Monday, December 20, 2004

"CHIPS: Analog decoders outdo digital in wireless test"
Advanced digital wireless standards like those overseen by the 3rd Generation Partnership Project use iterative communications protocols that provide error correction simultaneously with optimal compression. Until now, the most efficient way to correct errors in iterative codes has been to use rather power-hungry digital A/D converters and hardware multipliers to decode the wireless signals. But while digital decoders consume milliwatts of power, analog decoders use microwatts to achieve the lowest levels of noise interference and data corruption. Researchers at the University of Alberta have found a way to decode wireless signals using far less power than that consumed by digital A/D converters. "In one of our test chips, we have demonstrated that analog decoders can consume 100 times less power [40 picojoules of energy to decode one bit] while performing the same functions as a digital decoder. In another chip � with a block size of 256 � we showed that they could use up as little as a tenth of the area on the die," said University of Alberta EE David Nguyen.

Wednesday, December 08, 2004

"CHIPS: Groups move atomic lithography closer to fabs"
Two research groups in Holland have joined worldwide efforts to apply atomic lithography to nanoscale integration of semiconductors. Researchers using this method tackle the usual process in reverse: Instead of forcing light through a physical mask, they focus a physical beam of atoms with a mask made from standing waves of light. First demonstrated in 1997, atomic lithography has since been applied in labs in the United States, Japan and Europe for beams of matter as diverse as chromium, sodium and aluminum, as well as to indium and gallium. To that list, the Dutch researchers have added iron. "We have used iron, because we want to make magnetic nanostructures. Our substrate at the moment is simply a silicon wafer, but it is important to note that in principle any substrate material can be used � glass, metal, ceramic, even organic substrates," said Eindhoven University of Technology professor Ton van Leeuwen. Researchers in another Dutch group, led by professor Theo Rasing at Radboud University Nijmegen, report similar results.

Monday, December 06, 2004

"CHIPS: Unified transistor modeling on tap for IEDM"
A unified model for predicting the long-term reliability of semiconductors will be described next week at the 50th annual IEEE International Electron Devices Meeting. The technique, which simultaneously foretells negative-bias temperature instability and hot-carrier injection, could potentially save chip makers tens of millions of dollars annually. As nanoscale transistors shrink, the atomic-scale bonds that keep semiconductors reliable become fewer and fewer, making mean-time-to-failure predictions more important than ever. But to predict long-term reliability today, separate models must be maintained for the two primary causes of failure in semiconductors: negative-bias temperature instability (NBTI) and and hot-carrier injection (HCI). "Today, reliability is becoming much more important, because dimensions are getting so small," said Purdue University professor and semiconductor researcher Ashraf Alam, who will describe the details of a unified model at IEDM, to be held Dec. 13 to 15 in San Francisco ( "But only recently has reliability begun percolating into the design phase � rather than just being an afterthought. Our unified model will make it much easier for designers to measure reliability of new device architectures."

Monday, November 29, 2004

"SENSOR: Embedded sensors gauge materials' inner states"
Sensors developed by Elizabethtown College researchers could pave the way for next-generation materials that would be equipped with 50-ohm coaxial connections that engineers could "ping" to read out the material's internal state. The embedded capacitive sensors could be the cure for advanced processing of materials from carbon nanotube-reinforced composites to plain old concrete, enabling functions ranging from elaborate process control monitoring to simple electronic pop-up alerts that would go the traditional turkey timer one better. "The sensors we make are very small capacitors � I'm talking picofarad parallel-plate capacitors with the material serving as the dielectric. At those frequencies, you don't need much loading to get an effective match to a 50-ohm line," said Nathaniel Hager III, an adjunct professor in the physics and engineering department at Elizabethtown (Pa.) College. Hager performed the work with materials chemist Roman Domszy. A patent was awarded just days ago covering sensing and instrumentation using time-domain reflectometry (TDR) dielectric spectroscopy.
"OPTICAL: Flip-flops push forward era of all-optical computing"
Optical flip-flops could enable a new breed of all-optical chips, from communications switches to full-fledged optical computers, according to the Cobra Research Institute at Eindhoven (Netherlands) University of Technology. Optical flip-flops using light, instead of electrons, to store, process and move data around could eliminate the need for expensive optical-to-electronic-to-optical conversions. Today most semiconductor lasers are on discrete chips, but the Cobra Research Institute claims that the answer may be its ring lasers, fabricated in indium gallium arsenide phosphide. According to the researchers, ring lasers could enable optical signals' use not only for communications but also for memory and processing, thanks to a configuration that enables bistable states � an optical flip-flop. "Two ring lasers are required to form the bistable system," said Cobra researcher Martin Hill. He performed the work with Meint Smit, head of the Opto-Electronic Devices group at the Eindhoven university, and Harm Dorren, for whom Hill works at the Electro-Optical Communications group at Cobra.

Monday, November 22, 2004

"SOLAR: Sun catchers tuned to crank out the juice"
EEs are turning a 19th-century invention into a 21st-century alternative-energy source. The last leg of a two-decades-long effort by the U.S. Energy Deaprtment to unleash superefficient solar power by 2011 is homing in on the so-called Stirling engine, which is being used to drive solar generators. DOE test site measurements suggest the setup could bring the cost of solar power on a par with traditional fossil fuels and hydroelectric sources � assuming the project engineers can balance the separate power feeds from farms of thousands of simultaneously online 25-kilowatt Stirling solar dishes. The heart of the design, the engine itself, was invented by the Scottish minister Robert Stirling in 1816. "The Stirling engine makes solar power so much more efficiently than photovoltaic solar cells can," said Robert Liden, chief administrative officer at Stirling Energy Systems Inc. (Phoenix). "That's because the Stirling solar dish directly converts solar heat into mechanical energy, which turns an ac electrical generator." The bottom line, he said, "is that large farms of Stirling solar dishes � say, 20,000-dish farms � could deliver cheap solar electricity that rivals what we pay for electricity today." Under a multiyear Energy Department contract that started in 2004, Stirling Energy Systems will supply Sandia National Laboratories with solar dishes for integration into full-fledged power-generation substations capable of direct connections to the existing U.S. power grid.

