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Tapping a principle of quantum mechanics and a medieval-looking nanoparticle, a UK firm has created a composite material that may soon deliver efficient, pressure-sensitive touchscreens to numerous devices. Yorkshire-based Peratech has already licensed the technology to a division of Samsung that provides mobile components to other handset manufacturers, but it"s in the growing realm of touchscreen tech where the potential for Quantum Tunneling Composite (QTC) is most exciting.

The composite works on an idea in quantum mechanics that if you shoot a tiny particle at a solid wall, there is a slim probability that it will pass straight through, based on an effect known as quantum tunneling. QTC is made by evenly dispersing a bunch of spiky, conducting nanoparticles resembling tiny medieval maces in a thin polymer layer. The nanoparticles don"t touch one another, but the closer they get to a neighboring particle, the more likely a charge will tunnel through and connect the two. Press the layer with your finger and the current running through it smoothly increases in correlation to the increased force.

Of course, QTC isn"t the only means of making a pressure-sensitive touchscreen, but it has some important advantages over other screen designs, most notably its efficiency. Switches, buttons and screens can be made pressure sensitive with mechanical switches, but these take up more space than QTC, a layer of which is only 70 micrometers thick (that"s human-hair thick). The nanoparticles also don"t have a constant current running through them, but rather fire off a current only when pressed, keeping power consumption to a minimum.

Just how might this change your touchscreen experience Most basically, scrolling will become even more intuitive: press harder to scroll faster, or more lightly to slow your scroll. It could also add increase control to touchscreen gaming experiences (push harder to run faster or to throw the ball harder). It could even add a third dimension to 2-D touchscreen interfaces; by pressing hard you can move forward into a page on your phone"s homescreen for instance, rather than simply scrolling side to side or up and down.

That"s all a bit further beyond the horizon, but for now Samsung has already installed QTC in the basic joystick-style navigation button familiar on most non-touchscreen smartphones, making the up and down functions sensitive to pressure. Peratech is also developing pressure-sensitive materials for a variety of other uses including medical devices, robotic sensing, and industrial tools.

[BBC]

Plants are extremely efficient converters of light into energy, more or less setting the bar for researchers creating photovoltaic cells that convert sunlight into electricity. As such, researchers are constantly trying to mimic the tricks that millions of years of evolution and development have taught to plant biology. Now, a team of MIT scientists believe they"ve done it, creating a synthetic, self-assembling chloroplast that can be broken down and reassembled repeatedly, restoring solar cells that are damaged by the sun.

While the leaves on a tree appear to be as static as the PV cells on a solar panel, they"re not; sunlight is actually quite destructive, and to counter this effect leaves rapidly recycle their proteins as often as every 45 minutes when in direct summer sunlight. This rapid repair mechanism allows plants to take full advantage of the sun"s bountiful energy without losing efficiency over time.

To recreate this unique regenerative ability, the MIT team devised a novel set of self-assembling molecules that use photons to shake electrons loose in the form of electricity. The system contains seven different compounds, including carbon nanotubes that provide structure and a means to conduct the electricity away from the cells, synthetic phospholipids that form discs that also provide structural support, and other molecules that self-assemble into "reaction centers" that actually interact with the incoming photons to release electrons.

Under certain conditions, the compounds assemble themselves into uniform structures suitable for harvesting solar energy. But in the presence of a surfactant (similar to the stuff used to disperse oil during oil spills) the structures break down into a solution of nanotubes, phospholipids, and other constituent molecules. By pushing the solution through a membrane to remove the surfactant, the elements once again assemble into working, rejuvenated solar cells undamaged by their prior exposure to the sun.

The cells are work at 40 percent efficiency, and researchers think with some tweaks they could push that efficiency much higher. And because they don"t degrade over time - just give em a quick shake with the surfactant and they"re essentially brand new - the tech could be the next big step forward for solar technology.

[Eurekalert]

Hydrophobic materials have all kinds of practical applications, from creating surfaces that never have to be cleaned to making supertankers and container ships glide more efficiently through the water. But practical applications aside, this amazing video -- showing the crazy, beautifu; ways water droplets interact with a carbon nanotube array --might be mistaken for art rather than science.

