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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Cell Phone Sensors Detect Radiation To Thwart Nuclear Terrorism

Daily Science Journal (Jan. 29, 2008) — Researchers at Purdue University are working with the state of Indiana to develop a system that would use a network of cell phones to detect and track radiation to help prevent terrorist attacks with radiological "dirty bombs" and nuclear weapons.

Purdue physics professor Ephraim Fischbach, at right, and nuclear engineer Jere Jenkins review radiation-tracking data as part of research to develop a system that would use a network of cell phones to detect and track radiation. Such a system could help prevent terrorist attacks with radiological "dirty bombs" and nuclear weapons by blanketing the nation with millions of cell phones equipped with radiation sensors able to detect even light residues of radioactive material. Because cell phones already contain global positioning locators, the network of phones would serve as a tracking system. (Credit: Purdue News Service photo/David Umberger)

Such a system could blanket the nation with millions of cell phones equipped with radiation sensors able to detect even light residues of radioactive material. Because cell phones already contain global positioning locators, the network of phones would serve as a tracking system, said physics professor Ephraim Fischbach. Fischbach is working with Jere Jenkins, director of Purdue's radiation laboratories within the School of Nuclear Engineering.

"It's the ubiquitous nature of cell phones and other portable electronic devices that give this system its power," Fischbach said. "It's meant to be small, cheap and eventually built into laptops, personal digital assistants and cell phones."

The system was developed by Andrew Longman, a consulting instrumentation scientist. Longman developed the software for the system and then worked with Purdue researchers to integrate the software with radiation detectors and cell phones. Cellular data air time was provided by AT&T.

The research has been funded by the Indiana Department of Transportation through the Joint Transportation Research Program and School of Civil Engineering at Purdue.

"The likely targets of a potential terrorist attack would be big cities with concentrated populations, and a system like this would make it very difficult for someone to go undetected with a radiological dirty bomb in such an area," said Longman, who also is Purdue alumnus. "The more people are walking around with cell phones and PDAs, the easier it would be to detect and catch the perpetrator. We are asking the public to push for this."

Tiny solid-state radiation sensors are commercially available. The detection system would require additional circuitry and would not add significant bulk to portable electronic products, Fischbach said.

The technology is unlike any other system, particularly because the software can work with a variety of sensor types, he said.

"Cell phones today also function as Internet computers that can report their locations and data to their towers in real time," Fischbach said. "So this system would use the same process to send an extra signal to a home station. The software can uncover information from this data and evaluate the levels of radiation."

The researchers tested the system in November, demonstrating that it is capable of detecting a weak radiation source 15 feet from the sensors.

"We set up a test source on campus, and people randomly walked around carrying these detectors," Jenkins said. "The test was extremely safe because we used a very weak, sealed radiation source, and we went through all of the necessary approval processes required for radiological safety. This was a source much weaker than you would see with a radiological dirty bomb."

Officials from the Indiana Department of Transportation participated in the test.

"The threat from a radiological dirty bomb is significant, especially in metropolitan areas that have dense populations," said Barry Partridge, director of INDOT's Division of Research and Development.

Long before the sensors would detect significant radiation, the system would send data to a receiving center.

"The sensors don't really perform the detection task individually," Fischbach said. "The collective action of the sensors, combined with the software analysis, detects the source. The system would transmit signals to a data center, and the data center would transmit information to authorities without alerting the person carrying the phone. Say a car is transporting radioactive material for a bomb, and that car is driving down Meridian Street in Indianapolis or Fifth Avenue in New York. As the car passes people, their cell phones individually would send signals to a command center, allowing authorities to track the source."

The signal grows weaker with increasing distance from the source, and the software is able to use the data from many cell phones to pinpoint the location of the radiation source.

"So the system would know that you were getting closer or farther from something hot," Jenkins said. "If I had handled radioactive material and you were sitting near me at a restaurant, this system would be sensitive enough to detect the residue. "

The Purdue Research Foundation owns patents associated with the technology licensed through the Office of Technology Commercialization.

In addition to detecting radiological dirty bombs designed to scatter hazardous radioactive materials over an area, the system also could be used to detect nuclear weapons, which create a nuclear chain reaction that causes a powerful explosion. The system also could be used to detect spills of radioactive materials.

"It's impossible to completely shield a weapon's radioactive material without making the device too heavy to transport," Jenkins said.

The system could be trained to ignore known radiation sources, such as hospitals, and radiation from certain common items, such as bananas, which contain a radioactive isotope of potassium.

