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.
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
#First graphene-based flexible display produced A flexible display incorporating graphene in its pixels'electronics has been demonstrated successfully by the Cambridge Graphene Centre and Plastic Logic,
the first time graphene has been used in a transistor-based flexible device. The partnership between the two organisations combines the graphene expertise of the Cambridge Graphene Centre (CGC),
with the transistor and display processing steps that Plastic Logic has developed already for flexible electronics.
This prototype is a first example of how the partnership will accelerate the commercial development of graphene,
and is a first step towards the wider implementation of graphene and graphene-like materials into flexible electronics.
Graphene is a two-dimensional material made up of sheets of carbon atoms. It is among the strongest most lightweight and flexible materials known,
or backplane, of this display includes a solution-processed graphene electrode, which replaces the sputtered metal electrode layer within Plastic Logic's conventional devices,
Graphene is more flexible than conventional ceramic alternatives like indium-tin oxide (ITO) and more transparent than metal films.
The ultra-flexible graphene layer may enable a wide range of products including foldable electronics. Graphene can also be processed from solution bringing inherent benefits of using more efficient printed
and roll-to-roll manufacturing approaches. The new 150 pixel per inch (150 ppi) backplane was made at low temperatures (less than 100°C) using Plastic Logic's Organic Thin Film Transistor (OTFT) technology.
The graphene electrode was deposited from solution and subsequently patterned with micron-scale features to complete the backplane.
"We are happy to see our collaboration with Plastic Logic resulting in the first graphene-based electrophoretic display exploiting graphene in its pixels'electronics,
"said Professor Andrea Ferrari, Director of the Cambridge Graphene Centre.""This is a significant step forward to enable fully wearable and flexible devices.
This cements the Cambridge graphene technology cluster and shows how an effective academic-industrial partnership is key to help move graphene from the lab to the factory floor.""
""The potential of graphene is well-known, but industrial process engineering is required now to transition graphene from laboratories to industry,
"said Indro Mukerjee, CEO of Plastic Logic.""This demonstration puts Plastic Logic at the forefront of this development,
which will soon enable a new generation of ultra-flexible and even foldable electronics"This joint effort between Plastic Logic
within the'realising the graphene revolution'initiative. This will target the realisation of an advanced, full colour, OELD based display within the next 12 months h
#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 low-cost biosensors that can eventually allow single-molecule detectionhe holy grail of diagnostics and bioengineering research said Samir Mitragotri co-author and professor of chemical engineering and director of the Center for Bioengineering at UCSB.
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
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.
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.
Moreover the channel length of Mos2 FET biosensor can be scaled down to the dimensions similar to those of small biomolecules such as DNA
The Mos2 biosensors demonstrated by the UCSB team have provided already ultrasensitive and specific protein sensing with a sensitivity of 196 even at 100 femtomolar (a billionth of a millionth of a mole) concentrations.
Biosensors based on conventional FETS have been gaining momentum as a viable technology for the medical forensic
Such biosensors allow for scalability and label-free detection of biomoleculesemoving the step and expense of labeling target molecules with florescent dye.
and low-cost ultrasensitive biosensors continued Kis who is connected not to the project. Explore further: New rapid synthesis developed for bilayer graphene and high-performance transistors More information:
ACS Nano pubs. acs. org/doi/abs/10.1021/nn500914 i
#Atomically thin material opens door for integrated nanophotonic circuits A new combination of materials can efficiently guide electricity
Ever since the discovery of graphene a single layer of carbon that can be extracted from graphite with adhesive tape scientists have been rapidly exploring the world of two-dimensional materials These materials have unique properties not seen in their bulk form.
Like graphene Mos2 is made up of layers that are bonded weakly to each other so they can be separated easily.
Graphene is inefficient at light emission because it has no band gap. Combining electronics and photonics on the same integrated circuits could drastically improve the performance and efficiency of mobile technology.
#Ultrafast graphene based photodetectors with data rates up to 50 GBIT/s In cooperation with Alcatel Lucent Bell labs researcher from AMO realized the worldwide fastest Graphene based photodetectors.
