New research suggests that networks of single-walled carbon nanotubes printed onto bendable plastic perform well as semiconductors in integrated circuits. Researchers from the University of Illinois at Urbana-Champaign (UIUC) and Purdue University, whose work appears this week in Nature, say that these nanotube networks could replace organic semiconductors in applications such as flexible displays.

Development of flexible electronics has recently focused on organic molecules because, unlike silicon, they are compatible with bendable plastic substrates. Flexible electronics have potential in such applications as low-power electronic newspapers or PDAs that roll up into the size and shape of a pen. The problem with existing organic-electronic devices, however, is that "they aren't well developed for long-term reliability, and they perform far worse than silicon," says John A. Rogers, an engineering professor at UIUC and co-author of the Nature paper.

Carbon-nanotube networks, on the other hand, combine the performance of silicon with the flexibility of organic films on plastic. Rogers says that the speed of the nanotube device compares favorably with the speed of commercially used single-crystal silicon circuits. The transistors can also switch between on and off states in the range of several kilohertz, which is similar to the range of those used for liquid crystal displays and radio frequency identification (RFID) sensors. However, the on-off current ratio for carbon nanotubes is still a few orders of magnitude lower than that for silicon transistors.

The researchers made the networks by depositing nanotubes onto plastic by standard printing methods, which could lead to low-cost, large-scale fabrication. And the printed circuits can bend to a radius of about five millimeters without compromising the electrical performance of the device. "This method is good for flexible electronics that need to be printed over a large area," says Ali Javey, an assistant professor of electrical engineering at the University of California, Berkeley.

Using a technique called transfer printing, the researchers deposited randomly aligned carbon nanotubes onto a 50-micrometer-thick sheet of plastic, and then patterned gold electrodes and other circuit components onto the substrate. Because about one-third of the nanotubes in any network are metallic, which can short out the transistors, the researchers then etched narrow parallel lines through the network with soft lithography. By cutting the nanotubes, they can effectively eliminate the possibility of a purely metallic pathway connecting two electrodes while preserving the performance of the device.

Several challenges still remain before the nanotubes networks are ready for actual products. Devices need to be made in which the performance from device to device doesn't vary; billions of individual nanotubes have to be made with high purity and the right dimensions for optimal performance. The printing process also needs development, says George Gruner, a professor of physics at the University of California, Los Angeles. Gruner suggests that nanotubes could be dissolved into ink and then printed onto plastic. "These devices have to be cheap and disposable," especially for devices like RFID tags in food packaging, he adds.

Rogers's group's immediate goals are to work toward lower power and higher speed in the devices. "We want to push the limits to see how far we can go," he says.

via technologyreview 

Elvira Fortunato and colleagues from the Centro de Investigação de Materiais (Cenimat/I3N), at Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, made the first Field Effect Transistor (FET) with a paper «interstrate» layer.

There is an increased interest in the use of biopolymers for low-cost electronic applications. Since cellulose is the Earth’s major biopolymer, some international teams have reported using paper as the physical support (substrate) of electronic devices but no one had used paper as an interstrate component of a FET.

The electrical performance of the new device rivals oxide-based thin film transistors (TFTs) produced on glass or crystalline silicon substrates. Full results will be published in September's in IEEE Electron Device Letters.

In a new approach, scientists from Cenimat/I3N – a research group coordinated by Elvira Fortunato and Rodrigo Martins – used a common sheet of paper as the dielectric layer on oxide FETs.

The research team fabricated the devices on both sides of the paper sheet. This way, the paper acts simultaneously as the electric insulator and as the substrate. «Is a two in one», says Elvira Fortunato.

Furthermore, electric characterization of devices showed that the hybrid FETs’ performance outpace those of amorphous silicon TFTs, and rival with the actual state of the art of oxide thin film transistors.

These results suggest promising new disposable electronics devices, like paper displays, smart labels, smart packaging, bio-applications, RFID tags, among others.

