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 Post subject: This Message Will Self Destruct: Scientists Develop Programmable, Self-Erasing Documents
PostPosted: Wed Jul 08, 2009 9:34 pm 
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Researchers are harnessing nanoparticle properties to develop fading ink

Remember when, as a kid, you would pass “top-secret” notes written in lemon juice that your friends could only read in the right light? Well, in light of new nanotechnology research, this now sounds absurdly antiquated, like cave painting in the modern era. Instead, the youth of the future (and adults, too) could have to option to communicate via documents that self-erase at a programmed time.


The idea comes from Northwestern University, where a team of researchers led by Bartosz Grzybowski is making use of a unique property of certain nanoparticles-–their ability change color based on how close they are to one another. So, when spread out, gold nanoparticles are red, but once you pack them together, they turn violet, blue, and then become colorless. To change the distribution of the particles, you can coat them with MUA molecules, which, when struck by ultraviolet light, will relocate.


In their lab, Grzybowski and his colleagues have taken to shining UV light on a thin film made up of a gel of nanoparticles placed between two plastic sheets. The result? They were able to display images and text that disappeared after a programmed period of time.


This now-you-see-it-now-you-don’t concept is not entirely new: back in 2006, Xerox came up with a type of paper whose print would fade after about 16-24 hours, making it possible to reuse photocopies. That design, however, came with neither a color option nor the possibility to control the timing of the text’s vanishing--both of which Grzybowski’s team can do.


Future uses of this research include anything from limited-time bus tickets to military documents that would wipe themselves clean. Imagine the possibilities! I bet the Bush administration wishes it could have gotten its hands on this.


[New Scientist]




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 Post subject: Scientists Design Versatile Self-Assembling Nanogears
PostPosted: Fri Jul 24, 2009 6:39 am 
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For years, creating the gears and sprockets needed to make a microscopic robot has required the expensive and time-consuming process of silicon etching. Carving out each individual piece with a laser has made producing more than a couple of pieces prohibitively difficult and costly.


A team at Columbia University now seems to have found a way around that problem. By laying a thin sheet of metal over a special layer of polymer, the team has created nanogears that assemble themselves, opening the possibility of much faster, cheaper, widespread production.


To make the gears, a thin copper sheet is laid over a heat-expanded polymer. When the polymer cools, it shrinks faster than the metal, which causes the metal to bend. When the metal bends, it creates regularly spaced teeth in the polymer, effectively making a microscopic gear. Stiffer metal that"s harder to bend creates a gear with fewer, larger teeth, while a more supple metal creates gears with smaller, more numerous teeth.


The team has already made a number of different types of gears, all at the six-to-25 millimeter range, and are now ready to shrink the process down further, to create gears smaller than a micrometer.


However, even more than shrinking down the size of the gears, creating non-linear teeth looms as the real challenge, with the big payoff. If the Columbia team can figure out how to manipulate the polymer so that it cools preferentially in one or another direction, they can create the complicated gears needed to produce devices like a drive train. And once you can create self-assembling drive trains on the cheap, hordes of self-replicating nanobots are not far down the road.


[via New Scientist]




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 Post subject: The Incredibly Wide World of Smart Material d3o
PostPosted: Sun Aug 16, 2009 3:46 pm 
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From its humble beginnings in a ski beenie three years ago, the elastic polymer that stiffens immediately on impact has exploded

Here at PopSci, we love when our leading-edge reporting on the seemingly unbelievable, futuristic developments in science and tech end up, well, becoming reality. We reported three and a half years ago on d3o, the elastic polymer that"s flexible at rest but stiffens in response to quick movements, first found in winter beanie. Now, it can be found in 107 products made by 22 different companies, ranging from iPod cases to polo kneepads.


d3o was first introduced during the 2006 Winter Olympics in Turin, giving downhill skiers" millimeter-thin aerodynamic bodysuits a thin, flexible layer of protection. The protection comes d3o"s ability to stiffens on impact as the molecules lock together--the harder the hit, the tighter the lock, with the molecules instantaneously return to their original state after impact.


