Communication technologies including smartphones and laptops could now be 1,000 times faster, new study suggests

 Many of the communication tools of today rely on the function of light or, more specifically, on applying information to a light wave. Up until now, studies on electronic and optical devices with materials that are the foundations of modern electronics -- such as radio, TV, and computers -- have generally relied on nonlinear optical effects, producing devices whose bandwidth has been limited to the gigahertz (GHz) frequency region. (Hertz stands for cycles per second of a periodic phenomenon, in this case 1billion cycles).

Thanks to research performed at the University of Pittsburgh, a physical basis for terahertz bandwidth (THz, or 1 trillion cycles per second) -- the portion of the electromagnetic spectrum between infrared and microwave light -- has now been demonstrated.

In a paper published March 4 in Nature Photonics, Hrvoje Petek, a professor of physics and chemistry in Pitt's Kenneth P. Dietrich School of Arts and Sciences, and his colleague Muneaki Hase, a professor of applied physics at the University of Tsukuba in Japan and a visiting scientist in Petek's lab, detail their success in generating a frequency comb -- dividing a single color of light into a series of evenly spaced spectral lines for a variety of uses -- that spans a more than 100 terahertz bandwidth by exciting a coherent collective of atomic motions in a semiconductor silicon crystal.

"The ability to modulate light with such a bandwidth could increase the amount of information carried by more than 1,000 times when compared to the volume carried with today's technologies," says Petek. "Needless to say, this has been a long-awaited discovery in the field."

To investigate the optical properties of a silicon crystal, Petek and his team investigated the change in reflectivity after excitation with an intense laser pulse. Following the excitation, the team observed that the amount of reflected light oscillates at 15.6 THz, the highest mechanical frequency of atoms within a silicon lattice. This oscillation caused additional change in the absorption and reflection of light, multiplying the fundamental oscillation frequency by up to seven times to generate the comb of frequencies extending beyond 100 THz. Petek and his team were able to observe the production of such a comb of frequencies from a crystalline solid for the first time.

"Although we expected to see the oscillation at 15.6 THz, we did not realize that its excitation could change the properties of silicon in such dramatic fashion," says Petek. "The discovery was both the result of developing unique instrumentation and incisive analysis by the team members."

Petek notes the team's achievements are the result of developing experimental and theoretical tools to better understand how electrons and atoms interact in solids under intense optical excitation and of the invested interest by Pitt's Dietrich School in advanced instrumentation and laboratory infrastructure.

The team is currently investigating the coherent oscillation of electrons, which could further extend the ability of harnessing light-matter interactions from the terahertz- to the petahertz-frequency range. Petahertz is a unit of measure for very fast frequencies (1 quadrillion hertz).

This research was funded by a grant from the National Science Foundation.

Story Source:

The above story is reprinted from materials provided by University of Pittsburgh.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Muneaki Hase, Masayuki Katsuragawa, Anca Monia Constantinescu, Hrvoje Petek. Frequency comb generation at terahertz frequencies by coherent phonon excitation in silicon. Nature Photonics, 2012; DOI: 10.1038/nphoton.2012.35

Agilent Technologies Completes Acquisition of BioSystem Development Business

01-03-2012: Agilent Technologies Inc. announced it has completed the acquisition of the BioSystem Development business. BioSystem Development is a privately held company that develops and manufactures the AssayMAP Microchromatography platform to meet the analytical needs of the life sciences industry. Financial details of the transaction were not disclosed.

As life science discovery and development continues to move toward a better understanding of biological responses to disease, and has an increased emphasis on protein-based therapeutics by pharmaceutical companies, the need for automated, quality protein sample preparation and analysis has become critical.

BioSystem Development’s AssayMAP platform, based on disposable microchromatography cartridges, enables for the first time, automation of complex, multi-step sample preparation workflows. These include protein purification, characterization and analysis solutions for bioprocess development, biomarker identification and analysis, as well as a variety of other life science research applications.

The acquisition formalizes and streamlines the ongoing collaboration between BioSystem Development and Agilent to combine AssayMAP technology with Agilent's industry-leading automated liquid handling platforms, to reduce discovery and development time and increase lab efficiency.

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Graphene may open the gate to future terahertz technologies

 Researchers from the University of Notre Dame in Indiana have harnessed another one of graphene's remarkable properties to better control a relatively untamed portion of the electromagnetic spectrum: the terahertz band.

