20 most recent innovations in nanotechnology

New 'Smart' Material Can De-Ice Any Surface

Mon, 14 Nov 2016 00:00:00 Z

Researchers have discovered a 'smart' material that can be applied to any surface to repel ice and outperforms all others currently in use.

Icy conditions can be deadly, whether you are flying into bad weather or too close to power transmission lines during a storm, researchers said.

One side of the surface of the material known as a magnetic slippery surface (MAGSS) is coated with a magnetic material, while a thin layer of magnetic fluid - a mixture of fluid and iron oxide nanoparticles - is deposited on the other side. The magnetic fluid faces outside.

When a droplet of water hits the surface, the magnetic fluid acts as a barrier, stopping the droplet from reaching the solid surface.

Cheaper, Transparent Smart Skin Powers Itself

Mon, 18 Apr 2016 00:00:00 Z

Flexible, wearable sensors open the door for everything from more effective health monitoring to robots with a sense of touch that can respond to stimuli like humans. While numerous electronic skin technologies have been developed, getting costs down has remained a problem. A Chinese team of scientists has now developed a new transparent smart skin that they claim is not only cheaper to produce, but is also able to harvest mechanical energy to power itself from movement.

The researchers say that previous attempts to increase the sensitivity of electronic skins has generally meant a corresponding increase in the number of electrodes, thereby also making them more expensive. Some smart skins also need an external power source, which means more wires. Other technologies, such as the Paper Skin, have impressive capabilities, but their lack of transparency limits their potential for use in wearables.

Made of ultra-thin plastic films, the researchers' new skin achieves a touch resolution of 1.9 mm using just four silver-nanowire electrodes and an analog localizing technique. The system also includes a component which creates electric charge through friction in a similar fashion to the University of Wisconsin-Madison's nanogenerator car.

Energy is created through the triboelectric effect, harnessing the electrical charge created when certain materials come into contact with each other, like when you run a comb through your hair. The principle has been used to generate electricity in everything from clothing to touchscreens, and means the smart skin could harvest energy from the movement of prosthetic fingers without the need for external batteries.

The new smart skin's creators say it's sensitive enough to pinpoint the location and force of an interaction, and can even detect a bee flying toward or away from the surface. It is also electrically stable, with the smart skin subjected to over 30,000 cycles and maintaining the same level of output.

Ultimately, the team suggests their technology could move us a step closer to offering robots and prosthetics with a sense of touch at a reasonable price.

The team's study appears in the journal ACS Nano.

World's First "Porous Liquid"

Mon, 16 Nov 2015 00:00:00 Z

The Italians have a colorful expression – to make a hole in water – to describe an effort with no hope of succeeding. Researchers at Queen's University Belfast (QUB), however, have seemingly managed the impossible, creating a class of liquids that feature permanent holes at the molecular level. The properties of the new materials are still largely unknown, but what has been gleaned so far suggests they could be used for more convenient carbon capturing or as a molecular sieve to quickly separate different gases.

Porous materials are a jack-of-all-trades of the engineering world. Their larger surface area, lighter weight and filtering abilities are used to create high-performance batteries and supercapacitors, build lighweight supermaterials, or filter out CO2 before it leaves factory smokestacks.

When it comes to carbon sequestration in particular, scientists have already come up with plenty of readily available materials – including clay and coffee grounds – to do the job. But while effective and inexpensive, such solid-state materials are not easily retrofitted to existing plants.

Researchers Stuart James and team have now demonstrated a class of liquids that is permanently hollow at the molecular level and could be employed for more convenient carbon capturing or to manipulate gases in new and more effective ways.

To create a porous liquid, the scientists simply designed hollow cage molecules to place in a solvent. The solvent is chosen so its molecules are too big to enter the cages, leaving those spaces available for an external gas to fill. The resulting concentration of empty cages is about 500 times greater than in similar solutions.

The solvent picked for the study was the crown ether 15-crown-5, and the cages were designed to fit the molecules of carbon dioxide, methane, nitrogen and xenon. After testing, the scientists reported that their porous liquid was able to store eight times the amount of methane gas as bare crown ether.

Such a figure is remarkably high for a liquid, and opens the possibility to employ these materials for carbon sequestration. Porous solids are often more effective at collecting carbon in absolute terms, but a system based on liquids would likely be easier to retrofit.