"The radiological dirty bomb or a suitcase nuclear weapon is going to give off higher levels of radiation than those background sources," Fischbach said. "The system would be sensitive enough to detect these tiny levels of radiation, but it would be smart enough to discern which sources posed potential threats and which are harmless."

The team is working with Karen White, senior technology manager at the Purdue Research Foundation, to commercialize the system. For more information on licensing the cell phone sensor technology, contact White at (765) 494-2609

Adapted from materials provided by Purdue University.

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New Experimental Website Converts Photos Into 3D Models

Daily Science Journal (Jan. 28, 2008) — An artist might spend weeks fretting over questions of depth, scale and perspective in a landscape painting, but once it is done, what's left is a two-dimensional image with a fixed point of view. But the Make3d algorithm, developed by Stanford computer scientists, can take any two-dimensional image and create a three-dimensional "fly around" model of its content, giving viewers access to the scene's depth and a range of points of view.

Maui coast, Hawaii. A new program created by Stanford computer scientists, can take any two-dimensional image and create a three-dimensional "fly around" model of its content, giving viewers access to the scene's depth and a range of points of view. (Credit: Michele Hogan)

"The algorithm uses a variety of visual cues that humans use for estimating the 3-D aspects of a scene," said Ashutosh Saxena, a doctoral student in computer science who developed the Make3d website with Andrew Ng, an assistant professor of computer science. "If we look at a grass field, we can see that the texture changes in a particular way as it becomes more distant."

The applications of extracting 3-D models from 2-D images, the researchers say, could range from enhanced pictures for online real estate sites to quickly creating environments for video games and improving the vision and dexterity of mobile robots as they navigate through the spatial world.

Extracting 3-D information from still images is an emerging class of technology. In the past, some researchers have synthesized 3-D models by analyzing multiple images of a scene. Others, including Ng and Saxena in 2005, have developed algorithms that infer depth from single images by combining assumptions about what must be ground or sky with simple cues such as vertical lines in the image that represent walls or trees. But Make3d creates accurate and smooth models about twice as often as competing approaches, Ng said, by abandoning limiting assumptions in favor of a new, deeper analysis of each image and the powerful artificial intelligence technique "machine learning."

Restoring the third dimension

To "teach" the algorithm about depth, orientation and position in 2-D images, the researchers fed it still images of campus scenes along with 3-D data of the same scenes gathered with laser scanners. The algorithm correlated the two sets together, eventually gaining a good idea of the trends and patterns associated with being near or far. For example, it learned that abrupt changes along edges correlate well with one object occluding another, and it saw that things that are far away can be just a little hazier and more bluish than things that are close.

To make these judgments, the algorithm breaks the image up into tiny planes called "superpixels," which are within the image and have very uniform color, brightness and other attributes. By looking at a superpixel in concert with its neighbors, analyzing changes such as gradations of texture, the algorithm makes a judgment about how far it is from the viewer and what its orientation in space is. Unlike some previous algorithms, the Stanford one can account for planes at any angle, not just horizontal or vertical. This allows it to create models for scenes that have planes at many orientations, such as the curved branches of trees or the slopes of mountains.

On the Make3d website, the algorithm puts images uploaded by users into a processing queue and will send an e-mail when the model has been rendered. Users can then vote on whether the model looks good, and can see an alternative rendering and even tinker with the model to fix what might not have been rendered right the first time.

Photos can be uploaded directly or pulled into the site from the popular photo-sharing site Flickr.

Although the technology works better than any other has so far, Ng said, it is not perfect. The software is at its best with landscapes and scenery rather than close-ups of individual objects. Also, he and Saxena hope to improve it by introducing object recognition. The idea is that if the software can recognize a human form in a photo it can make more accurate distance judgments based on the size of the person in the photo.

A paper on the algorithm by Ng, Saxena and a fellow student, Min Sun, won the best paper award at the 3-D recognition and reconstruction workshop at the International Conference on Computer Vision in Rio de Janeiro in October 2007.

For many panoramic scenes, there is still no substitute for being there. But when flat photos become 3-D, viewers can feel a little closer—or farther. The algorithm runs at http://make3d.stanford.edu.

Adapted from materials provided by Stanford University.

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Palpable Computing: A Taste Of Things To Come

Daily Science Journal (Jan. 23, 2008) — Virtually everyone stands to benefit from the more pervasive use of computer technology. But while adding microchips to more everyday objects can make lives easier – and even save them – the approach creates some unique problems of its own. “Palpable” rather than “ubiquitous” computing promises a solution.

