Monday, March 29, 2010

NANO-BASED RFID TAGS COULD REPLACE BAR CODES

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Long lines at store checkouts could be history if a new technology created in part at Rice University comes to pass.

Rice researchers, in collaboration with a team led by Gyou-jin Cho at Sunchon National University in Korea, have come up with an inexpensive, printable transmitter that can be invisibly embedded in packaging. It would allow a customer to walk a cart full of groceries or other goods past a scanner on the way to the car; the scanner would read all items in the cart at once, total them up and charge the customer's account while adjusting the store's inventory.

More advanced versions could collect all the information about the contents of a store in an instant, letting a retailer know where every package is at any time.

The technology reported in the March issue of the journal IEEE Transactions on Electron Devices is based on a carbon-nanotube-infused ink for ink-jet printers first developed in the Rice lab of James Tour, the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science. The ink is used to make thin-film transistors, a key element in radio-frequency identification (RFID) tags that can be printed on paper or plastic.

"We are going to a society where RFID is a key player," said Cho, a professor of printed electronics engineering at Sunchon, who expects the technology to mature in five years. Cho and his team are developing the electronics as well as the roll-to-roll printing process that, he said, will bring the cost of printing the tags down to a penny apiece and make them ubiquitous.

RFID tags are almost everywhere already. The tiny electronic transmitters are used to identify and track products and farm animals. They're in passports, library books and devices that let drivers pass through tollbooths without digging for change.

The technology behind RFID goes back to the 1940s, when Léon Theremin, inventor of the self-named electronic music instrument heard in so many '50s science fiction and horror movies, came up with a spy tool for the Soviet Union that drew power from and retransmitted radio waves.

RFID itself came into being in the 1970s and has been widely adopted by the Department of Defense and industry to track shipping containers as they make their way around the world, among many other uses.

But RFID tags to date are largely silicon-based. Paper or plastic tags printed as part of a package would cut costs dramatically. Cho expects his roll-to-roll technique, which uses a gravure process rather than ink-jet printers, to replace the bar codes now festooned on just about everything you can buy.

Cho, Tour and their teams reported in the journal a three-step process to print one-bit tags, including the antenna, electrodes and dielectric layers, on plastic foil. Cho's lab is working on 16-bit tags that would hold a more practical amount of information and be printable on paper as well.

Cho came across Tour's inks while spending a sabbatical at Rice in 2005. "Professor Tour first recommended we use single-walled carbon nanotubes for printing thin-film transistors," Cho said.

Tour's lab continues to support the project in an advisory role and occasionally hosts Cho's students. Tour said Rice owns half of the patent, still pending, upon which all of the technology is based. "Gyou-jin has carried the brunt of this, and it's his sole project," Tour said. "We are advisers and we still send him the raw materials" -- the single-walled carbon nanotubes produced at Rice.

Printable RFIDs are practical because they're passive. The tags power up when hit by radio waves at the right frequency and return the information they contain. "If there's no power source, there's no lifetime limit. When they receive the RF signal, they emit," Tour said.

There are several hurdles to commercialization. First, the device must be reduced to the size of a bar code, about a third the size of the one reported in the paper, Tour said. Second, its range must increase.

"Right now, the emitter has to be pretty close to the tags, but it's getting farther all the time," he said. "The practical distance to have it ring up all the items in your shopping cart is a meter. But the ultimate would be to signal and get immediate response back from every item in your store – what's on the shelves, their dates, everything.

"At 300 meters, you're set – you have real-time information on every item in a warehouse. If something falls behind a shelf, you know about it. If a product is about to expire, you know to move it to the front – or to the bargain bin."

Tour allayed concerns about the fate of nanotubes in packaging. "The amount of nanotubes in an RFID tag is probably less than a picogram. That means you can produce one trillion of them from a gram of nanotubes – a miniscule amount. Our HiPco reactor produces a gram of nanotubes an hour, and that would be enough to handle every item in every Walmart.

"In fact, more nanotubes occur naturally in the environment, so it's not even fair to say the risk is minimal. It's infinitesimal."

(Photo: Gyou-Jin Cho/Sunchon National University)

Rice University

BEES SEE SUPER COLOUR AT SUPER SPEED

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Bees see the world almost five times faster than humans, according to new research from scientists at Queen Mary, University of London.

This gives bumblebees the fastest colour vision of all animals, allowing them to easily navigate shady bushes to find food, write Dr Peter Skorupski and Prof Lars Chittka in the Journal of Neuroscience.

