Search Results for graphene

Gold-Filled Graphene Patch Helps With Diabetes

Taking the special properties of the carbon based material graphene – light, transparent, strong – with the additional electrochemical properties of gold, researchers have produced a skin patch for the treatment of diabetes.

The patch provides an alternative treatment option to injections. The patch is electronic and it is configured to sense excess glucose in sweat. On detection, the patch automatically delivers anti-diabetes drugs (insulin or metformin) to the body. This happens through heating up microneedles that penetrate the skin.

The patch is composed of graphene studded with gold particles, as well as special sensors designed to detect humidity, glucose, pH, and temperature. If the pH and temperature hit a trigger, then enzymes in the sensor can assess glucose levels. When glucose levels cross a threshold, the needles are triggered and the drug is released just beneath the surface of the skin.

The official name for the device is a “closed-loop epidermal system.” By having electronic components, the device is able to store data on the delivery of the drug, providing data that can be used to analyse the health of the patient. Data could be collected via a table through wireless technology.

The patch was developed by scientists working at the Seoul National University. The research is described in a paper published in the journal Nature Nanotechnology. The research is titled “A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy.”

Graphene Moth’s Eyes Signal The Future Of Home Power

Graphene

Graphene can be altered to create a super most light-absorbent material. This could lead to a type of ‘smart’ wallpaper, capable of generating electricity from the light from a lamp. Imagine the possibility in the average family home – creating your own electricity just by having the lights on (assuming the home has been coated with the wallpaper, of course).

Regular readers of The Latest News will know about the remarkable properties of graphene. It is carbon-based, light-weight, transparent, very strong and highly conductive. It is the basis of many advances in electronic devices.

The new wallpaper would need only nanometer sized strips of graphene (the size equivalent to one millionth of a human hair). The graphene would be interwoven within the paper using a relatively new method called nanotexturing. To ensure that the maximum amount of light i captured, an additional placement technique is used called nano-patterning, used to localize light.

Graphene Solar Cell

Flexible graphene solar cell
(Image credit: University of Surrey)

For this process, the research team were inspired by moths’ eyes. Here the pattern produced by nature allows moths to seem even in the dimmest conditions. This works by light being channeled into the center. The same approach has been used with the positioning of the graphene.

A further application is with a new generation of solar panels, or even smart windows placed in skyscrapers.

The study was performed at the University of Surrey’s Advanced Technology Institute. The research is published in the journal Science Advances. The paper is titled “Ultra-broadband light trapping using nanotextured decoupled graphene multilayers.”

Why Is Graphene So Special?

Graphene

Graphene is the material that is set to change the world, possessing many stunning properties. It is a remarkable material, a two-dimensional form of carbon that is very strong, lightweight, conductive and transparent.

The Latest News has covered a number of potential applications for graphene including graphene-based electrodes that can be successfully implanted in the brain and can interface with neurones, which may help people with epilepsy; the use of graphene as synthetic skin for a new generation of robots; using graphene to help with the construction of lighter aircraft, to boost fuel efficiency; and improving the speed and efficiency of electronic devices.

How and why graphene behaves the way it does is down to several factors, some of which remain unknown. One new piece of research pushes the scientific understanding of graphene further forwards.

Scientists based at Harvard and Raytheon BBN Technology have noted electrons in graphene not behaving as expected in a metal, but instead behaving like they would in a fluid. This is thought to relate to graphene’s two-dimensional structure. The electrons have been observed moving very quickly, at 1/300 of the speed of light.

It is hoped that harnessing this newly discovered property of graphene will lead to a novel thermoelectric devices.

The findings are published in the journal Science, with the paper titled “Observation of the Dirac fluid and the breakdown of the Wiedemann-Franz law in graphene.”

Helping Paralyzed Patients With Graphene Electrodes

Brain Stimulation

A point-of-principle study has shown that graphene-based electrodes can be successfully implanted in the brain and can interface with neurones. Graphene is a remarkable material, a two-dimensional form of carbon that is very strong, lightweight, conductive and transparent.

