graphene
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New process for nanotube semiconductors could be graphene's ticket to primetime (video)
In many ways, graphene is one of technology's sickest jokes. The tantalizing promise of cheap to produce, efficient to run materials, that could turn the next page in gadget history has always remained frustratingly out of reach. Now, a new process for creating semiconductors grown on graphene could see the super material commercialized in the next five years. Developed at the Norwegian University of Science and Technology, the patented process "bombs" graphene with gallium, which forms droplets, and naturally arranges itself to match graphene's famous hexagonal pattern. Then, arsenic is added to the mix, which enters the droplets and crystallizes at the bottom, creating a stalk. After a few minutes of this process the droplets are raised by the desired height. The new process also does away with the need for a (relatively) thick substrate to grow the nanowire on, making it cheaper, more flexible and transparent. The inventors state that this could be used in flexible and efficient solar cells and light emitting diodes. We say forward the revolution.
Alt-week 8.18.12: Graphene sponges, zero-g athletics and tweets in space
Alt-week peels back the covers on some of the more curious sci-tech stories from the last seven days. We see a lot of crazy stories here at Engadget, especially when we spend our week poking around in dark and scary corners of the internet specifically in search of them, just so you don't have to. We consider it a service almost. One that we're delighted to provide, we must add. When else would we be able to share such delights as an astronaut triathlete, soft, color-changing robots and a recent response to a thirty-year-old alien broadcast? Exactly. This is alt-week.
Graphene heals itself, powers our dreams and nightmares
Slowly, but surely graphene is pushing our technological hopes, dreams and, yes, nightmares towards reality. The stuff is capable of extending battery life, generating electricity, powering high-speed data connections and super computer-worthy CPUs. It's water proof, stretchy, bendy and apparently self healing. (This space reserved for T-1000 reference.) Researchers at the University of Manchester discovered that, if you put a hole in a sheet of graphene, it simply stitches itself back together. This is thanks to carbon's tendency to latch on to other atoms, including its own, which can make the futuristic material difficult to work with, but gives it this highly unique quality. Thankfully, we're no where near self-healing robots. But, the discovery could lead to a simple method for molding it into almost any shape. Once pierced, the form of the mend is determined by the type of molecules introduced -- pure carbon simply regrows the perfect honeycomb structure, while a few foreign atoms can lead to "defects." Of course, if they're intentional and predictable, defects merely become "features." For more check out the source link.
Scientists use bilayer graphene to develop extra-sensitive photodetector
By now it goes without saying that graphene is something of a darling in the research community, with scientists using the material to develop transistors, batteries and circuits, among other devices. In 2011, MIT researchers discovered graphene's effectiveness as a photodetector, and a team at the University of Maryland has taken that line of thought a few steps further. By using bilayer graphene (two atoms thick instead of one atom thick), the scientists developed a temperature-sensitive device more than 1,000 times faster than existing technologies. Not to mention, it's capable of recognizing a very broad range of light energies, which means it could be useful in everything from biochemical weapons detection to airport body scanners. Still, the UMD researchers have their work cut out for them: the graphene photodetector has a high electrical resistance, and it will require tweaks to absorb enough light to be useful. Still, this is graphene we're talking about -- and we don't expect its popularity to wane any time soon.
Samsung pushes graphene one step closer to silicon supremacy
Graphene has long-held notions of grandeur over its current silicon overlord, but a few practical issues have always kept its takeover bid grounded. Samsung, however, thinks it's cracked at least one of those -- graphene's inability to switch off current. Previous attempts to use graphene as a transistor have involved converting it to a semi-conductor, but this also reduces its electron mobility, negating much of the benefit. Samsung's Advanced Institute of Technology has created a graphene-silicon "Schottky barrier" that brings graphene this much-needed current-killing ability, without losing its electron-shuffling potential. The research also explored potential logic device applications based on the same technology. So, does this mean we'll finally get our flea-sized super computer implant? Maybe, not just yet, but the wheels have certainly been oiled.