Graphene a two-dimensional layer of carbon atoms is currently one of the most promising materials for future ultrafast and compact telecommunication systems.
In the current work Graphene based photodetectors were integrated in a conventional silicon photonic platform designed for future on-chip applications in the area of ultrafast data communication.
In addition the specific features of Graphene-based photodetectors like dark current free and high speed operation
not only set a new benchmark for graphene based photodetectors but also demonstrate for the first time that Graphene based photodetectors surpass comparable detectors based on conventional materials concerning maximal data rates.
The work was supported by the European commission through the Flagship project Graphene and the integrated project Grafol as well as the DPG supported project Gratis.
The publication is published in the international renowned journal ACS Photonics and was chosen as Editor's Choice article.
Graphene and related materials promise cheap flexible printed cameras More information: 50 GBIT/s photodetectors based on wafer-scale graphene for integrated silicon photonic communication systems.
ACS Photonics Just Accepted Manuscript. DOI: 10.1021/ph500160 6
#Graphene reinvents the future For many scientists the discovery of one-atom-thick sheets of graphene is hugely significant something with the potential to affect just about every aspect of human activity and endeavour.
Graphene is hidden inside graphite an ore that has not been particularly sought after in the past. But a few years ago it revealed a secret.
At the molecular level it is a unique two-dimensional molecule: an electrically conductive latticelike layer just one carbon atom thick.
Graphene has usually cautious physicists and chemists itching with excitement mesmerised by the possibilities starting to take shape from flexible electronics embedded into clothing to biomedicine (imagine synthetic nerve cells) vastly superior forms of energy storage (tiny
but immensely powerful batteries) and an array of new materials that could make many of today's common metals and polymers redundant.
But despite the extraordinary potential for graphene's properties the stumbling block has been to get it into a useable form.
Professor Li has invented a cost-effective and scalable way to split graphite into microscopic graphene sheets and dissolve them in water.
From this he has developed two new graphene technology platforms the starting points for developing commercial applications. One is a graphene gel that works as a supercapacitor electrode
and the second is a 3-D porous graphene foam. The graphene gel provides the same functionality as porous carbon a material currently sourced from coconut husks for use in supercapacitors and other energy conversion and storage technologies but with vastly enhanced performance.
Supercapacitors have an expanding range of applications as their capabilities increase from powering computer memory backup to powering electric vehicles.
Professor Li's team has also been able to give graphene a more functional 3-D form by engineering it into an elastic graphene foam that retains its extraordinary qualities.
Professor Li likened his developments to having invented bricks and said it was time to bring in architects
#Competition for graphene: Researchers demonstrate ultrafast charge transfer in new family of 2-D semiconductors A new argument has just been added to the growing case for graphene being bumped off its pedestal as the next big thing in the high-tech world by the two-dimensional semiconductors
known as MX2 materials. An international collaboration of researchers led by a scientist with the U s. Department of energy (DOE)' s Lawrence Berkeley National Laboratory (Berkeley Lab) has reported the first experimental observation of ultrafast charge transfer in photo-excited
These 2d semiconductors feature the same hexagonal"honeycombed"structure as graphene and superfast electrical conductance,
but, unlike graphene, they have natural energy bandgaps. This facilitates their application in transistors and other electronic devices because
unlike graphene, their electrical conductance can be switched off.""Combining different MX2 layers together allows one to control their physical properties,
#Scientists fabricate defect-free graphene set record reversible capacity for Co3o4 anode in Li-ion batteries Graphene has already been demonstrated to be useful in Li-ion batteries,
despite the fact that the graphene used often contains defects. Large-scale fabrication of graphene that is chemically pure, structurally uniform,
and size-tunable for battery applications has remained so far elusive. Now in a new study, scientists have developed a method to fabricate defect-free graphene (df-G) without any trace of structural damage.
