Sunday, June 3, 2007

40. Conductors

The wonder stuff that could change the world: Graphene is so strong a sheet of it as thin as clingfilm could support an elephant

By David Derbyshire
Last updated at 7:39 AM on 7th October 2011

Revolutionary: Graphene, which is formed of honeycomb pattern of carbon atoms, could be the most important new material [transparent, electric, and strong building material as well] material for a century [it's a completely unique mixture of consumptive categories in this material: a thin, transparent, super-strong (harder than diamond) structural building material that has electrical conduction properties better than copper (copper is hardly a structural material), though graphene's lack of semiconductor principles may make it difficult for some fantasy computer operations that currently are based on mostly silicon's physical capacities of 'on/off' switching in the material itself (there are other options for this switching though than polluting silicon industries: see the category on communication materials for more options); thus with graphene always 'on' in other words, and very efficiently so, it makes it difficult to do any anticipated Boolean/operations in the material itself in base 2--the insight of all computers from Shannon onward.]

Revolutionary: Graphene, which is formed of honeycomb pattern of carbon atoms, could be the most important new material for a century

It is tougher than diamond, but stretches like rubber. It is virtually invisible, conducts electricity and heat better than any copper wire and weighs next to nothing. Meet graphene — an astonishing new material which could revolutionise almost every part of our lives.

Some researchers claim it’s the most important substance to be created since the first synthetic plastic more than 100 years ago.

If it lives up to its promise, it could lead to mobile phones that you roll up and put behind your ear, high definition televisions as thin as wallpaper, and bendy electronic newspapers that readers could fold away into a tiny square.

It could transform medicine, and replace silicon as the raw material used to make computer chips [perhaps everything except this however, see note above.]

The ‘miracle material’ was discovered in Britain just seven years ago, and the buzz around it is extraordinary.

Last year, it won two Manchester University scientists the Nobel Prize for physics, and this week Chancellor George Osborne pledged £50 million towards developing technologies based on the super-strong substance.

In terms of its economics, one of the most exciting parts of the graphene story is its cost. Normally when scientists develop a new wonder material, the price is eye-wateringly high.

But graphene is made by chemically processing graphite — the cheap material in the ‘lead’ of pencils.
Every few months researchers come up with new, cheaper ways of mass producing graphene, so that some experts believe it could eventually cost less than £4 per pound.

But is graphene really the wonder stuff of the 21st century?

For a material with so much promise, it has an incredibly simple chemical structure. A sheet of graphene is just a single layer of carbon atoms, locked together in a strongly-bonded honeycomb pattern.

Pledge: George Osborne, pictured visiting the University of Manchester lab where graphene is being researched, has said £50m will be set aside to help with development of technologies based on the substance

That makes it the thinnest material ever made. You would need to stack three million graphene sheets on top of each other to get a pile one milimetre high. It is also the strongest substance known to mankind — 200 times stronger than steel and several times tougher than diamond.

A sheet of graphene as thin as clingfilm could hold the weight of an elephant. In fact, according to one calculation, an elephant would need to balance precariously on the end of a pencil to break through that same sheet.

Despite its strength, it is extremely flexible and can be stretched by 20 per cent without any damage.

It is also a superb conductor of electricity — far better than copper, traditionally used for wiring — and is the best conductor of heat on the planet.

But perhaps the most remarkable feature of graphene is where it comes from. Graphene is made from graphite, a plentiful grey mineral mostly mined in Chile, India and Canada.

A pencil lead is made up of many millions of layers of graphene. These layers are held together only weakly — which is why they slide off each other when a pencil is moved across the page.

Graphene was first isolated by Professors Konstantin Novoselov and Andrew Geim at Manchester University in 2004. The pair used sticky tape to strip away thin flakes of graphite, then attached it to a silicon plate which allowed the researchers to identify the tiny layers through a microscope.

Discovery: Professors Andre Geim, left, and Dr Konstantin Novoselov first isolated graphene in 2004. They later won the Nobel Prize for Physics last year

Russian-born Prof Novoselov, 37, believes graphene could change everything from electronics to computers.

‘I don’t think it has been over-hyped,’ he said. ‘It has attracted a lot of attention because it is so simple — it is the thinnest possible matter — and yet it has so many unique properties.

‘There are hundreds of properties which are unique or superior to other materials. Because it is only one atom thick it is quite transparent — not many materials that can conduct electricity which are transparent.’

Its discovery has triggered a boom for material science. Last year, there were 3,000 research papers on its properties, and 400 patent applications.

