New Polymer Could Improve Semiconductor Manufacturing, Packaging

Daily Science Journal (Feb. 2, 2008) — Researchers at Rensselaer Polytechnic Institute and Polyset Company have developed a new inexpensive, quick-drying polymer that could lead to dramatic cost savings and efficiency gains in semiconductor manufacturing and computer chip packaging.

Researchers from Rensselaer Polytechnic Institute's Department of Physics and Center for Integrated Electronics have developed a new inexpensive, quick-drying polymer that could lead to dramatic cost savings and efficiency gains in semiconductor manufacturing and computer chip packaging. In this series of scanning electron microscope images of the new PES polymer in a UV-imprint lithography application, the well-defined pattern indicates the material’s potential for use in next-generation chip making techniques. (Credit: Rensselaer Polytechnic Institute)

Along with allowing enhanced performance and cost savings for conventional photolithography processes, the new material, called polyset epoxy siloxane (PES), should also enable a new generation of lower-cost, on-chip nanoimprinting lithography technology, according to the researchers.

"With this new material, chip manufacturers will be able to trim several steps from their production and packaging processes, and in turn realize a cost savings," said Toh-Ming Lu, the R.P. Baker Distinguished Professor of Physics at Rensselaer, who oversaw the study. "PES is cheaper and more reliable."

The widely adopted technique of photolithography involves using a mix of light and chemicals to generate intricate micro- and nano-scale patterns on tiny areas of silicon. As part of the process, a thin polymer film -- called a redistribution layer, and crucial to the effectiveness of device -- is deposited onto the silicon wafer, in order to ease the signal propagation delay and to protect the chip from different environmental and mechanical factors.

The new PES material developed by Lu's group and Polyset Company is one such thin polymer film, and it offers several advantages over the incumbent materials typically used in the semiconductor manufacturing industry. In addition, their new PES material can also be used as a thin polymer film for ultraviolet (UV) on-chip nanoimprinting lithography technology, which is still in the early phases of development. The consistency of using PES in conventional technology, and then continuing to use PES while academia and industry test and gradually migrate to the next generation of devices, should help ease the transition, Lu said.

"Having the ability to use one material -- our new PES -- for both photolithography and imprint will be very attractive to manufacturers," Lu said. "At its core, our project is basic research, but it also has important industry implications. It's very exciting."

Manufacturers today typically use benzocyclobutene and polyimide as polymers for redistribution layers, because of their low water absorption, thermal stability, low curing temperature, low thermal expansion, low dielectric constant, and low leakage current. Lu said PES offers significant advantages to these materials, particularly in the areas of cure temperature and water uptake.

PES cures, or dries and hardens, at 165 degrees Celsius, about 35 percent cooler than the other two materials. The need for less heat should translate directly into lower overhead costs for manufacturers, Lu said. Another advantage of PES is its low water uptake rate of less than 0.2 percent, less than the other materials. Additionally, PES adheres well to copper and can easily be made less brittle if needed. All of these attributes make PES a promising candidate for redistribution layer application and UV imprint lithography.

"The results demonstrate that PES is feasible to be used as UV-curable resist for both the redistribution application for electronic packaging and micro/nano imprint lithography," said Rensselaer Research Associate Pei-I Wang, co-author of the new paper, published recently in the Journal of Vacuum Science and Technology B.

Along with photolithography and on-chip nanoimprinting lithography, PES holds the potential for applications in other optical devices, flat-panel display, biotechnology devices, and microelectromechanical systems, Wang said.

In addition to Lu and Wang, co-authors on the paper include Rensselaer materials science and engineering professor Omkaram Nalamasu, who is also chief technical officer of Applied Materials Inc. in Santa Clara, Calif.; Rajat Ghoshal and Ram Ghoshal of Polyset Co. Inc. in Mechanicville, N.Y.; Charles Schaper of Transfer Devices Inc. in Santa Clara, Calif.; and Andrew Li of Applied Materials.

The project was funded through the New York State Foundation for Science, Technology and Innovation.

Adapted from materials provided by Rensselaer Polytechnic Institute.

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Computer Scientist Makes Splash With Academy Award For Fluid Simulation

Daily Science Journal (Jan. 31, 2008) — The rushing floodwaters in Evan Almighty, the heaving seas of the latter two Pirates of the Caribbean movies and the dragon's flaming breath in Harry Potter and the Goblet of Fire all featured computer-generated fluids in spectacular action. The science behind those splashy thrills will be recognized Feb. 9 with an Academy Award for Ron Fedkiw, associate professor of computer science at Stanford, and two collaborators at the special effects firm Industrial Light and Magic (ILM).

A computer-generated scene shows off the fluid simulation technology developed by computer science Associate Professor Ron Fedkiw, former students, and collaborators at Industrial Light and Magic. (Credit: Frank Losasso, Jerry Talton, Nipun Kwatra, Ron Fedkiw / courtesy of Stanford University)

"The primary work started a few years ago when we developed a system designed for the female liquid terminator in Terminator 3," Fedkiw said. "Almost immediately after that it was used in the first Pirates of the Caribbean movie to simulate the wine that the pirate skeleton was drinking out of the bottle in the moonlight. Things like the sinking ship in Poseidon and the large water whirlpool in Pirates of the Caribbean 3 are good examples of the system in action."

The system, co-developed with ILM scientists Nick Rasmussen and Frank Losasso Petterson (a former doctoral student of Fedkiw's), uses a method of simulating low-viscosity fluids such as water and fire, as in the explosions in Star Wars: Revenge of the Sith.

Contributing to a Star Wars movie was a particular honor for Fedkiw.

"George Lucas made Star Wars and, well, that changed the world for a lot of us," he said. "It's amazing what a movie can do to a civilization. I can only be grateful that he made three more of them and that I started working with ILM just in time to get a screen credit on the last one."

Lifelike liquids

Computer graphics experts typically have used particles and complex blobs to represent water, but these can give rise to unrealistically lumpy or grainy surfaces. Alternatively, they have used a technique called "the level set method" that gives a smooth surface representation, but some water is "under-resolved" and simply disappears when it breaks down into small volumes, as in a crashing wave.