Wrapping a large sheet of negatively charged df-G around a positively charged Co3o4 creates a very promising anode for high-performance Li-ion batteries.
current methods to fabricate high-quality graphene fall into two categories: mechanical approaches and chemical approaches. While mechanical cleavage provides high-quality graphene,
its low yield makes it insufficient for large-scale production. Chemical approaches, on the other hand, can produce bulk quantities
which causes the layers to expand away from each other to form graphene nanosheets that could later be cooled
because when a single graphene sheet is wrapped around a bundle of Co3o4 particles, the Co3o4 particles are prevented from becoming pulverized
whereas anodes with an imperfect graphene layer rapidly decrease with cycling. The large size of the graphene plays a key role in the performance
because a larger size provides a higher cycling stability of the nanosized anode materials by improving their mechanical integrity.
whether as artificial skin or electronic paper. Making such concepts affordable enough for general use remains a challenge
today scientists recognize the mechanism as surface plasmon resonance, and it is a phenomenon that continues to hold great scientific interest.
at the University of Cambridge in the UK, have used surface plasmon resonance as a new way to construct holograms.
#Graphene rubber bands could stretch limits of current healthcare New research published today in the journal ACS Nano identifies a new type of sensor that can monitor body movements
Now researchers from the University of Surrey and Trinity college Dublin have treated for the first time common elastic bands with graphene to create a flexible sensor that is sensitive enough for medical use
By fusing this material with graphene -which imparts an electromechanical response on movement the team discovered that the material can be used as a sensor to measure a patient's breathing heart rate
but our graphene-infused rubber bands could really help to revolutionise remote healthcare said Dr Alan Dalton from the University of Surrey.
Researchers from the Institut Català de Nanociència i Nanotecnologia's (ICN2 Catalan Institute of Nanoscience and Nanotechnology) Nanobioelectronics and Biosensors Group led by the ICREA Research Prof Arben Merkoçi work
#New graphene framework bridges gap between traditional capacitors batteries Researchers at the California Nanosystems Institute (CNSI) at UCLA have set the stage for a watershed in mobile energy storage by using a special graphene material
The material, called a holey graphene framework, has perforated a three-dimensional structure characterized by tiny holes;
Electrochemical capacitors, also known as ECS or supercapacitors, are an important technology for the future of energy storage and mobile power supplies,
In their study, published online August 8 in the journal Nature Communications, the CNSI researchers led by Duan used a highly interconnected 3d holey graphene framework as the electrode material to create an EC with unprecedented performance.
Lieber has been working to dramatically shrink cyborg science to a level that's thousands of times smaller and more flexible than other bioelectronic research efforts.
Graphene research on the cusp of new energy capabilities (Phys. org) There remains a lot to learn on the frontiers of solar power research particularly
Under the guidance of Canada Research Chair in Materials science with Synchrotron radiation Dr. Alexander Moewes University of Saskatchewan researcher Adrian Hunt spent his Phd investigating graphene oxide a cutting-edge material that he hopes will shape the future
To understand graphene oxide it is best to start with pure graphene which is a single-layer sheet of carbon atoms in a honeycomb lattice that was made first in 2004 by Andre Geim
All of this makes graphene a great candidate for solar cells. In particular its transparency and conductivity mean that it solves two problems of solar cells:
whereas graphene could be very cheap. Carbon is said abundant Hunt. Although graphene is a great conductor it is not very good at collecting the electrical current produced inside the solar cell
which is why researchers like Hunt are investigating ways to modify graphene to make it more useful.
Graphene oxide the focus of Hunt's Phd work has forced oxygen into the carbon lattice which makes it much less conductive but more transparent and a better charge collector.
Whether or not it will solve the solar panel problem is yet to be seen and researchers in the field are building up their understanding of how the new material works.
and SGM beamlines at the Canadian Light source as well as a Beamline 8. 0. 1 at the Advanced Light source Hunt set out to learn more about how oxide groups attached to the graphene lattice changed it
and how in particular they interacted with charge-carrying graphene atoms. Graphene oxide is fairly chaotic. You don't get a nice simple structure that you can model really easily but
I wanted to model graphene oxide and understand the interplay of these parts. Previous models had seemed simplistic to Hunt
and he wanted a model that would reflect graphene oxide's true complexity. Each different part of the graphene oxide has a unique electronic signature.