The best demonstration is playing with a wad of the raw orange material. In your hands the substance feels like something between Jell-O and Play-Doh. Pliable, moldable, rollable. You can rip off a chunk and then slap it back to itself. Touch it and your finger can go right through it. But roll it into a ball throw it down on the ground and the sucker behaves like the 25-cent bouncy balls your kid bought at the toy store.







With its most commercially successful product launched earlier this year (in a Head tennis raquet) and a contract with Britain’s Ministry of Defence sparking its entry into the military arena, d3o is certainly for real. We spoke with CEO Richard Palmer to figure what’s next for the magic material and the 15 person company protecting people everywhere from themselves.


BZ: Has the sheer number of applications for d3o surprised you?

RP: Overall I am amazed at the variety. I’m also still amazed at the quantities that continue to come in that we hadn’t previously considered. When I first wrote a business plan it was like we we’re going to conquer the world with this entire list of industries where I saw the technology being useful. But there’s a whole other world of products that I just never considered.

See our gallery of some of the more diverse applications of d3o here


Do you worry about over-exposure?

Obviously, there’s a balancing act. We would worry if the quality of those products was poor. But we maintain that there’s a lot of applications for a soft shock-absorbing material. If you position yourself exclusively within one market, so for example you’re a footwear technology, then as soon as you start to move into headwear, the consumer gets confused or even concerned as to how a footwear technology is supposed to work in the head. So if NIKE Air came out with NIKE air helmets how would the consumer react to that? By spreading across a wide range of applications it allows us to send a broad but consistent message that’s it’s all about shock absorption and protection, and that anyone who wants the best should look at d3o.


Are there limitations from a technical perspective? Are their things you can’t protect with d3o?

There’s a lot of technical challenges with the production process. There are many future manufacturing procedures that could open us up to products we can’t’ currently make. For example we can’t make sheets that are very large. That limits us.


Will the material itself evolve at all?

There is a range of polymers that we can use in the future to provide other areas of performance. For example we are not abrasion resistant right now and we are not staph (bacteria) resistant. Those are some of the areas where the future is looking pretty attractive.


How many projects are normally on your plate?

There will always be the small ones that are quick to resolve. For example we have someone in the petrochemical industry who wants some gloves. So, we’ll decide how we want to test the existing gloves, put in a piece of d3o, retest and send that back and decide how to progress. Other projects are much more extensive. We’ve won a development project with the Ministry of Defense to develop a helmet liner for a military helmet. That’s a whole program of development where it has to be washable, provide the right chemical resistance, provide the right protection combined with flexibility, combined with cost. That could be twelve months of activity. At any one time we’re probably dealing with 20-30 total projects and probably five big ones.


Do you have a formulaic way of deciding yes or no?

What we aim for is what I call the ‘three m’s’ of a technology adoption. First, whatever you’re saying should be measurable. If it’s not measurable than how can you say it exists? Secondly, that measurement should be meaningful. It should make a difference that the consumer actually wants. Third, it has to be marketable. So somehow we have to be able to communicate effectively the benefit that exists on the product. And once you have those three, then you have a story.


We love data as much as the next nerd but the Head tennis racket merely claims “softer touch and better feel” without anything numerical. We asked for data and they refused. We attempted to get hard measurable data and they wouldn’t offer it. What’s up with that?

As I understand they have a test facility and they want those procedures and methods to remain secret. I think that would be a problem if we wanted to further advance the vibration attenuation of a racket, but it’s not really core to our business. In the past we’ve done some work with ballistic tests and we had one company show us some fantastic results but wouldn’t tell us how they achieved them. So in certain areas we won’t start without an agreement that we’ll share the development data. But if someone wants to put it in a lacrosse stick, I’d be interested in the data, but I wouldn’t be upset if for commercial reasons they decided not to share.