The key innovation behind Fedkiw and former doctoral student Douglas Enright's novel "particle level set method" was to mix the use of particles and level sets so that studios could maintain smooth surfaces wherever possible and still keep all the fluid via the particle representation.

"As an added bonus, the method automatically generates spray particles and bubbles in under-resolved regions where the level set [method] loses mass and volume," Fedkiw said.

Fedkiw gives a lot of the credit to his colleagues for the system used to make the movies: "Nick made the system and Frank made it rock."

The effect's power is clearly evident in a movie on Fedkiw's website. There, gigantic waves crash against a lighthouse and produce huge sprays. In addition to incorporating the particle level set method, the rendering also uses an additional method to simulate how the spray interacts with itself and the surrounding water.

Such integrations are indicative of a future direction of Fedkiw's computer graphics research.

"This year we built a system that allows two-way coupling between rigid and deformable bodies, so we can fully physically simulate bones moving around under flesh—interacting with the environment," he said. "Another main result is a two-way, solid-fluid coupling method that can be used with it, so the environment can be water; that is, we're going to be simulating people swimming."

Of course the more immediate future calls for a trip to the Beverly Wilshire Hotel in Beverly Hills for the Scientific and Technical Academy Awards presentation Feb. 9. Fedkiw says he'll probably go to pick up his plaque.

"After wearing sandals for the last two years—even in the Lake Tahoe snow— it's going to be tough to go black tie," he said.

Adapted from materials provided by Stanford University.

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Computer-based Tool Aids Research, Helps Thwart Questionable Publication Practices

Daily Science Journal (Jan. 29, 2008) — A new computer-based text-searching tool developed by UT Southwestern Medical Center researchers automatically -- and quickly -- compares multiple documents in a database for similarities, providing a more efficient method to carry out literature searches, as well as offering scientific journal editors a new tool to thwart questionable publication practices.

Dr. Harold "Skip" Garner. (Credit: UT Southwestern Medical Center)

The eTBLAST computer program is efficient at flagging publications that are highly similar, said Dr. Harold "Skip" Garner, a professor of biochemistry and internal medicine at UT Southwestern who developed the computer code along with his colleagues. Not only does the code identify duplication of key words, but it also compares word proximity and order, among other variables.

The tool is especially useful for investigators who wish to analyze an unpublished abstract or project idea in order to find previous publications on the topic or identify possible collaborators working in the same field.

Another application of eTBLAST is to aid journal editors in detecting potentially plagiarized or duplicate articles submitted for publication. Dr. Garner and his colleagues explored that application in two recent articles: in a scientific paper in the Jan. 15 issue of Bioinformatics and in a commentary in the Jan. 24 issue of Nature.

In the first phase of the study, published in Bioinformatics, researchers used eTBLAST to analyze more than 62,000 abstracts from the past 12 years, randomly selected from Medline, one of the largest databases of biomedical research articles. They found that 0.04 percent of papers with no shared authors were highly similar and cases representing potential plagiarism. The small percentage found in the sample may appear insignificant, but when extrapolated to the 17 million scientific papers currently cited in the database, the number of potential plagiarism cases grows to nearly 7,000.

The researchers also found that 1.35 percent of papers with shared authors were sufficiently similar to be considered duplicate publications of the same data, another questionable practice.

In the second phase of the study, outlined in the Nature commentary, Dr. Garner and Dr. Mounir Errami, an instructor in internal medicine, refined their electronic search process so that is was thousands of times faster. An analysis of more than seven million Medline abstracts turned up nearly 70,000 highly similar papers.

Plagiarism may be the most extreme and nefarious form of unethical publication, Dr. Garner said, but simultaneously submitting the same research results to multiple journals or repeated publication of the same data may also be considered unacceptable in many circumstances.

When it comes to duplicate or repeated publications, however, there are some forms that are not only completely ethical, but also valuable to the scientific community. For example, long-term studies such as clinical trial updates and longitudinal surveys require annual or bi-annual publication of progress, and these updates often contain verbatim reproductions of much of the original text.

"We can identify near-duplicate publications using our search engine," said Dr. Garner, who is a faculty member in the Eugene McDermott Center for Human Growth and Development at UT Southwestern. "But neither the computer nor we can make judgment calls as to whether an article is plagiarized or otherwise unethical. That task must be left to human reviewers, such as university ethics committees and journal editors, the groups ultimately responsible for determining legitimacy."

Dr. Garner said eTBLAST not only detects the prevalence of duplicate publications, but also offers a possible solution to help prevent future unethical behavior.

"Our objective in this research is to make a significant impact on how scientific publications may be handled in the future," Dr. Garner said. "As it becomes more widely known that there are tools such as eTBLAST available, and that journal editors and others can use it to look at papers during the submission process, we hope to see the numbers of potentially unethical duplications diminish considerably."

Other UT Southwestern researchers in the McDermott Center who were involved in the research are computer programmer Justin Hicks, postdoctoral researcher Dr. Wayne Fisher, network analyst David Trusty and staff member Tara Long. Dr. Jonathan Wren at the Oklahoma Medical Research Foundation also participated.

The research was funded by the Hudson Foundation and the National Institutes of Health.

Adapted from materials provided by UT Southwestern Medical Center.

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Videos Extract Mechanical Properties Of Liquid-gel Interfaces

Daily Science Journal (Jan. 29, 2008) — Blood coursing through vessels, lubricated cartilage sliding against joints, ink jets splashing on paper--living and nonliving things abound with fluids meeting solids. However important these liquid/solid boundaries may be, conventional methods cannot measure basic mechanical properties of these interfaces in their natural environments. Now, researchers at the National Institute of Standards and Technology (NIST) and the University of Minnesota have demonstrated a video method that eventually may be able to make measurements on these types of biological and industrial systems.*

Microscopic beads embedded in a gel surface were used to trace the motion of a gel forming an interface with a liquid. As the gel/liquid interface was stirred, the beads followed a complicated trajectory (patterns above photos), which the researchers broke down into a range of small, fast movements to large, slow movements in order to determine the gel's underlying mechanical properties. As the strength of the flow is increased (from left to right), the scale of the motion increases. (Credit: NIST)

Optical microrheology--an emerging tool for studying flow in small samples--usually relies on heat to stir up motion. Analyzing this heat-induced movement can provide the information needed to determine important mechanical properties of fluids and the interfaces that fluids form with other materials. However, when strong flows overwhelm heat-based motion, this method isn't applicable.