Using the synchrotron Hunt could measure where electrons were on the graphene and how the different oxide groups modified that.
He showed that previous models were incorrect which he hopes will help improve understanding of the effects of small shifts in oxidization.
Moreover he studied how graphene oxide decays. Some of the oxide groups are not stable and can group together to tear the lattice;
others can react to make water. If graphene oxide device has water in it and it is heated up the water can actually burn the graphene oxide and produce carbon dioxide.
It's a pitfall that could be important to understand in the development of long-lasting solar cells where sun could provide risky heat into the equation.
More research like this will be the key to harnessing graphene for solar power as Hunt explains.
There's this complicated chain of interreactions that can happen over time and each one of those steps needs to be addressed
Super-stretchable yarn is made of graphene More information: Hunt Adrian Ernst Z. Kurmaev and Alex Moewes.
A Re evaluation of How Functional Groups Modify the Electronic Structure of Graphene oxide. Advanced Materials (2014.
#Used-cigarette butts offer energy storage solution A group of scientists from South korea have converted used-cigarette butts into a high-performing material that could be integrated into computers handheld devices electrical vehicles and wind turbines to store energy.
Presenting their findings today 5 august 2014 in the journal Nanotechnology the researchers have demonstrated the material's superior performance compared to commercially available carbon graphene and carbon nanotubes.
and also had a higher amount of storage compared to graphene and carbon nanotubes as reported in previous studies.
Preparation of energy storage material derived from a used cigarette filter for a supercapacitor electrode Nanotechnology iopscience. iop. org/0957-4484/25/34/345601 5
Research on two-dimensional materials started with graphene, a material made of a single layer of carbon atoms.
analyse and improve ultra-thin layers by working with graphene. This know-how has now been applied to other ultra-thin materials."
#Surprise discovery could see graphene used to improve health (Phys. org) chance discovery about the'wonder material'graphene already exciting scientists because of its potential uses in electronics,
energy storage and energy generation takes it a step closer to being used in medicine and human health.
Researchers from Monash University have discovered that graphene oxide sheets can change structure to become liquid crystal droplets spontaneously and without any specialist equipment.
With graphene droplets now easy to produce, researchers say this opens up possibilities for its use in drug delivery and disease detection.
build on existing knowledge about graphene. One of the thinnest and strongest materials known to man,
graphene is a 2d sheet of carbon just one atom Thick with a'honeycomb'structure the'wonder material'is 100 times stronger than steel, highly conductive and flexible.
because graphene droplets change their structure in response to the presence of an external magnetic field,
"In contrast, graphene doesn't contain any magnetic properties. This combined with the fact that we have proved it can be changed into liquid crystal simply
"Usually atomisers and mechanical equipment are needed to change graphene into a spherical form. In this case all the team did was to put the graphene sheets in a solution to process it for industrial use.
Under certain PH conditions they found that graphene behaves like a polymer-changing shape by itself.
First author of the paper, Ms Rachel Tkacz from the Faculty of engineering, said the surprise discovery happened during routine tests."
"To be able to spontaneously change the structure of graphene from single sheets to a spherical assembly is hugely significant.
"Now we know that graphene-based assemblies can spontaneously change shape under certain conditions, we can apply this knowledge to see
This provides us with crucial information about the organisation of graphene sheets, enabling us to recognise these unique structures,
and Monash University and was the first linkage grant for graphene research in Australia s
#Nanoscale details of electrochemical reactions in electric vehicle battery materials Using a new method to track the electrochemical reactions in a common electric vehicle battery material under operating conditions,
#Graphene and related materials promise cheap flexible printed cameras Dr Felice Torrisi University Lecturer in Graphene technology has been awarded a Young International Researchers'Fellowship from the National Science Foundation
of China to look at how graphene and two-dimensional materials could enable printed and flexible eyes.
Graphene the ultimate thin membrane along with a wide range of two-dimensional (2d)- crystals (e g. hexagonal Boron nitride (h-BN) Molybdenum Disulfide (Mos2) and Tungsten Disulfide (WS2)) have changed radically the landscape
of science and technology with attractive physical properties for (opto) electronics sensing catalysis and energy storage. These 2d crystals can be exfoliated from layered compounds.