Wednesday, November 17, 2004

"NANOTECH: Smart dust made to 'escort' molecules to sensors"
Researchers have shown recently that magnetic silicon nanoparticles-smart dust-can act as chaperones, surrounding and herding rare sample molecules so that the samples navigate channels to microfluidic sensors without leaving any residue. Someday such chaperones might surround cancer cells and "escort" them to the exit. "When you start talking about samples on the molecular scale, your surface-to-volume ratio is so high that you can't let any [part of the sample] stick to microfluidic channels," said professor Michael Sailor at the University of California at San Diego.

Wednesday, November 10, 2004

"OPTICS: Viscous entrainment builds nanoscale optics"
The extrusion techniques currently used to manufacture thin optical fibers require an aperture of the same diameter as the created cable, but physicists at the University of Chicago believe they have found a better way. With careful process controls that entrain a viscous liquid, a fiber of any nanoscale size can be manufactured without the need to extrude it through a like-sized aperture, the researchers claim. Both hollow and compound optical fibers can be made in a single step, instead of the two steps necessary today. "Entrainment enables a nonviscous liquid to flow through an aperture into a viscous liquid and pull along some of the viscous material to make a long, thin fiber that is smaller than the aperture," said Wendy Zhang, assistant professor of physics at the University of Chicago. "We believe that with careful control of the processing, you can use viscous entrainment to create [either] submicron hollow waveguides or compound fibers with a core that would have a different index of refraction." By adjusting the speed, pressure and viscosity of such a flow, its diameter can be shrunk without limit.
"ANIMAL ON-A-CHIP: Microfluidic chips come alive for medical research"
Microelectromechanical systems researchers are getting close to a complete "animal-on-chip" that would allow medical experiments now requiring live animals to be run in vitro on microfluidic chips. The new approach to medical research is based on housing every type of cell inside a microfluidic circulatory system, which is fabricated using semiconductor equipment. In addition to eliminating animals from experimentation, the new devices use commonly available real human cells that are kept alive in culture. The software and circuitry on the chip provide the cells with the chemicals that enable them to perform as if they were in a living body and built-in sensors constantly monitor cell response in real-time. "We believe the animal-on-chip is not only more ethically palatable than using lab animals, but it will also be more accurate because of its built-in sensors and because we will be using real human cells in our tests," said assistant professor Shuichi Takayama at the University of Michigan (Ann Arbor), whose lab has developed an animal-on-chip.

Monday, November 01, 2004

"BIO-ELECTRONICS: Replaceable Eyeball"
'Bionic eye' builds on prostheses milestones with an implanted artificial sight organ as the goal. Eye-implant technology is fighting a tough battle in the human body. Germs, infections, caustic body fluids, nerve degeneration, toxic reactions to chip-generated heat and the conflicting needs for high speed and ultralow power conspire against it. Nevertheless, scientists worldwide are hard at work on various projects to cure blindness, making it likely that many of these problems will be solved within the next 20 years. Pure medical science also promises solutions within 20 years-specifically, the ability to regress the DNA in dead retinal cells so that they regenerate themselves. Within 10 years, medical science also promises to perfect transplanting living retinal cells harvested from organ bank donors. In case that doesn't happen, the electronics industry is promising prostheses that outperform "original equipment" with every imaginable enhancement-from zooming to infrared to textual annotation and memory augmentation. But before these enhancements can be realized, two huge engineering problems face retinal implants, said Gene Frantz, principal fellow at Texas Instruments Inc. One is their interface to neurons; the other is the heat they generate. "How do you create a wetware interface-how do you connect electronics through the skin and inside the eye without introducing germs, paths for infection and other similar problems?" Frantz asked. "This is not a straightforward microelectronics problem, because you have to mimic biology in order to give the brain a better chance at 'seeing' with an artificial retina," said Mark Humayun, director of the National Science Foundation-sponsored Biomimetic MicroElectronic Systems Engineering Research Center at the University of Southern California. "Everything must be customized so it can mate with neurons-the packaging, the electronics, the software and everything else."

Friday, October 29, 2004

"OPTICS: Silicon circuit demonstrates optical switch"
The world's first silicon chip that switches optical wavelengths has been brought to light by Cornell University researchers using nanoscale techniques. "We have demonstrated for the first time a silicon structure that enables one low-power optical beam to switch another one on and off," said Cornell University EE Michal Lipson. Silicon circuits traditionally don't do optics. Because silicon is an indirect-bandgap material � meaning that the bottom of its conduction band is shifted with respect to the top of its valence band � the energy released during electron recombination with a hole is converted primarily into phonons (lattice vibration) instead of the photons you get from a "direct-bandgap" material like gallium arsenide. The key is a ring-shaped nanoscale cavity whose resonant frequency depends on its refractive index, which can be optically switched by virtue of a second light beam controlling free-carrier dispersion. According to Lipson, the technique should eventually enable terahertz switching of signals on silicon chips with integrated ultralow-power, high-modulation-depth picosecond optical switches fabricated alongside conventional silicon circuitry.

Monday, October 25, 2004

"QUANTUM: 'Spin filter' initializes quantum computing"
Purdue University researchers have invented a "spin filter" that can sort charge carriers by their spin state. "This component is essential to future quantum computers, which need to be initialized in a known state," said professor Leonid Rokhinson. "It will also be necessary for the many other 'spintronic' devices that people are working on today." Storing data on the polarized-wave function, or "spin," of a charge carrier- a mobile electron or hole in a semiconductor-holds promise for future single-electron transistors, nanoscale nonvolatile memories, quantum computers and other so-called spintronic devices. But even the simplest components necessary to make spintronics a reality-such as filters-have been lacking. Using the basic physics of a mass spectrometer as his model, Rokhinson fabricated a chip version that can sort particles based on their spin configuration. "Spin filters are one of the most crucial missing ingredients of spintronic devices because they allow you to create spin polarization," he said. The device uses magnetic focusing to enable the spatial separation of trajectories of carriers (in a two-dimensional "hole" gas fabricated from GaAs heterostructures) by virtue of their spin state. Two quantum-point contacts, acting as a monochromatic source of ballistic holes and a narrow detector, respectively, were demonstrated to work as a tunable spin filter.
"MAGNETISM: EEs needed to propel mag-beams"
EEs are desperately needed to help design magnetized-beam plasma propulsion systems that could send future spacecraft to Mars and back in 90 days. The systems would use a mag-beam to accelerate a craft out of Earth's orbit and another to decelerate it in Mars' orbit, eliminating or greatly reducing the need for on-board fuel or engines. Such systems would rejigger the cost and time calculations of manned flights to Mars, which would take more than two years with current propulsion technology. "We want to get the word out to electrical engineers, because this is a field where EEs can make major contributions," said Robert Winglee, an earth- and space-sciences professor at the University of Washington who is leading a multidisciplinary group at the school's Research Institute for Space Exploration. "Mag-beams could make space travel routine, and they are enabled by electrical engineering." NASA's Institute for Advanced Concepts ( has given Winglee's group $75,000 and six months to prove its plasma propulsion system can work. Eleven other teams have received similar funding, and, like Winglee's group, will be eligible for $400,000 of phase two monies.

