'Pressure cooker' method helps produce better batteries

US researchers claim they have found a way to improve battery technology by using a ‘pressure cooker’ technique to control the battery’s nanostructure.

The engineers from the University of California, Riverside, say creating nanoparticles with a controlled shape in the materials used for batteries’ cathodes could make them smaller, more powerful, more efficient.

They also hope to reduce charge times by modifying the size and shape of the battery components. This could make the technology particularly suitable for electric vehicle batteries, which are a major limiting factor in the cars’ performance.

The researchers have demonstrated their technique with cathodes made from lithium iron phosphate, which has been used in electric vehicles because of its low cost, low toxicity and thermal and chemical stability, but has limited commercial potential because of its poor electric conductivity.

The reactant materials used to make the cathode were heated under pressure with a mix of solvents to control the size, shape and crystallinity of the particles, making the lithium ions in the cathode more mobile and so improving its performance.

‘This is a critical, fundamental step in improving the efficiency of these batteries,’ said lead researcher David Kisailus in a statement.

The research was sponsored by the Winston Chung Global Energy Center and published in the journal Crystal Growth & Design.

Source: http://www.theengineer.co.uk/electronics/news/pressure-cooker-method-helps-produce-better-batteries/1017524.article#ixzz2lYbuR4Vg

Researchers Construct Graphene-Based Chips – With An Assist From DNA Molecules

DNA molecules contain the genetic instructions essential to the development and function of living organisms, but new research suggests that they could also play a key role in the future of computer chips.

Researchers from Stanford University believe that DNA could become the template of next generation microchipsconstructed from an experimental substance known as graphene, which is a one atom thick sheet of carbon atoms arrayed in a honeycomb pattern.

Engineers believe that graphene could be a better semiconductor than silicon, and new research led by Stanford chemical engineering professor Zhenan Bao suggests that the nucleotide polymers that contain our genetic code could help assemble graphene transistors.

In a recent edition of the journal Nature Communications, Bao and her colleagues describe how they set out to solve one of the great problems currently surrounding the future of the electronics industry: the demand for smaller, faster and cheaper silicon chips.

However, despite that demand, the nature of how silicon chips work could hamper the development of such highly-sought after products, explained Stanford School of Engineering associate director of communications Tom Abate.

“Everything starts with the notion of the semiconductor, a type of material that can be induced to either conduct or stop the flow of electricity. Silicon has long been the most popular semiconductor material used to make chips,” he said. “The basic working unit on a chip is the transistor. Transistors are tiny gates that switch electricity on or off, creating the zeroes and ones that run software.”

“To build more powerful chips, designers have done two things at the same time: they’ve shrunk transistors in size and also swung those gates open and shut faster and faster,” Abate added. “The net result of these actions has been to concentrate more electricity in a diminishing space. So far that has produced small, faster, cheaper chips. But at a certain point, heat and other forms of interference could disrupt the inner workings of silicon chips.”

According to Bao, developers need a material that will enable them to build smaller, faster transistors that use less power to function – and that’s where graphene comes in. The new substance has the physical and electrical properties that will enable it to be used to create next-gen semiconductors, provided a way can be found to mass-produce it.

The Stanford researchers believe that ribbons of the single-atom-thick substance could create semiconductor circuits if they are laid side-by-side. Due to graphene’s minute dimensions and favorable electrical properties, they assert that these nano-ribbons would be able to create chips that are extremely fast but require little power to operate.

“However, as one might imagine, making something that is only one atom thick and 20 to 50 atoms wide is a significant challenge,” said co-author and post-doctoral fellow Anatoliy Sokolov. To overcome that hurdle, the researchers came up with the idea of using DNA as an assembly mechanism, Abate added.

DNA strands are long and thin, and share roughly the same dimensions as the graphene ribbons that Bao and her associates intended to create. They also contain carbon atoms, which just so happens to be the material used to craft graphene. Using both those physical and chemical advantages, the researchers took a small sample of silicon to serve as a support for their experimental transistors.

“They dipped the silicon platter into a solution of DNA derived from bacteria and used a known technique to comb the DNA strands into relatively straight lines,” Abate said. “Next, the DNA on the platter was exposed to a copper salt solution. The chemical properties of the solution allowed the copper ions to be absorbed into the DNA.”

