New Quantum Computer Uses 10,000 Times Less Power

Japan has unveiled its first quantum computer prototype, amid a global race to build ever-more powerful machines with faster speeds and larger brute force that are key towards realising the full potential of artificial intelligence. Japan’s machine can theoretically make complex calculations 100 times faster than even a conventional supercomputer, but use just 1 kilowatt of power – about what is required by a large microwave oven – for every 10,000 kilowatts consumed by a supercomputer. Launched recently, the creators – the National Institute of Informatics, telecom giant NTT and the University of Tokyo – said they are building a cloud system to house their “quantum neural network” technology.

In a bid to spur further innovation, this will be made available for free to the public and fellow researchers for trials at https://qnncloud.com
The creators, who aim to commercialise their system by March 2020, touted its vast potential to help ease massive urban traffic congestion, connect tens of thousands of smartphones to different base stations for optimal use in a crowded area, and even develop innovative new drugs by finding the right combination of chemical compounds.

Quantum computers differ from conventional supercomputers in that they rely on theoretical particle physics and run on subatomic particles such as electrons in sub-zero temperatures. Most quantum computers, for this reason, destabilise easily and are error-prone, thereby limiting their functions.

We will seek to further improve the prototype so that the quantum computer can tackle problems with near-infinite combinations that are difficult to solve, even by modern computers at high speed,” said Stanford University Professor Emeritus Yoshihisa Yamamoto, who is heading the project.
Japan’s prototype taps into a 1km-long optical fibre cable packed with photons, and exploits the properties of light to make super-quick calculations. Its researchers said they deemed the prototype ready for public use, after tests showed that it was capable of operating stably around the clock at room temperature.

Source: http://www.straitstimes.com/

How To Keep Warm In Extreme Cold Weather

Some of the winter weather gear worn by the US Army was designed 30 years ago. It’s heavy and can cause overheating during exertion, while also not doing a very good job of keeping the extremities from going numb.

 

That’s problematic if soldiers have to operate weapons as soon as they land,” said Paola D’Angelo, a research bioengineer at the US Army’s Natick Soldier Research, Development and Engineering Center in Massachusetts. “So we want to pursue this fundamental research to see if we can modify hand wear for that extreme cold weather.”

Scientists are developing smart fabrics that heat up when powered and can capture sweat. The work, which was presented at the 254th National Meeting and Exposition of the American Chemical Society, is based on research from Stanford University in California. A team embedded a network of very fine silver nanowires in cotton, and was able to heat the fabric by applying power to the wires. D’Angelo and her colleagues are working to extend the approach to other fabrics more suitable for military uniforms, including polyester and a cotton/nylon blend. By applying three volts – the output of a typical watch battery – to a one-inch square of fabric, they were able to raise its temperature by almost 40 degrees C. The researchers are also incorporating a layer of hydrogel particles made of polyethylene glycol that will absorb sweat and stop the other layers of the fabric from getting wet.

Once we have optimised the coating, we can start looking at scaling up,” said D’Angelo. The fabric has been tested with up to three washes and still works the same as unwashed fabric for most of the textiles being tested.

Source: http://www.imeche.org/

How To Clean Up Space From Human-Made Debris

Right now, about 500,000 pieces of human-made debris are whizzing around space, orbiting our planet at speeds up to 17,500 miles per hour. This debris poses a threat to satellites, space vehicles and astronauts aboard those vehicles.

What makes tidying up especially challenging is that the debris exists in space. Suction cups don’t work in a vacuum. Traditional sticky substances, like tape, are largely useless because the chemicals they rely on can’t withstand the extreme temperature swings. Magnets only work on objects that are magnetic. Most proposed solutions, including debris harpoons, either require or cause forceful interaction with the debris, which could push those objects in unintended, unpredictable directions. To tackle the mess, researchers from Stanford University and NASA’s Jet Propulsion Laboratory (JPL) have designed a new kind of robotic gripper to grab and dispose of the debris, featured in the June 27 issue of Science Robotics.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

There are many missions that would benefit from this, like rendezvous and docking and orbital debris mitigation,” said Aaron Parness, MS ’06, PhD ’10, group leader of the Extreme Environment Robotics Group at JPL. “We could also eventually develop a climbing robot assistant that could crawl around on the spacecraft, doing repairs, filming and checking for defects.”

