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Submission + - Printing Flexible Lithium-Ion Batteries->

ckwu writes: The designs of pacemakers, watches, and other wearable gadgets have to be tailored around existing battery shapes, such as cylinders, coin cells, and rectangles. But a team of researchers hopes their fully printable, flexible lithium-ion batteries will one day free designers from these constraints. Battery shapes are now limited because of the need to contain liquid electrolytes. Two years ago, the researchers designed a printable, solid-state electrolyte composed of alumina nanoparticles and lithium combined with polymer that can be cured by ultraviolet light. In this latest work, they used a stencil printing technique to print full battery cells with the electrolyte and other printable materials for the electrodes. They printed batteries on paper and the curved surface of a glass mug. These printed Li-ion batteries can power small LEDs but still need a lot of improvements because they don't last long before needing recharging.
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Submission + - Transparent Paper Produces Power With Just A Touch->

ckwu writes: A new transparent-paper device can generate electrical power from a user’s touch. The paper energy-harvester could be used to make disposable, self-powered touch screens that fold; interactive light-up books; touch-sensitive skin for prosthetics; and security systems for art and documents, according to the researchers. The device is made out of nanopaper, a tangled mat made of nanometers-wide cellulose fibers that is transparent and smooth like plastic. The researchers deposit carbon nanotubes on the nanopaper to make a pair of electrodes, and then sandwich a polyethylene film in between. The generator works via electrostatic induction. Pressing one side of the device causes a change in the charge balance between the nanotube electrodes, resulting in a flow of current through the device. Releasing the pressure causes electrons to flow back, so repeated pressing and releasing creates continuous current. The researchers demonstrated that the generator could produce enough power when pressed to light up a small liquid-crystal display.
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Submission + - Airplane Coatings Help Recoup Fuel Efficiency Lost To Bug Splatter->

MTorrice writes: When bugs explode against the wings of oncoming airplanes, they create a sticky problem for aerospace engineers. Their blood, or hemolymph, clings to an airplane’s wings, disrupting the smooth airflow over them and sapping the aircraft’s fuel efficiency. NASA scientists are now developing coatings that help aircraft shed or repel bug guts during flight. After screening nearly 200 different coating formulations, the NASA researchers recently flight-tested a handful of promising candidates, showing that they could reduce the amount of insect insides stuck to the wings by up to 40%. With further optimization, such coatings could allow planes to use 5% less fuel.
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Submission + - Generating Power With Bacterial Spores->

MTorrice writes: Ozgur Sahin dreams of a future when panels floating on lakes and oceans generate renewable energy. But the panels the biophysicist from Columbia University has in mind don’t harvest wind or sunlight. They use bacterial spores to tap the power of evaporating water.

In a step toward that goal, Sahin and his team have created machines that produce electricity when spore-laden materials—a sort of artificial muscle—expand and contract with changes in humidity. Although these devices generate only about 1% of the energy produced by similarly sized commercial solar panels, the spore-powered generators cost about 100 times less, Sahin says.

Watch the spore muscles power a LED and a little car.

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Submission + - An extra-large nanocage molecule for quantum computing

JMarshall writes: Researchers have built a molecular nanocage 8 nm across that represents a step toward quantum computing.
It is difficult to make uniform nanoparticles more than 4 nm across, but new work solves this problem. Researchers made eight-membered metal rings from chromium and nickel that can act like a qubits in quantum computing. More connected rings means greater quantum computing capacity, so the team worked to combine many rings into one molecule. They managed to pull 24 rings together into an 8-nm sphere, secured by palladium ions at the core. The molecule had a surprisingly good phase memory, an indication of the molecule’s quantum computing potential. The researchers say building a molecule with 70-100 rings would allow them to do “some serious stuff” in quantum computing.

Submission + - Coating Stabilizes Lithium Electrodes For High Capacity Batteries

JMarshall writes: Lithium-metal battery anodes can store 10-fold more energy by weight than those in today’s best batteries, but they have been too unstable to be practical. Now, researchers have used atomic layer deposition—widely used in the semiconductor industry—to coat lithium-metal anodes with a thin protective layer that dramatically improved their performance. Coated lithium-metal anodes did not corrode under conditions that corrode unprotected lithium metal. When combined with sulfur cathodes, which also have the potential to store lots of energy but which typically react badly with lithium, the lithium metal anodes performed well with no sign of degradation after 100 charge cycles. If these better batteries could be commercialized, they could allow electric vehicles to drive farther between charges or offer a more compact power source for implanted medical devices.

Submission + - First Ultraviolet Quantum Dots Shine In An LED->

ckwu writes: Researchers in South Korea have made the first quantum dots that emit ultraviolet light and used them to make a flexible, light-emitting diode. Until now, no one had succeeded in making quantum dots that emit wavelengths shorter than about 400 nm, which marks the high end of the UV spectrum. To get quantum dots that emit UV, the researchers figured out how make them with light-emitting cores smaller than 3 nm in diameter. They did it by coating a light-emitting cadmium zinc selenide nanoparticle with a zinc sulfide shell, which caused the core to shrink to 2.5 nm. The quantum dots give off true UV light, at 377 nm. An LED made with the quantum dots could illuminate the anticounterfeiting marks on a paper bill. If their lifetimes can be improved, these potentially low-cost UV LEDs could find uses in counterfeit currency detection, water sterilization, and industrial applications.
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Submission + - Dissolvable Electronic Stent Can Monitor Blocked Arteries->