Porous liquids could also be used as an effective gas separator. Even when gas molecules saturate the liquid, they can be quickly displaced by other organic molecules whose size is a better fit for the cages. For instance, even as xenon gas is saturating the solution, a small amount of chloroform will suddenly cause the gas to be released.

James and team are now at work to further study these liquids and find how their properties can be used for practical applications. A paper describing the advance was published in the latest issue of the journal Nature.

Nanoparticles Heal Wounds 50 Percent Faster

Mon, 30 Mar 2015 00:00:00 Z

An experimental nanoparticle therapy cuts in half the time wounds take to heal compared to natural healing. The therapy has already been tested successfully in mice and will soon be tried on pigs, whose skin is similar to that of humans. If it reaches clinical use in humans, this sort of nanoparticle therapy could be used to speed healing of surgical incisions, chronic skin ulcers, and everyday cuts and burns and other wounds.

Researchers have found that an enzyme called fidgetin-like 2 (FL2) slows the rate at which skin cells migrate to wounds to heal them. If this enzyme is suppressed, skin cells move faster. Molecules of silencing RNA (siRNA) that bind to a gene's messenger RNA (mRNA) have been used to inhibit the development of FL2, but this alone won't be effective, the researchers note, unless the siRNAs are placed in some kind of delivery vehicle that can protect them from degradation.

For this purpose a research team at the Albert Einstein College of Medicine of Yeshiva University has developed nanoparticles that ferry the molecules safely to their intended targets, with impressive results in mice with skin excisions or burns.

"Not only did the cells move into the wounds faster, but they knew what to do when they got there," said co-lead researcher David Sharp. "We saw normal, well-orchestrated regeneration of tissue, including hair follicles and the skin's supportive collagen network."

The technique has been patented and licensed to a company called MicroCures, Inc., where David Sharp is currently acting as a chief scientific officer.

A paper describing the research was published in the Journal of Investigative Dermatology.

Boil Water Three Times Faster

Mon, 30 Mar 2015 00:00:00 Z

Scientists have found a way to boil water faster, although they admit the discovery is unlikely to revolutionise tea-making.

The technology works by coating a heating element with a virus found on tobacco plants. The coating dramatically reduces the size and number of bubbles that form around the element as it gets warmer. Air pockets caused by bubbles temporarily insulate heating elements from the surrounding water, slowing down the transfer of heat.

A coating made from the tobacco virus tripled the efficiency of boiling water, scientists said, which could save vast quantities of energy in industrial power plants or large-scale electronic cooling systems.

“Even slight improvements to technologies that are used so widely can be quite impactful,” said Matthew McCarthy, an engineer at Drexel University in Pennsylvania.

Controlling the formation of bubbles would also help guard against a scenario called “critical heat flux” that is undesirable – sometimes disastrous – in industrial boilers. This happens when so many bubbles are forming that they merge into a blanket surrounding the element, meaning that it can no longer transfer heat to the water.

“What happens then is the dry surface gets hotter and hotter, like a pan on the stove without water in it,” said McCarthy. “This failure can lead to the simple destruction of electronic components, or in power plant cooling applications, the catastrophic meltdown of a nuclear reactor.”

To counteract this effect, scientists have been attempting to develop surfaces that repel bubbles and keep the boiling surface wet. McCarthy’s team has identified tobacco mosaic virus, which is roughly pencil-shaped, as the perfect structure for wicking moisture downwards towards a surface.

The team has developed a genetically modified strain of the virus, with “molecular hooks” allowing it to adhere to nearly any surface. The researchers grow tobacco plants in the lab and infect them with the modified tobacco mosaic virus. “When the plants are really sick, we put them in the blender and you get a sort of green soup,” said McCarthy.

After several rounds of centrifuging and chemical separation, which takes two days, the scientists are left with a perfectly clear solution of concentrated virus. When poured over a surface, the virus self-assembles into a layer of nano-tendrils, each pointing upward like a blade of grass.

The surface is then covered with a microscopically thin layer of nickel, rendering the virus inert. The remaining “metallic grass” wicks liquids across the surface, allowing the water and element to remain in contact.

In tests, the coating has been shown to more than triple the heat transfer rate, depending on the surface to which it is applied.

The “metallic grass” coating resulted in the boiling process occurring three times more efficiently. So if two pots of water – one with the tobacco coating, one without – were heated to the same temperature, the coated pot would produce twice as much water vapour.

In a system designed to cool down a silicon electronic part, the coating almost tripled the temperature that the silicon could reach before critical heat flux occurred.