New material brings semiconducting to the graphene party
Scientists at the University of Wisconsin-Milwaukee have cooked up a new graphene-based material that could provide a speed boost for all electronics. We've seen the carbon allotrope turn up in circuitry and transistors before, but the new chemical modification -- graphene monoxide -- is said to be easier to scale up, and most importantly is semiconducting, unlike the insulating or conducting forms that have preceded it. This also means graphene can now provide the triad of electrical conductivity characteristics. The scientists were honest enough to admit the discovery was as much by chance as design, with it coming to light while investigating another material containing carbon nanotubes and tin oxide. We're sure they're not the first to make a discovery this way, we just haven't had time to check the notes to be sure of it.
NC State researcher finds more efficient way to cool devices, looks to cut costs too
Does your electronic device have you a bit hot under the collar these days? A researcher at NC State has developed a faster and less expensive method for cooling gadgets -- especially those that tend to crank the heat up. Dr. Jag Kasichainula, an Associate Professor of Materials Science and Engineering, authored a paper on the research that implements a "heat spreader' composed of a copper-graphene composite and an indium-graphene interface film to cool devices. Because the two materials exhibit a high thermal conductivity, they allow the device to cool more efficiently while distributing said heat -- 25 percent quicker than the pure copper in many pieces of tech. And if that wasn't enough, the research also details the process for creating the composite using electrochemical deposition. "Copper is expensive, so replacing some of the copper with graphene actually lowers the overall cost.," Kasichainula notes. If you're itching to read a full rundown of the findings, the full text can be accessed via the source link below.
Nokia Morph patent application raises hope well beyond expectation
Remember Nokia Morph? It's the Finnish manufacturer's long-standing project to build a transparent, flexible phone that you can contort to your hearts content. Now the company's submitting a second missive to the Patent and Trademark office in the hope of claiming dibs on the IP contained therein. While it's very broadly written (and doesn't commit to anything), it's interesting to note that the phone would switch between the leaf-shaped candybar (we played with it at MWC) and a wristband you can wear on the go. The patent also talks about a "remote processing unit," in a nearby device or in the cloud, so, if the company can ever turn the dream into reality, the real action will be handled elsewhere. Then again, it's equally as likely to never appear in our lifetimes, you just never can tell with patents.
Cambridge researchers translate graphene into printable circuitry material, bring basic 'Skynet' factory to you
Yes, graphene is amazing and possesses many useful / otherworldly properties. The ability to use graphene itself to print flexible, transparent thin-film transistors via an inkjet printer is just another one of them. Over at the University of Cambridge, researchers have discovered that it's possible to print standard CMOS transistors using a graphene component. Provided the graphene is chipped off a block of graphite using a chemical solvent and the larger (potentially print-head blocking) chips are removed, it can be turned into a polymer ink which can then run through a conventional inkjet printer. The potential result of this is flexible, transparent and wearable computer circuitry coming from ordinary printers as opposed to several multi-million-dollar machines in a factory, which has long been the historical standard. Besides, who wouldn't want to print their own circuitry on a PhotoSmart MFP rather than whatever report might be due the next day?
Researchers increase charging capacity, speed of lithium ion batteries by a factor of ten
It's not every day that we get to write about advancements in battery technology -- much less one as potentially groundbreaking as what a group of engineers at Northwestern University claim to have pulled off. In fact, Professor Harold Kung and his team say they've successfully managed to increase both the charging capacity and speed of lithium ion batteries by a factor of ten. The key, according to Kung, is the movement of the lithium ions nestled between layers of graphene. The speed at which these ions move across a battery's graphene sheets is directly related to how fast a device can recharge. To speed up this process, Kung decided to poke millions of tiny, 10-20nm-sized holes into a mobile battery's graphene layers, thereby providing the ions with a "shortcut" to the next level. As a result, Kung's perforated batteries were able to charge ten times faster than traditional cells, going from zero to hero in 15 minutes. Not satisfied with that achievement alone, Kung and his squad then set about increasing their battery's charging capacity, as well. Here, they increased the density of lithium ions by inserting small clusters of silicon between each graphene slice. This approach allows more ions to gather at the electrode and, by taking advantage of graphene's malleable properties, avoids some of the silicon expansion problems that have plagued previous attempts at capacity enhancement. The result? A battery that can run on a single charge for more than a week. "Now we almost have the best of both worlds," Kung said. "We have much higher energy density because of the silicon, and the sandwiching reduces the capacity loss caused by the silicon expanding and contracting. Even if the silicon clusters break up, the silicon won't be lost." There is, however, a downside, as both charging capacity and speed sharply fell off after 150 charges. But as Kung points out, the increase in charge retention would more than make up for this shortcoming. "Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today," he told the BBC. For more technical details, hit up the links below.