"High Performance Flexible Hybrid Field Effect Transistors based on Cellulose Fiber-Paper" will be published September in IEEE Electron Device Letters (http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=55)

via scientificblogging 

The good-natured competition between actor Ed Begley Jr. and Bill Nye, the host of the educational series Bill Nye, the Science Guy began when Nye moved into the neighborhood two years ago. Since then the two moderately famous and slightly geeky environmentalists have matched wits over whose home can leave a smaller carbon footprint.

Neighbor Frema Rood, 83, who lives between the two houses, said the competition started the day after Bill moved into the neighborhood.

"Bill announced it: 'I'm going to best Ed Begley at his own game. I'm going to get him,'" she recalled. "He ordered panels for the garage, then rain barrels, then he had his windows done and he put in a vegetable garden."

Nye, 52, pins the source of the rivalry on Begley, who became envious of Nye's new solar panels while filming a segment of his HGTV green living show called Living with Ed.

"Ed instantly got a little twinge — you could see it," Nye said. "My system, being 15 years younger, has a couple of nice little features that he doesn't have."

To liven up the segment, the neighbors pretended to spar over who had the better system. But in this city where the rich and famous jockey to be the first behind the wheel of a new alternative-fuel car, the jokes have given way to an environmental turf war.

Nye trumped Begley's old solar panels with a system that shows when he's making more power than he's using. Begley pushed to offset his wife's 20-minute showers with rain barrels to water the plants.

Begley long ago installed an Astro Turf lawn to save on water. He composts his garbage, cooks in an outdoor solar oven and grows his own produce. His sprinkler system electronically checks the forecast and shuts down if it's supposed to rain.

Instead of using pesticides, Begley lures slugs and snails away from his plants with trays of beer that kill them. Nye, who also has plots overflowing with produce, keeps raccoons away with an electric fence powered by a matchbox-sized solar panel.

The white picket fence that surrounds Begley's two bedroom, 1,585 square foot bungalow is made of recycled plastic milk cartons pressed into boards. Nye used the recycled plastic lumber to build a patio cover, and convinced Rood to use the same type of boards to repair their shared white fence.

While Begley calls the rivalry a "a friendly, humorous one-upmanship," he admits there are parts of the competition that are quite serious.

"He has these great copper rain gutters that I covet," Begley said.

Given Begley's 20-year head start, Nye admits that he may never fully catch up to his neighbor, who was green long before it was considered cool. Nye has called Begley the inspiration behind many of the changes he's made, including illuminating his American flag at night with a light bulb powered by a tiny solar panel.

Begley's daughter, Amanda, still remembers the days when her friends thought her father was a nut. His early electric car would start puttering out of energy as it climbed hills, and he would ask his daughter's friends — self-conscious teenage girls — how much they weighed.

"Now it's different," said Amanda Begley, now 30. "He went from being the kookiest guy around to the cool guy that everyone's calling and asking questions about things instead of just thinking, you know, that he was out of his mind."

These days Begley has his own all-purpose biodegradable cleaner called "Begley's Best" and is regularly approached by inventors to test new products.

Nye remains confidently in the lead in terms of aesthetics and order. Begley has wires poking out of appliances, bricks piled high and red rain barrels are an eyesore against the actor's blue home, Nye said.

"Ed claims — and this is an extraordinary claim — that he doesn't care how things look as long as they function well," Nye said. "I'm not in that camp. Things have to look good or don't bother."

Begley said his wife is not a fan of the barrels either. He admitted the barrels were unattractive but claims he didn't know they came in different colors and styles.

Begley has since settled on a new plan that should be acceptable to his wife — an underground cistern to store the water. More importantly, does he think his latest innovation will make Nye jealous?

"He already is," Begley said.

via usatoday 

An international team of researchers has shown that it can control the quantum state of a single electron in a silicon transistor--even putting the electron in two places at once. Their discovery could help pave the way toward a practical quantum computer.

Quantum computers take advantage of the strange properties of subatomic particles to perform certain types of calculations much faster than classical computers can. Researchers are exploring a host of different approaches to quantum computing, and some have even built primitive quantum circuits that can perform calculations. But practical quantum computing would require the ability to manufacture devices with millions of quantum circuits--rather than the 12 or 16 achievable now--that can be integrated with more-conventional electronics.