The electronics industry is convinced graphene will lead to gadgets that make the iPhone and Kindle seem like toys from the age of steam trains.

Modern touch-sensitive screens use indium tin oxide — a substance that is transparent but which carries electrical currents. But indium tin oxide is expensive, and gadgets made from it shatter or crack easily when dropped. Replacing indium tin oxide with graphene-based compounds could allow for flexible, paper-thin computer and television screens. South Korean researchers have created a 25in flexible touch-screen using graphene.

Ancient history: If the development of graphene is successful it will make the iPad and Kindle seem like toys from the age of the steam train

Imagine reading your Daily Mail on a sheet of electric paper. Tapping a button on the corner could instantly update the contents or move to the next page. Once you’ve finished reading the paper, it could be folded up and used afresh tomorrow.

Other researchers are looking at many ways of using graphene in medicine. It is also being touted as an alternative to the carbon-fibre bodywork of boats and bikes [and car tires?] Graphene in tyres could make them stronger.

Some even claim it will replace the silicon in computer chips. In the future, a graphene credit card could store as much information as today’s computers.

‘We are talking of a number of unique properties combined in one material which probably hasn’t happened before,’ said Prof Novoselov. ‘You might want to compare it to plastic. But graphene is as versatile as all the plastics put together.

‘It’s a big claim, but it’s not bold. That’s exactly why there are so many researchers working on it.’

Dr Sue Mossman, curator of materials at the Science Museum in London, says graphene has parallels with Bakelite — the first man-made plastic, invented in 1907.

Resistant to heat and chemicals, and an excellent electrical insulator, Bakelite easily made electric plugs, radios, cameras and telephones.

‘Bakelite was the material of its time. Is this the material of our times?’ she says. ‘Historically we have been really good at invention in this country, but we’ve been really bad at capitalising on it.’

If graphene isn’t to go the same way as other great British inventions which were never properly exploited commercially at home — such as polythene and carbon fibre — it will need massive investment in research and development.

Core material: Graphene comes from a base material of graphite and is so thin that three millions sheets of the substance would be needed to make a layer 1mm thick

That’s why the Government’s move to support its development in the UK got a warm round of applause at the Conservative Party conference.

But compared to the investment in graphene in America and Asia, the £50 million promised by the Chancellor is negligible. South Korea is investing £195million into the technology. The European Commission is expected to invest one billion euros into graphene in the next ten years.

Yet despite the flurry of excitement, many researchers doubt graphene can live up to such high expectations.

It wouldn’t be the first wonder material that failed to deliver. In 1985 another form of carbon, called fullerenes or buckyballs, was hailed as the revolutionary new material of the era. Despite the hype, there has yet to be a major practical application.

And there are already some problems with using graphene. It is so good at conducting electricity that turning it into devices like transistors — which control the flow of electrical currents, so need to be able to stop electricity flowing through them — has so far proved problematic.

Earlier this year computer company IBM admitted that it was ‘difficult to imagine’ graphene replacing silicon in computer chips.

And sceptics point out that most new materials — such as carbon-fibre — take 20 years from invention before they can be used commercial use.

You might think from all the hype, that the road to a great graphene revolution has already been mapped out.

But its future is far from certain. In fact it’s barely been penciled out in rough.

Read more:

What is Graphene?
6 min.

Ideas of flexible graphene:
2 min.


Mark said...

Plasma is a better conductor of electricity than copper

Plasma - The Other 99.9%

By Ian Tresman

How do you see the Solar System? The simple view is gas giants and rocky asteroids and planets moving through nearly empty space. The sophisticated view shows the heliospheric current sheet, a component of the interplanetary plasma we call the Solar Wind, awash throughout the Solar System.

Over 99.9% of the universe is made of plasma, including the Sun and all stars, and most of the space in between. So if you don't know the basic properties of plasmas, then you might not understand the properties of most of the universe.

Did you know...

1. Plasmas are formed by adding energy to gas, causing it to ionize (an atom looses one or more electrons). For example, if hydrogen ionizes, it produces equal numbers of negatively charged electrons and positive ions (in this case, protons). Even a one percent ionized gas may be considered to be a plasma, and have the properties of a fully ionized plasma.

2. Plasmas are affected by electromagnetic forces a thousand billion billion billion billion times greater than the force of gravity. So strong is its influence that it creates the ballerina's skirt shaped heliospheric current sheet, the largest structure in the Solar System, extending out beyond the orbit of Pluto.