“In the future this could be used in nuclear power stations, really kick-ass computers or for the liquid cooling of high-powered electronic devices like radar systems,” said McCarthy.

Coating Coloring Technique

Wed, 24 Dec 2014 00:00:00 Z

Most people probably don't think of a coating of paint as being a particularly major component of a manufactured item. If the object is quite large, however, or if a lot of them are being made, paint can add considerably to its weight and/or production costs. With that in mind, researchers from Harvard University's Laboratory for Integrated Science and Engineering have created a new lightweight, low-cost coloring technology for both rough and smooth surfaces.

Developed by PhD student Mikhail Kats and his advisor Prof. Federico Capasso, the process involves using a machine known as an electron-beam evaporator to vaporize pieces of metal, by striking them with a stream of electrons. The vapor travels upwards through a vacuum chamber within the evaporator, and collects on the surface of a metallic item placed at the top (if the item isn't metallic, an initial base layer of vaporized metal vapor can first be applied). By repeating this process, multiple layers can be deposited on the item.

What results is an ultra-thin coating. Due to the nature in which that coating scatters reflected light, it appears to the human eye as a given color – exactly which color depends upon the metals used, and the ratios in which they're applied.

In a test of the technology, Kats coated a piece of paper with a film made up of gold and germanium. While a previous study had shown that the technique worked on smooth surfaces, this was the first time that it had been successfully applied to a rough surface.

The paper remained flexible, even after the coating was applied. Although the color appeared basically the same when viewed from different angles, the "hills and valleys" within its microstructure added some subtle variation to the light-scattering process. This caused it to have a somewhat pearlescent appearance, which could be desirable in many applications. Using a different application technique, however, the color could be made to appear completely uniform from any angle.

Although gold is an expensive metal, very little of it was required. Additionally, a number of other metals can be used, including not only germanium but also aluminum. "This is a way of coloring something with a very thin layer of material, so in principle, if it's a metal to begin with, you can just use 10 nanometers to color it, and if it's not, you can deposit a metal that's 30 nm thick and then another 10 nm," said Kats. "That's a lot thinner than a conventional paint coating that might be between a micron and 10 microns thick."

According to the university, the technology could be used to color virtually any material, including those that are rough or flexible. Additionally, because the coatings absorb a lot of light, they could find their way into optoelectronic devices such as photodetectors and solar cells.

Spider-Inspired Discs Could Be The New Glue

Thu, 22 May 2014 00:00:00 Z

Researchers from the University of Akron have recently created their own version of the "attachment discs" that spiders use to secure their silk fibers to surfaces, when building webs. These man-made discs could conceivably prove superior to conventional glues as a form of adhesive.

When spiders want to join a silk fiber to a surface, they don't simply press the end of that one fiber to the surface and hope that it holds. Instead, they pin it down by depositing an array of finer fibers that criss-cross over top of it – sort of like the staked-down ropes that the Lilliputians used to hold down Gulliver, in Gulliver's Travels. That jumble of fibers is known as a pyriform attachment disc.

Led by Prof. Ali Dhinojwala, the U Akron team created artificial versions of these discs, using electrospun polyurethane fibers. These were used to effectively hold underlying nylon threads to surfaces.

It is now hoped that such discs could one day serve as a type of inexpensive biomedical adhesive, perhaps being used to bind fractures or bond ligaments onto bone. They might also simply become a stronger alternative to conventional glue and tape.

The Drinkable Book Provides Safe Drinking Water

Wed, 14 May 2014 00:00:00 Z

One of the biggest problems in the developing world is access to safe, reliable drinking water. The charity organisation Water is Life dedicates its energies to providing this most basic of necessities. Its latest project seeks to combine education with actual resources.

Called The Drinkable Book, it combines a variety of technologies to achieve this goal. On each of its tear-out pages, water safety tips are written in various languages -- the first print run, intended for Kenya, is printed in English and Swahili -- in food-grade ink, providing much-needed information to people in areas where access to education about such matters may be low.

Each book comes packaged in a 3D printed box, which converts into a filtration tray. When you tear out one of the pages and slip it into the tray, you can use it to filter water.

Each page is impregnated with silver nanoparticles (which gives the paper its distinctive orange colouring). The nanoparticles don't quite work like a traditional filter. Rather than providing a barrier, they actually kill the bacteria as they pass through the paper. As the water runs through, the bacteria absorb the silver ions, which kill the bacteria. The paper kills over 99.9 percent of harmful bacteria, which puts the resulting water on a par with tap water in the US. It has proven effective at destroying bacteria that cause diseases such as cholera, E.coli and typhoid.