Shot with a high-speed camera at various frame rates, the precisely controlled water droplets were launched at the nanotube arrays at different velocities and at different impact angles. The first segment of the video shows a simple 30 microliter droplet of water striking the array at two different speeds. At a slower 1.03 meters per second the droplet bounces off the nanotubes almost completely intact; at increased velocity it breaks into several smaller droplets and scatters in different directions.

But the really interesting segments of the video come later when the researchers start playing with the tilt and the shape of the nanotube array. We don"t want to spoil the climactic ending, but it involves two identical 14 microliter droplets rushing toward each other like star-crossed lovers racing across a field of tiny nanotubes. Who says science lacks romance?

[arXiv]

A humble spice found in nearly every kitchen could yield a safer, simpler way to produce gold nanoparticles, according to a new study. Researchers say the cinnamon-infused particles can even be used to fight cancer.

Gold nanoparticles are heralded for their potential to detect tumors, search for oil, light the streets and cure diseases, but their production requires dangerous toxic chemicals. There are several ways to produce gold particles, but most involve dissolving chloroauric acid, also called gold salts, in liquid and adding chemicals to precipitate gold atoms. Common mixtures include sodium citrates, sodium borohydride (also used to bleach wood pulp) and ammonium compounds, all of which can be toxic to humans and the environment.

Hoping to promote green nanotechnology, researchers at the University of Missouri mixed gold salts with cinnamon instead and stirred the mixture in water. The combination produced gold nanoparticles and phytochemicals, an active chemical in cinnamon. When combined with the nanoparticles, the phytochemicals can enter cancer cells and destroy them or help image them for more accurate medical procedures.

"Our gold nanoparticles are not only ecologically and biologically benign, they also are biologically active against cancer cells," said Kattesh Katti, a professor of radiology and physics at the University of Missouri School of Medicine.

The process uses no electricity and no chemicals, other than the initial gold salts. The researchers reported their work in the journal Pharmaceutical Research.

Katti said cinnamon and other seeds, leaves and herbs could be used to convert metals into nanoparticles without using harsh chemicals.

"Our approach to green" nanotechnology creates a renaissance symbolizing the indispensable role of Mother Nature in all future nanotechnological developments," he said.

[Eurekalert]

Japanese researchers have developed a new viscoelastic super-rubber, a carbon nanotube-based material that flows like honey, stretches like elastic and can survive a huge range of temperatures.

Normally, viscoelastic materials, like foam earplugs and mattresses, perform well in moderate temperatures - but they break down when they get too hot and harden when they get too cold. Silicone rubber hardens into glass around 575 degrees F, for instance. The new material deforms under extreme temperatures, but it maintains its strength and quickly recovers its shape. To test its mettle, the researchers let it sit at room temperature, blasted it with a butane torch and froze it with liquid nitrogen. It withstands temperatures from -320 F to 1,832 F, according to the study, which is published today in the journal Science.

This exceptional range could be used to build anything from spacecraft to sneaker shock absorbers, notes Yury Gogotsi, a nanotechnologist at Drexel University who wrote a Perspective in Science to accompany the research.

The new material is made of a random network of interconnected single-, double- and triple-walled nanotubes - the researchers say the random connections are analogous to a clump of hair. Each carbon nanotube makes connections with numerous other carbon nanotubes. The researchers think its incredible flexibility stems from the entangled network of connections, which work like springs creating elasticity, and from energy dissipation through the zipping and unzipping of carbon nanotubes at these points of contact.

It"s still prohibitively expensive to produce the super-rubber for mass consumption, Gogotsi said. But someday, it could be used to make wrinkle-free fabrics, electricity-harvesting shoes and new spacecraft materials.

[via Discovery News]

Building a synthetic brain is no easy undertaking, but researchers working on the problem have to start somewhere. In doing so, engineers at the University of Southern California have taken a huge step by building a synthetic synapse from carbon nanotubes.

In tests, their synapse circuit functions very much like a real neuron--neurons being the very building blocks of the brain. Tapping the unique properties of carbon nanotubes, their lab was able to essentially recreate brain function in a very fractional way.

Of course, duplicating synapse firings in a nanotube circuit and creating synthetic brain function are two very different things. The human brain, as we well know, is very complex and hardly static like the inner workings of a computer. Over time it makes new connections, adapts to changes, and produces new neurons.

But while a functioning synthetic brain may be decades away, the synthetic synapse is here now, which could help researchers model neuron communications and otherwise begin building, from the ground up, an artificial mimic of one of biologys biggest mysteries.