Source: http://news.stanford.edu/
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http://www.reuters.com/

New Perovskite Solar Cell Outperforms Silicon Cells

Stanford and Oxford have created novel solar cells from crystalline perovskite that could outperform existing silicon cells on the market today. This design converts sunlight to electricity at efficiencies of 20 percent, similar to current technology but at much lower cost. Writing in the journal Science, researchers from Stanford and Oxford describe using tin and other abundant elements to create novel forms of perovskite – a photovoltaic crystalline material that’s thinner, more flexible and easier to manufacture than silicon crystals.

perovskite solar panelCLICK ON THE IMAGE TO ENJOY THE VIDEO

Perovskite semiconductors have shown great promise for making high-efficiency solar cells at low cost,” said study co-author Michael McGehee, a professor of materials science and engineering at Stanford. “We have designed a robust, all-perovskite device that converts sunlight into electricity with an efficiency of 20.3 percent, a rate comparable to silicon solar cells on the market today.”

The new device consists of two perovskite solar cells stacked in tandem. Each cell is printed on glass, but the same technology could be used to print the cells on plastic, McGehee added.

The all-perovskite tandem cells we have demonstrated clearly outline a roadmap for thin-film solar cells to deliver over 30 percent efficiency,” said co-author Henry Snaith, a professor of physics at Oxford. “This is just the beginning.”

Previous studies showed that adding a layer of perovskite can improve the efficiency of silicon solar cells. But a tandem device consisting of two all-perovskite cells would be cheaper and less energy-intensive to build, the authors said.

Source: http://news.stanford.edu/

Nano Device Cleans Germs from Water In 20 Minutes

In many parts of the world, the only way to make germy water safe is by boiling, which consumes precious fuel, or by putting it out in the sun in a plastic bottle so ultraviolet rays will kill the microbes. But because UV rays carry only 4 percent of the sun’s total energy, the UV method takes six to 48 hours, limiting the amount of water people can disinfect this way.

Now researchers at the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University have created a nanostructured device, about half the size of a postage stamp, that disinfects water much faster than the UV method by also making use of the visible part of the solar spectrum, which contains 50 percent of the sun’s energy.

clean waterA researcher holds a small, nanostructured device that uses sunlight to disinfect water. By harnessing a broad spectrum of sunlight, it works faster than devices that use only ultraviolet rays

In experiments reported today in Nature Nanotechnology, sunlight falling on the little device triggered the formation of hydrogen peroxide and other disinfecting chemicals that killed more than 99.999 percent of bacteria in just 20 minutes. When their work was done the killer chemicals quickly dissipated, leaving pure water behind.

Our device looks like a little rectangle of black glass. We just dropped it into the water and put everything under the sun, and the sun did all the work,” said Chong Liu, lead author of the report. She is a postdoctoral researcher in the laboratory of Yi Cui, a SLAC/Stanford associate professor and investigator with SIMES, the Stanford Institute for Materials and Energy Sciences at SLAC.

Under an electron microscope the surface of the device looks like a fingerprint, with many closely spaced lines. Those lines are very thin films – the researchers call them “nanoflakes” – of molybdenum disulfide that are stacked on edge, like the walls of a labyrinth, atop a rectangle of glass. In ordinary life, molybdenum disulfide is an industrial lubricant. But like many materials, it takes on entirely different properties when made in layers just a few atoms thick. In this case it becomes a photocatalyst.

By making their molybdenum disulfide walls in just the right thickness, the scientists got them to absorb the full range of visible sunlight. And by topping each tiny wall with a thin layer of copper, which also acts as a catalyst, they were able to use that sunlight to trigger exactly the reactions they wanted – reactions that produce “reactive oxygen species” like hydrogen peroxide, a commonly used disinfectant, which kill bacteria in the surrounding water.

Source: https://www6.slac.stanford.edu/

Hydrogen Fuel Stations

A Stanford University research lab has developed new technologies to tackle two of the world’s biggest energy challenges – clean fuel for transportation and grid-scale energy storageHydrogen fuel has long been touted as a clean alternative to gasoline. Automakers began offering hydrogen-powered cars to American consumers last year, but only a handful have sold, mainly because hydrogen refueling stations are few and far between.

silicone nanoconesStanford engineers created arrays of silicon nanocones to trap sunlight and improve the performance of solar cells made of bismuth vanadate

Millions of cars could be powered by clean hydrogen fuel if it were cheap and widely available,” said Yi Cui, associate professor of materials science and engineering at Stanford.