“Palpable computing”, a term coined by Morten Kyng, a researcher at the University of Aarhus in Denmark, refers to pervasive computer technology that is also tangible and comprehensible to its users.

Ubiquitous computing, in the traditional sense, is based on the vision of making the computers invisible, Kyng suggests. “The problem is that when the technology is invisible you can’t see what it is doing, how it functions or comprehend it.”

Anyone who has tried to connect their mobile phone to their laptop can attest to that. But while the invisibility of ubiquitous computing technology may be a mere inconvenience for many, in some cases it can be a serious, even life-threatening problem. A breakdown in communications that cannot be quickly fixed during a natural disaster can cost lives, as too can interoperability failures in hospital equipment.

By making the technology visible when it needs to be and comprehensible all the time, palpable computing reduces the complications of using the technology, while opening the door to developers creating new applications more easily.

Putting the user in control

The vision of ubiquitous computing has focused on tools honed through use over time and well suited to what they are designed to do, comments Kyng. “The problems arise when you want or need to do something new or different from what the designers intended: the user is not really in control,” he adds.

Over the last four years, Kyng has led a team of more than a hundred researchers from across Europe working on making palpable computing a reality. They have developed software architecture for palpable computing systems as well as a toolbox for developers to create applications that has recently been made available under an open source licence. The researchers, who received EU funding in the PalCom project, also developed several test platforms that have served to highlight the benefits of their approach.

One of them was used when the Tall Ships’ Races – the world’s biggest competition for sailing ships – visited Aarhus in July 2007. The platform enabled police and fire fighters to interact with a three-dimensional (3D) workspace of the Aarhus harbour and its surroundings, displaying the location of key personnel, cars, ships and equipment to give a general overview of what was going on.

“Large-scale events, such as the Tall Ships’ Races, can be very hard to gain an overview of. With a million visitors and a huge area, it is challenging to monitor every critical spot. In my opinion, PalCom’s technology has enormous potential – not only for events [like this] but also for monitoring major accident scenes,” notes Aarhus fire chief Jakob Andersen.

A second test platform was created to enhance therapy for disabled children, while a third was designed to help landscape architects visualise the location and assess the visual impact of large development projects (wind farms, industrial buildings, etc.).

The system involves a camera, placed on the roof of a car, connected with a laptop running an advanced 3D-visualisation programme which provides landscape architects with a much more precise indication of where a new building will be located and its impact on the surrounding landscape as they drive around.

Key markets: emergency response and healthcare

“The potential uses for palpable computing are diverse, although initially I think the key markets will be in areas, such as emergency response and healthcare, where there is an urgent need for increasingly more efficient and effective technology,” Kyng says.

The University of Aarhus and several other project partners are concentrating on the development of applications using PalCom’s architecture in those fields. Kyng’s team, for example, is applying the technology to help women through pregnancies and to improve the treatment of hip-replacement patients. One palpable computing system being developed to enhance post-surgery monitoring will allow hip patients to leave the hospital 24 hours after surgery, he estimates, rather than the current three or four days.

The PalCom coordinator notes that the trial systems have elicited considerable interest and expects the open source release of the toolbox to lead to new applications.

“Ultimately, success in the marketplace will drive the technology forward,” he says.

Adapted from materials provided by ICT Results.

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Software Wrapper For Smarter, Networked Homes

Daily Science Journal (Dec. 22, 2007) — Homes today are filled with increasing numbers of high-tech gadgets, from smart phones and PCs to state-of-the-art TV and audio systems, many of them with built-in networking capabilities. Combined, these devices could form the building blocks of the smart homes of the future, but only if they can be made to work together intelligently.

Although the idea of creating intelligent networked home environments as a way to make life easier, safer and more enjoyable has been around for some time, the technology has yet to catch up with the vision. Home automation systems have become more commonplace and consumer electronics have more networking capability, but no one has, so far, gotten all the high-tech and not so high-tech gadgetry cluttering modern homes to work together in an intelligent way. It is not yet common for fridges to talk to your TV to warn that the door has been left open or for heating systems to turn on when you return home, for example.

“People are finding themselves with all these networkable devices and are wondering where the applications are that can use these devices to make life easier and how they could be of more value together than individually,” says Maddy Janse, a researcher for Dutch consumer electronics group Philips.