Memory Crystals That Can Store Data Virtually Forever

Tue, 06 May 2014 00:00:00 Z

While most of us are just getting used to the idea of 3D printing, scientists are already working on technological marvels that operate two dimensions deeper. Researchers at the University of Southampton have succeeded in recording and retrieving five dimensional digital data using a quartz crystal. The ‘Superman’ memory crystal is a futuristic storage technique with unprecedented features – including a 360 terabyte per disc data capacity, thermal stability up to 1000°C and a practically unlimited lifetime.

We’ve all seen those sci-fi movies where a gorgeous alien shoves a pointy crystal into some mega computer and the world is saved. Well, it appears that sci-fi has now become sci-reality. Although it probably won’t save the human world, the researchers working on the ‘Superman’ memory crystal say it will most definitely stick around to share a record of our race with whatever beings excavate the remains of our civilization.

So how does it work? “…the data is recorded via self-assembled nanostructures created in fused quartz, which is able to store vast quantities of data for over a million years,” explains a press release. “The information encoding is realised in five dimensions: the size and orientation in addition to the three dimensional position of these nanostructures.” That sounds complicated, but what it basically means is that, using ultrafast lasers, we can now encode a piece of quartz with 5D information in the form of nanostructured dots separated by only one millionth of a meter.

“The self-assembled nanostructures change the way light travels through glass, modifying polarization of light that can then be read by combination of optical microscope and a polarizer, similar to that found in Polaroid sunglasses,” states the release.

So leave a note for your great-great-grandkids to throw on some 5D glasses, and upload that file containing your life story to their cyborg brain by scanning it with their polarizing eyeballs – easy-peasy.

“It is thrilling to think that we have created the first document which will likely survive the human race,” said Professor Peter Kazansky a supervising researcher on the project. “This technology can secure the last evidence of civilisation: all we’ve learnt will not be forgotten.” The team is now looking for industry partners to commercialize this ground-breaking new technology.

Bio-Organic Battery That Recharges In 30 Seconds

Tue, 08 Apr 2014 00:00:00 Z

As we all know only too well, recharging our portable electronics can take a painfully long time. This is because reversing the chemical reactions that caused the battery to deplete is a process that can hardly be rushed, for considerations of both safety and energy efficiency.

But now, a radically new battery design advanced by StoreDot could bring charge times down to the order of a few seconds. The company produces so-called nanodots, chemically synthesized bio-organic peptide molecules that, thanks to their small size, improve electrode capacitance and electrolyte performance. The end result is batteries that can be fully charged in seconds rather than hours.

'In essence, we have developed a new generation of electrodes with new materials – we call it MFE – Multi Function Electrode," StoreDot CEO Doron Myersdorf told Gizmag. "On one side it acts like a supercapacitor (with very fast charging), and on the other is like a lithium electrode (with slow discharge). The electrolyte is modified with our nanodots in order to make the multifunction electrode more effective."

The company says that unlike other nanodot and quantum-dot technologies that are heavy metal based, making them toxic, its nanodots are made from a vast range of bio-organic raw materials that are environmentally-friendly. These materials are also naturally abundant, and the nanodots employ a basic biological mechanism of self-assembly, making them cheap to manufacture.

Self-discharge characteristics are similar to those of lithium-ion cells and, for its first prototype, the company targeted the approximate capacity of a smartphone battery (around 2,000 mAh).

But Myersdorf told us that the technology could also be adapted to electric cars, by modifying the electrode so it could sustain higher currents (and, of course, configuring a large number of cells in parallel).

Charge Your Phone Using Vibrations From Your Car

Mon, 03 Mar 2014 00:00:00 Z

While it's already possible to wirelessly recharge smartphones in cars, those cars need to be equipped with a special charging pad that the phone has to be placed on. Thanks to a newly-developed "nanogenerator," however, it might eventually be possible to place the phone anywhere in any car, letting the vehicle's vibrations provide the power.

Developed by a team of scientists from the University of Wisconsin-Madison, the University of Minnesota Duluth, and China's Sun Yat-Sen University, the nanogenerator could be incorporated directly into a phone's housing.