Motivated by this, researchers developed a video method that can extract optically basic properties of the liquid/solid interface in strong flows. The solid material they chose was a gel, a substance that has both solid-like properties such as elasticity and liquid-like properties such as viscosity (resistance to flow).

In between a pair of centimeter-scale circular plates, the researchers deposited a gel of polydimethylsiloxane (a common material used in contact lenses and microfluidics devices). Pouring a liquid solution of polypropylene glycol on the gel, they then rotated the top plate to create forces at the liquid/gel interface. The results could be observed by tracking the motion of styrene beads in the gel.

The researchers discovered that the boundary between the liquid and gel became unstable in response to "mechanical noise" (irregularities in the motion of the plates). Such "noise" occurs in real-world physical systems. Surprisingly, a small amount of this mechanical noise produced a lot of motion at the fluid/gel interface. This motion provided so much useful information that the researchers could determine the gel's mechanical properties--namely its "viscoelasticity"--at the liquid/gel interface.

The encouraging results from this model system show that this new approach could potentially be applied to determining properties of many useful and important liquid/solid interfaces. The NIST/Minnesota approach has possible applications in areas as diverse as speech therapy where observing the flow of air over vocal cords could enable noninvasive measures of vocal tissue elasticity and help clinicians detect problems at an early stage. Also, this research may help clarify specific plastics manufacturing problems, such as "shear banding," in which flow can separate a uniformly blended polymer undesirably into different components.

* E.K. Hobbie, S. Lin-Gibson, and S. Kumar Non-Brownian microrheology of a fluid-gel interface, To appear in Physical Review Letters.

Adapted from materials provided by National Institute of Standards and Technology.

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New Scoring System Protects Credit Card Transactions

Daily Science Journal (Nov. 11, 2007) — As this year's holiday season approaches, your credit card transactions may be a little more secure thanks to standards adopted by the payment card industry. The latest incarnation of these standards include the Common Vulnerability Scoring System (CVSS) Version 2 that was coauthored this year by researchers at the National Institute of Standards and Technology and Carnegie Mellon University in collaboration with 23 other organizations.

When you make an electronic transaction--either swiping a card at a checkout counter or through a commercial Web site--you enter personal payment information into a computer. That information is sent to a payment-card "server," a computer system often run by the bank or merchant that sponsors the particular card. The server processes the payment data, communicates the transaction to the vendor, and authorizes the purchase.

According to NIST's Peter Mell, lead author of CVSS Version 2, a payment-card server is like a house with many doors. Each door represents a potential vulnerability in the operating system or programs. Attackers check to see if any of the "doors" are open, and if they find one, they can often take control of all or part of the server and potentially steal financial information, such as credit card numbers.

For every potential vulnerability, CVSS Version 2 calculates its risks on a scale from zero to 10, assesses how the vulnerability could compromise confidentiality (exposing private information such as credit card numbers), availability (could it be used to shut down the credit card system") and integrity (can it change credit card data"). The CVSS scores used by the credit card industry are those for the 28,000 vulnerabilities provided by the NIST National Vulnerability Database (NVD), sponsored by the Department of Homeland Security.

To assess the security of their servers, payment card vendors use software that scans their systems for vulnerabilities. To promote uniform standards in this important software, the PCI (Payment Card Industry) Security Standards Council, an industry organization, maintains the Approved Scanning Vendor (ASV) compliance program, which currently covers 135 vendors, including assessors who do onsite audits of PCI information security. By June 2008, all ASV scanners must use the current version of CVSS in order to identify security vulnerabilities and score them.

Requiring ASV software to use CVSS, according to Bob Russo, General Manager of the PCI Security Standards Council, promotes consistency between vendors and ultimately provides good information for protecting electronic transactions. The council also plans to use NIST's upcoming enhancements to CVSS, which will go beyond scoring vulnerabilities to identify secure configurations on operation systems and applications.

Adapted from materials provided by National Institute of Standards and Technology, via EurekAlert!, a service of AAAS.

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Face Recognition Made Possible With New Computer Program

Daily Science Journal (Jan. 25, 2008) — Hung-Son Le, Umeå University, Sweden, has developed in his PhD dissertation the algorithms that give a computer the possibility of recognising a face, even if only one picture is taken. The results can be used for safe and secure identity control or, on the light side, to find out to which famous persons you look alike.

If a non-authorised person gets access to your pin code and credit card, most likely your money will disappear from your account. Nevertheless, this would be impossible if the ATM could recognize your face as you look at a camera. Now, the algorithms to carry out this function, face recognition, exist. Face recognition can also be used in other functions, for instance in a dating service. Maybe the customer is interested in a man that looks like Brad Pitt or a woman that looks like Angelina Jolie.

Systems that can identify different faces are normally trained through a database with a large collection of face images in different illumination and pose. Nevertheless to collect such a large number of face images for each person is difficult and quite often expensive. Moreover these systems have problems due to the bad quality of the pictures, as well as facial expressions, the variety of angles and the different illuminations. These problems are now over.

The effective algorithms developed by Hung-Son Le make it possible to have a system that can identify a face even when there is only one picture in the database for each person. Moreover, the effectiveness of the system is a considerable improvement when taking into account light conditions, or facial expressions. His algorithms use a method than improves contrast in underexposed and overexposed pictures. Thus details can be made visible which otherwise would be difficult for a computer to identify. Given the method used (Hidden Markov Model, HMM), once the system is in place, it needs no time for retraining, when compared to existing HMM-based competitors, to “know” new pictures with different expressions taken under different illumination conditions.

The experiments carried out with the system and tested against international standards such as FERET and the Yale database, have demonstrated that it outperforms the leading competitors.

Commercial applications based on the PhD dissertation results are under development and will soon be presented. Among others, a face websearch engine is under final development phase.

Adapted from materials provided by Umeå University, via AlphaGalileo.

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Integrated Receiver For High Frequency Applications On A Tiny Chip

Daily Science Journal (Dec. 31, 2007) — Researchers at Chalmers University in Sweden have succeeded in combining a receiver for high frequencies with an antenna on a small chip.