Terahertz radiation offers tantalizing new opportunities in communications, medical imaging, and chemical detection. Straddling the transition between the highest energy radio waves and the lowest energy infrared light, terahertz waves are notoriously difficult to produce, detect, and modulate. Modulation, or varying the height of the terahertz waves, is particularly important because a modulated signal can carry information and is more versatile for applications such as chemical and biological sensing.

Some of today's most promising terahertz technologies are based on small semiconductor transistor-like structures that are able to modulate a terahertz signal at room temperature, which is a significant advantage over earlier modulators that could only operate at extremely cold temperatures.

Unfortunately, these transistor-like devices rely on a thin layer of metal called a "metal gate" to tune the terahertz signal. This metal gate significantly reduces the signal strength and limits how much the signal can be modulated to a lackluster 30 percent. As reported in the AIP's journal Applied Physics Letters, by replacing the metal gate with a single layer of graphene, the researchers have predicted that the modulation range can be significantly expanded to be in excess of 90 percent.

This modulation is controlled by applying a voltage between the graphene and semiconductor. Unlike the metal gate modulator, the graphene design barely diminished the output power of the terahertz energy. Made up of a one-atom-thick sheet of carbon atoms, graphene boasts a host of amazing properties: it's remarkably strong, a superb thermal insulator, a conductor of electricity, and now a better means to modulate terahertz radiation.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by American Institute of Physics.

Journal Reference:

Berardi Sensale-Rodriguez, Tian Fang, Rusen Yan, Michelle M. Kelly, Debdeep Jena, Lei Liu, Huili (Grace) Xing. Unique prospects for graphene-based terahertz modulators. Applied Physics Letters, 2011; 99 (11): 113104 DOI: 10.1063/1.3636435

Laser, electric fields combined for new 'lab-on-chip' technologies

Researchers are developing new technologies that combine a laser and electric fields to manipulate fluids and tiny particles such as bacteria, viruses and DNA for a range of potential applications, from drug manufacturing to food safety.

The technologies could bring innovative sensors and analytical devices for "lab-on-a-chip" applications, or miniature instruments that perform measurements normally requiring large laboratory equipment, said Steven T. Wereley, a Purdue University professor of mechanical engineering.

The method, called "hybrid optoelectric manipulation in microfluidics," is a potential new tool for applications including medical diagnostics, testing food and water, crime-scene forensics, and pharmaceutical manufacturing.

"This is a cutting-edge technology that has developed over the last decade from research at a handful of universities," said Aloke Kumar, a Wigner Fellow and staff member at Oak Ridge National Laboratory.

He is lead author of an article about the technology featured on the cover of the July 7 issue of Lab on a Chip magazine, published by the Royal Society of Chemistry.

The article is written by Wereley; Kumar; Stuart J. Williams, an assistant professor of mechanical engineering at the University of Louisville; Han-Sheng Chuang, an assistant professor in the Department of Biomedical Engineering at National Cheng Kung University; and Nicolas G. Green, a researcher at the University of Southampton.

"A very important aspect is that we have achieved an integration of technologies that enables manipulation across a very wide length scale spectrum," Kumar said. "This enables us to manipulate not only big-sized objects like droplets but also tiny DNA molecules inside droplets by using one combined technique. This can greatly enhance efficiency of lab-on-a-chip sensors."

Kumar, Williams and Chuang are past Purdue doctoral students who worked with Wereley. Much of the research has been based at the Birck Nanotechnology Center at Purdue's Discovery Park.

The technologies are ready for some applications, including medical diagnostics and environmental samples, Williams said.

"There are two main thrusts in applications," he said. "The first is micro- and nanomanufacturing and the second is lab-on-a-chip sensors. The latter has demonstrated biologically relevant applications in the past couple of years, and its expansion in this field is immediate and ongoing."

The technology works by first using a red laser to position a droplet on a platform specially fabricated at Purdue. Next, a highly focused infrared laser is used to heat the droplets, and then electric fields cause the heated liquid to circulate in a "microfluidic vortex." This vortex is used to isolate specific types of particles in the circulating liquid, like a micro centrifuge. Particle concentrations replicate the size, location and shape of the infrared laser pattern.

"This works very fast," Wereley said. "It takes less than a second for particles to respond and get pulled out of solution."

Systems using the hybrid optoelectric approach can be designed to precisely detect, manipulate and screen certain types of bacteria, including particular strains that render heavy metals less toxic.

"We are shooting for biological applications, such as groundwater remediation," Wereley said. "Even within the same strain of bacteria some are good at the task and some are not, and this technology makes it possible to efficiently cull those bacteria from others. The bacteria could be injected into the contaminated ground. You seed the ground with the bacteria, but first you need to find an economical way to separate it."