3. Plasma is not always electrically neutral. In general it is quasi-neutral, meaning that localized regions of charge separation may occur. And objects that comes into contact with a plasma will charge negatively, such as dust, spacecraft and the surface of the Moon.

4. Plasma is a better conductor of electricity than copper. Its conductivity and response to electromagnetic influences distinguishes it from a gas. Indeed, metals can be classified as plasma, too, because they contain free electrons.

5. Moving plasma can self-generate electromagnetic fields.

6. Plasma can store energy in magnetic fields.

7. Plasmas form double layers between regions of different densities, temperatures or magnetic field strengths. A double layer:

(a) consists of two layers of opposite charge

(b) tends to form cellular structures with the double layer as the "cell wall." (eg. magnetosphere, photosphere, heliosphere)

(c) can form in filamentary current channels known as "Birkeland currents" (see below);

(d) can explode, as discovered in mercury rectifiers used in high-power direct-current transmission lines;

(e) can accelerate charged particles, in opposite directions up to velocities approaching the speed of light.

8. Relative movement of different plasma regions produces electric currents within them.

9. Electric current in plasma produces "pinched" filaments known as Birkeland currents. Birkeland currents form the cosmic power lines and the "wires" of cosmic circuits. An example is found in the ionosphere where these filaments carry up to a million amps, and power the aurora. Those in the Sun's prominences have been estimated to carry up to 100 billion amps (1011 A).

10. Birkeland currents collimate "jets" of matter and charged particles. Astronomical "jets" were so named by astrophysicists because they look somewhat like fluid jets produced in the laboratory. Yet astronomical jets look nothing like a supersonic jet coming out of a nozzle, with all the attendant fluid instabilities. Heated gas should quickly disperse in space but the magnetic pinch of a Birkeland current can maintain filaments of glowing matter over thousands of light years.

11. Synchrotron radiation from pinched current filaments can be in the form of x-rays and gamma rays.

12. The pinch effect can be used in nuclear fusion reactors.

13. Plasma phenomena scale in size over at least 14 orders of magnitude. So the same phenomena may be seen in a dense laboratory plasma and a tenuous space plasma.

14. Parallel plasma filaments attract one another with a force inversely proportional to their distance apart. Compare this with gravity, which attracts matter with a force inversely proportional to the SQUARE of the distance. That makes pinched Birkeland currents by far the most effective way of condensing rarefied dust and gas to form molecular clouds and stars.

So, since the Universe is 99.9% plasma, the important question is not IF the properties of plasma are important in cosmology, but HOW come we focus on the puny force of gravity?

"The space data from astronomical telescopes should be treated by scientists who are familiar with laboratory and magnetospheric physics, circuit theory, and of course modern plasma physics." Hannes Alfvén, Double Layers and Circuits in Astrophysics, IEEE Transactions on Plasma Science, Vol. PS-14, No. 6, December 1986.

Archived TPODS related to "Plasma" may be read at:

Mark said...

[remove all toxic metals from the electronics industries]


conductors modified a plastic so its ability to conduct electricity can be altered during manufacturing polyaniline

Breaking News

Updated every 15 minutes (powered by UPI)
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Plastic modified to meet electronic needs

AUSTIN, Texas, April 9 (UPI) -- A U.S. scientist has modified a plastic so its ability to conduct electricity can be altered during manufacturing to meet future electronic device needs.

Yueh-Lin Loo, an assistant professor of chemical engineering at The University of Texas at Austin, conducted her research with a plastic called polyaniline, which could serve as flexible, inexpensive wiring in future products such as military camouflage that changes colors, foldable electronic displays and medical sensors.

By combining polyaniline with a chemical that gives it conductivity, Loo discovered she could increase the plastic's conductivity one- to six-fold based on the version of the chemical added.

The results of her research involving the chemical polymer acid appear in the April 7 issue of the Journal of Materials Chemistry.

2007 United Press International.

Science Daily

Mark said...

Spray-On nano solar cells

Breakthrough - Spray-On
Nanotech Solar Power Cells
By Stefan Lovgren
National Geographic News

Scientists have invented a plastic solar cell that can turn the sun's power into electrical energy, even on a cloudy day.

The plastic material uses nanotechnology and contains the first solar cells able to harness the sun's invisible, infrared rays.

The breakthrough has led theorists to predict that plastic solar cells could one day become five times more efficient than current solar cell technology.

Like paint, the composite can be sprayed onto other materials and used as portable electricity.

A sweater coated in the material could power a cell phone or other wireless devices.