It's made from a piezoelectric polymer known as polyvinylidene fluoride, or PVDF. Like other piezoelectric materials, PVDF generates electricity when subjected to mechanical strain.

The scientists deposited nanoparticles of zinc oxide into a thin film of the polymer, but then etched those particles out again, leaving tiny interconnected pores where they had been. The presence of those pores caused the ordinarily rigid PVDF to take on a sponge-like consistency, allowing it to flex and thus generate electricity when subjected to even slight vibrations – having the weight of a phone pressing down on it would amplify the effect.

That film is sandwiched between two electrode sheets, the whole multilayer nanogenerator still remaining quite thin and flexible. Because of this quality, it could conceivably conform not just to the flat, rigid housings of phones or other devices, but also to a variety of irregular surfaces including human skin.

"Most Waterproof Material Ever" Is Inspired By Nature

Tue, 03 Dec 2013 00:00:00 Z

A team at MIT has what it says is the most waterproof material ever, taking inspiration from the plant and insect world. The scientist heading up the research, Professor Kripa Varanasi--he brought us LiquiGlide, squeezing every last drop out of our ketchup bottles last year--says this new super-hydrophobic surface could be used in next-generational waterproof clothing, and revolutionize the energy and travel industries. Airplane engines, for example, could use the material to fly planes through extremely cold conditions.

Tiny ridges similar to those found on both nasturtium leaves and the wings of the Morpho butterfly were added to a silicon surface, which made the water droplets bounce off up to 40% faster than existing waterproof substances. The more intersecting ridges you have, the more the droplets of water break up. Smaller droplets mean less water on the surface, making it more waterproof. "I'm looking forward to working with the fabrics industry to develop new clothing that stays dry longer," said Professor Varanasi.

Flexible silicon for flexible electronics

Tue, 08 Oct 2013 00:00:00 Z

Imagine a smartphone you can roll up and slip into your shirt pocket. Or a tablet that can be folded like a newspaper and slipped in your back pocket. It's an idea that's been tossed around in science fiction for a years, but now it's a small step closer to reality because researchers at Sun Yat-sen University in Guangzhou, China have developed the world's first flexible silicon.

The crystal structure that makes silicon a widely used semiconductor also means it's very brittle and resists bending. So while we're slowly seeing the advent of flexible displays, they're always attached to a controller filled with chips and microprocessors that don't bend along with it.

But the breakthrough at Sun Yat-sen University—which involved vaporizing silicon monoxide powder and then cooling it until the particles collected into paper-like interwoven nanowires—means that almost every component in a device could be made flexible one day. Of course, that 'one day' is years and years away while the researchers work to create larger and more usable sheets of this new material.

Graphene Supercapacitors

Fri, 22 Mar 2013 00:00:00 Z

Sheet of laser-scribed graphene micro-supercapacitors (credit: UCLA)

UCLA researchers have developed a groundbreaking technique that uses a DVD burner to fabricate miniature graphene-based supercapacitors — devices that can charge and discharge a hundred to a thousand times faster than standard batteries. nThese micro-supercapacitors, made from a one-atom–thick layer of carbon, can be easily manufactured and readily integrated into small devices, such as next-generation pacemakers.

The new cost-effective fabrication method holds promise for the mass production of these supercapacitors, which have the potential to transform electronics and other fields.

“The integration of energy-storage units with electronic circuits is challenging and often limits the miniaturization of the entire system,” said Richard Kaner, a member of the California NanoSystems Institute at UCLA, a professor of chemistry and biochemistry, materials science, and engineering at UCLA’s Henry Samueli School of Engineering and Applied Science. “This is because the necessary energy-storage components scale down poorly in size and are not well suited to the planar geometries of most integrated fabrication processes.”

Fabrication process for laser-scribed graphene micro-supercapacitors. (a) A grapene-based film supported on a sheet is placed on a DVD media disc. The disc is inserted into a LightScribe DVD drive and a computer-designed microcircuit is etched onto the film at precise locations to produce graphene circuits. (b) Copper tape is applied along the edges to improve the electrical contacts, and the interdigitated area is defined by polyimide (Kapton) tape. (c) An electrolyte overcoat is then added. Result is (d,e) a planar micro-supercapacitor. (Credit: UCLA)

“Traditional methods for the fabrication of micro-supercapacitors involve labor-intensive lithographic techniques that have proven difficult for building cost-effective devices, thus limiting their commercial application,” said Maher El-Kady, a graduate student in Kaner’s laboratory.

