Physicists build circuit that generates clean, limitless power from graphene

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A team of University of Arkansas physicists has successfully developed a circuit capable of capturing graphene’s thermal motion and converting it into an electrical current.

“An energy-harvesting circuit based on graphene could be incorporated into a chip to provide clean, limitless, low-voltage power for small devices or sensors,” said Paul Thibado, professor of physics and lead researcher in the discovery.

The findings, published in the journal Physical Review E, are proof of a theory the physicists developed at the U of A three years ago that freestanding graphene—a single layer of carbon atoms—ripples and buckles in a way that holds promise for energy harvesting.

The idea of harvesting energy from graphene is controversial because it refutes physicist Richard Feynman’s well-known assertion that the thermal motion of atoms, known as Brownian motion, cannot do work. Thibado’s team found that at room temperature the thermal motion of graphene does in fact induce an alternating current (AC) in a circuit, an achievement thought to be impossible.

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Atom-by-atom assembly makes for cheap, tuneable graphene nanoribbons

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Graphene nanoribbons could serve a variety of purposes, and a new way to produce then could help unleash this potential

The wonder material graphene can take many forms for many different purposes, from transparent films that repel mosquitoes to crumpled balls that could boost the safety of batteries. One that has scientists particularly excited is nanoribbons for applications in energy storage and computing, but producing these ultra-thin strips of graphene has proven a difficult undertaking. Scientists are claiming a breakthrough in this area, devising a method that has enabled them to efficiently produce graphene nanoribbons directly on the surface of semiconductors for the first time.

The wonder material graphene can take many forms for many different purposes, from transparent films that repel mosquitoes to crumpled balls that could boost the safety of batteries. One that has scientists particularly excited is nanoribbons for applications in energy storage and computing, but producing these ultra-thin strips of graphene has proven a difficult undertaking. Scientists are claiming a breakthrough in this area, devising a method that has enabled them to efficiently produce graphene nanoribbons directly on the surface of semiconductors for the first time.

As opposed to the sheets of carbon atoms arranged in honeycomb patterns that make up traditional graphene, graphene nanoribbons consist of thin strips just a handful of atoms wide. This material has great potential as a cheaper and smaller alternative to silicon transistors that would also run faster and use less power, or as electrodes for batteries that can charge in as little as five minutes.

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Simple new method makes graphene “paint” possible

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Researchers have found a simple way to make graphene disperse in water, paving the way for graphene-based inks or paints

 Graphene may be versatile, but there’s one thing it’s not all that good at – dispersing in water. Now, researchers at Umeå University have found a relatively simple way to do it. Graphene oxide is a different form of the material that can make for stable water dispersion, which can then be used as a kind of graphene paint.

Graphene is essentially a two-dimensional sheet of carbon atoms, arranged in a hexagonal pattern. This deceptively simple material has a range of useful properties – it’s incredibly lightweight, thin and flexible, but still strong. It’s also an excellent conductor of electricity and heat, so it’s turning up in everything from electronics to water filters to clothing.

Ideally, one useful way to get graphene into the right configurations could involve dispersing it in water. This solution could then be painted or sprayed onto a surface to make, for example, supercapacitor electrodes or conductive coatings.

The problem is that graphene and similar forms of carbon, like graphite and carbon nanotubes, are hydrophobic, meaning they repel water. They can be made to disperse using harsh organic solvents or mechanical treatments, but the former is toxic and the latter can introduce defects.

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Energy-harvesting design aims to turn Wi-Fi signals into usable power

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Terahertz waves are pervasive in our daily lives, and if harnessed, their concentrated power could potentially serve as an alternate energy source. Imagine, for instance, a cellphone add-on that passively soaks up ambient T-rays and uses their energy to charge your phone.

Any device that sends out a Wi-Fi signal also emits terahertz waves —electromagnetic waves with a frequency somewhere between microwaves and infrared light. These high-frequency radiation waves, known as “T-rays,” are also produced by almost anything that registers a temperature, including our own bodies and the inanimate objects around us.

Terahertz waves are pervasive in our daily lives, and if harnessed, their concentrated power could potentially serve as an alternate energy source. Imagine, for instance, a cellphone add-on that passively soaks up ambient T-rays and uses their energy to charge your phone. However, to date, terahertz waves are wasted energy, as there has been no practical way to capture and convert them into any usable form.

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Graphene amplifier unlocks hidden frequencies in the electromagnetic spectrum

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Light in the THz frequencies hits the ‘sandwich’ and is reflected with additional energy. Credit: Loughborough University

Researchers have created a unique device which will unlock the elusive terahertz wavelengths and make revolutionary new technologies possible.

Terahertz waves (THz) sit between microwaves and infrared in the light frequency spectrum, but due to their low energy, scientists have been unable to harness their potential. The conundrum is known in scientific circles as the “terahertz gap.”

Being able to detect and amplify THz waves (T-rays) would open up a new era of medical, communications, satellite, cosmological and other technologies. One major application would be as a safe, non-destructive alternative to X-rays. However, until now, the wavelengths, which range between 3mm and 30μm, have proved impossible to use due to relatively weak signals from all existing sources.