The ability to see at high speed is common in fast-flying insects; allowing them to escape predators and catch their mates mid-air. However, until now it wasn't known whether the bees' full colour vision was able to keep up with their high speed flight. This research sheds new light on the matter; suggesting that although slower, it is also about twice as fast as human vision.

Dr Skorupski, who carried out the work at Queen Mary's Research Centre for Psychology in the School of Biological and Chemical Sciences says; "We can't easily follow a fast flying insect by eye, but they can follow each other, thanks to their very fast vision. How fast you can see depends on how quickly the light-detecting cells in your eye can capture snapshots of the world and send them to your brain. Most flying insects can see much quicker than humans, for example so they can avoid getting swatted!"

Bumblebees use their advanced colour vision in many ways. Dr Skorupski explains: "Bees were the first animals that scientists proved to have colour vision, and they have since been shown to put it to good use; navigating dappled light and shady areas, recognising shapes like their hive entrance, and particularly for finding nectar-bearing coloured flowers."

The experiments show that the bees burn more energy to see in colour than they would to see in monochrome (black and white), raising questions about how they make the most of it. "Bees' energy can't be used frivolously, as they need so much of it just to stay alive. It seems they only see colours at half the speed they see white light, which give them enough detail to find their favourite flowers and navigate back home," suggests Dr Skorupski.

(Photo: Helga Heilmann, BEEgroup Wuerzburg)

Queen Mary, University of London

RARE ARMOR-PLATED CREATURE DISCOVERED IN CANADA'S CAPITAL

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Scientists have unearthed the remains of one of the World’s rarest fossils - in downtown Ottawa. The 450 million year old fossil preserves the complete skeleton of a plumulitid machaeridian, one of only 8 such specimens known. Plumulitids were annelid worms - the group including earthworms, bristleworms and leeches, today found everywhere from the deepest sea to the soil in your yard - and although plumulitids were small they reveal important evidence of how this major group of organisms evolved.

"Such significant new fossils are generally discovered in remote or little studied areas of the globe, requiring difficult journeys and a bit of adventure to reach them" notes Jakob Vinther of Yale University, lead author of the paper describing the specimen. "Not this one though. It was found in a place that has an address rather than map co-ordinates!"

Plumulites canadensis, Albert Street, Ottawa, Canada K1P1A4. The fossil is described by Vinther and Dave Rudkin, of Toronto's Royal Ontario Museum, in the current issue of the journal Palaeontology.

It was Rudkin who first recognised its scientific significance: "This nifty little specimen first came to my notice when I received a letter from an amateur fossil collector in Nepean, Ontario. In prospecting for fossils in rock from a temporary building excavation he had turned up a small block containing a complete trilobite, but next to it was something else and he sent me a slightly fuzzy but very intriguing photo. The mystery fossil was clearly not another trilobite, and I although couldn't be certain, I thought it might be some sort of annelid worm with broad, flattened scales. James, the collector, generously agreed to lend me the specimen and I realised immediately it was a complete, fully articulated machaeridian! The first I had ever seen."

At that time it was not known that machaeridians were annelids. "James was happy to donate the specimen to the Royal Ontario Museum, in exchange for a promise that I'd someday publish his discovery."

It was not until 2008 that Rudkin's hunch was confirmed, when a team of palaeontologists, including Jakob Vinther, decribed new machaeridian fossils from remote mountain localities in Morocco, revealing their relationship to annelid worms. Rudkin and Vinther agreed to work together to interpret the Ottawa specimen, and it is the results of that collaboration that are published in the current Palaeontology.

Plumulitid machaeridians look like modern bristleworms, with stout walking limbs bearing long bundles of bristles, but on their back they carried a set of mineralized plates. According to Vinther, "the plates themselves were rigid, but they could move relative to one other, providing plumulitids with a protective body armour very similar to the flexible metal armour invented by humans 450 million years later. Machaeridian body armour is unique among annelids, and probably helped them to succeed as ubiquitous components of marine ecosystems for more than 200 million years."

With the publication of this paper Rudkin is finally able to make good on his promise "It's great to be able to acknowledge the collector", says Rudkin, but there is a twist to this tale: the man who found the specimen has now gone missing. "Regrettably, I lost contact with James and numerous enquiries as to his whereabouts have come up empty. I hope he somehow gets wind of all this."

John Wiley & Sons, Inc.

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