Korean researchers create stretchy transistors made of graphene
Graphene's greatness comes from its flexibility, both figurative -- you can make everything from transparent speakers to stain resistant pants with the stuff -- and literal. And now researchers in Korea have given us another pliable graphene product by creating a stretchy transistor from the carbon allotrope. The trick was accomplished by first layering sheets of graphene on copper foil and bonding it all to a rubber substrate. To complete the transistor channels were etched onto its surface, then electrodes and gate insulators made of ion gel were printed onto the device. What resulted was a transistor that could stretch up to five percent without losing any electrical efficiency, and the plan is to increase its elasticity through continued research. Keep up the good work, fellas, we can't wait for our flexible phone future.
MIT researchers suggest graphene could be used to build a better camera sensor
As you may have noticed from the pace of research over the past few years, graphene is promising to make a whole lot of things a whole lot better. Now, it seems, you can also add camera sensors to the list. A team of MIT researchers recently discovered that graphene can serve as a photodetector over a "very wide energy range," and that it works particularly well in infrared light, where other types of detectors often come up short. That, the researchers say, could open to the door to everything from better nightvision systems to more advanced detectors for astronomical telescopes -- not to mention more inexpensive camera sensors in general, since graphene is cheap to work with. What's more, the researchers also suggest that those same light-detecting abilities could make graphene a good material for collecting solar energy, although they note that there's still much more research needed to determine if it's truly an efficient means of generating energy.
Dipping capacitors and batteries in nanotubes could improve capacity
Stanford researchers figured out that, by dipping electrodes for super capacitors in a solution of carbon nanotubes or a conductive polymer they could increase the charging capacity by up to 45-percent. The team started working with composite electrodes of graphene and manganese oxide, since manganese is cheap and plentiful, but were hamstrung by its low conductivity. The thin coating of more conductive material greatly boosted the capacitance of the electrodes, and thus their ability to hold a charge. Further tests are still required to find the actual energy density of the dipped electrodes, but lead researchers Yi Cui and Zhenan Bao are already working on a way to apply the same technique to batteries.
Rice University chemists bake graphene out of Girl Scout cookies, redefine low-carb diets (video)
Would you like some cookies? Well, you're gonna have to buy them, and then get thee to a Rice University chem lab, stat! The Texas institution of higher learning recently played host to Girl Scouts Troop Beverly Hills 25080, turning their om nom carbohydrated delights into billion dollar graphene. Resident scientist James Tour gathered his gaggle of grad students for a hands-on demo, walking the future Phyllis Neflers through the transformative steps that convert carbon-based material (see: a box of Samoas), into $15 billion worth of scientific loot -- or as one astute troopster put it, "... a lot of cash." Indeed it is young lady, but something tells us your well-earned Science in Action badge won't go too well with those cookie-bought Louboutins. Skip past the break for the full video and a little "Cookie Time" nostalgia.
Researchers use graphene and tin sandwich to make better battery electrodes
Graphene, that microscopic chicken wire made of carbon atoms, has a great many theoretical uses. Among these is to improve Lithium-ion battery technologies, and the big brains at the Lawrence Berkeley National Laboratory have created a graphene and tin composite material for use in battery electrodes. When it's baked at 572 degrees Fahrenheit (300 degrees Celsius) the tin turns into nanopillars that widen the gap between the graphene layers. The greater volume of tin provided by these tiny towers improves electrode performance (read: faster charging), and the flexibility of the graphene prevents electrode degradation. Naturally, current prototypes can only maintain capacity over 30 charge cycles -- as opposed to the hundreds required for commercial applications -- so some serious improvement has to happen before we see it strut its stuff in any phones or EVs. This leaves us, once again, extolling the virtues of graphene, but lamenting its exclusively academic application.