A hydrogen-powered car painted with the film could potentially convert enough energy into electricity to continually recharge the car's battery.

The researchers envision that one day "solar farms" consisting of the plastic material could be rolled across deserts to generate enough clean energy to supply the entire planet's power needs.

"The sun that reaches the Earth's surface delivers 10,000 times more energy than we consume," said Ted Sargent, an electrical and computer engineering professor at the University of Toronto. Sargent is one of the inventors of the new plastic material.

"If we could cover 0.1 percent of the Earth's surface with [very efficient] large-area solar cells," he said, "we could in principle replace all of our energy habits with a source of power which is clean and renewable."

Infrared Power

Plastic solar cells are not new. But existing materials are only able to harness the sun's visible light. While half of the sun's power lies in the visible spectrum, the other half lies in the infrared spectrum.

The new material is the first plastic composite that is able to harness the infrared portion.

"Everything that's warm gives off some heat. Even people and animals give off heat," Sargent said. "So there actually is some power remaining in the infrared [spectrum], even when it appears to us to be dark outside."

The researchers combined specially designed nano particles called quantum dots with a polymer to make the plastic that can detect energy in the infrared.

With further advances, the new plastic "could allow up to 30 percent of the sun's radiant energy to be harnessed, compared to 6 percent in today's best plastic solar cells," said Peter Peumans, a Stanford University electrical engineering professor, who studied the work.

Electrical Sweaters

The new material could make technology truly wireless.

"We have this expectation that we don't have to plug into a phone jack anymore to talk on the phone, but we're resigned to the fact that we have to plug into an electrical outlet to recharge the batteries," Sargent said. "That's only communications wireless, not power wireless."

He said the plastic coating could be woven into a shirt or sweater and used to charge an item like a cell phone. [from your body heat]

"A sweater is already absorbing all sorts of light both in the infrared and the visible," said Sargent. "Instead of just turning that into heat, as it currently does, imagine if it were to turn that into electricity."

Other possibilities include energy-saving plastic sheeting that could be unfurled onto a rooftop to supply heating needs, or solar cell window coating that could let in enough infrared light to power home appliances.


Ultimately, a large amount of the sun's energy could be harnessed through "solar farms" and used to power all our energy needs, the researchers predict.

"This could potentially displace other sources of electrical production that produce greenhouse gases, such as coal," Sargent said.

In Japan, the world's largest solar-power market, the government expects that 50 percent of residential power supply will come from solar power by 2030, up from a fraction of a percent today.

The biggest hurdle facing solar power is cost-effectiveness.

At a current cost of 25 to 50 cents per kilowatt-hour, solar power is significantly more expensive than conventional electrical power for residences. Average U.S. residential power prices are less than ten cents per kilowatt-hour, according to experts.

But that could change with the new material.

"Flexible, roller-processed solar cells have the potential to turn the sun's power into a clean, green, convenient source of energy," said John Wolfe, a nanotechnology venture capital investor at Lux Capital in New York City."

Mark said...

Metal Rubber
Chemists Create Self-assembling Conductive Rubber

April 1, 2007 — Polymer chemists have created a flexible, indestructible material, called metal rubber, that can be heated, frozen, washed or doused with jet fuel, and still retain its electricity-conducting properties.

To make metal rubber, chemists and engineers use a process called self-assembly.

The material is repeatedly dipped into positively charged and negatively charged solutions. The positive and negative charges bond, forming layers that conduct electricity. Uses of metal rubber include bendy, electrically charged aircraft wings, artificial muscles and wearable computers.

Portable gadgets were meant to be taken on the move. Portable also means accidents and damage can happen. Now, imagine electronics that can take a beating and bounce back!

It's soon possible with a shocking new flexible, indestructible material, called metal rubber.

"You can heat it. You can freeze it. You can stretch it. You can douse it with jet fuel," Jennifer Lalli, a polymer chemist at NanoSonic, Inc., in Blacksburg, Va., tells DBIS.

Abuse it, and metal rubber snaps back to its original shape. But the best part of this rubbery material? It conducts electricity just like metal and is also lightweight.

To make metal rubber, chemists and engineers use a process called self-assembly. The material is repeatedly dipped into positively charged and negatively charged solutions. The positive and negative charges bond, forming layers that conduct electricity.

"Electricity flows through metal rubber because there are little metal particles, and the electricity flows from little metal particle, to little metal particle, to little metal particle, between the two ends just like a piece of copper metal," Rick Claus, a NanoSonic electrical engineer, tells DBIS.