For example graphene is highly conductive flexible and transparent and it is superior to conductive polymers in terms of cost stability and performance;
In 2012 Drs Felice Torrisi Tawfique Hasan and Professor Andrea Ferrari at the Cambridge Graphene Centre invented a graphene ink
The graphene-based ink enables cost-effective printed electronics on plastic. Felice explains: Other conductive inks are made from precious metals such as silver
and process whereas graphene is both cheap environmentally stable and does not require much processing after printing.
and centrifugation process to unveil graphene potential in inks and coating for printed electronicsover the last two years Dr Torrisi
and the team at the Cambridge Graphene Centre have been looking to formulate a set of inks based on various 2d crystals setting a new platform for printed electronics.
based on graphene and 2d crystal-inks. The optical response of the printed 2d crystal inks combined with their flexibility on plastic substrate
#Cost-effective solvothermal synthesis of heteroatom (S or N)- doped graphene developed A research team led by group leader Yung-Eun Sung has announced that they have developed cost-effective technology to synthesize sulfur-doped and nitrogen-doped graphenes
and cost effectiveness processes that can produce heteroatom (S or N)- doped graphenes. Moreover these materials enhance the performance of secondary batteries
and nitrogen-doped graphenes by using a simple, single-step solvothermal method. These heteroatom-doped graphene exhibited high surface areas and high contents of heteroatoms.
In addition, the lithium-ion batteries that had applied modified graphenes to it, exhibited a higher capacity than the theoretical capacity of graphite
which was used previously in lithium-ion batteries. It presented high chemical stability which resulted in no capacity degradation in charge and discharge experiments.
The heteroatom-doped graphenes suggest the potential to be employed as an effective, alternative chemical material by demonstrating performance comparable to that of the expensive platinum catalyst used for the cathode of fuel cell batteries.
and using the optical gain from the semiconductor to amplify the light energy. Zhang said the amplified sensor creates a much stronger signal than the passive plasmon sensors currently available
These atom-thin sheets including the famed super material graphene feature exceptional and untapped mechanical and electronic properties.
The team virtually examined this exotic phase transition in graphene boron nitride molybdenum disulfide and graphane all promising monolayer materials.
Within the honeycomb-like lattices of monolayers like graphene boron nitride and graphane the atoms rapidly vibrate in place.
In the case of graphene boron nitride and graphane the backbone of the perfect crystalline lattice distorted toward isolated hexagonal rings.
The soft mode distortion ended up breaking graphene boron nitride and molybdenum disulfide. As the monolayers were strained the energetic cost of changing the bond lengths became significantly weaker in other words under enough stress the emergent soft mode encourages the atoms to rearrange themselves into unstable configurations.
Our work demonstrates that the soft mode failure mechanism is not unique to graphene and suggests it might be an intrinsic feature of monolayer materials Isaacs said.
and exploit graphene and its cousins Isaacs said. For example we've been working with Columbia experimentalists who use a technique called'nanoindentation'to experimentally measure some of
#Designing ultra-sensitive biosensors for early personalised diagnostics A new type of high-sensitivity and low-cost sensors,
called plasmonic biosensors, could ultimately become a key asset in personalised medicine by helping to diagnose diseases at an early stage.
In biosensors, protein molecules are identified by irradiating them with infrared light and by analysing the spectrum of the light they emit, known as a Raman spectrum.
To do so, the researchers attached bioreceptors, fragments of DNA engineered to recognise specific proteins, to the nanoantennas.
When the nanoantennas studded with the bioreceptors are incubated in a solution that contains the biomarkers to be detected,
they show the Raman fingerprints of both the bioreceptor and the biomarker, as Gucciardi points out.
who has been developing plasmonic biosensors at the University of Victoria, British columbia, Canada. He also believes that such approach will make medical care more cost effective."
The"end-users"of these biosensors have to understand that the development of these devices by researchers in many disciplines is a long process, notes Estévez.
She adds that these biosensors will need to be integrated with optical components, with electronics for reading out the measurements, software to process all data,
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