Monday, October 18, 2004

"OPTICS: Photoluminescent method detects explosives at a distance"
Experience in photoluminescent spectroscopy has helped university researchers bring to light a method by which explosives can be detected at a distance. In contrast, to detect the presence of explosives today, airport and other screeners must swab an object like a suitcase or clothing, use a dog to sniff it, or blast puffs of air across a filter that traps airborne explosive particles. The advantages of the photoluminescence-based explosive detection method are that it can be remotely applied and that it requires neither time-consuming and expensive machines nor trained dogs. All you do is shine a laser on an object and watch for the photoluminescent "signature" distinctive of explosives. Whether it's an approaching ship, a suitcase, a moving car or a pile of trash half a mile up the road, if you can shine a green laser on it, professor Rolf Hummel at the University of Florida (Gainesville) says he can tell you whether it's an explosive device.

Tuesday, October 12, 2004

"BIOSENSOR: slashes time to detect Listeria bacteria"
A fiber-optic biosensor that reduces testing time for a deadly form of the Listeria bacteria from one week to less than 24 hours has been created by two Purdue University microbiologists and a control engineer. Listeriosis kills one in five that it infects and accounts for the highest rate of hospitalization and mortality among foodborne illnesses. Usually, when the (monocytogenes) Listeria bacteria is detected in a food sample, it has already been on store shelves for up to a week, because the detecting sensors are so crude that the food has to be cultured in petri dishes for that long before enough bacteria multiply to trip the alarm. "We still need to culture the food sample with our new biosensor, but for a much shorter time-less than a day," said Arun Bhunia, associate professor of food microbiology. Bhunia developed the sensor with Tao Geng, research associate in the Department of Food Science. Mark Morgan, an engineering professor in Purdue's Food Science Sensors and Controls Laboratory, also participated in the research. "Instead of having to recall food that is already on the shelves, we want test results before it gets delivered to stores," said Bhunia. The researchers are aiming eventually for real-time operation of the biosensor.

Friday, October 08, 2004

"OPTICAL: NEMS tunes the 'most sensitive' accelerometer"
By coupling a nanoscale etched diffraction grating to an optical sensor, Sandia National Laboratories researchers have demonstrated an accelerometer that they say is the most sensitive in the world. The nanoelectromechanical system (NEMS) could measure vibrations as low as 10 nano-G's, compared with the 100 milli-G vibrations measurable with today's accelerometers, by making mechanical motions as small as 10 nanometers visible to the naked eye. "Because the wavelength of light from our laser is much smaller than the dimensions of our [diffraction] grating, very very small motions have a disproportionate effect," said Sandia researcher Dustin Carr. Team member Bianca Keeler will describe the work later this month at the SPIE Optics East convention in Philadelphia. Today's best integrated accelerometers, such as those that trigger automotive air bags, can detect hundreds of milli-G's. But many unfulfilled apps need more-sensitive accelerometers, such as those that can anticipate earthquakes or sense a skid where the back end of a car is moving in a different direction than the front end.
"ANTITERROR: EEs seek way to ID triggers of Iraq's IEDs"
One of the United States' largest electromagnetic-emission "shielding" labs has switched roles to help armed-services personnel detect bombs. The University of Missouri at Rolla's Electromagnetic Compatibility Laboratory is trying to sense, rather than shield, emissions from the triggering mechanisms in improvised explosive devices (IEDs), which could alert troops to unexploded munitions. EE professor Todd Hubing and assistant professor Daryl Beetner said they saw the benefit of reorienting their work when visiting nearby Fort Leonard Wood, Mo., where they viewed IED training tapes. They saw that the emissions from many command-initiated IEDs, which are normally placed at the side of a road, were sufficient to be sensed from a distance. Hubing and Beetner immediately began thinking that it would be possible to detect the signature of electronically triggered IEDs, even when they are not transmitting, but merely "waiting" beside a road in Iraq to receive a detonation signal. "We started looking at unintended electromagnetic emission from improvised explosive devices and found that if we shifted their frequency to the audio range, almost anyone could recognize their distinctive 'signature' sound," Beetner said. "And if you can hear the difference, then there has got to be a way to build a device for soldiers to use that detects radio-controlled IEDs from a distance." That's the opposite of the lab's typical practice. "At our lab we try to shield devices, so we know just how very difficult it is to make an electronic device not emit electromagnetic energy � even when it's just a receiver," Beetner said. According to the engineers, sophisticated electronic devices like cell phones cannot be completely turned off � there is always active circuitry inside

Wednesday, October 06, 2004

"METAMATERIAL: Demo takes subwavelength focusing to visible light "
Engineers at Purdue University claim to have conjured a mathematical model for metamaterials that designers can use to improve the resolution of lenses below the wavelength of light. Subwavelength focusing, for instance, could enable semiconductor lithography to plumb the nanoscale without having to use ultrashort-wavelength extreme-ultraviolet or X-rays. Others have already demonstrated metamaterials with subwavelength focusing for microwaves and acoustic waves. Now, engineers at Purdue and elsewhere are working toward photonic metamaterials that provide subwavelength focusing for visible light. Professor Kevin Webb, a EE at Purdue performed the work with his EE assistant Ming-Chuan Yang and MIT professor Keith Nelson, assisted by one of his doctoral candidates, David Ward. Metamaterials put macroscopic objects sized for a desired subwavelength into a giant-sized crystalline lattice, which interacts in the opposite way from natural materials.