One theoretical approach to practical quantum electronics is to use conventional electronics--tiny semiconductor transistors--to control the state of a quantum system. Researchers led by Sven Rogge, a researcher at Delft University of Technology, in the Netherlands, performed the first practical experiments to verify the approach's theoretical predictions. The team--which also included researchers from Purdue University; the University of Melbourne, in Australia; and IMEC, in Belgium--found that it could control the quantum state of a single electron simply by altering the voltage applied to a transistor. "This represents a nice step towards future devices where performance is determined by manipulation of quantum states of single atoms," says Thomas Schenkel, a scientist at Lawrence Berkeley National Laboratory.

The researchers used prefabricated transistors built for nanotech research, each of which consisted of two crossed silicon nanowires. One of the nanowires--the bottom one--was connected to electrodes that contained arsenic. When that wire was charged, it would sometimes draw arsenic atoms into the transistor. After applying a voltage across about 100 transistors, the team found six that appeared to have individual arsenic atoms embedded in the nanowire. They then found that varying the voltage across the top wire would control the quantum state of one of the atom's electrons. Using an imaging technique called scanning tunneling spectroscopy, they were able to distinguish three states of the atoms in all six devices. One of those states corresponded with the electron's being in two places at the same time--a property necessary for quantum computing.

"But to understand the behavior of one atom, you have to model millions," says Rogge. So he and his colleagues used an off-the-shelf program called NEMO 3D to characterize a large-scale system containing 1.4 million atoms. They found that the measurements of their model system were in good agreement with the spectroscopy results. "It is really cool to see how well their simulations can describe randomly doped transistors, which are all different in detail," Schenkel says.

via .technologyreview 

Mammograms are one thing that if you bring it up in a room full of women, you’re bound to here a bit of grumbling. They are uncomfortable and apparently not always that accurate. Well now there is a new method in the works that is more accurate and one that is hopefully less painful.

Instead they are now using stereo mammograms, which is basically taking X-rays at slightly different angles. Then to see those in 3-D they wear special 3-D glasses.

They did a recent study and discovered that the stereo mammogram increased detection by 23% and decreased false alarms by 46%. Hopefully they will start using this new method more often and soon, since it quite obviously is the more superior way to go.

via  slashgear

Computer trained to "read" mind images of words

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - A computer has been trained to "read" people's minds by looking at scans of their brains as they thought about specific words, researchers said on Thursday.

They hope their study, published in the journal Science, might lead to better understanding of how and where the brain stores information.

This might lead to better treatments for language disorders and learning disabilities, said Tom Mitchell of the Machine Learning Department at Carnegie Mellon University in Pittsburgh, who helped lead the study.

"The question we are trying to get at is one people have been thinking about for centuries, which is: How does the brain organize knowledge?" Mitchell said in a telephone interview.

"It is only in the last 10 or 15 years that we have this way that we can study this question."

Mitchell's team used functional magnetic resonance imaging, a type of brain scan that can see real-time brain activity.

They calibrated the computer by having nine student volunteers think of 58 different words, while imaging their brain activity.

"We gave instructions to people where we would tell them, 'We are going to show you words and we would like you, when you see this word, to think about its properties,'" Mitchell said.

They imaged each of the nine people thinking about the 58 different words, to create a kind of "average" image of a word.

"If I show you the brain images for two words, the main thing you notice is that they look pretty much alike. If you look at them for a while you might see subtle differences," Mitchell said.

"We have the program calculate the mean brain activity over all of the words that somebody has looked at. That gives us the average when somebody thinks about a word, and then we subtract that average out from all those images," Mitchell added.

Then the test came.

"After we train on the other 58 words, we can say 'Here are two new words you have not seen, celery and airplane.'" The computer was asked to choose which brain image corresponded with which word.

The computer passed the test, predicting when a brain image was taken when a person thought about the word "celery" and when the assigned word was "airplane."

The next step is to study brain activity for phrases.

"If I say 'rabbit' or 'fast rabbit' or 'cuddly rabbit', those are very different ideas," Mitchell said.

"I want to basically use that as a kind of scaffolding for studying language processing in the brain."