The aim with the graphene based electrodes is to help those who have lost sensory function – for example, paralyzed patients or amputees. The electrodes may also help those who suffer from epilepsy or even from neurodegenerative diseases.

Key to the new electrodes is the conductive properties of graphene. Since the neurons in the brain use electrical activity, the theoretical premise was worth exploring. Researchers think that by measuring and stimulating the brain’s electrical impulses, then sensory functions can be recovered. This technique could, for example, be used to control robotic arms for amputee patients.

Materials currently used to make electrodes, such as tungsten, lose properties over time. It is hoped that graphene-based electrodes last for much longer. Graphene is biomedically compatible and, based on studies to date, it appears a suitable material for deep brain implants.

One of the lead researchers, Professor Andrea Ferrari, Director of the Cambridge Graphene Centre, stated in a briefing note:

“These initial results show how we are just at the tip of the iceberg when it comes to the potential of graphene and related materials in bio-applications and medicine.”

The study was carried out at the University of Trieste in Italy and the Cambridge Graphene Centre. The findings are published in journal ACS Nano. The paper is titled “Graphene-Based Interfaces Do Not Alter Target Nerve Cells.”

Is Graphene The Basis Of Next-Gen Airplanes?

Graphene Airplanes

Graphene could become the basis of a new generation of faster, lighter aircraft. The research is examining the potential of graphene reinforced aluminum matrix nanocomposites.

Graphene, in its basic form, is a one-atom thick sheet of carbon. The material is light, transparent, strong and very conductive.

In this new development, scientists are looking at graphene reinforced aluminum matrix nanocomposites as this basis of building a new generation of aircraft. The new material would be used for certain parts of an aeroplane, and these would be lighter, stronger and more conductive compared with existing materials.

There is also a possibility that the shell of an aircraft could be manufactured from graphene, through incorporating the material into traditional carbon fibre composites. This would be based on ‘graphene paper,’ which is a form that can be reshaped and reformed from its original raw material state. This material would be lighter, stronger, harder and more flexible than steel. In other words, an effective material for the development of stronger and more fuel-efficient aircraft.

The research takes the form of a project between The University of Manchester (the institution where graphene was discovered) and a leading Chinese aviation company called Beijing Institute of Aeronautical Materials. The research group is also looking into graphene energy storage materials, environmental purification materials and information materials.

In parallel research, scientists are looking at “graphene sponges”, as devices to conduct electricity and heat. With this, graphene absorbs laser energy and builds up a charge of electrons. At the point where the graphene is unable to retain anymore, the extra electrons are released which pushes the sponge in the opposite direction.

Schematic diagrams of the proposed mechanism

Schematic diagrams of the proposed mechanism

As a theoretical debate, researchers are wondering if this concept could one-day lead to a fuel free aircraft, in that the principles could propel a large object through the air. This is very much at the ‘ideas’ stage, although the concept is explored further in a white paper. The paper, from Nankai University in China, is titled “Macroscopic and Direct Light Propulsion of Bulk Graphene Material.”

Researchers Have Produced Cheaper And Higher Quality Graphene Which Could Lead To Synthetic Skin

Artificial Skin

Only a few materials in the world of science strike as much awe as graphene,  which was first measurably produced and isolated from graphite in 2004. In 2010, Andre Geim and Konstantin Novoselov won the Nobel Peace Prize for cutting-edge experiments on it.

Graphene is virtually a two-dimensional material that is only a single atom thick. Astonishingly, it is at least 200 times stronger than steel, nearly transparent, flexible, and has top performing heat and electricity conducting properties.

Cheaper

Nonetheless, graphene is expensive to produce. Though it boasts of a wide range of applications, production cost has hampered the proliferation of graphene into new consumer technologies.

However, a team of researchers at the University of Glasgow has broken the gridlock with an innovative process to produce large sheets of graphene using cheap copper that is the same as the type used in the manufacture of the now ubiquitous lithium-ion batteries found in most battery-powered consumer tech.