Friday, October 01, 2004

"MATERIALS: Darpa funds work on rigid shape-shifting materials"
A new world of applications for shape-changing materials might become available if man-made rigid structures � like an airplane wing, which derives its strength from being "fixed" � could adopt the abilities of rigid structures that can change shape, like a flower stem that twists to follow the sun. Airplane wings imbued with such ability might, for example, self-trim as they sensed the plane's speed, or prepare for an imminent landing by cupping the air as a bird's wing does. The Defense Advanced Research Projects Agency has granted four contracts under its Nastic Materials Program ( to explore these possibilities. One includes a 17-month, $2.1 million effort at the Virginia Polytechnic Institute and State University in Blacksburg, Va. "We will use the concept of nastic biological transport to create a synthetic template for making shape-changing materials," said Virginia Tech professor Don Leo, leader of a team that will develop a class of materials that mimic plant protein structures.
"QUANTUM: encryption milestone reached"
A prototype quantum-key distribution system may move from lab to commercial systems as early as next year, NEC Corp. reports. Company researchers have completed the prototype, NEC said, and the needed software is now being written. NEC described its progress to the 30th European Conference on Optical Communication ( At the conference, held last month in Stockholm, Sweden, NEC described how it overcame previously reported obstacles. It said researchers had successfully encoded, modulated and added a clock signal to their single-photon transmissions, achieving a sustained quantum-key distribution (QKD) rate of 100 kbits/second over a distance of about 25 miles. The researchers predicted that NEC will likely begin delivering commercial QKD systems based on their prototype by the end of 2005.

Wednesday, September 29, 2004

"NANOTECH: Low-temp polymer nanotubes foretell plastic circuits"
Chemists at Central Michigan University have grown carbon nanotubes at a record-low 175 degrees C using a polymer type known as dendrimers as the substrate. "This is the first time anyone has grown carbon nanotubes directly from a dendrimer catalyst at temperatures low enough that the dendrimer is not destroyed," said CMU professor Bradley Fahlman, lead researcher on the project. Whereas conventional polymers grow in long, tangled chains, dendrimers branch out from a core in a symmetrical, tree-like arrangement. In the growth process, the ends of one generation of branches sprout new polymer chains, creating a next-generation shell. The process grows nanotubes from the ends of the dendrimer's branches. Functionalizing the tubes with metal, semiconducting or photoelectric molecules will create materials with varied properties, the researchers said.

Friday, September 24, 2004

"METAMATERIAL: Composites enable 'perfect' lens"
Composite metamaterials that exhibit a negative index of refraction are being harnessed to enable a variety of hitherto impossible applications, promising to reduce size and cost while simultaneously increasing accuracy and range. "Electrical engineers will be interested to know that our metamaterial technology is now being adapted to make microwave devices and antennas with unprecedented levels of performance and functionality," said University of Toronto professor George Eleftheriades, himself an EE. "Our latest results are very promising for both basestation and handheld hardware. . . . Now is the time for electrical engineers to really start creating a whole new range of useful devices for the cell phone industry." Metamaterials enable lenses without an optical axis, despite their planarity, to focus waves by means of refraction. Metamaterials substitute macroscopic objects for atoms in a giant, crystalline-like lattice. The Toronto team's lattice was constructed of perpendicular wires that defined a grid whose spacing was set to a subwavelength of the wavelength affected.

Thursday, September 23, 2004

"METAMATERIAL: Lens focuses sound, not light"
Metamaterials reverse the ordinary laws of nature, such as Snell's "right-hand" law for electromagnetism, which states that magnetism curls in the same direction in which the fingers of your right hand curl around a wire when you point with your thumb in the direction of current flow. By 2003, researchers had verified that not only were these engineered materials possible, but they also could enable "perfect" lenses that were nevertheless flat. Now metamaterials are being demonstrated not just for electromagnetic waves, but for anything that can be described by wave functions, thereby reversing the laws of nature for acoustic engineering, ultrasound, microwaves, light and magnetism. "What we have is a larger version, structurally, of a photonic crystal, adjusted for the wavelength of ultrasound," said John Page, a professor at the University of Manitoba in Winnipeg. "Our metamaterials use artificial atoms arranged in a lattice that filters acoustic wavelengths the way that photonic crystals filter optical wavelengths." Metamaterials substitute macroscopic objects for atoms in a giant crystalline lattice-here made from tungsten carbide beads surrounded by water and packed flat into planes, with a spacing between beads set to a subwavelength of the wavelength you want to affect.

Friday, September 17, 2004

"CHIPS:IBM taps spintronics to reset molecular memories"
IBM Corp.'s progress in characterizing the magnetic spin of individual atoms and in flipping them from "up" to "down" could lead to molecular-cascade memories, a new type of memory chip that would pack a bit of data in every atom. IBM Fellow Don Eigler's group at Almaden Research Center (San Jose, Calif.) recently demonstrated IBM's new nanoscale characterization method, dubbed "spin-flip spectroscopy." To study how to switch the spin of individual atoms, IBM constructed a new type of measuring device. It combines a scanning tunneling microscope with a superconducting coil providing a high-strength magnetic field. The whole machine is supercooled to near-absolute zero. "We invented spin-flip spectroscopy so that we can study how to use magnetic spin for information storage, because at IBM our ultimate goal is the ultimate memory density possible � storing bits on individual atoms," said Andreas Heinrich, a researcher in Eigler's lab. "For instance, we demonstrated our molecular-cascade memories two years ago, but at that time we didn't have a way to reset them � they just fell over like dominoes, then we had to pick them back up one by one. Now we think we can use magnetism to reset a future version of molecular cascades." Eigler and Heinrich performed the work with IBM researcher Christopher Lutz and Jay Gupta, an assistant professor at Ohio State University. With the machine, IBM was able to characterize the precise amount of energy required to flip the spin of an atom from up to down � which is usually encoded to mean "1" and "0." The result was 0.0005 electron-volts, some 10,000 times less than the energy of a single molecular bond.
"NANOTECH: Tuned radio frequency oscillator built from nanotubes"
Researchers at Cornell University have created the world's smallest mechanical oscillator that is capable of being tuned electrically. The nanoelectromechanical system (NEMS), which might be a forerunner of sensors that can detect individual atoms, stretches a 1-nanometer-diameter nanotube across a 1,500-nm-wide trench. The system creates a guitar-stringlike device that could also be used as a mechanical RF oscillator or as a clock reference in future nanoscale chips. "Very simply, what we have here is a smaller version of a MEMS [microelectromechanical systems] RF oscillator, but using carbon nanotubes and being electrically tunable," said Paul McEuen, a Cornell physics professor. "All of its applications are years away from being practical, but it is an interesting new direction for researchers plumbing the nanoscale." To construct the nanoscale oscillator, which the researchers tuned as high as 200 MHz in the lab, the team first grew an oxide on a standard single-crystal silicon wafer. Next they grew nanotubes with 1- to 4-nm diameters and laid them on the oxide's surface, then etched a micronwide trench under the nanotubes' middle so that they were suspended. "We use an atomic-force microscope to locate the nanotube. Then we use lithography to define a trench with photoresist. Then we just etch out about a 1-micron-wide section underneath the nanotube. The middle of the nanotube was suspended over the trench with nothing more than van der Waals forces holding it there," said McEuen. Since the width of the trench � about 1.2 to 1.5 microns � is more than 1,000x wider than the width of the nanotube, the arrangement is similar to a stretched guitar string.