Mitchell was surprised at how similar brain activity was among the nine volunteers, although the work was painstaking. For an MRI to work well, the patient must sit or lie very still for several minutes.

"It can be hard to focus," Mitchell said. "Somewhere in the middle of that their stomach growls. And all of sudden they think, 'I'm hungry -- oops.' It's not a controllable experiment."

(Editing by Eric Walsh)...

via reuters 

Functionalized graphene sheets for polymer nanocomposites

T. Ramanathan¹, A. A. Abdala^2,7, S. Stankovich³, D. A. Dikin¹, M. Herrera-Alonso², R. D. Piner^1,6, D. H. Adamson⁴, H. C. Schniepp², X. Chen¹, R. S. Ruoff^1,6, S. T. Nguyen³, I. A. Aksay², R. K. Prud'Homme² & L. C. Brinson^1,5

Cold-fusion demonstration a success

On 23 March 1989 Martin Fleischmann of the University of Southampton, UK, and Stanley Pons of the University of Utah, US, announced that they had observed controlled nuclear fusion in a glass jar at room temperature, and — for around a month — the world was under the impression that the world's energy woes had been remedied. But, even as other groups claimed to repeat the pair's results, sceptical reports began trickle in. An editorial in Nature predicted cold fusion to be unfounded. And a US Department of Energy report judged that the experiments did "not provide convincing evidence that useful sources of energy will result from cold fusion."

This hasn't prevented a handful of scientists persevering with cold-fusion research. They stand on the sidelines, diligently getting on with their experiments and, every so often, they wave their arms frantically when they think have made some progress.

Nobody notices, though. Why? These days the mainstream science media wouldn't touch cold-fusion experiments with a barge pole. They have learnt their lesson from 1989, and now treat "cold fusion" as a byword for bad science. Most scientists agree, and some even go so far as to brand cold fusion a "pathological science" — science that is plagued by falsehood but practiced nonetheless.

There is a reasonable chance that the naysayers are (to some extent) right and that cold fusion experiments in their current form will not amount to anything. But it's too easy to be drawn in by the crowd and overlook a genuine breakthrough, which is why I'd like to let you know that one of the handful of diligent cold-fusion practitioners has started waving his arms again. His name is Yoshiaki Arata, a retired (now emeritus) physics professor at Osaka University, Japan. Yesterday, Arata performed a demonstration at Osaka of one his cold-fusion experiments.

Although I couldn't attend the demonstration (it was in Japanese, anyway), I know that it was based on reports published here and here. Essentially Arata, together with his co-researcher Yue-Chang Zhang, uses pressure to force deuterium (D) gas into an evacuated cell containing a sample of palladium dispersed in zirconium oxide (ZrO₂–Pd). He claims the deuterium is absorbed by the sample in large amounts — producing what he calls dense or "pynco" deuterium — so that the deuterium nuclei become close enough together to fuse.

So, did this method work yesterday? Here's an email I received from Akito Takahashi, a colleague of Arata's, this morning:

"Arata's demonstration...was successfully done. There came about 60 people from universities and companies in Japan and few foreign people. Six major newspapers and two TV [stations] (Asahi, Nikkei, Mainichi, NHK, et al.) were there...Demonstrated live data looked just similar to the data they reported in [the] papers...This showed the method highly reproducible. Arata's lecture and Q&A were also attractive and active."

I also received a detailed account from Jed Rothwell, who is editor of the US site LENR (Low Energy Nuclear Reactions) and who has long thought that cold-fusion research shows promise. He said that, after Arata had started the injection of gas, the temperature rose to about 70 °C, which according to Arata was due to both chemical and nuclear reactions. When the gas was shut off, the temperature in the centre of the cell remained significantly warmer than the cell wall for 50 hours. This, according to Arata, was due solely to nuclear fusion.

Rothwell also pointed out that Arata performed three other control experiments: hydrogen with the ZrO₂–Pd sample (no lasting heat); deuterium with no ZrO₂–Pd sample (no heating at all); and hydrogen with no ZrO₂–Pd sample (again, no heating). Nevertheless, Rothwell added that Arata neglected to mention certain details, such as the method of calibration. "His lecture was very difficult to follow, even for native speakers, so I may have overlooked something," he wrote.