Purdue researchers also are pursuing the technology for pharmaceutical manufacturing, he said.

"These types of technology are good at being very dynamic, which means you can decide in real time to grab all particles of one size or one type and put them somewhere," Wereley said. "This is important for the field of pharmacy because a number of drugs are manufactured from solid particles suspended in liquid. The particles have to be collected and separated from the liquid."

This process is now done using filters and centrifuges.

"A centrifuge does the same sort of thing but it's global, it creates a force on every particle, whereas this new technology can specifically isolate only certain particles," Wereley said. "We can, say, collect all the particles that are one micron in diameter or get rid of anything bigger than two microns, so you can dynamically select which particles you want to keep."

The technology also may be used as a tool for nanomanufacturing because it shows promise for the assembly of suspended particles, called colloids. The ability to construct objects with colloids makes it possible to create structures with particular mechanical and thermal characteristics to manufacture electronic devices and tiny mechanical parts. The nanomanufacturing applications are at least five years away, he said.

The technology also can be used to learn fundamental electrokinetic forces of molecules and biological structures, which is difficult to do with existing technologies.

"Thus there are very fundamental science applications of these technologies as well," Kumar said.

Story Source:

The above story is reprinted (with editorial adaptations ) from materials provided by Purdue University. The original article was written by Emil Venere.

Journal Reference:

Aloke Kumar, Stuart J. Williams, Han-Sheng Chuang, Nicolas G. Green, Steven T. Wereley. Hybrid opto-electric manipulation in microfluidics—opportunities and challenges. Lab on a Chip, 2011; 11 (13): 2135 DOI: 10.1039/C1LC20208A

Iowa State hybrid lab combines technologies to make biorenewable fuels and products

Laura Jarboe pointed to a collection of test tubes in her Iowa State University laboratory.

Some of the tubes looked like they were holding very weak coffee. That meant microorganisms – in this case, Shewanella bacteria – were growing and biochemically converting sugars into hydrocarbons, said Jarboe, an Iowa State assistant professor of chemical and biological engineering.

Some of the sugars in those test tubes were produced by the fast pyrolysis of biomass. That's a thermochemical process that quickly heats biomass (such as corn stalks and leaves) in the absence of oxygen to produce a liquid product known as bio-oil and a solid product called biochar. The bio-oil can be used to manufacture fuels and chemicals; the biochar can be used to enrich soil and remove greenhouse gases from the atmosphere.

Iowa State's Hybrid Processing Laboratory on the first floor of the new, state-built Biorenewables Research Laboratory is all about encouraging that unique mix of biochemical and thermochemical technologies. The goal is for biologists and engineers to use the lab's incubators, reactors, gas chromatography instruments and anaerobic chambers to find new and better ways to produce biorenewable fuels and chemicals.

"Biological processes occur well below the boiling point of water, while thermal processes are usually performed hundreds of degrees higher, which makes it hard to imagine how these processes can be combined," said Robert C. Brown, an Anson Marston Distinguished Professor in Engineering, the Gary and Donna Hoover Chair in Mechanical Engineering, and the Iowa Farm Bureau Director of Iowa State's Bioeconomy Institute.

"In fact, these differences in operating regimes represent one of the major advantages of hybrid processing," Brown said. "High temperatures readily break down biomass to substrates that can be fermented to desirable products."

Jarboe's research is one example. She's trying to develop bacteria that can grow and thrive in the chemicals and compounds that make up bio-oil. That way, they can ferment the sugars from bio-oil with greater efficiency and produce more biorenewable fuels or chemicals.

Another example of mixing the biochemical with the thermochemical is the work of Zhiyou Wen, an associate professor of food science and human nutrition, and Yanwen Shen, a doctoral student in his research group.

They're working to break down a bottleneck in the fermentation of synthesis gas – a mixture of carbon monoxide and hydrogen that's produced by the partial combustion of biomass in a gasifier. The fermentation process slows when researchers dissolve the gas into a liquid that can be used by microorganisms to produce biofuels. They're looking for bioreactor technologies that boost the mass transfer of the synthesis gas without adding energy costs.

A third example is the work of DongWon Choi, a former doctoral student and post-doctoral research associate at Iowa State who's now an assistant professor of biological and environmental sciences at Texas A&M University Commerce. He continues to collaborate in the hybrid lab by working with microalgae that convert carbon dioxide into oil that can be used to produce biofuels.