After that, the platter was heated and engulfed in methane gas, which also contains carbon atoms. The heat wound up serving as a catalyst that assisted the assembly process, freeing some of those carbon atoms in the DNA and methane. Once free, those atoms rapidly connected with one another to form stable graphene honeycombs.

“We demonstrated for the first time that you can use DNA to grow narrow ribbons and then make working transistors,” Sokolov said. Bao added that the process required a lot of refinement, but that it could potentially be a step forward in making graphene-based semiconductors a reality. Their research was supported by the National Science Foundation and the Stanford Global Climate and Energy Program.

Source: redOrbit.com

Feather-light electronics creates e-skin

An 'imperceptible' electronic skin that can monitor the body, or help people to communicate through touch, is now possible thanks to a new ultra-light and flexible sensor foil, say researchers.

Materials scientist Dr Martin Kaltenbrunner from theUniversity of Tokyo, and colleagues, report their findings today in the journal Nature.

"You could even put it on the inside of the mouth," says Kaltenbrunner. "You would hardly feel that it's there."

Kaltenbrunner says healthcare and monitoring systems that measure such things as temperature, moisture or pressure in the body need to be light, thin and flexible so they don't interfere with the patient.

"The advantage of this very thin material is that it doesn't disturb you when you are moving," he says.

Kaltenbrunner and colleagues have for the first time made an electronic skin from a complex integrated circuit that is just 2 micrometres thick.

"This is 1/50th the thickness of a human hair," he says.

Weighing just 3 grams per metre - 27-fold lighter than office paper - the foil can float through the air like a feather and is extraordinarily tough, say the researchers.

"You can crumple it, you can throw it down, you can tramp on it, and the surface doesn't break," says Kaltenbrunner, adding the foil can be squashed into a radius of just 5 micrometres without bending.

The researchers tested the foil and found it also works at 160°C, and in wet environments.

Putting strips of the foil on a flat piece of stretched rubber could also enable the e-skin to be used, for example, around joints.

Tactile sensor

Kaltenbrunner and colleagues made the electronic sensor foil using a lightweight plastic substrate called polyethylene naphthalate, which last year they used to make solar cells.

On top of this, they placed an array of organic transistors, covered by another plastic layer containing pressure sensors.

They then showed that the electronic skin could act as a tactile sensor on a model of the upper human jaw.

"You could have a touch interface for a person who could not communicate in any other way," says Kaltenbrunner.

He says the sensors in the top layer of the foil could be substituted for others, for example those that measure temperature or moisture.

"Everything your skin can do, can be replicated in electronic form," says Kaltenbrunner.

Alternatively, light or heat emitting diodes could be put in this layer, he adds.

Before the technology is used in the body, however, Kaltenbrunner says it can be used for consumer products, including wearable electronics, which are currently around 100 micrometres thick.

"You can imagine putting them anywhere," says Kaltenbrunner. "You can give electronic functionality to everyday objects."

The research was funded by the Japanese government and the European Research Council.

Source: http://www.abc.net.au/science/

Plastic: The new material for solar cells

Professors Nunzio Motta and John Bell use world-standard super microscopes in the race to develop cheap plastic solar cells for mobile devices.

QUT's research to develop cheap plastic solar cells to charge mobile phones and other electronic devices has been boosted with the installation of one of the most powerful nanotechnology microscopes in the world.

The only one if its kind in Australia, the Zeiss Orion NanoFab enables researchers to examine natural or manmade structures in incredible detail, and will create new insights wherever it is applied.

By increasing the microscope beam current, researchers are able to etch away material to create patterns or structures with features of only a few nanometres. This is a tool that can write lines 100,000 times finer than the text on a printed page. Imagine War and Peace etched on the head of a pin - 200 times over.

QUT nanotechnology expert, Professor Nunzio Motta, said the new microscope complemented QUT's existing tunnelling microscope, the only one of its kind in Queensland, and would cement the university's place at the cutting edge of Australiannanotechnology research.

He said the super microscopes would be used to create new nanostructures which could be used in electronic devices, solar cells, gas sensors and for a range of other uses.