Any particularly technically challenging products that you’re proud of?



I think the limited edition Puma football we did. It was deliberately limited edition because we couldn’t make large sheets. And the challenge in manufacturing that that product was outside of our knowledge when we started. The way it’s’ constructed and the thinness of d30 that we needed to get to was a real production challenge. It was a great result but in practice it was a lot of work to make it functional.


What’s the next frontier?

We understand blunt trauma in terms of receiving a blow to the body or how we might participate in a hard shell helmet for the military. But we don’t really understand our benefits in ballistic and blast protection. We’re hoping we can secure a contract to research that. We found that our material seems to work better and better the faster you try to move it. So once you get to ballistic type speeds you might be gaining a greater benefit that even with blunt trauma.




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 Post subject: IBM Scientists Harness DNA Self-Assembly to Build Faster, Cheaper Chips
PostPosted: Wed Aug 19, 2009 10:04 pm 
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The next generation of semiconductor technology could take a page from nature’s book, letting DNA do the heavy lifting. Straight-laced researchers at IBM, afraid of breaking Moore’s Law, have figured out a way to combine lithographic patterning and DNA self-assembly to create semiconductors that built themselves into chips that are smaller, more efficient and less expensive than anything made conventionally.


Building microcircuits on the face of a silicon chip is a very precise, and therefore costly, process, and finding ways to cram more and more circuits onto smaller and smaller chips has driven the cost of increasing computing power skyward. But IBM’s team, in conjunction with California Institute of Technology researchers, think they’ve figured out a way to coax DNA molecules into self-assembling the necessary nano-structures to pack increased power onto less silicon, without the use of an army of costly machines.


DNA origami—in which a long strand of DNA is folded using shorter “staple” strands—is difficult to control, usually occurring in solution and bending to its own whims rather than into the highly ordered patterns needed to build circuitry at the nano level. Using electron-beam lithography, the researchers created special binding sites on silicon and other chip-making materials. These binding sites are patterned in a way that is conducive to micro-circuitry, creating a lattice on which the DNA molecules self-assemble in a pre-determined way. The DNA nano-structures in turn serve as a scaffold upon which other nano-structures—carbon nanotubes, nanowires, etc.—can be built at scales significantly smaller than those achievable with conventional machining methods.


If researchers can scale the technology to mass-produce chips (they"re already making tiny nanocar parts), they’ll be able to churn out more computing power far more cheaply than they can now. That’s the spot-on definition of “more bang for your buck,” and it just might open up a new era in computing. Don’t throw out your old desktop just yet though; the team still needs several years to refine the process and scale the technology for mass production.


[Nature [Paid] via PhysOrg, FT]




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 Post subject: New Disappearing Nanoparticle Ink Keeps Messages Cryptic
PostPosted: Fri Aug 28, 2009 7:42 am 
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Remember when, as a kid, you would pen secret messages with disappearing ink by writing on paper with lemon juice? A team of researchers at Northwestern have taken the idea just a little bit further, engineering a nanoparticle ink that fades away at a predetermined time, keeping maps or messages away from spying eyes.


The scientists used gold and silver nanoparticles -- just 5 nanometers wide -- embedded in a thin organic gel film to create the disappearing medium. Each nanoparticle is covered in molecules that change shape and attract each other in the presence of ultraviolet light. Using an ultraviolet pen or a patterned mask to apply light to the surface causes the molecules struck by UV to cluster and change color, allowing a message or image to be penned on the medium. The more light, the stronger the colors, as the particles bond more tightly. In the absence of light, the particles fall apart, erasing the image/message. How quickly they fall apart depends on how many of the glue-like molecules are coating each nanoparticle, so scientists can precisely control how long it will take an image to fade completely.