That oil is currently harvested with solvents or mechanical presses. Both processes produce a lot of waste and the resulting waste management problems. Choi is using pyrolysis technology to heat the algae and convert it into jet and diesel fuels without the waste.

And the researchers say the hybrid lab's mix of people, technologies, equipment and ideas is beginning to show results.

"The hybrid lab provides enormous opportunities for performing biological-based processes for producing biofuel from thermochemically treated biomass," Wen said.

Yes, said Jarboe, "I think it is working well. This is a long process, but we're writing research proposals and papers. Everybody loves the idea of this hybrid approach. It has such a promising future; the challenge is in the collaboration."

The hybrid lab is starting to make the collaboration easier, though.

Brown said he's noticed the students who work in the hybrid lab seem to be comfortable crossing thermochemical and biochemical lines: "Just like children from different cultures often learn to communicate with one another more quickly than do their parents, graduate students seem to pick up cross disciplinary culture and language faster than their faculty advisers."

Provided by Iowa State University (news : web)

Agilent Technologies Publishes Industry’s First Compendium to Test for Synthetic Marijuana Compounds

05-27-2011: Agilent Technologies Inc. announced availability of the industry’s first GC/MS compendium to test for synthetic cannabinoids, recently declared controlled substances by the U.S. Drug Enforcement Agency. They are most commonly found in “herbal incense” blends.

The compendium, available from Agilent at no cost to qualified forensics labs, contains detailed procedures for sample preparation and GC/MS method, plus a searchable mass-spectral library to test for 35 synthetic cannabinoids and their derivatives. The method and library were developed in collaboration with the Criminalistics Division of NMS Labs, an independent forensic laboratory certified by the American Board of Forensic Toxicology and the American Society of Crime Laboratory Directors.

“These compounds had not been controlled until November of 2010, when health concerns prompted the DEA to evoke an emergency ban,” said Tom Gluodenis, Ph.D., Agilent forensic and toxicology business manager. “They present a number of analytical challenges. Formulations are rapidly evolving. When one is banned, it can quickly be replaced by a new one. They’re often sold in botanical matrixes as ‘herbal incense’ and other products, which presents additional challenges. We published this compendium to help labs get a handle on this dynamic situation.”

The DEA currently controls six versions of synthetic cannabinoids: JWH-018, JWH-073, JWH-200, CP-47-497 (C7), CP-47-497 (C8) and HU-210. There are more than 20 uncontrolled forms, and this number is expected to grow.

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Leicester researchers develop technologies to crack down on counterfeit whisky

Experts at the University of Leicester's Space Research Centre are working with colleagues at De Montfort University to create a handheld device which will detect fake whisky and wine – through the bottle.

The exciting research project to crack down on counterfeit whisky and wine is being supported by The Food and Drink iNet.

The technology has already been developed by the University of Leicester team to spot counterfeit medicines by scrutinising the packaging. Now the experts are working to transfer the technology to analyse liquids in bottles.

As well as helping to stamp out the big problem of counterfeit whisky and fine wine, this could also have major potential for airline security systems, they believe.

The technique relies on detecting the differences between the characteristics of light reflected from printed packaging. Originally developed from a spectrometer designed and built by the Space Research Centre for astronomical research, the technique was adapted for use in the pharmaceutical world by the University of Leicester team in conjunction with university spin-out firm Perpetuity Research and Consultancy International Limited which is a specialist crime and security consultancy.

Now the technology is being adapted again by the University of Leicester team for use in detecting fake liquids, with experts at De Montfort University providing skills in product design and rapid proto-typing so that a handheld device can be created.

“The support from the Food and Drink iNet will allow us to take the technology and apply it in the case of whisky and fine wines,” said Tim Maskell, Knowledge Transfer Manager in the Space Research Centre at the University of Leicester. “The iNet funding will enable us to design, build and test a laboratory prototype that will allow us to prove the technology works. If we can then take the technology and do something similar with other liquids there are potential airport security opportunities too.”

The project is one of five Collaborative Research and Development grants worth a total of more than L235,000 announced by the Food and Drink iNet, which co-ordinates innovation support for businesses, universities and individuals working in the food and drink sector in the East Midlands. The team has been awarded L50,000 towards the almost L71,000 cost of the research project.

Funded by East Midlands Development Agency (emda) and the European Regional Development Fund (ERDF), the Food and Drink iNet is one of four regional iNets that has developed an effective network to link academic and private sector expertise and knowledge with local food and drink business innovation needs.