The receiver is just a few square millimetre and is suitable for new safety systems, image sensors, and radio communication for high bitrates. The receiver is an electronic circuit including antenna, low noise amplifier, and frequency converter monolithically integrated on gallium arsenide.

"This is a breakthrough in our research. Our result opens the possibility to manufacture systems for very high frequencies within the so called 'THZ-electronics' area, to a relatively low cost. In the next phase of this project even more functions can be integrated on the same chip", according to Herbert Zirath, professor at the department of Microwave Electronics.

This circuit can be used, for instance, in radiometer systems in future safety systems looking for concealed weapons without personal intrusive search. Other applications for this circuit are imaging sensors that can look through darkness, smoke or fog. This is an important safety function for vehicles such as cars and aircrafts.

"Thanks to this technology, we now have the possibility of integrating imaging sensors by using circuits of a few square millimetre which is much smaller that the present technology at a lower cost. For automotive applications such as cars, aircrafts and satellites, the size and weight is of utmost importance. The present systems consist of many pieces and demands several cubic decimetres volume", says Herbert Zirath.

The new circuit is designed to work at the frequency of 220 gigahertz, but this is not an upper limit. According to professor Zirath, the technology can be used up to and above 300GHz in a near future.

The technology is also interesting for wireless data communication because, due to the very high bandwidth, data rate well above 10 Gbit/s is possible to realize in future radio links. Together with Omnisys Instruments in Gothenburg, we are also implementing receivers for future earth observation satellites for environmental studies and weather forecasts at frequencies 118 and 183 GHz, using the same technology.

This work is the results of a co-operation between Chalmers, Saab Microwave Systems, Omnisys Instruments AB, FOI, The Fraunhofer Institute IAF in Freiburg and FGAN, Germany, within the project "nanoComp".

Adapted from materials provided by Chalmers University.

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Biometrics: Unlocking Doors With Your Eyes

Daily Science Journal (Dec. 14, 2007) — It is not science fiction to think that our eyes could very soon be the key to unlocking our homes, accessing our bank accounts and logging on to our computers, according to Queensland University of Technology researcher Sammy Phang.

QUT researcher Sammy Phang. (Credit: Image courtesy of Queensland University of Technology)

Research by Ms Phang, from QUT's Faculty of Built Environment and Engineering, is helping to remove one of the final obstacles to the everyday application of iris scanning technology.

Ms Phang said the pattern of an iris was like a fingerprint in that every iris was unique. "Every individual iris is unique and even the iris pattern of the left eye is different from the right. The iris pattern is fixed throughout a person's lifetime" she said.

"By using iris recognition it is possible to confirm the identity of a person based on who the person is rather than what the person possesses, such as an ID card or password.

"It is already being used around the world and it is possible that within the next 10 to 20 years it will be part of our everyday lives."

Ms Phang said although iris recognition systems were being used in a number of civilian applications, the system was not perfect. "Changes in lighting conditions change a person's pupil size and distort the iris pattern," she said.

"If the pupil size is very different, the distortion of the iris pattern can be significant, and makes it hard for the iris recognition system to work properly."

To overcome this flaw, Ms Phang has developed the technology to estimate the effect of the change in the iris pattern as a result of changes in surrounding lighting conditions. "It is possible for a pupil to change in size from 0.8mm to 8mm, depending on lighting conditions," she said.

Ms Phang said by using a high-speed camera which could capture up to 1200 images per second it was possible to track the iris surface's movements to study how the iris pattern changed depending on the variation of pupil sizes caused by the light. "The study showed that everyone's iris surface movement is different."

She said results of tests conducted using iris images showed it was possible to estimate the change on the surface of the iris and account for the way the iris features changed due to different lighting conditions.

"Preliminary image similarity comparisons between the actual iris image and the estimated iris image based on this study suggest that this can possibly improve iris verification performance."

Adapted from materials provided by Queensland University of Technology.

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Cooler, Faster, Cheaper: Researchers Advance Process To Manufacture Silicon Chips

Daily Science Journal (Dec. 11, 2007) — The next generation of laptops, desk computers, cell phones and other semiconductor devices may get faster and more cost-effective with research from Clemson University.

Prototype of the semiconductor processing equipment may lead to commercial manufacturing tools for developing future generations of silicon chips. (Credit: Image courtesy of Clemson University)

“We’ve developed a new process and equipment that will lead to a significant reduction in heat generated by silicon chips or microprocessors while speeding up the rate at which information is sent,” says Rajendra Singh, D. Houser Banks Professor and director for the Center for Silicon Nanoelectronics at Clemson University.

The heart of many high-tech devices is the microprocessor that performs the logic functions. These devices produce heat depending on the speed at which the microprocessor operates. Higher speed microprocessors generate more heat than lower speed ones. Presently, dual-core or quad-core microprocessors are packaged as a single product in laptops so that heat is reduced without compromising overall speed of the computing system. The problem, according to Singh, is that writing software for these multicore processors, along with making them profitable, remains a challenge.

“Our new process and equipment improve the performance of the materials produced, resulting in less power lost through leakage. Based on our work, microprocessors can operate faster and cooler. In the future it will be possible to use a smaller number of microprocessors in a single chip since we’ve increased the speed of the individual microprocessors. At the same time, we’ve reduced power loss six-fold to a level never seen before. Heat loss and, therefore, lost power has been a major obstacle in the past,” said Singh.

The researchers say the patented technique has the potential to improve the performance and lower the cost of next-generation computer chips and a number of semiconductor devices, which include green energy conversion devices such as solar cells.

“The potential of this new process and equipment is the low cost of manufacturing, along with better performance, reliability and yield,” Singh said. “The semiconductor industry is currently debating whether to change from smaller (300 mm wafer) manufacturing tools to larger ones that provide more chips (450 mm). Cost is the barrier to change right now. This invention potentially will enable a reduction of many processing steps and will result in a reduction in overall costs.”