"At the moment plastic solar cells are quite inefficient and researchers around the world are trying to determine how to make the cells efficient and able to be commercialised," Professor Motta said.

"The advantages cheap solar cells would produce would be enormous.

"In the future plastic solar cells could generate enough energy not only to recharge the batteries of laptops and mobiles, but even to obtain power from canopies on parking areas which could be fed back into grids.

"They could even be developed as a clear film on glass windows to produce power."

Professor Motta is currently using the tunnelling microscope to improve plastic solar cells by mixing them with graphene, an atomic-scale honeycomb lattice made ofcarbon atoms

. He has found that adding gold nano-particles traps light and improves efficiency.

"While it's difficult to put a timeframe on the development of efficient plastic solar cells, a five to ten year goal is probably not unrealistic," he said.

Professor Motta said his research team also hoped to create a new class of solar-powered nano-sensors capable of detecting pollution and monitoring the environment in remote areas.

He said nanoscale science was critical to the world's future economy as advances would transform a range of scientific and engineering disciplines.

Professor Motta said QUT was organizing NanoS-E3, an International Workshop and School on nanotechnology at Airlie Beach in September.

Source: phys.org

Google Buys a Quantum Computer

Google and a corporation associated with NASA are forming a laboratory to study artificial intelligence by means of computers that use the unusual properties of quantum physics. Their quantum computer, which performs complex calculations thousands of times faster than existing supercomputers, is expected to be in active use in the third quarter of this year.

The Quantum Artificial Intelligence Lab, as the entity is called, will focus on machine learning, which is the way computers take note of patterns of information to improve their outputs. Personalized Internet search and predictions of traffic congestion based on GPS data are examples of machine learning. The field is particularly important for things like facial or voice recognition, biological behavior, or the management of very large and complex systems.

“If we want to create effective environmental policies, we need better models of what’s happening to our climate,” Google said in a blog postannouncing the partnership. “Classical computers aren’t well suited to these types of creative problems.”

Google said it had already devised machine-learning algorithms that work inside the quantum computer, which is made by D-Wave Systems of Burnaby, British Columbia. One could quickly recognize information, saving power on mobile devices, while another was successful at sorting out bad or mislabeled data. The most effective methods for using quantum computation, Google said, involved combining the advanced machines with its clouds of traditional computers.

Google bought the machine in cooperation with the Universities Space Research Association, a nonprofit research corporation that works with NASA and others to advance space science and technology. Outside researchers will be invited to the lab as well.

This year D-Wave sold its first commercial quantum computer to Lockheed Martin. Lockheed officials said the computer would be used for the test and measurement of things like jet aircraft designs, or the reliability of satellite systems.

The D-Wave computer works by framing complex problems in terms of optimal outcomes. The classic example of this type of problem is figuring out the most efficient way a traveling salesman can visit 10 customers, but real-world problems now include hundreds of such variables and contingencies. D-Wave’s machine frames the problem in terms of energy states, and uses quantum physics to rapidly determine an outcome that satisfies the variables with the least use of energy.

In tests last September, an independent researcher found that for some types of problems the quantum computer was 3,600 times faster than traditional supercomputers. According to a D-Wave official, the machine performed even better in Google’s tests, which involved 500 variables with different constraints.

“The tougher, more complex ones had better performance,” said Colin Williams, D-Wave’s director of business development. “For most problems, it was 11,000 times faster, but in the more difficult 50 percent, it was 33,000 times faster. In the top 25 percent, it was 50,000 times faster.” Google declined to comment, aside from the blog post.

The machine Google will use at NASA’s Ames Research facility, located near Google headquarters, makes use of the interactions of 512 quantum bits, or qubits, to determine optimization. They plan to upgrade the machine to 2,048 qubits when this becomes available, probably within the next year or two. That machine could be exponentially more powerful.

Google did not say how it might deploy a quantum computer into its existing global network of computer-intensive data centers, which are among the world’s largest. D-Wave, however, intends eventually for its quantum machine to hook into cloud computing systems, doing the exceptionally hard problems that can then be finished off by regular servers.