Wednesday, September 15, 2004

"QUANTUM: Yale team builds chips for quantum computing"
Demonstrating a new paradigm for quantum computing, Yale University researchers have built what they call QED integrated circuits to manipulate quantum bits. While the almost mystical allure of quantum computing has been verified time and again using qubits in a physics lab, building real circuitry on silicon chips has had only sporadic success, until now. The QED-for quantum electrodynamics-circuits operate on quantum bits by using a superconducting "Cooper box" to store oscillating microwave photons that can be read and written without disturbing their quantum states. Quantum computers promise to outpace digital computers by using qubits, which can represent a superposition of simultaneous values, thereby achieving parallel processing without parallel hardware. "I think that EEs understand how qubits involve a superposition of quantum states, but they may not know that you can build integrated circuits that way," said Steven Girvin, a professor of physics at Yale. By superpositioning quantum states that simultaneously perform parallel operations, quantum computers can break encryption codes and work other technological miracles that a digital computer would find impossible. Many quantum state mechanisms, some of them potential building blocks for future quantum computers, have been demonstrated in physics labs. But Yale's demonstration of how to build chips using what it calls "qutons"-a qubit on a photon-enable quantum computers using QED circuits to be put onto chips today

Friday, September 10, 2004

"QUANTUM: computer chip circuitry demonstrated"
Yale University researchers have demonstrated how to build a quantum computer operating on quantum bits, or qubits, which hold a superposition of quantum states. The computer uses a superconducting "Cooper box" to store oscillating microwave photons which can be read and written without disturbing their quantum states. Qubits based on the superposition of quantum states can be used to make integrated circuits. "Heisenberg's Uncertainty principle says you can't measure the velocity and position of a particle, and likewise in QED [quantum electrodynamic] circuits you can't measure the voltage and the current at the same time," explained Yale University professor Steven Girvin. Quantum computers derive their power from enabling a superposition of quantum states to simultaneously perform many parallel operations. Those operations allow quantum computers to perform tasks like breaking encryption codes that are impossible for digital computers. Many quantum-state mechanisms have been demonstrated in physics labs, some of which could serve as building blocks for future quantum computers. Likewise, Yale's "qutons," or "qubit on a photon," invention may enable quantum computers to be placed on chips even sooner. The advantages of Yale's method include the relatively small size of its qubit repositories � about a square micron � and the ability to read a qubit's state without disturbing it � the bane of quantum computers to date.
"CHIPS: Self-assembly technique enables 10-nm litho"
A novel processing technique that combines known molecules to realize a new class of synthesized material has enabled 10-nanometer precision lithography. The invention enables the lithographic-like self-assembly of molecules into one-, two- or three-dimensional nanoscale structures by combining a block copolymer with a dendrimer. The latter is a "cascade molecule" in which the atoms are arrayed along a backbone of carbon. "In our experiment we demonstrated 10-nm feature sizes, but we envision our invention working with traditional lithography to encode information into a material that enables it to self-assemble into domains with angstrom-scale precision," said Ulrich Wiesner, professor of materials science and engineering at Cornell University. He performed the work at the university with the help of physics professor Sol Gruner, director of the Cornell High Energy Synchrotron Source; postdoctoral researcher Byoung-Ki Cho; and doctoral candidate Anurag Jain. The researchers said their invention could lead to ultraprecise nanoscale features that improve the efficiency of batteries, solar cells and fuel cells.

Thursday, September 09, 2004

"NANOTECH: Researchers demonstrate nanoscale self-assembly"
A new processing technique developed by Cornell University researchers promises to usher in lithographic-like self-assembly into single and multidimensional nanoscale structures. The technique enabled 10-nm precision lithography. One-, two- and three-dimensional nanoscale structures self-assembled by combining a block copolymer with a "cascade molecule" called a dendrimer in which atoms are arrayed along a carbon backbone, the researchers said. "We demonstrated 10-nanometer feature sizes, but we envision our invention working with traditional lithography to encode information into a material that enables it to self-assemble into domains with angstrom-scale precision," said Ulrich Wiesner, professor of materials science and engineering at Cornell University. Besides subnanoscale precision lithography, the researchers said their invention could lead to ultraprecise nanoscale features that improve the efficiency of batteries, solar cells and fuel cells.

Wednesday, September 08, 2004

"NANOTECH: thermal dip pens read, write, repair nanostructures"
Creating ultratiny, nanoscale systems is often easier than verifying the accuracy of the resulting structures. Indeed, in some instances the structures can actually be lost. Nanoscale techniques produce minute features, but imaging tools are sometimes too crude to spot breaks in them. To the rescue come atomic-force microscopy and now its interactive "can-do" sibling, thermal dip pen nanolithography. Traditional atomic-force microscopy (AFM) techniques drag a probe with a 100-nanometer tip over nanoscale structures to record a small deflection, thereby producing an image of the surface by mapping its valleys and peaks. By first dipping the AFM tip in liquid metal, a semiconductor or an oxide, dip pen nanolithography (DPN) can directly write 100-nanometer lines-but can't interactively switch between read/write.

Friday, September 03, 2004

"NANOTECH: Nanodots to launch large memories"
Arrays of 7-nanometer magnetic nickel nanodots, assembled by researchers at the National Science Foundation's Center for Advanced Materials and Smart Structures (CAMSS), aim at a 500x increase in memory density, to 10 trillion bits per square inch. At such densities, coin-sized chips holding 5 terabits each could pack the entire Library of Congress into "a pocket full of change," said Jagdish Narayan, professor of materials science and engineering at North Carolina State University and CAMSS director at the university. Narayan performed the work with research associate Ashutosh Tiwari. The technique, which uses pulsed-laser ablation to make nanodots that are said to be 10 times smaller than previously possible, can also be used to make more-efficient LEDs, single-electron transistors, spin transistors, hybrid devices, superhard coatings and novel biomaterials.