Participants in the research included Aarthi Venkateshan, Kelvin F. Poole, James Harriss, Herman Senter, Robert Teague of Clemson and J. Narayan of North Carolina State University at Raleigh. Results were published in Electronics Letters, Oct. 11, 2007, Volume: 43, Issue: 21,
 pages: 1130-1131. The work reported here is covered by a broad-base patent of Singh and Poole issued to Clemson University in 2003.

Adapted from materials provided by Clemson University.

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World's Most Complex Silicon Phased-array Chip Developed

Daily Science Journal (Nov. 4, 2007) — UC San Diego electrical engineers have developed the world's most complex “phased array” -- or radio frequency integrated circuit. This DARPA-funded advance is expected to find its way into U.S. defense satellite communication and radar systems. In addition, the innovations in this chip design will likely spill over into commercial applications, such as automotive satellite systems for direct broadcast TV, and new methods for high speed wireless data transfer.

The UCSD DARPA Smart Q-Band 4x4 Array Transmitter, the world’s most complex silicon phased array chip. (Credit: Image courtesy of University of California - San Diego)

“This is the first 16 element phased array chip that can send at 30-50 GHz. The uniformity and low coupling between the elements, the low current consumption and the small size – it is just 3.2 by 2.6 square millimeters – are all unprecedented. As a whole system, there are many many firsts,” said Gabriel Rebeiz, the electrical engineering professor from the UCSD Jacobs School of Engineering leading the project.

This chip – the UCSD DARPA Smart Q-Band 4x4 Array Transmitter – is strictly a transmitter. “We are working on a chip that can do a transmit and receive function,” said Rebeiz.

“This compact beamforming chip will enable a breakthrough in size, weight, performance and cost in next-generation phased arrays for millimeter-wave military sensor and communication systems,” DARPA officials wrote in a statement.

“DARPA has funded us to try to get everything on a single silicon chip – which would reduce the cost of phased arrays tremendously. In large quantities, this new chip would cost a few dollars to manufacture. Obviously, this is only the transmitter. You still need the receiver but one can easily build the receiver chip based on the designs available in the transmitter chip. Our work addresses the most costly part of the phased array – the 16:1 divider, phase shifters, amplitude controllers and the uniformity and isolation between channels,” said Rebeiz

The chip also contains all the CMOS digital circuits necessary for complete digital control of the phased array, and was done using the commercial Jazz SBC18HX process. This is a first and greatly reduces the fabrication complexity of the phased array. The chip has been designed for use at the defense satellite communications frequency – the Q-band - which goes from 40 to 50 GHz.

“If you take the same design and move it to the 24 or 60 GHz range, you can use it for commercial terrestrial communications,” said Rebeiz who is also a lead on a separate project, funded by Intel and a UC-Discovery Grant, to create silicon CMOS phased array chips that could be embedded into laptops and serve as high speed data transfer tools.

The Intel project is a collaboration between Rebeiz, Larry Larson and Ian Galton – all electrical engineering professors at the UCSD Jacobs School of Engineering. Larson also serves as the chair of the Department of Electrical and Computer Engineering.

“If you wanted to download a large movie file, a base station could find you, zoom onto you, and direct a beam to your receiver chip. This could enable data transfer of hundreds of gigabytes of information very quickly, and without connecting a cable or adhering to the alignment requirements of wireless optical data transfer,” explained Rebeiz who estimated that this kind of system could be available in as little as three years.

Phased Array Background Information

Phased arrays have been around for more than half a century. They are groups of antennas in which the relative phases of the signals that feed them are varied so that the effective radiation pattern of the array is reinforced in a particular direction and suppressed in undesired directions. This property – combined with the fact that radio waves can pass through clouds and most other materials that stymie optical communication systems – has led engineers to use phased arrays for satellite communications, and for detecting incoming airplanes, ships and missiles.

Some phased arrays are larger than highway billboards and the most powerful – used as sophisticated radar, surveillance and communications systems for military aircraft and ships – can cost hundreds of millions of dollars. The high cost has prevented significant spread beyond military and high-end satellite communication applications. Engineers are now working to miniaturize them and fully integrate them into silicon-based electronic systems for both military and commercial applications.

The new UCSD chip packs 16 channels into a 3.2 by 2.6 mm² chip. The input signal is divided on-chip into 16 different paths with equal amplitude and phase using an innovative design, and the phase and gain of each of the 16 channels is controlled electronically to direct the antenna pattern (beam) into a specific direction.

By manipulating the phase, you can steer the beam electronically in nanoseconds. With the amplitude, you control the width of the beam, which is critical, for example, when you send information to from one satellite to another but you don’t want the signal to reach any nearby satellites. And with amplitude and phase control, you can synthesize deep nulls in the antenna pattern so as to greatly reduce the effect of interfering signals from neighboring transmitters.

The work was done by two graduate students, Kwang-Jin Koh and Jason May, both at the Electrical and Computer Engineering Department (ECE) at UCSD. Rebeiz presented the new chip at DARPA TEAM Meeting, August 28-29, 2007 in Chicago, Illinois. Additional details of the chip will be submitted to an academic journal later this year.

Adapted from materials provided by University of California - San Diego.

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Robotic System On Space Station Improved

Daily Science Journal (Oct. 15, 2007) — Software for a robotic extension of existing NASA technology for remote operations on the International Space Station has been shown to improve astronauts' performance on high-precision tasks. Using graphical overlay information, researchers were able to achieve significant results in efficiency and accuracy. The new technology can be added to existing flight hardware.

Special Purpose Dexterous Manipulator. The new software was developed for use with the Special Purpose Dexterous Manipulator, which works in conjunction with the current Space Station Remote Manipulator System. (Credit: NASA)

Researchers from NASA and Lockheed Martin have successfully tested software the robotic extension device.

James C. Maida, Charles K. Bowen, and John Pace developed the method for use with the Special Purpose Dexterous Manipulator, which works in conjunction with the current Space Station Remote Manipulator System (SSRMS).

Robotic devices on the ISS make it possible for astronauts to perform tasks without leaving the vehicle. Manipulating these devices is challenging, particularly in bright sunlight and deep darkness. Maida and colleagues employed augmented reality techniques to create a graphical informational overlay that can be used in simulations of robotic installation tasks to improve operator performance.