Researchers use graphene to draw energy from flowing water, self-powered micro-robots to follow?
What can't graphene do? The wonder material's been at the heart of a stunning number of technological breakthroughs of late, and now it's adding oil exploration to its long list of achievements. A team of researchers at Rensselaer Polytechnic Institute have discovered that the flow of good old H2O over a sheet of graphene can generate enough electricity to power "tiny sensors" used in tracking down oil deposits. The gang, led by professor Nikhil Koratkar, was able to suck 85 nanowatts of power out of a slab of graphene measuring .03 by .015 millimeters. The little sensors the researchers speak of are pumped into potential oil wells via a stream of water, and are then put to work sniffing out hydrocarbons indicative of hidden pockets of oil and natural gas. Of course, that doesn't have a whole lot of practical application for your average gadget consumer, but Koraktar sees a future filled with tiny water-powered robots and micro-submarines -- we can dig it.
Transparent graphene speakers printed with inkjets, lo-fi musical windows are on their way
Add that magical material known as graphene to the list of things you can make with inkjet printers alongside OLEDs, solar panels, and light-bending metamaterials. Scientists at the Seoul National University used printers and a technique known as vapor deposition to leave a thin film of the graphite-based conductor on sheets of PVDF (poly vinylidene fluoride). By sandwiching the the PVDF between graphene electrodes and applying a current from a sound source researchers were able to create a flat and transparent loudspeaker that could be integrated into windows or screens. Don't expect this low-power sound source to replace your hi-fi though -- since it relies on the distortion-prone piezoelectric effect, it probably won't sound much better than the earpiece on your cellphone.
Dry ice makes graphene cheaper, greener, and by the (relative) boatload
Dry ice isn't just great for keeping steaks cold and filling your bathtub with fog, it may also play a major role in producing the miracle metal material graphene. Researchers at Northern Illinois University have discovered that burning magnesium in frozen carbon dioxide produces a thin layer of the hyped-to-the-lattices carbon nanostructure. The so-called dry-ice method has several advantages over previous techniques, not the least of which is the ability to pump out the relative of pencil lead on a much larger scale. It also happens to be faster, cheaper, and more environmentally friendly compared with the lengthy processes involving hazardous chemicals used in most graphene production. It's pretty great news but, honestly, all we want to know is when the stuff is going to start powering super-fast internet connections -- that complete Flying Circus collection isn't going to download itself.
IBM outs integrated circuit that's made from wafer-size graphene, smaller than a grain of salt
Lest you don't care what your circuits are made of, listen up: graphene's the thinnest electrical material, comprising just a single atomic layer. In addition to its electrical, thermal, mechanical, and optical properties, researchers dig it because it has the potential to be less expensive, more energy-efficient, and more compact than your garden-variety silicon. So imagine IBM's delight when a team of company researchers built the first circuit that fits all the components, including inductors and a graphene transistor, on a single wafer -- a setup that consumes less space than a grain of salt. The advantage, scientists say, is better performance than what you'd get from a circuit combining a graphene transistor with external components. In fact, the researchers got the circuit's broadband frequency mixer to operate at 10GHz , a feat that could have implications for wireless gadgets running the gamut from Bluetooth headsets to RFID tags. That's all just a layman's explanation, of course -- check out the latest issue of Science for the full paper in all of its technical glory.
Graphene-powered web could download 3-D movies in seconds, give MPAA nightmares
Graphene, is there anything it can't do? Researchers are already trying to put it in processors, fuel cells, and batteries -- now your internet connection might get ten-times faster thanks to the silicon successor. Researchers at UC Berkeley have created tiny, one-atom-thick modulators that could switch the data-carrying light on and off in a fiber-optic connection much faster than current technology. In addition to running at a higher frequency (the team believes it will scale up to 500GHz -- modern modulators run at about 1GHz) the smaller, 25-micron size means thinner cables could be used, reducing capacitance and further boosting speeds. Labs have already crossed the 100 terabit threshold and graphene could push that even higher, yet we're still stuck staring at a buffering screen every time we try to Netflix Degrassi.