“Instead, we used a consumer-grade LightScribe DVD burner to produce graphene micro-supercapacitors over large areas at a fraction of the cost of traditional devices. Using this technique, we have been able to produce more than 100 micro-supercapacitors on a single disc in less than 30 minutes, using inexpensive materials.”

The process of miniaturization often relies on flattening technology, making devices thinner and more like a geometric plane that has only two dimensions. In developing their new micro-supercapacitor, Kaner and El-Kady used a two-dimensional sheet of carbon, known as graphene, which only has the thickness of a single atom in the third dimension.

Kaner and El-Kady took advantage of a new structural design during the fabrication. For any supercapacitor to be effective, two separated electrodes have to be positioned so that the available surface area between them is maximized. This allows the supercapacitor to store a greater charge.

In their new design, the researchers placed the electrodes side by side using an interdigitated pattern, akin to interwoven fingers. This helped to maximize the accessible surface area available for each of the two electrodes while also reducing the path over which ions in the electrolyte would need to diffuse. As a result, the new supercapacitors have more charge capacity and rate capability than their stacked counterparts.

The researchers found that by placing more electrodes per unit area, they boosted the micro-supercapacitor’s ability to store even more charge.

Could be made at home with DVD burner and graphite oxide in water

Kaner and El-Kady were able to fabricate these intricate supercapacitors using an affordable and scalable technique that they had developed earlier. They glued a layer of plastic onto the surface of a DVD and then coated the plastic with a layer of graphite oxide.

Then, they simply inserted the coated disc into a commercially available LightScribe optical drive — traditionally used to label DVDs — and took advantage of the drive’s own laser to create the interdigitated pattern. The laser scribing is so precise that none of the “interwoven fingers” touch each other, which would short-circuit the supercapacitor.

“The process is straightforward, cost-effective and can be done at home,” El-Kady said. “One only needs a DVD burner and graphite oxide dispersion in water, which is commercially available at a moderate cost.”

The new micro-supercapacitors are also highly bendable and twistable, making them potentially useful as energy-storage devices in flexible electronics like roll-up displays and TVs, e-paper, and even wearable electronics.

The micro-supercapacitors can also be fabricated directly on a chip using the same technique, making them highly useful for integration into micro-electromechanical systems (MEMS) or complementary metal-oxide-semiconductors (CMOS).

Laser-scribed graphene micro-supercapacitors (LSG-MSC) exhibit ultrahigh power and energy densities compared with a commercially available AC-SC, an aluminum electrolytic capacitor and a lithium thin-ï¬lm battery. LSG micro-devices can deliver ultrahigh power density comparable to those of an aluminum electrolytic capacitor, while providing three orders of magnitude higher energy density. (Credit: UCLA. Data is from Pech, D. et al. Ultrahigh-power micrometre-sized supercapacitors based on onion-like carbon. Nat. Nanotech. 5, 651–654 (2010).)

These micro-supercapacitors show excellent cycling stability, an important advantage over micro-batteries, which have shorter lifespans and which could pose a major problem when embedded in permanent structures — such as biomedical implants, active radio-frequency identification tags and embedded micro-sensors — for which no maintenance or replacement is possible.

As they can be directly integrated on-chip, these micro-supercapacitors may help to better extract energy from solar, mechanical and thermal sources and thus make more efficient self-powered systems. They could also be fabricated on the backside of solar cells in both portable devices and rooftop installations to store power generated during the day for use after sundown, helping to provide electricity around the clock when connection to the grid is not possible.

Integrated optics and electronics on a single chip

Mon, 18 Feb 2013 00:00:00 Z

IBM researchers have managed to shrink optical components to fit alongside their electrical counterparts on a single chip. This advance in the realm of “silicon nanophotonics” paves the road to much higher-performance servers, data centers and supercomputers in the years to come.

The performance of microprocessors increases exponentially as years go by and yet, when it comes to putting together tens of thousands of them to create a supercomputer or a big data center, this doesn't automatically translate into proportionally higher speeds. A system of this magnitude can only move as fast as the slowest of its components and, as it turns out, the main bottleneck here is the speed at which data can be sent across the different processors. The existing copper interconnects are limited in bandwidth and are expensive relative to their performance, costing several dollars per Gbit/s.

The development is expected to bring costs down considerably,to less than a cent per Gbit/s. IBM has already demonstrated optical transceivers exceeding 25 Gbit/s per channel, and showed that multiplexers embedded in the chip can feed parallel streams of optical data into a single fiber to reach much higher speeds.