A team of physicists has created a new type of optical transistor—a working THz amplifier—using graphene and a high-temperature superconductor. The physics behind the simple amplifier relies on the properties of graphene, which is transparent and is not sensitive to light and whose electrons have no mass. It is made up of two layers of graphene and a superconductor that trap the graphene massless electrons between them like a sandwich.

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New graphene battery recharges blazingly fast, and it’s already on the market

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Faster charging, longer lasting, and lower temperatures. These are the three major benefits from a lithium battery that has been infused with wonder-material graphene. Thing is, we’ve all heard about the benefits of graphene before, but despite all the hype, we’ve yet to really see it used in devices and products that you can actually buy.

That’s about to change according to Real Graphene, a Los Angeles-based technology company working on graphene-enhanced battery cells. Digital Trends spoke to CEO Samuel Gong about what benefits integrating graphene into a lithium battery will bring, and they’re extremely compelling. Even better news is that the tech is almost ready for mainstream use.

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Graphene nanoribbons lay the groundwork for ultrapowerful computers

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Graphene nanoribbons on silicon wafers could help lead the way toward super fast computer chips. Image courtesy of Mike Arnold.

 Smaller, better semiconductors have consistently allowed computers to become faster and more energy-efficient than ever before.

But the 18-month cycle of exponential increases in computing power that has held since the mid 1960s now has leveled off. That’s because there are fundamental limits to integrated circuits made strictly from silicon—the material that forms the backbone of our modern computer infrastructure.

As they look to the future, however, engineers at the University of Wisconsin-Madison are turning to new materials to lay down the foundations for more powerful computers.

They have devised a method to grow tiny ribbons of graphene—the single-atom-thick carbon material—directly on top of silicon wafers.

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Graphene sponge helps lithium sulphur batteries reach new potential

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An illustration of the Chalmers design for a lithium sulfur battery. The highly porous quality of the graphene aerogel allows for high enough soaking of sulfur to make the catholyte concept worthwhile. Credit: Yen Strandqvist/Chalmers University of Technology

To meet the demands of an electric future, new battery technologies will be essential. One option is lithium sulphur batteries, which offer a theoretical energy density more than five times that of lithium ion batteries. Researchers at Chalmers University of Technology, Sweden, recently unveiled a promising breakthrough for this type of battery, using a catholyte with the help of a graphene sponge.

The researchers’ novel idea is a porous, sponge-like aerogel made of reduced graphene oxide that acts as a free-standing electrode in the battery cell and allows for better and higher utilisation of sulphur.

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The holy grail of lithium batteries

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Mark Bissett, lecturer in nanomaterials at The University of Manchester, poses for a photograph holding a model showing the hexagonal structure of graphene inside a laboratory at the National Graphene Institute facility, part of the The University of Manchester, in Manchester, U.K., on Thursday, April 12, 2018. Researchers are studying ways to use graphene in batteries, and the material has the potential to significantly boost performance in a much-needed technology.

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Sorry, graphene—borophene is the new wonder material that’s got everyone excited

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Stronger and more flexible than graphene, a single-atom layer of boron could revolutionize sensors, batteries, and catalytic chemistry.

Not so long ago, graphene was the great new wonder material. A super-strong, atom-thick sheet of carbon “chicken wire,” it can form tubes, balls, and other curious shapes. And because it conducts electricity, materials scientists raised the prospect of a new era of graphene-based computer processing and a lucrative graphene chip industry to boot. The European Union invested €1 billion to kick-start a graphene industry.

This brave new graphene-based world has yet to materialize. But it has triggered an interest in other two-dimensional materials. And the most exciting of all is borophene: a single layer of boron atoms that form various crystalline structures.

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Scientists forge ahead with electron microscopy to build quantum materials atom by atom

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With a STEM microscope, ORNL’s Ondrej Dyck brought two, three and four silicon atoms together to build clusters and make them rotate within a layer of graphene, a two-dimensional layer of carbon atoms that exhibits unprecedented strength and high electrical conductivity. Credit: Ondrej Dyck/Oak Ridge National Laboratory, U.S. Dept. of Energy

A novel technique that nudges single atoms to switch places within an atomically thin material could bring scientists another step closer to realizing theoretical physicist Richard Feynman’s vision of building tiny machines from the atom up.

A significant push to develop materials that harness the quantum nature of atoms is driving the need for methods to build atomically precise electronics and sensors. Fabricating nanoscale devices atom by atom requires delicacy and precision, which has been demonstrated by a microscopy team at the Department of Energy’s Oak Ridge National Laboratory.

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A revolutionary new space launch idea: Introducing The Pythagoras Sling

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The Pythagoras Sling uses a lengthy graphene string pulled via two hoops suspended from simple parachutes to rapidly accelerate a projectile into orbit. Graphene string will likely become widely available over the next two decades. If it works as expected, the Pythagoras Sling launch system could greatly reduce the cost of getting into space compared to any current rocket-based system and could help accelerate space development. Total cost of the fully reusable launch system could be as low as $1M for small and medium sized satellites so cost per kg could be two orders of magnitude cheaper than today. Apart for human spacecraft or more delicate satellites that need low g-forces, the system needs little or no fuel to achieve orbit, only ground electricity, so would be safer and more environmentally friendly as well as cheaper than current rocket-based approaches.

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