Monday, August 30, 2004

"CHIPS: Toyota reports silicon carbide wafer advance"
Toyota Central Research and Development Laboratories Inc. (Aichi, Japan) will announce the development of ultrahigh-quality single-crystal silicon carbide 3-inch wafers at the Fifth European Conference on Silicon Carbide and Related Materials, which begins August 31, 2004 in Bologna, Italy. The results, which were developed in cooperation with Denso Corp., could herald a new era of high-power, high-temperature electronic devices that are impervious to radiation.

Friday, August 27, 2004

"QUANTUM: don't exceed speed of light"
In Einstein's prophetic world, fact is stranger than fiction. In the TV show Star Trek, beam-me-up-Scotty teleportation was only possible within the range of the "transporter," but in Einstein's world, teleportation is not limited by range. It does, however, require "entangled pairs" that have to be preinstalled like Sci-Fi channel Stargates. Teleportation is only possible if Alice keeps one half of an entangled pair at point A, while the other half is physically moved to Bob's location at point B. After that, it's as if anything goes � as long as it doesn't lead to exceeding the speed of light.
"QUANTUM: tangled states hold promise"
The intense search for semiconductors that can house quantum states can be traced to the promise they hold for the future of computing. Today, even experimental single-electron transistors can only represent a digital "1" or "0" depending upon whether the charge is present or absent. However, quantum states encode bits into the wave function of the electron � called its "spin" state � thereby enabling a superposition of any number of bits onto a single electron. For instance, as long as the spin of an electron is undisturbed, it can represent a 1, a 0 and any other in-between values simultaneously. When the spin of one electron interacts with that of another, the result can perform parallel computations on all the values represented in their complex waveforms.
"QUANTUM: teleportation exits realm of sci-fi"
The problem with teleportation � the real beam-me-up-Scotty kind--is not its principles, which appear to be sound, but in the devil's details. Fact: There is no way to "encode" all the detailed information in a single quantum state, much less the entire human body (which is composed of about 100,000,000,000,000,000,000,000,000,000,000 "quantum bits," or qubits). It would take a 1,000-km cube to house that much information on CD-ROMs. Even if you could automatically assemble them into Captain Kirk, just to transmit their data with theoretically perfect fat-pipe optical fibers would take more than 100 million centuries. Nevertheless, researchers in the lab have begun to demonstrate true teleportation--not the sort that disassembles Kirk and puts him back together on the planet surface, but the kind that delivers the devil's details from point A (for Alice) to B (for Bob) despite there being no way to encode all that data. How? By not encoding it. Instead, Alice mixes the unencodable data with the quantum state of an entangled pair for which Bob has the twin--and presto! The phenomenon that Albert Einstein called "spooky action at a distance" teleports the unencodable quantum states, qubit per qubit.

Monday, August 23, 2004

"NANOSCALE: parts get binding aid to self-assembly"
Nanoscale particles that are easy to manufacture piecemeal � but hard to assemble � may benefit from a new "sticky patch" technology that researchers at the University of Michigan say enables nanoscale self-assembly. "By mimicking biological assembly, we are exploring ways to nanoengineer materials that are self-assembling, self-sensing, self-healing and self-regulating," said Sharon Glotzer, an associate professor of chemical engineering on the Ann Arbor campus. The researchers' method � using sticky patches that enable parts to put themselves together in programmable ways � could help fabricate new nanoscale materials and devices. In computer simulation, Glotzer and research fellow Zhenli Zhang showed how to self-assemble nanoparticles into wires, sheets, shells and other even more-complex structures.

Friday, August 13, 2004

"CHIPS: bonding breakthrough may ease MRAM design"
For all their promise, magnetic random-access memories have barely made it out of the lab due to problems plaguing their scaling to smaller sizes--namely, the need for lower drive current and thinner metallization. Now researchers at Sandia National Laboratories claim to have patented a method for solving MRAM and other such metal-on-insulator problems. "Ordinarily, putting metal on an insulator is like putting water on a waxed car," said Dwight Jennison, a theoretical physicist at Sandia National Laboratories (Albuquerque, N.M.). "What we are offering here, to anyone who is trying to mix insulators and metals, is the ability to make a strong interface between them, resulting in more reliable devices that are less likely to develop cracks--in everything from thin films to macroscale metal-clad ceramics." The method--discovered by Jennison with chemist Scott Chambers at the Pacific Northwest National Laboratory and Jeffrey Kelber, a professor of chemistry at the University of North Texas--could have implications well beyond MRAMs. It could also revolutionize every macroscale industrial process that involves putting metal on insulators, such as metal-clad ceramics that today require extensive brazing.

Tuesday, August 10, 2004

"QUANTUM: dots poised for production line"
University researchers are using self-assembly techniques and chip-related chemistry to develop a process for mass producing tiny crystals called quantum dots. Semiconductor nanocrystals promise a quantum leap over traditional optoelectronics due to their unique and size-tunable properties. Quantum dots measure a few nanometers in size and are already revolutionizing biological and environmental sensing due to their size-dependent luminescence. Other applications include telecommunications, photovoltaics, lasers and quantum computing. A research team at the University at Buffalo claims to have discovered a simple way to mass-produce quantum dots with extreme precision, in nearly any desirable size, using a technique based on self assembly and room-temperature chemistry.

Friday, August 06, 2004

"WIRELESS: Futuristic factories make mesh"
It is the holy grail of the factory floor: hundreds of sensors wirelessly connected, monitoring motors for problems and drastically reducing energy consumption � all with the precision and rhythm of a philharmonic orchestra. The need is there, the software is there, the topology is fairly well understood and the silicon costs are falling. One market forecaster sees 169 million nodes and a $5.9 billion end-user market by 2010. Still, it's not as easy as it looks. Wireless mesh is a new paradigm with lingering unknowns, and some wireless silicon is still more expensive than wired solutions. The goal, in the eyes of many, remains a ways off. GE Global Research, Sensicast Systems Inc. and Rensselaer Polytechnic Institute have teamed up to push the agenda forward. They are engaged in a three-year, $6 million proof of concept funded by the U.S. Department of Energy that is scheduled to yield a working prototype within a year and a complete wireless-factory installation by 2006.