This gel is liquid when cold and stiffens when heated

Wed, 13 Feb 2013 00:00:00 Z

Gelatins take on a semi-solid state when cool, and become a liquid when heated, right? Well, not always. Chemists from Radboud University Nijmegen, in The Netherlands, have created a “super gel” that behaves in the opposite manner – it’s liquid when cool, and stiffens when heated. What’s more, it reportedly absorbs water 100 times better than other gels. To make it, the researchers copied the protein structure of human cells.

A team led by Prof. Alan Rowan and Dr. Paul Kouwer made the gel using a synthetic polymer known as polyisocyanide. Its molecules twist together to form strong, stiff networks of what are referred to as “nano ropes.” Each cell in our bodies contains thousands of protein structures that are structurally very similar to these ropes.

The gel’s molecular structure is what’s responsible for its seemingly reversed temperature responses, and for its ability to suck up water. “A bucket” of water can be transformed into a gelatinous state, by adding less than a gram of the material. Additionally, the temperature at which the gel changes states can be manipulated – depending on what’s required, that can range from room temperature to body temperature.

Hybrid integrated circuits

Mon, 15 Oct 2012 00:00:00 Z

The Westervelt Group (Harvard University) presents an integrated circuit/microfluidic chip that traps and moves individual living biological cells and chemical droplets along programmable paths using dielectrophoresis (DEP). The chip combines the biocompatibility of microfluidics with the programmability and complexity of integrated circuits (ICs). The chip is capable of simultaneously and independently controlling the location of thousands of dielectric objects, such as cells and chemical droplets. The chip consists of an array of 128 × 256 pixels, 11 × 11 µm in size, controlled by built-in SRAM memory, also similar in architecture to a computer display or a CCD; each pixel can be energized by a radio frequency (RF) voltage of up to 5 Vpp. The IC was built in a commercial foundry and the microfluidic chamber was fabricated on its top surface at Harvard. Using this hybrid chip, they have moved yeast and mammalian cells through a microfluidic chamber at speeds up to 30 µm sec-1. Thousands of cells can be individually trapped and simultaneously positioned in controlled patterns. The chip can trap and move pL droplets of water in oil, split one droplet into two, and mix two droplets into one. The IC/microfluidic chip provides a versatile platform to trap and move large numbers of cells and fluid droplets individually for lab-on-a-chip applications

Highest-res color printer ever

Mon, 13 Aug 2012 00:00:00 Z

This image might look a little grainy to you, but you really should give it a chance. What you're looking at is the output from the world's highest resolution color printer, and it's actually an extreme close-up of an image that measures just 50 micrometers across—the same width as a human hair.

The printer, developed by researchers at the Agency for Science, Technology and Research (A*STAR) in Singapore, prints images at a staggering 100,000 dots per inch, in full color. To do that, each pixel in the ultra-resolution image is printed by depositing four nanoscale pillars just tens of nanometers tall, which are then capped with silver and gold nanodisks.

By varying the diameter and spacing of these microscopic structures, it's possible to control what color of light they reflect—a concept known as structural color—to develop a palette that can be used for full-color printing. The technique is described in Nature Nanotechnology.

The new method boasts resolution ten times higher than the highest-res laser and inkjet printers. In fact, this image is at the limit of optical resolution: if the researchers put the pixels any closer together, light reflecting off them will diffract, and the two objects blur together. In other words, scientists currently believe that printing can never get higher-res than this.

Highly targeted nano-particles to beat drug-resistant bacteria

Mon, 07 May 2012 00:00:00 Z

Over the past several decades, scientists have faced challenges in developing new antibiotics even as bacteria have become increasingly resistant to existing drugs. One strategy that might combat such resistance would be to overwhelm bacterial defenses by using highly targeted nanoparticles to deliver large doses of existing antibiotics.

In a step toward that goal, researchers at MIT and Brigham and Women’s Hospital have developed a nanoparticle designed to evade the immune system and home in on infection sites, then unleash a focused antibiotic attack.

This approach would mitigate the side effects of some antibiotics and protect the beneficial bacteria that normally live inside our bodies, says Aleks Radovic-Moreno, an MIT graduate student and lead author of a paper describing the particles in the journal ACS Nano.