The installation task requires intense concentration by the astronaut to align an external orbital replacement unit (ORU) within ¼ inch and ½ degree at its installation point. The task is accomplished by viewing the scene of the installation through a camera and manipulating robotic arms. The researchers used enhanced live video with dynamic overlay information superimposed on features in the operators' field of view to guide them regarding the direction of motion of the robotic arm, the type of motion, and the correct position for installation.

Twelve highly skilled robotics operators were tested on four installation tasks under conditions of dynamic sunlight and very dark nights with and without the overlay. In all cases, accuracy and efficiency improved significantly when using the new overlay system, and all 12 operators found the overlay information extremely helpful in performing the ORU alignment operation. Time to complete the task was also reduced.

The researchers conclude that because the graphics are relatively simple and the computational requirements are low, the overlay system could be implemented on existing flight hardware used on the space shuttle and the ISS.

They presented their research paper, “Improving Robotic Operator Performance Using Augmented Reality,” at the Human Factors and Ergonomics Society 51st Annual Meeting on October 3 in Baltimore, Maryland.

Adapted from materials provided by Human Factors and Ergonomics Society.

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Quantum Computing Possibilites Enhanced With New Material

Daily Science Journal (Oct. 9, 2007) — Scientists at Florida State University's National High Magnetic Field Laboratory and the university's Department of Chemistry and Biochemistry have introduced a new material that could be to computers of the future what silicon is to the computers of today.

Crystal structure of the potassium-niobium-oxygen compound doped with chromium ions. Brown arrows show well-separated electron spins. The electromagnetic radiation used to control the spins is shown in black. (Credit: Image courtesy of Florida State University)

The material -- a compound made from the elements potassium, niobium and oxygen, along with chromium ions -- could provide a technological breakthrough that leads to the development of new quantum computing technologies. Quantum computers would harness the power of atoms and molecules to perform memory and processing tasks on a scale far beyond those of current computers.

"The field of quantum information technology is in its infancy, and our work is another step forward in this fascinating field," said Saritha Nellutla, a postdoctoral associate at the magnet lab and lead author of the paper published in Physical Review Letters.

Semiconductor technology is close to reaching its performance limit. Over the years, processors have shrunk to their current size, with the components of a computer chip more than 1,000 times smaller than the thickness of a human hair. At those very small scales, quantum effects -- behaviors in matter that occur at the atomic and subatomic levels -- can start playing a role. By exploiting those behaviors, scientists hope to take computing to the next level.

In current computers, the basic unit of information is the "bit," which can have a value of 0 or 1. In so-called quantum computers, which currently exist only in theory, the basic unit is the "qubit" (short for quantum bit). A qubit can have not only a value of 0 or 1, but also all kinds of combinations of 0 and 1 -- including 0 and 1 at the same time -- meaning quantum computers could perform certain kinds of calculations much more effectively than current ones.

How scientists realize the promise of the theoretical qubit is not clear. Various designs and paths have been proposed, and one very promising idea is to use tiny magnetic fields, called "spins." Spins are associated with electrons and various atomic nuclei.

Magnet lab scientists used high magnetic fields and microwave radiation to "operate" on the spins in the new material they developed to get an indication of how long the spin could be controlled. Based on their experiments, the material could enable 500 operations in 10 microseconds before losing its ability to retain information, making it a good candidate for a qubit.

Putting this spin to work would usher in a technological revolution, because the spin state of an electron, in addition to its charge, could be used to carry, manipulate and store information.

"This material is very promising," said Naresh Dalal, a professor of chemistry and biochemistry at FSU and one of the paper's authors. "But additional synthetic and magnetic characterization work is needed before it could be made suitable for use in a device."

Dalal also serves as an adviser to FSU chemistry graduate student Mekhala Pati, who created the material.

Adapted from materials provided by Florida State University.

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Reading Process Is Surprisingly Different That Previously Thought, Technology Shows

Daily Science Journal (Sep. 11, 2007) — Being able to read competently is one of the most important skills we need to function in today’s fast-paced society. Analysing the way we read can offer valuable insights into how we process visual information.

When we read, our eyes look at different letters in the same word and then combine the different images through a process known as fusion, researchers have found. (Credit: iStockphoto/Shannon Long)

Scientists have been interested in the movements of our eyes while reading for forty years. However, until now most assumed that when we read both eyes look at the same letter of a word concurrently.

Now ground-breaking research by cognitive psychologist Professor Simon Liversedge and his team at the University of Southampton has shown that this is not actually the case. They found that our eyes are actually up to something much more exciting when we read - our eyes look at different letters in the same word and then combine the different images through a process known as fusion.

The research Prof. Liversedge will present at the BA Festival of Science in York shows that the reading process is not as simple as one might think; it is rarely a case of the eyes scanning the page smoothly from left to right. Depending on what we are reading and how hard we are finding the information to digest our eyes make small jerky movements, that allow us to focus on a particularly difficult word or often re-read passages we didn’t get the first time. Analysing these eye movements enables psychologists to understand how our brain processes the sentence.

With sophisticated eye tracking equipment able to determine which letter of a font-size 14 word a person is looking at every millisecond from 1 metre away, Prof. Liversedge’s team went one further and looked at the letters within the word within the sentence. They were able to deduce that when our eyes are not looking at the same letter of the word, they are usually about two letters apart. Prof. Liversedge explains: ‘Although this difference might sound small, in fact it represents a very substantial difference in terms of the precise "picture" of the world that each eye delivers to the brain.'

So if our eyes are looking at different parts of the same word, thereby receiving different information from each eye, how is it that we are able to see the words clearly enough to read them? There are two ways the brain can do this; either the image from one of the eyes is blocked or the two different images are somehow fused together. To test how the latter mechanism might work, the team chose words that could easily split in two, such as cowboy, and presented half of the word to the left eye, and half to the right eye separately. They then analysed readers’ eye movements when reading sentences containing these particular words presented in this way.

‘We were able to clearly show that we experience a single, very clear and crisp visual representation due to fusion of the two different images from each eye,’ he explains. ‘Also when we decide which word to look at next we work out how far to move our eyes based on the fused visual representation built from the disparate signals of each eye.