According to the team led by Dr Ravinder Dahiya, the cost of producing graphene with their process is about 100 times cheaper than using existing processes. A paper detailing the process has been published in the journal Scientific Reports.

Picture credit: University of Glasgow

Dr Ravinder Dahiya (Image credit: University of Glasgow)

Currently, the common process of manufacturing graphene, called CVD or chemical vapor deposition, involves turning gaseous reactants into a film of graphene on a special surface referred to as a substrate.

The process used by the research team is similar to the CVD process. However, it uses commercially available copper foils like those used as the negative electrodes in lithium-ion batteries as the special surface or substrate.

Higher Quality

In addition, the researchers found that the transistors they made using the graphene they produced exhibited a marked improvement in their optical and electrical performance compared to similar materials manufactured using the older expensive process.

A new dawn

According to Dr Dahiya, the cost of the special copper used in production currently is $115 per square meter. In contrast, the commercially available copper used by the team of researchers cost only $1 per square meter.

This outstanding reduction in manufacturing cost and the marked improved quality of graphene produced by the new process may be instrumental in the introduction of affordable and more efficient electronic devices that incorporate top performing graphene.

The applications of these electronics and graphene in particular are manifold including use in mobile healthcare and the smart cities of the future. Graphene could lead to the production of commercially available synthetic skin capable of providing sensory feedback to people using limb prostheses, a feat that is impossible for even the most advanced prosthetics today.

Graphene Aids Water Desalination

Graphene water destilation

As a result of recurrent droughts in the U.S. state of California, research is going into desalination so that sea water can be turned into water suitable for drinking (through the removal of salts). Most desalination efforts, using polyamide filters, have faltered due to the costs and levels of energy required. The method used is reverse osmosis, where a semipermeable membrane is used to remove larger particles from water through the application of pressure (designed to overcome the osmotic pressure of the water).

A way to lower costs and reduce energy consumption could rest with graphene. Graphene is a material derived from carbon, where graphite is taken and atom thick layers are sliced away. Professor Jeffrey Grossman, of MIT’s Department of Materials Science and Engineering, has been examining graphene in relation to desalination.

In laboratory trials, reported to Controlled Environments magazine, a newly designed filter made from graphene has been trailed and the early results are showing reduced energy costs.

The reason why graphene is proving effective is because, at only one atom thick, when sea water is pushed through the filter there is less friction and the process of filtering out salts thereby requires less energy. A 50 percent reduction has been achieved in laboratory studies.

A further advantage is that graphene does not appear to be affected by microbial growth, meaning that the characteristic ‘green slime’ that appears on many filters over time is missing.

To keep filters free from microorganisms they require chlorine treatment. This can damage most filters; however, graphene-based filters are resistant to this type of chemical disinfection.

The results have yet to be published in a peer reviewed journal, although trials are progressing well. The first industrial trial will be to clean brackish water, such as found in estuaries.

Graphene Nanoribbon Creates Super-Fast Electronics

Graphene

Graphene is appearing in the news with a high degree of regulatory. Discovered in 2004, graphene is a variant of carbon. The material is just one atom thick, very light, strong, near transparent and an effective conductor of electricity.

It is thought that the Nobel-prize winning material can herald next generation electronic devices. However, researchers have struggled to slice the material thin enough to be effective. By efficiently and repeatedly making nanoribbons of graphene, this could enable the use of graphene in high-performance semiconductor electronics. ‘Semiconductor’ describes a material with ability of electrical conductivity rating that falls between that of a conductor, such as copper, and an insulator, such as glass. Semiconductors are the basis of all modern electronic devices and their properties are based on the ability to switch the current running through them on and off.