Tuesday, August 03, 2004

"WIRELESS: transceiver-on-chip now possible"
A research team from Michigan-based universities says it has succeeded in integrating the last two components needed to create a one-chip wireless transceiver. "Our research group picked up the challenge to integrate the last two off-chip components onto a wireless transceiver," said Michael Flynn, head of the wireless-interface group at the Wireless Integrated Microsystems Engineering Research Center (WIMS ERC) at the University of Michigan (Ann Arbor). "Thanks to Kamal Sarabandi, we have demonstrated a Zigbee [2.4-GHz] wireless link using our 1-centimeter-square slot antenna and thanks to probably the world's foremost expert on RF MEMS [microelectromechanical systems for radio frequencies], Clark Nguyen, we have also developed a wineglass-like resonator to replace the off-chip quartz crystal. "Now all the wireless components can be on one chip � enabling everything from hearing aide-sized cell phones to smart dust," said Flynn. Kamal Sarabandi, a member of the WIMS ERC, is director of the Radiation Laboratory at the Electrical Engineering Computer Science (EECS) College of Engineering at the University of Michigan. Clark Nguyen, who developed the wineglass resonator, is an EECS associate professor. "Sarabandi's group has been talking to Intel about commercializing the antenna design in wireless laptop computers, and others have been showing interest in the wineglass resonator," said Flynn.

Tuesday, July 27, 2004

"VR: Software uses sculptor's touch on virtual objects"
Virtual reality software has long held the promise of enabling designers to sculpt the sleek curves and contours of a new product from "virtual clay," but until recently designers had to learn a whole new procedure for working with computer-aided design (CAD). Until now, virtual shapes could only be sculpted via keyboard and mouse input to define "splines" or similar mathematical objects that determine a curve's shape, but have nothing to do with sculpting. More recently, haptic feedback devices have arrived that offer a more direct relationship between the hand and a virtual object, but they still lack the naturalness of hand-shaped clay. A project of the State University of New York at Buffalo is seeking a direct intuitive method for working with virtual shapes in a CAD system using the type of glove developed in virtual reality systems. Using the approach, it is possible to work with actual clay to sculpt a shape, which is then automatically transferred to a CAD representation. "Ours is the only technology capable of transferring touch directly from the user's hand to the virtual object," said associate professor Thenkurussi Kesavadas, director of the Virtual Reality Lab
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Friday, July 23, 2004

"LED: Reflector lets LEDs replace light bulbs"
Light bulbs create more heat than light. But a professor at Rensselaer Polytechnic Institute (Troy, N.Y.) has invented a 99 percent efficient, omnidirectional reflector that he claims will allow light-emitting diodes to replace conventional light bulbs within five years, saving energy and related cost. Fred Schubert, Wellfleet senior constellation professor of the Future Chips Constellation at Rensselaer, has demonstrated his LEDs in red and blue but is pursuing white LEDs for light bulb replacement. "In an LED, light emits from inside the semiconductor in every direction, but our mirror reflects light equally well no matter what the angle of incidence. Other types of reflectors are only efficient when the angle is normal [90� perpendicular to the surface]," Schubert said.
"QUANTUM: Cure in sight for 'pink noise' in quantum dots"
The troublesome flickering that plagues quantum-dot development today may be closer to a cure, thanks to a team of researchers at the University of Chicago. By analyzing the power spectrum of quantum-dot blinks, the group found that, unlike semiconductors, individual quantum dots exhibit exactly the same qualities as their aggregations, thereby simplifying the measuring apparatus needed to fix the problem. "This blinking phenomenon happens everywhere in nature at the nanoscale," said Matthew Pelton, a research associate at the university's James Franck Institute. In MOSFETs, for example, "current blinks when electrons get stuck in these nanoscale traps," each of which holds the electrons for a particular time. "One trap might hold electrons for a short amount of time and another holds them for a long time," Pelton said, but together they exhibit so-called 1/f noise, or "pink noise." If quantum dots behaved like MOSFETs, which until now was the common wisdom, then curing a flickering problem would mean studying the individual quantum dots, since each would have a characteristic blinking frequency. However, Pelton and his colleagues Philippe Guyot-Sionnest and David Grier (who has since moved to New York University) found that each quantum dot exhibited the same pink-noise profile all by itself. Thus, when quantum dots are observed at the macroscale, the same phenomenon is seen as when the output of a single quantum dot is observed.

Friday, July 16, 2004

"EDUCATION: Engineering schools abrim with talent"
The coursework is no picnic, and once you finish, the job market can be iffy. And yet, more U.S. students are enrolled in engineering graduate schools than ever before, according to a new report from the National Science Foundation. They numbered almost half a million in 2002, NSF says, a figure that surpasses by 5 percent the previous peak, achieved in 1993.
"To some extent the all-time high in graduate enrollment in science and engineering is following trends in the total U.S. college-age population," said Jean Johnson, an NSF senior analyst. But demographics alone can't account for the entire uptick, Johnson said, especially in fields like electrical and biomedical engineering, which jumped 10.7 percent and 20.3 percent respectively. Here, according to Johnson, engineering specialties on the rise reflect the students' practical eye for interesting employment opportunities. "Much of the increase in specific fields of science and engineering can be attributable to students going where they perceive the jobs to be," said Johnson. That's certainly the case for a trio of would-be engineers who have already begun to make a mark in the profession � Dat Truong and Landon Unninayar of Johns Hopkins and Alia Sabur from Drexel University.

Wednesday, July 14, 2004

"CHIPS: Electron spin detector may yield denser chips"
Spin-dependent transistors could one day harness electron spin to encode up to 10 states (as opposed to binary logic's mere two) in single-electron devices-enabling chips with a million times the density of today's memories, according to the University of Arkansas. A precise understanding of how an electron's spin rotates as it moves through a material could enable such single-electron, spin-dependent devices. Unfortunately, there has been no instrument available to measure electron spin, so even the first step toward a spin-dependent computer has not been taken-that is, to carefully characterize the properties of a spin-dependent transistor, according to Paul Thibado, associate professor of physics at the University of Arkansas.