‘A comprehensive understanding of the psychological processes underlying reading is vital if we are to develop better methods of teaching children to read and offer remedial treatments for those with reading disorders such as dyslexia. Our team are now measuring the range of visual disparities over which both adult and child readers can successfully fuse words.’

Professor Simon Liversedge will give his talk, ‘What our eyes get up to while we read’ as part of the session entitled ‘What eye movements tell us about the brain and language’ on 14 September at Vanbrugh V/045, University of York as part of the BA Festival of Science.

Adapted from materials provided by British Association for the Advancement of Science.

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Quantum Light Beams Good For Fast Technology

Daily Science Journal (Aug. 27, 2007) — Australian and French scientists have made another breakthrough in the technology that will drive next generation computers and teleportation.

The researchers have successfully superposed light beams, which produces a state that appears to be both on and off at once.

Light beams that are simultaneously on and off are vital for the next-generation super computers which should be faster than current computers based on bits, that are either on or off.

Previously, only smaller light particles had been superposed and the group has also proved a quantum physics theory known as Schrödinger's cat.

This theory, named after an Austrian physicist Erwin Schrödinger, proposed that a large object such as a cat could be simultaneously alive and dead.

Researchers from The University of Queensland and University of Paris South have published the latest breakthrough in the journal Nature.

UQ Centre for Quantum Computer Technology researcher Dr Hyunseok Jeong devised the scheme to generate and superpose the beams which was tested and proved by his French collaborators.

Dr Jeong said his group used special lasers, crystals, photon detectors, half-mirrors and other optical devices to generate and measure the superposition of light beams.

"It has been known to be extremely hard to generate Schrödinger cat states, particularly with traveling light," Dr Jeong said.

"Even though one could generate such Schrodinger cat states, it would be extremely hard to observe them because in a very short time, they would be reduced to either alive or dead states."

He said his group's research findings would help speed up the development of quantum information technologies such as quantum computers, quantum cryptography and quantum teleportation.

"Using Schrödinger cat states, quantum teleportation may be performed with nearly 100 percent success probability."

Adapted from materials provided by University of Queensland, via EurekAlert!, a service of AAAS.

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Scientists Will Be Assessing Methods To Stop Identity Theft

Daily Science Journal (Aug. 12, 2007) — The National Physical Laboratory (NPL) is part of Biotesting Europe, a new €358,000 biometrics project, part-funded by the European Union. The project will ensure that future testing procedures and facilities meet the needs of systems users and developers, building confidence in this growing industry.

Biometric recognition systems measure unique behavioural or physical traits to recognise people. These can be as varied as iris images, fingerprints, the structure of veins in the hand, or even an individual's typing rhythm. Currently they are predominantly used in national government systems for border control or criminal justice. They could equally be used in a domestic context to reduce identity theft by helping to secure bank accounts or corporate IT systems. For example the use of fingerprint readers when paying by credit or debit card could make identity fraud more difficult.

With a range of approaches and technologies available for biometric recognition and new ones constantly in development, the field is a fast moving one. Before investing in systems, buyers need to be assured of the usability and reliability of products. Similarly, technology developers benefit from independent testing regimes that allow them to prove their products and trial them in combination with existing systems.

There is a need for a European network of resources for testing systems and products. This network would improve access to testing and avoid duplicating existing facilities. Before significant additional investment is made, there is a need for an audit of the resources currently available and the needs of customers.

NPL has expertise in the evaluation and calibration of biometric systems.

The results that emerge from Biotesting Europe will provide a clear direction for the future development of shared resources for biometric testing.

Notes: Biotesting Europe is a nine month project that will be completed by early 2008. It is co-ordinated by the European Biometric Forum, with partnership from the UK's National Physical Laboratory, Germany's Fraunhofer-Institut für Graphische Verarberaitung, and the European Commission Joint Research Centre.

Adapted from materials provided by National Physical Laboratory, via EurekAlert!, a service of AAAS.

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The New Face Of Identity Protection: You

Daily Science Journal (Aug. 5, 2007) — Trying to remember dozens of personal identification numbers (PIN), passwords and credit card numbers may not be necessary for much longer, thanks to a University of Houston professor and his team.

Taking a radically new approach, UH Eckhard Pfeiffer Professor Ioannis Kakadiaris and his Computational Biomedicine Lab (CBL) developed the URxD face recognition software that uses a three-dimensional snapshot of a person’s face to create a unique identifier, a biometric. Shown in government testing to be tops in its field, URxD can be used for everything from gaining access to secure facilities to authorizing credit card purchases. The identification procedure is as effortless as taking a photograph.

URxD leads the pack for 3D face recognition solutions based on the face’s shape, according to the results of the Face Recognition Vendor Test (FRVT 2006). The National Institute of Standards and Technology conducted the rigorous testing for FRVT 2006, which was sponsored by several U.S. government agencies. FRVT 2006 is the first independent performance benchmark for 3-D face recognition technology.

“Accuracy is the name of the game in 3-D face recognition,” Kakadiaris said. “What makes our system so accurate is the strength of the variables that we use to describe a person’s face.

“Remembering dozens of personal identification numbers and passwords is not the solution to identity theft. PINs and passwords are not only inconvenient to memorize, but also are impractical to safeguard. In essence, they merely tie two pieces of information together; once the secret is compromised, the rest follows. The solution is to be able to tie your private information to your person in a way that cannot be compromised.”

The software and technology also could play a role in national security.

“With the growing concern for security at the personal, national and international level, the University of Houston is pleased that Dr. Kakadiaris and his team have demonstrated a very promising technology for personal identification,” said John Warren, UH associate general counsel for research and intellectual property management. “We look forward to its adoption by government and industry.”

URxD inventors are hoping for corporate interest in bringing the technology, now at the advanced prototype stage, to the marketplace.

“This technology will have a positive impact on some of today’s hottest issues,” Kakadiaris said. “Imagine a day when you simply sit in front of your computer, and it recognizes who you are. Everything will be both easier and more secure, from online purchases to parental control of what Web sites your children can visit.”

Note: Use of results from the Facial Recognition Vendor Test 2006 does not constitute the U.S. government’s endorsement of any particular system.

Adapted from materials provided by University of Houston.

