing graphene may be the most basic way to control its electrical properties, according to calculations by theoretical physicists at Rice university and in Russia.
and predictable in nanocones and should apply equally to other forms of graphene. The researchers discovered it may be possible to access
which the electronic properties of a sheet of graphene can be manipulated simply by twisting it a certain way.
The work will be of interest to those considering graphene elements in flexible touchscreens or memories that store bits by controlling electric dipole moments of carbon atoms
Perfect graphene an atom-thick sheet of carbon is a conductor, as its atomselectrical charges balance each other out across the plane.
But curvature in graphene compresses the electron clouds of the bonds on the concave side and stretches them on the convex side,
The researchers who published their results this month in the American Chemical Society Journal of Physical chemistry Letters discovered they could calculate the flexoelectric effect of graphene rolled into a cone of any size and length.
The researchers used density functional theory to compute dipole moments for individual atoms in a graphene lattice
and then figure out their cumulative effect They suggested their technique could be used to calculate the effect for graphene in other more complex shapes, like wrinkled sheets or distorted fullerenes,
several of which they also analyzed. hile the dipole moment is zero for flat graphene or cylindrical nanotubes,
Carbon nanotubes, seamless cylinders of graphene, do not display a total dipole moment, he said. While not zero, the vector-induced moments cancel each other out.
physicists have used graphene to build lightweight ultrasonic loudspeakers and microphones, enabling people to mimic bats
Graphene consists of carbon atoms laid out in a hexagonal, chicken-wire arrangement, which creates a tough,
or more years. here a lot of talk about using graphene in electronics and small nanoscale devices, but theye all a ways away, said Zettl,
because wee worked out how to make the graphene and mount it, and it easy to scale up. ettl,
UC Berkeley postdoctoral fellow Qin Zhou and colleagues describe their graphene microphone and ultrasonic radio in a paper appearing online this week in the Proceedings of the National Academy of Sciences.
Zhou built loudspeakers using a sheet of graphene for the diaphragm, and since then has been developing the electronic circuitry to build a microphone with a similar graphene diaphragm.
An atom-thick layer of carbon atoms, called graphene (black mesh), provides the vibrating diaphragm for both an ultrasonic microphone and loudspeaker.
Image credit: UC Berkeleyone big advantage of graphene is that the atom-thick sheet is so lightweight that it responds immediately to an electronic pulse, unlike today piezoelectric microphones and speakers.
This comes in handy when using ultrasonic transmitters and receivers to transmit large amounts of information through many different frequency channels simultaneously,
The use of graphene allows the authors to obtain very flat frequency responses in a wide range of frequencies,
and will permit a detailed study of the auditory pulses that are used by bats. ettl noted that audiophiles would also appreciate the graphene loudspeakers and headphones,
Zettl said. ut over the past decade the graphene community has come together to develop techniques to grow,
transport and mount graphene, so building a device like this is now very straightforward; the design is simple. ource:
#Graphene-Based Biosensor Could Detect Cancer within Minutes One of the main reasons why treating most cancers is such a difficult task is our inability to detect its presence before it becomes widespread.
The new, graphene-based immunosensor could soon lead to a quantum leap in cancer diagnosis. Image credit:
it took graphene to also make it sensitive to cancer. e showed experimentally that simply the addition of graphene led to a clear increase in the sensor signal, aid Dr. Georg Duesberg,
Consequently, materials scientists have been falling over themselves to discover the extraordinary properties of graphene, boron nitride, molybdenum disulphide, and so on.
The big advantage of black phosphorus over graphene is that it has a natural bandgap that physicists can exploit to make electronic devices
What more, black phosphorus is better at this even than graphene. Finally, they measured the current through the nanosheets
All this could mark an interesting step change in research associated with black phosphorus. Many people will have seen the excitement associated with the remarkable properties of graphene.
#Graphene sheaths could boost processor signal speeds by 30 per cent Scientists at Stanford have found a new use for graphene that will significantly increase the speed of standard computer processors.
instead used an atom-thick layer of graphene to sheath the copper, and found that could boost the data transfer speeds of the wires:
the graphene-coated interconnects, depending on their length, can reliably transfer data between four and 17 per cent faster than the equivalent interconnects in today's processor designs, apparently."
"Graphene has been promised to benefit the electronics industry for a long time, and using it as a copper barrier is perhaps the first realization of this promise."
"The advantages of using graphene in this way are twofold. Firstly, from an engineering standpoint, graphene is a much more efficient material,
taking up a ninth of the space of tantalum nitride coatings. But the biggest advantage is that the graphene actually acts both as an insulator,
but also a conductor. The team found that electrons would travel through the graphene as well as through the copper wire,
and it was there that the speed benefits really kicked in. The team, which will present its findings at the Symposia of VLSI Technology And circuits in Kyoto,
if the graphene tech is shrunk down to next-generation process sizes. The research is interesting,
The team are now looking into how to grow the graphene directly onto copper wires,
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