The self-assembly process coats almost anything -- even fabric can be made to carry electrical power. Lalli says you can wash the metal rubber textiles and they maintain electrical current.

Scientists are looking into uses of metal rubber like bendy, electrically charged aircraft wings and artificial muscles -- and wearable computers. Abuse-resistant, flexible circuits, like cell phones, are still years away, but the future looks bright -- and powerful -- for bendable products.

The Materials Research Society contributed to the information contained in the TV portion of this report.


Mark said...

Solving The Mysteries Of Metallic Glass

Tuesday, December 30th, 2008
by Lockergnome

Researchers at MIT have made significant progress in understanding a class of materials that has resisted analysis for decades. Their findings could lead to the rapid discovery of a variety of useful new kinds of glass made of metallic alloys with potentially significant mechanical, chemical and magnetic applications.

The first examples of metallic alloys that could be made into glass were discovered back in the late 1950s and led to a flurry of research activity, but, despite intense study, so far nobody had solved the riddle of why some specific alloys could form glasses and others could not, or how to identify the promising candidates, said Carl. V. Thompson, the Stavros Salapatas Professor of Materials Science & Engineering and director of the Materials Processing Center at MIT. A report on the new work, which describes a way to systematically find the promising mixes from among dozens of candidates, is being published this week in Science.

Glasses are solids whose structure is essentially that of a liquid, with atoms arranged randomly instead of in the ordered patterns of a crystal. Generally, they are produced by quickly cooling a material from a molten state, a process called quenching.

“It is very difficult to make glasses from metals compared to any other class of materials, such as semiconductors, ceramics and polymers,” Thompson said. Decades of effort by scientists around the world have focused on “understanding and on exploiting the remarkable properties of these materials, and on understanding why some alloy compositions can be made into glasses and others cannot,” he said.

They still haven’t solved that “why,” Thompson said. But this new work does “provide a very specific and quantitative new insight into the characteristics of liquid alloys that can most readily be quenched into the glassy state,” he said, and thus provides a much more rapid way of discovering new alloys that have the right properties.

The research was the result of a collaboration between Thompson and MIT post-doc Johannes A. Kalb with Professor Yi Li and graduate student Qiang Guo at the National University of Singapore, working together across thousands of miles of separation through the Singapore-MIT Alliance. Essentially, the work consisted of producing an array of different alloys with slightly varying proportions of two metals, each deposited on a separate microscopic finger of metal. Then, they analyzed the changes in density of each different mixture when the glass crystallized, and found that there were a few specific proportions that had significantly higher density than the others — and those particular alloys were the ones that could readily form glasses. Of three of these special proportions they found, two were already known glass-forming alloys, but the third was a new discovery.

The new work could even lead to a solution to the longstanding puzzle of why only certain alloys make glasses, he said. “I expect these new results, and the technique we developed to obtain them, will play a key, and hopefully decisive, role in solving the mystery of metallic glass formation.”

Such materials could have a variety of applications because of their unusual physical and magnetic properties, Thompson said. They are “soft” magnetically, meaning that it’s very easy to change the magnetic orientation of the material. This is a highly desirable characteristic for the cores of transformers, for example, which must switch their magnetic orientation dozens of times per second. Transformers made from metallic glasses could potentially greatly reduce the amount of electricity wasted as excess heat in conventional transformers, reducing the need for new generating plants.

In addition, these glasses are unusually hard mechanically and have a high degree of springiness (known technically as a high “elastic modulus”). This springiness could make them a useful material for some sports equipment such as golf clubs or tennis rackets, Thompson said. Although metallic glasses are relatively expensive, he said, for some people interested in the best-performing sports equipment, or in virtually unbreakable housings for cellphones, for example, “no expense is too high.”

The new research is a major accomplishment for the Singapore-MIT Alliance, Thompson said, and would not have been possible without the high-quality communications and collaboration tools it provides. Despite their physical separation, “Prof. Li and I have been working together now for almost ten years,” he said. “We routinely meet via video conferencing and have both been deeply involved in the co-supervision of the remarkable PhD student, Qiang Guo, who carried out this research.”

Thompson said he sees such collaborations as a significant example of a growing trend. “I think this and other accomplishments within the SMA program demonstrate that the future of research lies in technology-mediated collaborations among people with common interests and complementary capabilities, regardless of where the different parts of the team are located,” he said.

The research was supported by the SMA program, and Kalb was partially supported through a fellowship from the German Alexander Von Humboldt Foundation.

[Elizabeth Thomson @ Massachusetts Institute of Technology