Hydrate-phobic coating to prevent undersea ice clogs deep-sea oil and gas wells

Fri, 27 Apr 2012 00:00:00 Z

During the massive oil spill from the ruptured Deepwater Horizon well in 2010, it seemed at first like there might be a quick fix: a containment dome lowered onto the broken pipe to capture the flow so it could be pumped to the surface and disposed of properly. But that attempt quickly failed, because the dome almost instantly became clogged with frozen methane hydrate.

Methane hydrates, which can freeze upon contact with cold water in the deep ocean, are a chronic problem for deep-sea oil and gas wells. Sometimes these frozen hydrates form inside the well casing, where they can restrict or even block the flow, at enormous cost to the well operators.

Now researchers at MIT, led by associate professor of mechanical engineering Kripa Varanasi, say they have found a solution, described recently in the journal Physical Chemistry Chemical Physics. The paper’s lead author is J. David Smith, a graduate student in mechanical engineering.

The deep sea is becoming “a key source” of new oil and gas wells, Varanasi says, as the world’s energy demands continue to increase rapidly. But one of the crucial issues in making these deep wells viable is “flow assurance”: finding ways to avoid the buildup of methane hydrates. Presently, this is done primarily through the use of expensive heating systems or chemical additives.

“The oil and gas industries currently spend at least $200 million a year just on chemicals” to prevent such buildups, Varanasi says; industry sources say the total figure for prevention and lost production due to hydrates could be in the billions. His team’s new method would instead use passive coatings on the insides of the pipes that are designed to prevent the hydrates from adhering.

These hydrates form a cage-like crystalline structure, called clathrate, in which molecules of methane are trapped in a lattice of water molecules. Although they look like ordinary ice, methane hydrates form only under very high pressure: in deep waters or beneath the seafloor, Smith says. By some estimates, the total amount of methane (the main ingredient of natural gas) contained in the world’s seafloor clathrates greatly exceeds the total known reserves of all other fossil fuels combined.

Inside the pipes that carry oil or gas from the depths, methane hydrates can attach to the inner walls — much like plaque building up inside the body’s arteries — and, in some cases, eventually block the flow entirely. Blockages can happen without warning, and in severe cases require the blocked section of pipe to be cut out and replaced, resulting in long shutdowns of production. Present prevention efforts include expensive heating or insulation of the pipes or additives such as methanol dumped into the flow of gas or oil. “Methanol is a good inhibitor,” Varanasi says, but is “very environmentally unfriendly” if it escapes.

Varanasi’s research group began looking into the problem before the Deepwater Horizon spill in the Gulf of Mexico. The group has long focused on ways of preventing the buildup of ordinary ice — such as on airplane wings — and on the creation of superhydrophobic surfaces, which prevent water droplets from adhering to a surface. So Varanasi decided to explore the potential for creating what he calls “hydrate-phobic” surfaces to prevent hydrates from adhering tightly to pipe walls. Because methane hydrates themselves are dangerous, the researchers worked mostly with a model clathrate hydrate system that exhibits similar properties.

The study produced several significant results: First, by using a simple coating, Varanasi and his colleagues were able to reduce hydrate adhesion in the pipe to one-quarter of the amount on untreated surfaces. Second, the test system they devised provides a simple and inexpensive way of searching for even more effective inhibitors. Finally, the researchers also found a strong correlation between the “hydrate-phobic” properties of a surface and its wettability — a measure of how well liquid spreads on the surface.

The basic findings also apply to other adhesive solids, Varanasi says — for example, solder adhering to a circuit board, or calcite deposits inside plumbing lines — so the same testing methods could be used to screen coatings for a wide variety of commercial and industrial processes.

Richard Camilli, an associate scientist in applied ocean physics and engineering at Woods Hole Oceanographic Institution who was not involved in this study, says, “The energy industry has been grappling with safety and flow-assurance issues relating to hydrate formation and blockage for nearly a century.” He adds that the issue is becoming more significant as drilling progresses into ever-deeper water and says the work by Varanasi’s team “is a big step forward toward finding more environmentally friendly ways to prevent hydrate obstruction in pipes.”

The research team included MIT postdoc Adam Meuler and undergraduate Harrison Bralower; professor of mechanical engineering Gareth McKinley; St. Laurent Professor of Chemical Engineering Robert Cohen; and Siva Subramanian and Rama Venkatesan, two researchers from Chevron Energy Technology Company. The work was funded by the MIT Energy Initiative-Chevron program and Varanasi’s Doherty Chair in Ocean Utilization.