Unlike gasoline-powered vehicles, which emit carbon dioxide, hydrogen cars themselves are emissions free. Making hydrogen fuel, however, is not emission free: Today, making most hydrogen fuel involves natural gas in a process that releases carbon dioxide into the atmosphere.

To address the problem, Cui and his colleagues have focused on photovoltaic water splitting. This emerging technology consists of a solar-powered electrode immersed in water. When sunlight hits the electrode, it generates an electric current that splits the water into its constituent parts, hydrogen and oxygen. Finding an affordable way to produce clean hydrogen from water has been a challenge. Conventional solar electrodes made of silicon quickly corrode when exposed to oxygen, a key byproduct of water splitting. Several research teams have reduced corrosion by coating the silicon with iridium and other precious metals.
The researchers described their findings in two studies published this month in the journals Science Advances and Nature Communications. 

Writing in the June 17 edition of Sciences Advances, Cui and his colleagues presented a new approach using bismuth vanadate, an inexpensive compound that absorbs sunlight and generates modest amounts of electricity.

Bismuth vanadate has been widely regarded as a promising material for photoelectrochemical water splitting, in part because of its low cost and high stability against corrosion,” said Cui, who is also an associate professor of photon science at SLAC National Accelerator Laboratory. “However, the performance of this material remains well below its theoretical solar-to-hydrogen conversion efficiency.”

Bismuth vanadate absorbs light but is a poor conductor of electricity. To carry a current, a solar cell made of bismuth vanadate must be sliced very thin, 200 nanometers or less, making it virtually transparent. As a result, visible light that could be used to generate electricity simply passes through the cell.

To capture sunlight before it escapes, Cui’s team turned to nanotechnology. The researchers created microscopic arrays containing thousands of silicon nanocones, each about 600 nanometers tall.

Nanocone structures have shown a promising light-trapping capability over a broad range of wavelengths,” Cui explained. “Each cone is optimally shaped to capture sunlight that would otherwise pass through the thin solar cell.”

In the experiment, Cui and his colleagues deposited the nanocone arrays on a thin film of bismuth vanadate. Both layers were then placed on a solar cell made of perovskite, another promising photovoltaic material.

When submerged, the three-layer tandem device immediately began splitting water at a solar-to-hydrogen conversion efficiency of 6.2 percent, already matching the theoretical maximum rate for a bismuth vanadate cell.

Source: http://news.stanford.edu/

Nanotechnologies Boost Electric Car Batteries

On a drizzly, gray morning in April, Yi Cui weaves his scarlet red Tesla in and out of Silicon Valley traffic. Cui, a materials scientist at Stanford University here, is headed to visit Amprius, a battery company he founded 6 years ago. It’s no coincidence that he is driving a battery-powered car, and that he has leased rather than bought it. In a few years, he says, he plans to upgrade to a new model, with a crucial improvement: “Hopefully our batteries will be in it.” Cui and Amprius are trying to take lithium–ion batteries—today’s best commercial technology—to the next level. They have plenty of company. Massive corporations such as Panasonic, Samsung, LG Chem, Apple, and Tesla are vying to make batteries smaller, lighter, and more powerful. But among these power players, Cui remains a pioneering force.
Unlike others who focus on tweaking the chemical composition of a battery’s electrodes or its charge-conducting electrolyte, Cui is marrying battery chemistry with nanotechnology. He is building intricately structured battery electrodes that can soak up and release charge-carrying ions in greater quantities, and faster, than standard electrodes can, without producing troublesome side reactions.

Tesla Model 3

“He’s taking the innovation of nanotechnology and using it to control chemistry,” says Wei Luo, a materials scientist and battery expert at the University of Maryland, College Park.
In a series of lab demonstrations, Cui has shown how his architectural approach to electrodes can domesticate a host of battery chemistries that have long tantalized researchers but remained problematic. Among them: lithium-ion batteries with electrodes of silicon instead of the standard graphite, batteries with an electrode made of bare lithium metal, and batteries relying on lithium-sulfur chemistry, which are potentially more powerful than any lithium-ion battery. The nanoscale architectures he is exploring include silicon nanowires that expand and contract as they absorb and shed lithium ions, and tiny egglike structures with carbon shells protecting lithium-rich silicon yolks.