Potential applications include finance, health care, and national security, said Vern Brownell, D-Wave’s chief executive. “The long-term vision is the quantum cloud, with a few high-end systems in the back end,” he said. “You could use it to train an algorithm that goes into a phone, or do lots of simulations for a financial institution.”

Mr. Brownell, who founded a computer server company, was also the chief technical officer at Goldman Sachs. Goldman is an investor in D-Wave, with Jeff Bezos, the founder of Amazon.com. Amazon Web Services is another global cloud, which rents data storage, computing, and applications to thousands of companies.

This month D-Wave established an American company, considered necessary for certain types of sales of national security technology to the United States government.

Source: NYtimes

Graphene Ink Could Lead To Bendable Electronics

Lee Rannals for redOrbit.com – Your Universe Online

Researchers writing in the Journal of Physical Chemistry Letters say they have developed a graphene-based ink that could be the beginnings of inkjet-printed graphene.

The team’s graphene-based ink is highly conductive and tolerant to bending, which could eventually pave the way for bendable tablet computers or electronic newspapers.

“Graphene has a unique combination of properties that is ideal for next-generation electronics, including high electrical conductivity, mechanical flexibility, and chemical stability,” said Mark Hersam, professor of materials science and engineering at Northwestern’s McCormick School of Engineering and Applied Science. “By formulating an inkjet-printable ink based on graphene, we now have an inexpensive and scalable path for exploiting these properties in real-world technologies.”

The new method for mass-producing graphene can be carried out at room temperature using ethanol and ethyl cellulose to exfoliate graphite. This process minimizes residues and results in a powder with a high concentration of nanometer-sized graphene flakes.

The team demonstrated printing ink in multiple layers, each 14 nanometers thick, in order to create precise patterns. The ink’s conductivity remained unchanged, suggesting that it could be used to create foldable electronic devices.

Inkjet printing with graphene has remained a challenge because it is difficult to harvest a sufficient amount of graphene without compromising its electronic properties. The team’s method surpasses some of these challenges, opening up the door to a future with bendable smartphones.

Graphene was discovered in 2004, and scientists believe the material holds plenty of promise in the future. Scientists discovered the material by peeling off carbon layers from graphite using ordinary scotch tape. It is the world’s thinnest, strongest and most conductive material. Scientists could eventually use the material for applications like computer chips, broadband connections and drug delivery.

Researchers from the University of Manchester and National University of Singapore wrote in the journal Scienceabout how graphene could lead to photovoltaic structures that could be placed on the outer walls of buildings to absorb sunlight. The team said they found that graphene could also help environmental conditions like temperature and brightness by directing energy to change the transparency and reflectivity of individual fixtures and windows.

“Such photoactive heterostructures add yet new possibilities, and pave the road for new types of experiments,” said Professor Kostya Novoselov of the University of Manchester. “As we create more and more complex heterostructures, so the functionalities of the devices will become richer, entering the realm of multifunctional devices.”

Source: Lee Rannals for redOrbit.com - Your Universe Online

Glowing Plants For Sustainable Lighting Wins Strong Crowdfunding Support

With 30 days yet to go, the Glowing Plant initiative has already raised more than a quarter million dollars – far surpassing its initial goal of $65,000 – from more than 4,500 backers, each of which are promised seeds for glowing plants in exchange for their investment.

The team behind the project says they will use Synthetic Biology techniques and Genome Compiler‘s software to insert bioluminescence genes into Arabidopsis, a small flowering plant and member of the mustard family, to create a plant that visibly glows in the dark.

Arabidopsis was selected because it is easy to experiment with and carries only a slight risk for spreading into the wild. But the team hopes the same process will work for a rose, which will likely be more commercially appealing.

“Inspired by fireflies…our team of Stanford-trained PhDs are using off-the-shelf methods to create real glowing plants in a do-it-yourself bio lab in California,” the Glowing Plants team told BBC News.

The funds raised through Kickstarter will be used “to print the DNA sequences we have designed using Genome Compiler and to transform the plants by inserting these sequences into the plant and then growing the resultant plant in the lab,” wrote team leader Antony Evans on the project’s Kickstarter page.