Graphene Nanoribbons

Graphene nanoribbons grown on germanium automatically align perpendicularly and naturally grow in what is known as the armchair edge configuration.
(Image Credits: Arnold Research Group / Guisinger Research Group)

Researchers have come up with an answer to the nanoribbon conundrum. The solution is to grow thin slices of graphene directly onto the surface of a semiconductor fashioned from germanium (a lustrous, hard, grayish-white metalloid in the carbon group.)

The process is referred to as “assisted organic synthesis”. Here molecular precursors react on a surface, like germanium, in order to polymerize nanoribbons of graphene, through a technique called chemical vapor deposition. With this technique the process begins with methane, which function is to absorb the germanium surface and then decomposes to form various hydrocarbons. These hydrocarbons react with each other on the surface and eventually form graphene.

These nanoribbons are ultra-fine, being less than 10 nanometers thick. A nanometer is one billionth of a meter in length. Thus the sizes of the nanoribbons required for next-gen electronics are incredibly small.

The research has been conducted at the University of Wisconsin-Madison. The experiments have been reported to the journal Nature Communications. The research is headed “Direct oriented growth of armchair graphene nanoribbons on germanium.”

Cooling Down Electronics With Graphene Film

Graphene Cooling

Overheating is one of the stumbling blocks for the next generation of electronic devices. For devices to hold greater power, the build-up of heat needs to be dealt with, which is where graphene comes in.

Scientists working at Chalmers University of Technology have found that a graphene-based film has a thermal conductivity capacity four times better than copper.   Not only does graphene help to cool down electronic devices, it reduces the power required to achieve the same functionality.

Graphene is a remarkable material, composed of carbon (extracted from graphite), it is light weight, transparent, very strong, flexible, and an excellent conductor.

Chalmers University researchers have been investigating how well graphene performs in relation to silicone-based electronic systems. Through various trials they settled on a 20 micrometer thickness of the graphene film which can reach a thermal conductivity value of 1600 W/mK, four times better than copper.

The main obstacle in the development was finding ways for graphene to adhere to silicone and overcome the repulsion between the two materials. With this sorted, the new conductive coating could lead to a new generation of better performing electronic devices, such as highly efficient Light Emitting Diodes, lasers, and radio frequency components.

The research has been published in the journal Advanced Functional Materials. The paper is titled “Improved Heat Spreading Performance of Functionalized Graphene in Microelectronic Device Application.”

Scientists Make Super-Energy Efficient Graphene Light Bulb

Graphene Light Bulb

A light bulb made with graphene (a form of super-strong carbon) is set to hit retail outlets later in 2015.

The bulb contains a filament-shaped LED coated in graphene. Graphene is a very strong, low weight material. It is 100 times stronger than steel and it conducts heat and electricity with great efficiency. Graphene was discovered at the University of Manchester in 2004 by Andre Geim and Konstantin Novoselov. The material continues to be investigated for many potential applications, including water purification.

The key aspect of the bulb, according to BBC News, is that it requires 10 percent less energy compared with the types of low-energy light bulbs currently available for consumers to purchase. The graphene bulb should also last considerably longer. Both of these features are due to its conductivity properties, which allows for an efficient transfer of heat. The exact technical details about the bulb remain a secret.

Graphene

Graphene is an atomic-scale honeycomb made from carbon making it 100 times stronger than steel

Commenting on the development, Professor Colin Bailey, Deputy President and Deputy Vice-Chancellor of The University of Manchester said: “This lightbulb shows that graphene products are becoming a reality, just a little more than a decade after it was first isolated – a very short time in scientific terms.

“This is just the start. Our partners are looking at a range of exciting applications, all of which started right here in Manchester. It is very exciting that the NGI has launched its first product despite barely opening its doors yet.”

The bulb was developed at The University of Manchester and a commercial model manufactured by Graphene Lighting, a Canadian company. At the University of Manchester a National Graphene Institute has recently been opened in order to further research into the material. Other potential uses include quantum computing. Another potential area is with nanomedicine.

One of the biggest obstacles is with making graphene in large quantities. The process of making graphene involves passing methane through a copper wire at high temperatures.