It will be interesting to see what other scientists think of Arata's demonstration. Last week I got in touch with Augustin McEvoy, a retired condensed-matter physicist who has studied Arata's previous cold-fusion experiments in detail. He said that he has found "no conclusive evidence of excess heat" before, though he would like to know how this demonstration turned out.

I will update you if and when I get any more information about the demonstration (apparently there might be some videos circulating soon). For now, though, you can form your own opinions about the reliability of cold fusion...

via physicsworld 

Giant telescope links London, New York

LONDON, England (CNN) -- As the first splinters of sunlight spread their warmth on the south bank of the River Thames on Thursday, it became clear that after more than a century, the vision of Victorian engineer Alexander Stanhope St. George had finally been realized.

In all its optical brilliance and brass and wood, there stood the Telectroscope: an 11.2-meter-(37 feet) long by 3.3-meter-(11 feet) tall dream of a device allowing people on one side of the Atlantic to look into its person-size lens and, in real time, see those on the other side via a recently completed tunnel running under the ocean. (Think 19th-century Webcam. Or maybe Victorian-age video phone.)

And all the credit goes to British artist Paul St. George. If he had not been rummaging through great-grandpa Alexander's personal effects a few years ago, the Telectroscope might still exist only on paper, hidden away deep inside some old box.

But fortunately, St. George could not bear that thought and thus decided he should be the one to finish what his great-grandfather had started. It was quite simply the right thing to do. Plus, it would make a pretty cool public art exhibit. Send us your videos, images or stories

During the twilight hours Tuesday, massive dirt-covered metal drill bits miraculously emerged -- one by the Thames near the Tower Bridge and the other on Fulton Ferry Landing by the Brooklyn Bridge in New York -- completing the final sections of great-grandfather Alexander's transatlantic tunnel.

The drills were removed Wednesday night and replaced with identical Telectroscopes at both ends, allowing Londoners and New Yorkers to wake up Thursday, look over to the far and distant shore and stare at each other for a while (the telescope-like contraption permits visual but not vocal communication).

Of course, only part of this story is true.

St. George is an artist in Britain who does have a grandfather -- minus the great prefix -- named Alexander.

And the trans-Atlantic tunnel is really a trans-Atlantic broadband network rounded off on each end with HD cameras, according to Tiscali, an Italian Internet provider handling the technical side of the project.

As for the Telectroscope, well, it was a fanciful idea that, according to St. George, came about from a typo made by a 19th-century reporter who misspelled Electroscope, a device used to measure electrostatic charges - as Telectroscope.

"The journalist also misunderstood what it was about and wrote in the article that it was a device for the suppression of absence," St. George said. "The accidental hope captured their imagination, and lots of people at the end of the 19th century thought it was a great idea."

The Telectroscope captured St. George's imagination five years ago, when he began pondering how to do a project on the childhood fantasy of digging a hole to the opposite side of the Earth. And because the artist also happens to have an expertise in Victorian chronophotography -- a precursor to cinematography -- he had a slight idea of where to look for the proper equipment.

"We all have that idea in our head if we could make a tunnel to the other side of the Earth," St. George said."But we are not all crazy enough to actually try and do it."

St. George was crazy enough to actually try and do it, but he realized he could not do the digging alone. So about two years ago, he pitched the idea to Artichoke, the British arts group responsible for taking the Sultan's Elephant -- a 42-ton mechanical creature -- for a stroll through central London in 2006. The company was immediately taken by St. George's idea.

"The whole thing is about seeing what is real and what isn't real and how the world is," said Nicki Webb, a co-founder of Artichoke. "Is it nighttime when we are in daytime, and does it look familiar to us or not?"

When the sun illuminated the lens of the Telectroscope next to the Thames, it was, of course, still nighttime in New York. So the screen inside the scope broadcast back only an empty sidewalk silently framed by the Brooklyn Bridge and the Manhattan skyline.

But then something miraculous occurred.

A police officer and a street cleaner walked into the frame. Stopped. And waved.

via cnn 

  Giant telescope links London, New York,england, london, new york, NewYork, ny, science, Telectroscope, telescope