Printing DNA costs a minimum of 25 cents per base pair, and the team will use sequences about 10,000 base pairs long.

“We plan to print a number of sequences so that we can test the results of trying different promoters – this will allow us to optimize the result,” Evans wrote.

Transforming the plant will initially be done using the Agrobacterium method, in which the printed DNA is inserted into a special type of bacteria that can insert its DNA into the plant.

“Flowers of the plant are then dipped into a solution containing the transformed bacteria,” Evans explained.

“The bacteria injects our DNA into the cell nucleus of the flowers which pass it onto their seeds which we can grow until they glow!”

Agrobacteria are increasingly being used in genetic engineering because they can transfer DNA between themselves and plants. The team posted a video of this process on their Kickstarter page.

The Agrobacterium method will only be used for prototypes, as the bacteria are plant pests and any use of such organisms is heavily regulated.

For the seeds that will be sent to the public, the team will use a gene gun that coats nanoparticles with DNA and inserts them into plants.

This step is more complicated, and there are risks the gene sequence gets scrambled, “but the result will be unregulated by the USDA and thus suitable for release,” Evans said.

The Kickstarter funds will also be used to develop an open policy framework for DIY Bio work involving recombinant DNA.

“This framework will provide guidelines to help others who are inspired by this project navigate the regulatory and social challenges inherent in community based synthetic biology.”

The framework will include recommendations for what kinds of projects are safe for DIY Bio enthusiasts, and recommendations for the processes that should be enacted.

All of the project’s output, including the DNA constructs and the plants, will be released open-source, the team said on its Glowing Plant Web site.

Harvard Medical School professor of genetics George Church, a backer of the project, said that biology could provide great inspiration for more sustainable light sources.

“Biology is very energy-efficient and energy packets are more dense than batteries. Even a weakly glowing flower would be a great icon,” he said according to BBC News.

Austen Heinz, founder of Cambrian Genomics, is another backer of the project. The Glowing Plants team will use Cambrian’s breakthrough laser printing system, which dramatically reduces the cost of DNA synthesis.

“DNA laser printing will change life as we know it, starting with glowing plants,” Heinz said.

Evans, along with fellow team leaders Omri Amirav-Drory, a synthetic biologist, and Kyle Taylor, a plant scientist, said they could envision glowing trees someday being used as streetlights.

With a month of fundraising left to go, the project seems off to a spectacular start.

Source: redOrbit Staff & Wire Reports - Your Universe Online

Sound cloaks enter the third dimension

Concept could lead to sonar-defeating submarines or noise-cancelling highway barriers

A simple plastic shell has cloaked a three-dimensional object from sound waves for the first time. With some improvements, a similar cloak could eventually be used to reduce noise pollution and to allow ships and submarines to evade enemy detection. The experiments appear March 20 in Physical Review Letters.

“This paper implements a simplified version of invisibility using well-designed but relatively simple materials,” says Steven Cummer, an electrical engineer at Duke University, who was not involved in the study. Cummer proposed the concept of a sound cloak in 2007.

Scientists’ recent efforts to render objects invisible to the eye are based on the fact that our perception of the world depends on the scattering of waves. We can see objects because waves of light strike them and scatter. Similarly, the Navy can detect faraway submarines because they scatter sound waves (sonar) that hit them.

So for the last several years scientists have been developing cloaks that prevent scattering by steering light or sound waves around an object. The drawback of this approach, however, is that it requires complex synthetic materials that are difficult to produce.

José Sánchez-Dehesa, an electrical engineer at the Polytechnic Institute of Valencia in Spain, and his colleagues pursued a different method: Instead of preventing sound waves from hitting an object — in this case an 8-centimeter plastic sphere — they built a cloak to eliminate the scattered waves left in the sphere’s wake.

Using computer algorithms, the researchers came up with a design made up of 60 rings of various sizes that form a cagelike structure around the sphere. Simulations indicated that sound waves scattering off the sphere and the ringed cloak would interfere with each other and cancel out. (Noise-cancelling headphones exploit this phenomenon by emitting sound waves that minimize ambient sounds in a room.)