There are two fundamental obstacles to realising the vision of the intelligent networked home: lack of interoperability between individual devices and the need for context-aware artificial intelligence to manage them. And, to make smart homes a reality, the two issues must be addressed together.

Software wrapper to get gadgets talking

The EU-funded Amigo project, coordinated by Janse, is doing just that, creating a middleware software platform that will get all networkable devices in the home talking to each other and providing an artificial intelligence layer to control them.

“With the Amigo system, you can take any networkable device, create a software wrapper for it and dynamically integrate it into the networked home environment,” Janse explains.

The project, which involves several big industrial and research partners, is unique in that it is addressing the issues of interoperability and intelligence together and, most significantly, its software is modular and open source.

By steering away from creating a monolithic system and making the software accessible to all, the partners believe they can overcome the complications that have held back other smart home projects. For consumer electronics companies and telecoms firms, the system has the additional benefit of providing a test bed for new products and services.

“What we are trying to do is so large and so complex that it has to be broken down into smaller parts. By making it open source and letting third-party developers create applications we can ensure the system addresses whatever challenges arise,” Janse says.

The Amigo architecture consists of a base middleware layer, an intelligent user services layer, and a programming and deployment framework that developers can use to create individual applications and services. These individual software modules form the building blocks of the networked home environment, which has the flexibility to grow as and when new devices and applications are added.

Interoperability is ensured through support for and abstraction of common interaction and home automation standards and protocols, such as UPnP and DNLA as well as web services, while the definition of appropriate ontologies enables common understanding at a semantic level.

“A lot of applications are already available today and more will be created as more developers start to use the software,” Janse says.

Vision of the future

A video created by the project partners underscores their vision for the future in which homes adapt to the behaviour of occupants, automatically setting ambient lighting for watching a movie, locking the doors when someone leaves or contacting relatives or emergency services if someone is ill or has an accident. In an extended home environment, the homes of friends and relatives are interconnected, allowing information and experiences to be shared more easily and setting the stage for the use of tele-presence applications to communicate and interact socially.

Initially, Janse sees such networked systems being employed in larger scale environments than an individual home or for specific purposes. Some subsets of applications could be rolled out in hotels or hospitals or used to monitor the wellbeing of the elderly or infirm, for example.

“With the exception of people with a lot of money building their homes from scratch, it will be a while before intelligent networked homes become commonplace,” the coordinator notes. “In addition, this isn’t something average consumers can easily set up themselves, currently some degree of programming knowledge is needed and installers need to become familiar with the concepts and their potential.”

Even so, the project is hoping to continue to stimulate the growth of the sector.

In October, it launched the Amigo Challenge, a competition in which third-party programmers have been invited to come up with new applications using the Amigo software. Janse expects the initiative will lead to the software being used in even more innovative and possibly unexpected ways.

Adapted from materials provided by ICT Results.

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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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Cell Phones Should Be Kept Away From Hospital Beds, Dutch Experts Say

Daily Science Journal (Sep. 9, 2007) — Cell phones should come no closer than one meter to hospital beds and equipment, according Dutch research published in the online open access journal, Critical Care. Scientists demonstrated that incidents of electromagnetic interference (EMI) from second and third generation mobile phones occurred even at distance of three meters.

Hazardous incidents of electromagnetic interference from second and third generation mobile phones varied from a total switch off and restart of mechanical ventilator and complete stops without alarms in syringe pumps to incorrect pulsing by an external pacemaker. (Credit: iStockphoto/Bakaleev Aleksey)

In this particular study, the research team examined the effects of General Packet Radio Service (GPRS) and Universal Mobile Telecommunications System (UMTS) signals on critical care equipment such as ventilators and pacemakers. Almost 50 EMI incidents were recorded; 75% were significant or hazardous. Hazardous incidents varied from a total switch off and restart of mechanical ventilator and complete stops without alarms in syringe pumps to incorrect pulsing by an external pacemaker.

The second generation (2.5G) GPRS signal caused the highest number of EMI incidents at over 60% whereas the third generation (3G) UMTS signal was responsible for just 13%. EMI incidents also occurred a greater distance with GPRS with a hazardous incident even at three meters.

While first generation mobile phones are used mainly for voice transmission, 2.5G and 3G phones enable internet access, sending and receiving data. They entered the market, however, with little proof regarding their safe use in the medical environment.

Dr Erik van Lieshout, lead researcher from the Academic Medical Center, University of Amsterdam, said; "Our work has real implications for present hospital restrictions of mobile phone use in patient areas."