Source: http://www.sciencemag.org/

How To Store 10 Times More Energy In A Li-ion Battery

Scientists have been trying for years to make a practical lithium-ion battery anode out of silicon, which could store 10 times more energy per charge than today’s commercial anodes and make high-performance batteries a lot smaller and lighter. But two major problems have stood in the way: Silicon particles swell, crack and shatter during battery charging, and they react with the battery electrolyte to form a coating that saps their performance. Now, a team from Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory has come up with a possible solution: Wrap each and every silicon anode particle in a custom-fit cage made of graphene, a pure form of carbon that is the thinnest and strongest material known and a great conductor of electricity.

In a report published Jan. 25 in Nature Energy, they describe a simple, three-step method for building microscopic graphene cages of just the right size: roomy enough to let the silicon particle expand as the battery charges, yet tight enough to hold all the pieces together when the particle falls apart, so it can continue to function at high capacity. The strong, flexible cages also block destructive chemical reactions with the electrolyte.

graphene_cageThis time-lapse movie from an electron microscope shows the new battery material in action: a silicon particle expanding and cracking inside a graphene cage while being charged. The cage holds the pieces of the particle together and preserves its electrical conductivity and performance

In testing, the graphene cages actually enhanced the electrical conductivity of the particles and provided high charge capacity, chemical stability and efficiency,” said Yi Cui, an associate professor at SLAC and Stanford who led the research. “The method can be applied to other electrode materials, too, making energy-dense, low-cost battery materials a realistic possibility.

This new method allows us to use much larger silicon particles that are one to three microns, or millionths of a meter, in diameter, which are cheap and widely available,” Cui adds. “In fact, the particles we used are very similar to the waste created by milling silicon ingots to make semiconductor chips; they’re like bits of sawdust of all shapes and sizes. Particles this big have never performed well in battery anodes before, so this is a very exciting new achievement, and we think it offers a practical solution.

Source: https://www6.slac.stanford.edu/

Battery Shuts Down When Overheating, Then Restarts

Stanford researchers have developed the first lithium-ion battery that shuts down before overheating, then restarts immediately when the temperature cools. The new technology could prevent the kind of fires that have prompted recalls and bans on a wide range of battery-powered devices, from recliners and computers to navigation systems and hoverboards.

hoverboard

People have tried different strategies to solve the problem of accidental fires in lithium-ion batteries,” said Zhenan Bao, a professor of chemical engineering at Stanford. “We’ve designed the first battery that can be shut down and revived over repeated heating and cooling cycles without compromising performance.

Several techniques have been used to prevent battery fires, such as adding flame retardants to the electrolyte. In 2014, Stanford engineer Yi Cui created a “smart” battery that provides ample warning before it gets too hot. “Unfortunately, these techniques are irreversible, so the battery is no longer functional after it overheats,” said study co-author Cui, an associate professor of materials science and engineering and of photon science. “Clearly, in spite of the many efforts made thus far, battery safety remains an important concern and requires a new approach.”

Bao and her colleagues describe the new battery in a study published in the Jan. 11 issue of the new journal Nature Energy.

Source: http://news.stanford.edu/

Nanotechnology Hero

Judith Driscoll, 49, is professor of materials science at the University of Cambridge and an expert on nanotechnology. She read materials science at Imperial College London, followed by a PhD in superconductivity at Cambridge and post-doctoral research at Stanford University, California and IBM Almaden Research Centre. Following  is her testimony.

DRISCOLL.J

Science is Passion

I’m always surprised more people don’t study materials science. It’s broad and creative and so important to our everyday lives. I loved physics, chemistry and maths at school and hit on materials science as a great way of continuing with them.”