Because the cloak did not need to steer sound waves in complicated ways, Sánchez-Dehesa and his team built it out of plastic with the help of a 3-D printer.  They hung their creation from the ceiling of an echo-free chamber, pointed a speaker at it and played a range of sound frequencies. For most frequencies, the sphere scattered an easily detectable amount of sound. But at 8.55 kilohertz — an audible high pitch — the cloaked sphere became imperceptible to the sensors behind it.

The study marks the first time scientists have ever cloaked a three-dimensional object from sound. That’s probably music to the ears of the U.S. Office of Naval Research, which partially funded the study to explore the possibility of sonar invisibility.

However, this cloak is just a small step toward stealth submarines. It has to be custom designed and built for each object, and it works only for a narrow frequency range coming from one direction. If the speaker had been set up anywhere else, the cloak would not have worked. Sánchez-Dehesa’s team plans to develop broadband and multidirectional cloaks.

But Cummer points out that even a limited cloak can have useful applications. He suggests that structures capable of manipulating a specific sound frequency from one direction could help minimize noise pollution from a congested highway. “The cloak does one thing quite well, with a very simple structure,” he says.

Source: sciencenews.org

Graphene May Be Future Of Headphones, But Some Audiophiles Remain Unimpressed

Michael Harper for redOrbit.com – Your Universe Online

One of the coolest scientific advancements of the century is the discovery of graphene. This material is the only two-dimensional element and, when gathered together, it can take on incredibly thin shapes. It’s been called a “super material” because despite it’s incredibly thin and light-weight makeup, it’s also stronger than diamonds or steel and is a great conductor of electricity.

Scientists only learned how to capture graphene and study it in 2004. Prior to that, it was thought to be unstable in its free form. Over the past nine years, the study of graphene has taken off as scientists and researchers begin to use it in a variety of applications. For instance, scientists from the University of California in Berkeley have now created a pair of headphones with graphene diaphragms. While the existence of such a pair of cans is exciting enough for some, the Berkeley scientists should have been prepared for the resulting debates amongst audiophiles.

The common speaker creates sound by running vibrations through a diaphragm, often made of paper. The vibrations of the diaphragm create sound waves. Depending on the speed of these vibrations and the length of the waves (or frequency) the sound can go from high to low.

“For human audibility, an ideal speaker or earphone should generate a constant sound pressure level from 20 Hz to 20 kHz, ie it should have a flat frequency response,” say Qin Zhou and Alex Zettl, both of UC Berkeley, speaking to TechnologyReview.com.

The graphene diaphragms are said to deliver this kind of flat performance naturally and all in a thin and light package.

The headphones are made from just a few layers of super thin graphene sandwiched between two electrodes. These electrodes are responsible for vibrating the graphene layers and thus replicating the sounds.

Graphene’s incredible strength and ability to withstand considerable stress is what Zhou and Zettl were after.

Paper can also generate sound, but it’s an incredibly weak substance. To prevent the paper diaphragms from blowing out at a certain frequency, headphone makers typically dampen the air flow and restrict the level of frequencies handled by the headphones. This dampening is often achieved by making the diaphragm small and thin while keeping the frequencies within a certain range so that the air performs much of the dampening.

This is where graphene is expected to shine in art of sound reproduction.

“It is electrically conducting, has extremely small mass density, and can be configured to have very small effective spring constant,” say Zhou and Zettl. The fact that graphene is also incredibly strong means that it doesn’t need to be dampened and can therefore handle a larger range of frequencies while remaining mostly flat.

Zhou and Zettl compared the new graphene headphones to a pair of Sennheiser MX-400 headphones, a set of headphones which doesn’t live up to the exacting standards of audiophiles but are commonly used by regular listeners.

“Even without optimization, the speaker is able to produce excellent frequency response across the whole audible region (20 Hz~20 KHz), comparable or superior to performance of conventional-design commercial counterparts,” explained Zhou and Zettl.

Graphene is also incredibly efficient, meaning more energy is translated into sound that traditional headphones.

There’s no word on how much these headphones will cost and when they might arrive to market, but once these become a real thing, be sure to catch the audiophile debates on the quality of their sound production.