Due to this unique chemistry, the paper can be engineered to self-erase in a few hours or a few days. If exposed to very bright light or heat, it can be erased immediately, and once erased, there is no way to retrieve the lost message, making the medium ideal for sensitive correspondence. Moreover, because of its sensitivity to bright light, it can"t be placed on a copier. Unlike previous attempts at self-erasing paper, it can be erased and rewritten on hundreds of times without losing quality, and it"s also flexible, so it can be bent, twisted, or rolled up.


Though its Cold War applications are apparent, the creators of the paper also envision self-expiring bus and train tickets. Security firms might also be interested in incorporating the technology into anti-forgery measures for everything from security badges to financial documents. A UK-based firm has already voiced an interest in the tech.


[MIT Technology Review]




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 Post subject: Air-Driven Microprocessor Runs on Hand-Pumped Power
PostPosted: Sat Sep 05, 2009 12:55 am 
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Scientists at the University of Michigan have created an air-powered microprocessor that is able to function without an electrical power source. It runs with just pneumatic valves and a handpump that pushes air through the system. The end result is a CPU that could eventually be used in a lab-on-a-chip device aimed at developing countries where electricity is scarce.


Minsoung Rhee and Mark Burns created the chip, which reads binary 0s and 1s as air goes in and out of the valves. The valves are controlled by changing the air pressure in a chamber below the flowing air, which closes the valve when full. Using this system, the researchers managed to create an 8-bit system of flip-flops, logic gates, and shift registers that is more mechanical than electronic.



And because pneumatic valves are already used by the same team"s microfluidic systems on a chip, implementing the technology shouldn"t come at a great extra cost.


[via New Scientist]




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 Post subject: UCSB Scientists Create Cancer-Stopping Nanoparticle-and-Laser Treatment
PostPosted: Sat Sep 12, 2009 10:37 am 
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Nanotechnology, lasers, genetics, and cancer? If there was also something about space, this story might have been a PopSci full house. Scientists at the University of California, Santa Barbara (UCSB), have figured out a way to deliver cancer-stopping RNA directly into the nucleus of a diseased cell. To get into the nucleus, the RNA is wrapped in special gold nanoshells which are then selectively opened by a laser.


The UCSB scientists performed the experiment on cultured cancerous mouse cells. The cells took up the gold-wrapped RNA, which was then activated by the non-harmful laser. The RNA in the capsule was specially designed to silence the genes responsible for dividing the cancerous cells. With the division stopped, the cancer culture couldn"t spread, and would eventually die off.


By using a laser to activate the RNA, this technique allows for ultra-precise dosing and drug targeting. A whole group of cells can be giving the gold-coated drug, but with the laser, a doctor could ensure that only specially targeted cells actually receive the RNA.


This technique is still in the early stages, and the UCSB scientists freely admit that they don"t currently have a plan for expanding this method to larger targets like tissue samples or whole organisms. However, the major technical hurdle was the design of the gold nanocapsule, not the laser, so once they figure out how to utilize this technique on a larger scale, it could expand to include many other kinds of drugs.


[via Nanowerk]




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 Post subject: Nanotubes Could Enable Self-Repairing Electronic Circuits
PostPosted: Sat Sep 12, 2009 10:40 am 
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Researchers develop nanotubes that can help circuits repair critical breaks

Many people know the familiar wince when a cell phone or laptop hits the floor. But electronic devices of the future may self-repair tiny cracks or breaks in their circuitry with the help of nanotubes.


Researchers from the University of Illinois at Urbana-Champaign have created capsules that hold conductive nanotubes and can sit on circuit boards. Mechanical stress that causes a crack in the circuit would also split open some capsules and release the nanotubes to help bridge the gap.


Technology Review reports that outside experts praised the concept, which appeared last week in the Journal of Materials Chemistry.


The concept of self-repairing electric circuits could especially help submarines or satellites in situations when manual repair becomes impractical. Even lithium-ion batteries could benefit and avoid failures that could occasionally lead to explosive fires.