“Studying for a PhD was tough. It’s completely different from a first degree. Intelligence isn’t enough. You have to be creative, have your own ideas, cope with setbacks and work largely unaided. But it is a great way of finding out whether a career in research is right for you.” “The research for which I’m most famous happened on sabbatical. After eight years mostly spent teaching, doing admin and raising money I really wanted to get back into the lab, so I went to Los Alamos National Laboratory in New Mexico to work on a new idea I had to combine superconductivity and nanotechnology.” “Nanotechnology is unbelievably small. A nanometre is one billionth of a metre, roughly the length a human hair grows in the time it takes to pick up a razor.” “Nanotechnology lets you create substances as small as one molecule thick, giving enormous surface area for speeding up chemical reactions. You can also miniaturise computer components, potentially storing a terabyte of data per square inch.” “And you can achieve quantum confinement, where particles are so small that electrons behave differently from normal, enabling new optical, electrical and magnetic properties to be realised.”

“My big breakthrough concerned the creation of “perfectdefects in very thin films of superconductors. My brainwave was to create nanoparticles within a thin film superconductor using a different material that I knew the superconductor wouldn’t react with.” “It worked right away, achieving very much higher currents in the superconductor and opening up a whole new world of applications in power transmission, conversion and storage, and in high-power magnets for important science experiments such as the Large Hadron Collider and fusion research.” Nanotechnology may be tiny but its potential is huge. It could give us much more efficient solar power, better storage of renewable energy, cancer-killing drugs delivered to just the right cells in the body, biotechnology to clean polluted environments, even molecular-scale robots called nanobots.

“My latest research involves making new kinds of composite thin films that mimic how the brain works.”

“Being a senior academic is rather like running a small business. Your “product” is your research output and you have to raise funding, manage the lab and the people, supervise the work and “market” your work to other academics.” “The wonderful thing about my job is the freedom. In my research nobody tells me what to do or when, and when my daughters were young I was able to work very flexibly”. “You need to be really passionate to succeed in science. If you’re not the type to give up your weekend to really understand something then you’re probably not cut out for it.”

Source: http://www.telegraph.co.uk/
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Graphene Boosts By 30 Percent Chips Speeds

A typical computer chip includes millions of transistors connected with an extensive network of copper wires. Although chip wires are unimaginably short and thin compared with household wires, both have one thing in common: in each case the copper is wrapped within a protective sheath. For years a material called tantalum nitride has formed a protective layer around chip wires.

Now Stanford-led experiments demonstrate that a different sheathing material, graphene, can help electrons scoot through tiny copper wires in chips more quickly.

Graphene is a single layer of carbon atoms arranged in a strong yet thin lattice. Stanford electrical engineer H.-S. Philip Wong says this modest fix, using graphene to wrap wires, could allow transistors to exchange data faster than is currently possible.  And the advantages of using graphene could become greater in the future as transistors continue to shrink.

graphene Stanford

“Researchers have made tremendous advances on all of the other components in chips, but recently there hasn’t been much progress on improving the performance of the wires,” he said.

Wong, the Willard R. and Inez Kerr Bell Professor in the School of Engineering, led a team of six researchers, including two from the University of Wisconsin-Madison, who will present their findings at the Symposia of VLSI Technology and Circuits in Kyoto, Japan, a leading venue for the electronics industry. Ling Li, a graduate student in electrical engineering at Stanford and first author of the research paper, will explain why changing the exterior wrapper on connecting wires can have such a big impact on chip performance.

Source: http://engineering.stanford.edu/

How To Boost Battery Performance

Stanford University scientists have created a new carbon material that significantly boosts the performance of energy-storage technologies.
designer-carbon-300x200
A new ”designer carbon” invented by Stanford scientists significantly improved the power-delivery rate of this supercapacitor

We have developed a ‘designer carbon’ that is both versatile and controllable,” said Zhenan Bao, the senior author of the study and a professor of chemical engineering at Stanford. “Our study shows that this material has exceptional energy-storage capacity, enabling unprecedented performance in lithium-sulfur batteries and supercapacitors.”

According to Bao, the new designer carbon represents a dramatic improvement over conventional activated carbon, an inexpensive material widely used in products ranging from water filters and air deodorizers to energy-storage devices.

A lot of cheap activated carbon is made from coconut shells,” Bao said. “To activate the carbon, manufacturers burn the coconut at high temperatures and then chemically treat it.

The findings are featured on the cover of the journal ACS Central Science.

Source: http://news.stanford.edu/