ckwu writes: To restore blood flow in a narrowed or blocked artery, doctors can implant a metal stent to hold open the vessel. But over time, stents can cause inflammation and turbulent blood flow that lead to new blockages. Now, researchers have designed a stent carrying a suite of onboard electronic blood-flow and temperature sensors, drug delivery particles, data storage, and communication capabilities to detect and overcome these problems. The entire device is designed to dissolve as the artery heals. Medical device companies and cardiologists could look at this electronic stent as a kind of menu from which they can pick whatever components are most promising for treating certain kinds of cardiovascular disease, the researchers say.
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Submission + - Tiny Capsules Tailor Light->

ckwu writes: Dyes that can convert low-energy and ambient light to higher energy green or blue light could help boost the efficiency of solar cells and enable new kinds of medical imaging and light-based therapies. In a step that could help make these so-called upconverters more practical, researchers have demonstrated a way to encapsulate the dyes within particles. They make the particles with a microfluidic system that traps a droplet of a solution of upconversion dyes within three protective layers: a surfactant to help stabilize the droplet, a thin layer of water, and a polymer shell. These triple-layer coatings protect the sensitive dyes from oxygen without dimming their light.
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Submission + - Making Legal Marijuana Safe->

MTorrice writes: Where once the use of Cannabis strains such as banana kush, Dr. Greenthumb’s ghost, and gorilla glue #4 was hidden behind closed doors, it is now increasingly in the open. Four states—Colorado, Washington, Alaska, and Oregon—have legalized both recreational and medicinal use, and another 19 allow medicinal use only. With that openness, however, comes new challenges in the form of safety concerns and evolving regulations to protect production workers and consumers. Companies are working on those issues, in particular finding ways to safely extract cannabinoids and other compounds from the plant material to yield concentrated oils and waxes used in vaporizers, foods, salves, or other products.
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Submission + - Self-Healing Coating Turns Cotton Into Superhero-Worthy Fabric->

ckwu writes: Superprotective garb for withstanding both flood and fire is on the horizon now that chemists have come up with a self-healing, triple-dip coating that renders cotton flame resistant and waterproof. Flame-retardant fabric coatings often wash away, so researchers wanted to see if adding a waterproof layer could extend the life of water-soluble fire retardants.The chemists dipped cotton samples in two flame-retardant compounds and then in a superhydrophobic compound called F-POSS that has self-healing properties. They tested the coating by holding a flame to the bottom of a 30-cm-long vertical strip of fabric for 12 seconds. Untreated cotton burned away in 14 seconds, yet no more than 4 cm of the treated cotton burned before the flame extinguished itself. Even after mimicking sun damage and mechanical wear-and-tear, the fabric retained its flame retardancy and regained its water repellency after a few hours.
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Submission + - Some Biodegradable Plastics Don't Live Up To Their Claims-> 1

ckwu writes: From bread bags to beverage bottles, many plastics now contain additives designed to make the materials biodegradable. But a new study shows that plastics made with such additives do not biodegrade in the environment significantly faster than those without the compounds. Researchers prepared films of commercial plastics with three different types of additives supplied by their manufacturers. The researchers then treated the film samples to mimic disposal of such plastics in a compost pile, a landfill, and soil. After about six months of composting, a year and a half of landfill-like conditions, and three years of soil burial, the plastics with additives did not show any more evidence of biodegradation than plastics without them.
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Submission + - Motion-Powered Fabric Could Charge Small Electronics->

ckwu writes: Wrapped around a person’s wrist, a new foldable fabric patch can scavenge enough energy from arm movement to power small electronic devices. The fabric patch paves the way to clothing that can charge smart watches and cell phones while the wearer moves or walks around, the researchers say. The new energy-generating textile relies on the triboelectric effect, the phenomenon behind static electricity. The researchers made a flexible generator out of four layers of the textile that put out 170 V and 120 microamps, and it maintained this output for more than 12,000 compression cycles. The researchers attached the generator to a jacket sleeve and embedded six LEDs, a small liquid-crystal display, and a keyless car remote control in the jacket. When the wearer moved his arms or wrists, the generator produced enough power to turn each gadget on one at a time.
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Submission + - Polymers Brighten Hopes For Visible Light Communication->

ckwu writes: Today nearly all computers, tablets, and smartphones have Wi-Fi capabilities, receiving and transmitting data over a range of radio frequencies. But a burgeoning technology known as visible light communication could someday carry those data in the same light that illuminates a room. Now a tag team of semiconducting organic polymers is bringing that dream one step closer. When excited with a blue LED, the polymer pair helps to create white light that can be rapidly switched on and off to encode information. A proof-of-principle device using the polymers sent data at 350 Mbps over a distance of 5 cm with minimal errors, a rate 35 times faster than a commercially available phosphor used for blue-light color conversion.
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Submission + - Novel Fluorinated Compounds Discovered in Firefighters' Blood->

ckwu writes: Perfluorinated compounds help firefighting foams rapidly flow over flaming liquids such as gasoline and jet fuel, cooling and quenching fires. But despite environmental scientists’ concerns about these possibly toxic compounds, researchers don’t know the identity of many of the chemicals in the mixtures on the market. For the first time, a new study borrows a medical research tool to pinpoint fluorochemicals in the blood of firefighters, identifying novel compounds that have never before been publicly reported.
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The confusion of a staff member is measured by the length of his memos. -- New York Times, Jan. 20, 1981