PopSci has previously examined self-healing materials, ranging from rubber to remixed concrete and paint. But self-repairing electronic devices could represent one of the best steps yet.


[via Technology Review]




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 Post subject: New Material Brings IBM"s Super-High-Density Memory Closer to Market
PostPosted: Fri Sep 18, 2009 11:02 am 
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Millipede MEMS storage could hold 1 terabyte of data per square inch

Even though computer memory has become cheaper and cheaper, the materials chemistry behind storage has not changed significantly in a long time. Now, thanks to a breakthrough by Korean scientists, that"s all about to change.


The scientists have created the first material that could allow millipede data storage, a super-dense form of memory that first debuted ten years ago but has not yet become practical. Millipede memory can store a terabyte of memory per square inch, but until now, it required extremely high temperatures to operate. Thanks to this new material though, chips the size of pencil erasers with more storage space than the largest iPod could soon find their way into watches, pencils, and really almost anything.


Millipede data works the same way as an analog record player, with a super-fine needle carving microscopic grooves into a material, and then running along those pits and grooves to read it. Previous millipede systems invented by IBM required an incredibly hot needle to do the burning, and the same amount of heat to reform the storage material for rewriting.


The breakthrough pioneered by scientists at Pohang University of Science and Technology in Kyungbuk, Korea, utilizes a special polymer called a baroplastic. Baroplastic polymers are usually hard, but they soften under pressure. In this system, pressure replaces heat in the reading and writing of the millipede storage chip, thus allowing the process to occur at room temperature.


However, this does introduce some new problems. The extreme pressure needed to convert the baroplastic polymer from its hard state to its soft state would put considerable wear and tear on the needle, and the need to constantly replace a microscopic needle detracts from the practicality of the system. Luckily, current research into multilayered materials that combines the baroplastic polymers with another material that"s easier on the needle offer a way around that problem.


The applications for millipede memory are obvious and vast. I, for one, look forward to finally getting an iPod that I can fit my entire music collection onto. And my entire movie collection. And my entire collection of...you know, never mind.


[via New Scientist]




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 Post subject: Making Powerful, Lightweight Batteries From Nothing But Nano
PostPosted: Tue Dec 08, 2009 8:21 pm 
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Making Powerful, Lightweight Batteries From Nothing But Nanotube Ink and Paper

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Reading the electronic-media narrative as it plays out in many popular tech and news blogs, one would think we are hurtling toward a future where paper is all but unnecessary. But a new development in battery technology could bring paper right back around to its former place of prominence, using it to power the very digital devices -- smartphones, Kindles, laptops, etc. -- that are increasingly replacing print.


By coating regular copier paper in ink made of carbon nanotubes and silver nanowires, Stanford researchers have created highly conductive storage devices that can be bent, folded, and wrapped around other surfaces (energy-storing wallpaper, anyone). The carbon nanotube ink adheres to the surface of the paper just like normal ink would, making paper the ideal vehicle for these thin, lightweight storage devices.


Since earlier research has shown that silicon nanowire batteries can be up to 10 times more powerful than lithium-ion batteries, researchers are hopeful the paper batteries will be able to power everything from automobiles to laptops to phones with smaller, lighter, more powerful and longer-lasting batteries. The method can also create simple supercapacitors with large surface areas that allow rapid energy discharge, a requirement for automobile power sources that lithium-ion batteries have trouble satisfying.


All of that would just be more pie-in-the-sky battery research if it were not for this: the paper battery technology is basically market-ready. That"s not to say that researchers won"t need some time to iron out the kinks, but power sources based on this technology could be commercialized very soon compared to a lot of the nano-noise circulating in scientific circles. The fact that the process is also very cheap means devices like these could be powering your paper-replacing devices sooner than you think. Get the details straight from Stanford"s Yi Cui below.



[PhysOrg, Forbes]




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