Source: Michael Harper for redOrbit.com – Your Universe Online

High-Speed 3D Nanostructure Printer Demonstrated At Photonics West Conference

Image Caption: Writing time for a miniaturized spacecraft is reduced to less than one minute without loss of quality. Credit: Nanoscribe

redOrbit Staff & Wire Reports – Your Universe Online

A device capable of quickly manufacturing three-dimensional objects smaller than the diameter of a human hair was recently presented by researchers from the Karlsruhe Institute of Technology (KIT).

The researchers, who are officially affiliated with KIT spin-off organization Nanoscribe GmbH, demonstrated what they claim is the world’s fastest 3D printer of microstructures and nanostructures at the Photonics West international science fair, held from February 2 through February 7 in San Francisco, California.

The device is “based on a novel laser lithography method” and can create miniscule three-dimensional objects “with minimum time consumption and maximum resolution,” officials from the high-tech company explained Wednesday in a statement. “By means of the new laser lithography method, printing speed is increased by factor of about 100.”

“This increase in speed results from the use of a galvo mirror system, a technology that is also applied in laser show devices or scanning units of CD and DVD drives. Reflecting a laser beam off the rotating galvo mirrors facilitates rapid and precise laser focus positioning,” they added.

Using this technology, Martin Hermatschweiler, the managing director of Nanoscribe GmbH, said that the company is “revolutionizing 3D printing on the micrometer scale.”

Their laser-writing technique is based on two-photon polymerization, which utilizes extremely short laser pulses to create a chemical reaction in photosensitive materials that are in the laser focus, which results in only the exposed or unexposed volume being dissolved and written areas remaining as self-supporting nanostructures following a developer bath, officials with the laser lithography system development firm explained.

“By means of the galvo technology, three-dimensional micro- and nanostructures can be printed rapidly and, hence, on large areas in principle,” Nanoscribe representatives said. “At highest resolution, however, the scanning field is limited physically to a few 100 µm due to the optical properties of the focusing objective. Just as floor tiles must be joined precisely, the respective scanning fields have to be connected seamlessly and accurately. By the so-called stitching, areas can be extended nearly arbitrarily.”

“The 3D laser litho-graphy systems developed by Nanoscribe… are used for research by KIT and scientists worldwide. Work in the area of photonics concentrates on replacing conventional electronics by optical circuits of higher performance,” they added. “For this purpose, Nanoscribe systems are used to print polymer waveguides reaching data transfer rates of more than 5 terabits per second.”

Source: redOrbit Staff & Wire Reports - Your Universe Online

The cloak of invisibility

Many "invisibility cloak" efforts have been demonstrated, but all have reflected some of the incident light, making the illusion incomplete.

A Nature Materials study has now shown how to pull off the trick flawlessly.

The idea of invisibility cloaking got its start in 2006 when John Pendry of Imperial College London and David Schurig and David Smith of Duke University laid out the theory of "transformation optics" in a paper in Science, demonstrating it for the first time using microwaves (much longer wavelengths than we can see) in another Science paper later that year.

The structures that can pull off this extraordinary trick of the light are difficult to manufacture, and each attempt has made an approximation to the theoretical idea that results in reflections.

So someone would not see a cloaked object but rather the scene behind it - however, the reflections from the cloak would make that scene appear somewhat darkened.

Now, Prof Smith and his Duke colleague Nathan Landy have taken another tack, reworking how the edges of a microwave cloak line up, ensuring that the light passes around the cloak completely with no reflections.

The trick was to use a diamond-shaped cloak, with properties carefully matched at the diamond's corners, to shuttle light perfectly around a cylinder 7.5cm in diameter and 1cm tall.

"This to our knowledge is the first cloak that really addresses getting the transformation exactly right to get you that perfect invisibility," Prof Smith told BBC News.

However, the cloaking game is always one of trade-offs; though the illusion is perfect, it only works in one direction.

The design principles that make the cloak work in microwaves would be difficult to implement at optical wavelengths. But microwaves are important in many applications, principally telecommunications and radar, and improved versions of cloaking could vastly improve microwave performance.

Sources: Scishow ( https://www.youtube.com/watch?v=qcTOPFMEEkM )

                 http://www.bbc.co.uk/news/science-environment-20265623