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Computer Models Suggest Planetary And Extrasolar Planet Atmospheres

Daily Science Journal (Jun. 21, 2007) — The world is abuzz with the discovery of an extrasolar, Earth-like planet around the star Gliese 581 that is relatively close to our Earth at 20 light years away in the constellation Libra.

Artist's impression of the five-Earth mass planet, Gliese 581 c, found in the habitable zone around the red dwarf Gliese 581, with the instrument HARPS on the ESO 3.6-m telescope. (Credit: European Southern Observatory)

Bruce Fegley, Jr., Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, has worked on computer models that can provide hints to what comprises the atmosphere of such planets and better-known celestial bodies in our own solar system.

New computer models, from both Earth-based spectroscopy and space mission data, are providing space scientists compelling evidence for a better understanding of planetary atmospheric chemistry. Recent findings suggest a trend of increasing water content in going from Jupiter (depleted in water), to Saturn (less enriched in water than other volatiles), to Uranus and Neptune, which have large water enrichments.

"The farther out you go in the solar system, the more water you find," said Fegley.

Fegley provided an overview of comparative planetary atmospheric chemistry at the 233rd American Chemical Society National Meeting, held March 25-29, 2007, in Chicago. Fegley and Katharina Lodders-Fegley, Ph.D., research associate professor of earth and planetary sciences, direct the university's Planetary Chemistry Laboratory.

"The theory about the Gas Giant planets (Jupiter, Saturn, Uranus, and Neptune) is that they have primary atmospheres, which means that their atmospheres were captured directly from the solar nebula during accretion of the planets," Fegley said.

Gas Giants

He said that Jupiter has more hydrogen and helium and less carbon, nitrogen and oxygen than the other Gas Giant planets, making its composition closer to that of the hydrogen- and helium-rich sun. The elements hydrogen, carbon and oxygen are predominantly found as water, the gases molecular hydrogen and methane and in the atmospheres of the Gas Giant planets.

"Spectroscopic observations and interior models show that Saturn, Uranus and Neptune are enriched in heavier elements," he said. "Jupiter, based on observations from the Galileo Probe, is depleted in water. People have thought that Galileo might just have gone into a dry area. But Earth-based observations show that the carbon monoxide abundance in Jupiter's atmosphere is consistent with the observed abundances of methane, hydrogen and water vapor. This pretty much validates the Galileo Probe finding."

The abundances of these four gases are related by the reaction CH4+H20 = CO+3H2. Thus, observations of the methane, hydrogen and CO abundances can be used to calculate the water vapor abundance. Likewise, Earth-based observations of methane, hydrogen and carbon monoxide in Saturn's atmosphere show that water is less enriched than methane.

In contrast, observations of methane, hydrogen and carbon monoxide in the atmospheres of Uranus and Neptune show that water is greatly enriched in these two planets. Although generally classed with Jupiter and Saturn, Uranus and Neptune are water planets with relatively thin gaseous envelopes.

"On the other hand, the terrestrial planets Venus, Earth and Mars have secondary atmospheres formed afterwards by outgassing — heating up the solid material that was accreted and then releasing the volatile compounds from it," Fegley said. "That then formed the earliest atmosphere."

He said that by plugging in models he's done on the outgassing of chondritic materials and using photochemical models of the effects of UV sunlight, he and his collaborator Laura Schaefer, a research assistant in the Washington University Department of Earth and Planetary Sciences, can speculate on the atmospheric composition of Earth-like planets in other solar systems.

"With new theoretical models we are able to surmise the outgassing of materials that went into forming the planets, and even make predictions about the atmospheres of extrasolar terrestrial planets," he said.

"Because the composition of the galaxy is relatively uniform, most stars are like the sun — hydrogen-rich with about the same abundances of rocky elements — we can predict what these planetary atmospheres would be like," Fegley said. "I think that the atmospheres of extrasolar Earth-like plants would be more like Mars or Venus than the Earth."

Fegley said that photosynthesis accounts for the oxygen in Earth's atmosphere; without it, the Earth's atmosphere would consist of nitrogen, carbon dioxide and water vapor, with only small amounts of oxygen. Oxygen is 21 percent of Earth's atmosphere; in contrast, Mars has about one-tenth of one percent made by UV sunlight destroying carbon dioxide.

"I see Mars today as a great natural laboratory for photochemistry; Venus is the same for thermochemistry, and Earth for biochemistry," he said. "Mars has such a thin atmosphere compared to Earth or Venus. UV light can penetrate all the way down to the Martian surface before it's absorbed. That same light on Earth is mainly absorbed in the ozone layer in the lower Earth stratosphere. Venus is so dense that light is absorbed by a cloud layer about 45 kilometers or so above the Venusian surface."

Adapted from materials provided by Washington University in St. Louis.

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Two Qubits In Action, New Step Towards The Quantum Computer

Daily Science Journal (Jun. 17, 2007) — Researchers at Delft University of Technology have succeeded in carrying out calculations with two quantum bits, the building blocks of a possible future quantum computer. The Delft researchers are publishing an article about this important step towards a workable quantum computer in this week's issue of Nature.

Superconducting rings on a chip. (Credit: TU Delft)

Quantum computers have superior qualities in comparison to the type of computers currently in use. If they are realised, then quantum computers will be able to carry out tasks that are beyond the abilities of all normal computers.

A quantum computer is based on the amazing properties of quantum systems. In these a quantum bit, also known as a qubit, exists in two states at the same time and the information from two qubits is entangled in a way that has no equivalent whatsoever in the normal world.

It is highly likely that workable quantum computers will need to be produced using existing manufacturing techniques from the chip industry. Working on this basis, scientists at Delft University of Technology are currently studying two types of qubits: one type makes use of tiny superconducting rings, and the other makes use of 'quantum dots'.

Now for the first time a 'controlled-NOT' calculation with two qubits has been realised with the superconducting rings. This is important because it allows any given quantum calculation to be realised.

The result was achieved by the PhD student Jelle Plantenberg in the team led by Kees Harmans and Hans Mooij. The research took place within the FOM (Dutch Foundation for Fundamental Research on Matter) concentration group for Solid State Quantum Information Processing.

Adapted from materials provided by Delft University of Technology, via EurekAlert!, a service of AAAS.

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