“This is a fascinating research project between the University of Leicester, De Montfort University, the Scotch Whisky Research Institute and Leicestershire brewery Everards, which brings together space technology and the food and drink sector and offers real commercial benefit,” said Food and Drink iNet Director Richard Worrall. “Being able to test a liquid such as whisky or wine for authenticity without opening the bottle would bring major benefits to the drinks industry, as well as having opportunities in other fields, such as airport and airline security.

“The Food and Drink iNet Collaborative Research and Development programme is designed to provide help for innovative research schemes that will benefit the food and drink sector in the future, and this is one of the more interesting and beneficial.”

The team is working with The Scotch Whisky Research Institute and Leicestershire brewery Everards to help with the research and product trials.

The Food and Drink iNet aims to build on the tradition of innovation in the food and drink industry in the region by helping to create opportunities to develop knowledge and skills, and to help research, develop and implement new products, markets, services and processes. It is managed by a consortium, led by the Food and Drink Forum and including Food Processing Faraday, Nottingham Trent University, the University of Lincoln, and the University of Nottingham. It is based at Southglade Food Park, Nottingham, with advisors covering the East Midlands region.

Provided by University of Leicester (news : web)

Atom-thick sheets unlock future technologies

A new way of splitting layered materials, similar to graphite, into sheets of material just one atom thick could lead to revolutionary new electronic and energy storage technologies.

An international team, led by Oxford University and Trinity College Dublin scientists, has invented a versatile method for creating these one-atom thick 'nanosheets' from a range of materials using mild ultrasonic pulses, like those generated by jewellery cleaning devices, and common solvents. The new method is simple, fast, and inexpensive, and could be scaled up to work on an industrial scale.

The team publish a report of the research in this week's Science.

Each one-millimetre-thick layer of graphite is made up of around three million layers of graphene -- a flat sheet of carbon one atom thick -- stacked one on top of the other.

'Because of its extraordinary electronic properties graphene has been getting all the attention, including a recent Nobel Prize, as physicists hope that it might, one day, compete with silicon in electronics,' said Dr Valeria Nicolosi of Oxford University's Department of Materials, who led the research with Professor Jonathan Coleman of Trinity College Dublin. 'But in fact there are hundreds of other layered materials that could enable us to create powerful new technologies.'

Professor Coleman, of Trinity College Dublin, said: 'These novel materials have chemical and electronic properties which are well suited for applications in new electronic devices, super-strong composite materials and energy generation and storage. In particular, this research represents a major breakthrough towards the development of efficient thermoelectric materials.'

There are over 150 of these exotic layered materials -- such as Boron Nitride, Molybdenum disulfide, and Tungsten disulfide -- that have the potential to be metallic, semi-metallic or semiconducting depending on their chemical composition and how their atoms are arranged.

For decades researchers have tried to create nanosheets of these kind of materials as arranging them in atom-thick layers would enable us to unlock their unusual electronic and thermoelectric properties. However, all previous methods were extremely time consuming and laborious and the resulting materials were fragile and unsuited to most applications.

'Our new method offers low-costs, a very high yield and a very large throughput: within a couple of hours, and with just 1 mg of material, billions and billions of one-atom-thick graphene-like nanosheets can be made at the same time from a wide variety of exotic layered materials,' said Dr Nicolosi.

Nanosheets created using this method can be sprayed onto the surface of other materials, such as silicon, to produce 'hybrid films' which, potentially, enable their exotic abilities to be integrated with conventional technologies. Such films could be used to construct, among other things, new designs of computing devices, sensors or batteries.

The work was conducted by a team including scientists from Oxford University, Trinity College Dublin, Imperial College London, Korea University, and Texas A&M University (USA).

Story Source:

The above story is reprinted (with editorial adaptations ) from materials provided by University of Oxford.

Journal Reference:

J. N. Coleman, M. Lotya, A. O'Neill, S. D. Bergin, P. J. King, U. Khan, K. Young, A. Gaucher, S. De, R. J. Smith, I. V. Shvets, S. K. Arora, G. Stanton, H.-Y. Kim, K. Lee, G. T. Kim, G. S. Duesberg, T. Hallam, J. J. Boland, J. J. Wang, J. F. Donegan, J. C. Grunlan, G. Moriarty, A. Shmeliov, R. J. Nicholls, J. M. Perkins, E. M. Grieveson, K. Theuwissen, D. W. McComb, P. D. Nellist, V. Nicolosi. Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials. Science, 2011; 331 (6017): 568 DOI: 10.1126/science.1194975