"It is unlikely that mobile phone induced EMI in hospitals will be eradicated in the near future so the one meter rule currently in place should continue, as it is relatively safe," commented Dr van Lieshout.

Article: "Interference by new generations mobile phones on critical care medical equipment," Erik Jan van Lieshout, Sabine N van der Veer, Reinout Hensbroek, Johanna C Korevaar, Margreeth B Vroom and Marcus J Schultz, Critical Care (in press)

Adapted from materials provided by BioMed Central, via EurekAlert!, a service of AAAS.

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A Blueprint For 'Smart' Health Care

Daily Science Journal (Jul. 30, 2007) — Always on, connected, cheap and on sale everywhere.

A cell phone displays a patient's health information in this photo illustration of new technology for providing smart health care announced recently by the University of Florida and IBM. (Credit: Image courtesy of University of Florida)

What people have come to expect in cell phones and personal communicators may soon become common in health-care devices and products at home and in medical offices, thanks to new technology announced recently by the University of Florida and IBM.

The technology creates the first-ever roadmap for widespread commercial development of "smart" devices that, for example, take a person's blood pressure, temperature or respiration rate the minute a person steps into his or her house -- then transmit it immediately and automatically to doctors or family.

That could eliminate the need for many doctor's visits, which are often difficult for the elderly or sick. By enabling regular updates via text message or e-mail, the technology also could pave the way for people to share real-time information on their health or well-being with absent loved ones. And it could prove useful for doctors who need to keep tabs on many patients at one time by helping the doctors to prioritize whom to treat first.

"We call it quality-of-life engineering," said Sumi Helal, professor of computer engineering and the project's lead UF researcher. "It's really a change of mindset."

The idea of using technology to provide medical care at a distance is nothing new. Doctors have relied on "telemedicine" to communicate with specialists for years. More recently, telemedicine has been expanded to include, for example, surgeons performing robotic procedures on distant patients.

But the UF-IBM advance goes a step further: It provides the technological "stepstones" to make it easy for any company to manufacture and sell smart networked devices -- while also making them more user-friendly for consumers.

"UF and IBM both see the need and the opportunity to integrate the physical world of sensors and other devices directly into enterprise systems," said Richard Bakalar, Chief Medical Officer for IBM. "Doing so in an open environment will remove market inhibitors that impede innovation in critical industries like health care and open a broader device market that's fueled by uninterrupted networking."

Helal has devoted the past several years to developing smart devices for the elderly in a model home known as the "Gator Tech Smart Home" in Gainesville.

He and his students pioneered the "Smart Wave" microwave oven that can automatically determine how much time to cook a frozen meal or keep track of how much salt it contains. Among other devices, they also created an instrument that records how many steps a person takes, information that can tell absent caregivers how active its occupants are.

But these and other devices currently have a major shortcoming: They require "a team of engineers" to install them, Helal said. In a world where consumers are accustomed to electronics that require no more than a power outlet, that dramatically limits their appeal. "We decided to create a technology that self integrates," Helal said. "When you bring it in to the house and plug it in, it automatically provides its service and finds a path to the outside world."

With $60,000 in research funding from IBM, Helal designed "middleware," or software and hardware that glues together different systems, that can give his and any similar health-aid devices this independence and connectivity. Importantly, the software is based on open standards, or publicly available specifications useable by anyone, such as those now being made available by consortiums of technology companies including Eclipse, W3C and OSGi.

Open standards make it easy for product developers to tap the technology in any new smart assistive devices, Helal said. That, in turn, will make the devices more common.

The hardware component of the system is an inexpensive sensor platform about half the size of a business card. Developed at UF and licensed to Pervasa, a Gainesville-based UF spinoff company headed by Helal, the "Atlas" platform makes it easy to create a network of sensors and make their information available on a computer network.

The advance is crucial given the increasing number of elderly Americans. The number of people 85 and over is expected to rise from 4.2 million in 2000 to 6.1 million in 2010 and 9.6 million by 2030, according to federal government statistics. Meanwhile, the percentage of older Americans living alone will either remain high or continue to grow: About half of women and nearly a quarter of men aged 75 and older currently live alone.

But the UF-IBM technology may also prove useful in many other medical settings. For example, Helal said, it could help emergency rooms operate more safely. Rather than a standard waiting list, patients could be equipped with networked wireless monitors of their vital signs, allowing doctors to determine who in a waiting room needs the most immediate care.

Adapted from materials provided by University of Florida.

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