Friday, July 09, 2004

"ROBOT: copies cats to eliminate spin in free fall"
The National Aeronautics and Space Administration's "weightless wonder" aircraft will be the testbed this week for a robot that exhibits catlike motion in free fall. The work could one day lead to designs that eliminate the need for retrorockets, gas jets and gyroscopes in satellites and other spacecraft. The robot rotates without angular momentum by changing the length of parts of its body while rotating them in opposite directions, much as a falling cat does. Managing that momentum is the bane of space navigation today, complicating almost every space-based maneuver, introducing unwanted spin that must be compensated for with retrorockets or gas jets. In devising the concept, project leader Gregory Ojakangas, a physics professor at Drury University (Springfield, Miss.), borrowed from a species that flouts the rules of angular momentum. "When you drop a cat upside down, it always lands on its feet, with no spin. It doesn't paddle the air � that would impart spin � it just expands its upper body and rotates it, then contracts its upper body and rotates in the opposite direction," said Ojakangas. "In that sense, ours is not a new idea; nature has been doing it for I don't know how many millions of years."

Monday, July 05, 2004

"MAGNETISM: Jumbo magnet in Florida exerts worldwide pull"
An enormous magnet, boasting a rock-steady field and a bore twice the size found elsewhere, is expected to draw the global scientific community to its Florida home. Opened last month in Tallahassee, the magnetic system offers a 105-millimeter bore and a record birth "weight," or magnetic field. Standing 16 feet tall and weighing more than 15 tons, the National High Magnetic Field Laboratory magnet is expected to live at least 10 years, and could survive for decades. On its inception date, July 21, the magnet produced a uniform field of 21.1 Tesla, which is expected to hold steady for years, a product of the resistanceless state of the superconducting electrons orbiting its bore. The magnet is now being readied for an international user community and, thanks to its superconducting coils, it will stay running for years to clean up a backlog of experiments waiting for such a device.

Friday, July 02, 2004

"QUANTUM: wells shed light on lightbulb alternative"
A promise of future lightbulb replacements that are almost 100 percent efficient came to light in a recent proof-of-concept experiment carried out by the National Nuclear Security Administration's Los Alamos National Laboratory and Sandia National Laboratories. In demonstrating these "light engines," experimental quantum wells emitted ultraviolet energy so rapidly that before that energy could become radiation, it was absorbed by integrated nanocrystals that glowed like a fluorescent tube. Now, "the process is 55 percent efficient," reported Sandia researcher Daniel Koleske, "because, unlike the fluorescent bulb, which must radiate its ultraviolet energy to the phosphor in the form of photons, the quantum well here delivers its ultraviolet energy to the nanocrystal very rapidly, before photons even form." As a consequence of the conversion process from UV photons to visible photons, normal fluorescent lightbulbs are less than 10 percent efficient. But in the future, light engines currently under development by companies working with the national laboratories could increase that efficiency to almost 100 percent.

Wednesday, June 30, 2004

"CHIPS: NASA preps labs-on-chip for space exploration"
The National Aeronautics and Space Administration is harnessing lab-on-chip technology to detect life on other planets and monitor microbes inside spacecraft. Employing recent advances in microfluidic and sensor technology, NASA scientists are engineering an array of labs-on-chip. Each is specialized to detect certain types of life. "Lab-on-a-chip technology is maturing rapidly here on Earth, but to use it in spacecraft or on other planets we need to develop a set of unique chips with miniaturized controllers and analysis units so that scientists can conduct many different chemical and biological assays with each lab-on-a-chip," said Lisa Monaco, the project scientist for the Lab-on-a-Chip Applications Development program at NASA. "Lab-on-a-chip technology can be used to detect bacteria and life-forms on Earth and other planets as well as for protecting astronauts by monitoring crew health and detecting microbes and contaminants in spacecraft," said Helen Cole, project manager for the Lab-on-a-Chip Applications Development program. On Earth, early implementations of lab-on-chip technologies include home pregnancy tests as well as doctors' in-office tests for strep throat. These one-shot labs-on-a-chip mix, concentrate and control a specialized test that yields quick results in an inexpensive disposable device. But for use in space, almost everything about their design has to changed.
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Friday, June 25, 2004

"QUANTUM: researchers successfully teleport quantum bits"
Physicists at the National Institute of Standards and Technology (NIST) in the United States and the University of Innsbruck, Austria have demonstrated the transfer of information between two locations without any intervening physical medium. The separate efforts mark the first teleportation of material states, a concept long postulated and one that could open new avenues for unbreakable encryption technology � information would never be eavesdropped upon because it is not actually being transmitted. "We and another group at the University of Innsbruck are the first to demonstrate teleportation of quantum states from one location to another," said NIST physicist David Wineland. "Both groups have followed Bennett's original algorithm very closely, and we both successfully teleported qubits." Wineland was referring to a 1993 finding by IBM fellow Charles Bennett and five colleagues that because matter was based on quantum-mechanical waves, "beam me up, Scotty" teleportation was possible in principle. The caveat: The original of the item being teleported would be destroyed in the process.
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Monday, June 21, 2004

"ROBOT: student team's robot safely detects land mines"
Johns Hopkins University engineering students recently completed a remote-controlled robot that can find land mines in rugged terrain and mark their location by spraying paint. "I challenged the students to develop a vehicle that could get into rougher terrain, like bushes and high grass," said Carl Nelson, a principal staff physicist at the university's Applied Physics Laboratory. "I wanted it to be able to get off the roads and clear paths � where mine detection can be difficult to do by hand." Four Johns Hopkins engineering students rose to the challenge and spent almost a year designing a prototype robot. The machine is being evaluated by explosive-detection experts as a model for a low-cost robot for soldiers and humanitarian groups. It was designed by engineering students Edoardo Biancheri, Dan Hake, Dat Truong and Landon Unninayar. The project encompassed a two-semester course called the Engineering Design Project.
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Thursday, June 17, 2004

"FERROELECTRIC: X-rays probe failures in ferroelectric memories"
Unlike a conventional random-access memory, a ferroelectric RAM can switch its magnetic domains electrically between zero and one without having to call on standby power. Since ferroelectric memories already store data on smart cards and transform electrical pulses into sound in watch buzzers and ultrasound machines, it might seem that their properties were well-understood. Instead, as an advanced X-ray technique showed recently, the opposite is true. Conventional wisdom maintained that a single mechanism caused ferroelectric switches to get stuck after a few hundred thousand transitions between one and zero-making them unsuitable ro replace other RAM. But researchers at the University of Wisconsin (Madison), seeking ways to extend ferroelectrics' lifetimes, unveiled at least two mechanisms that cause ferroelectrics to fail.

Monday, June 14, 2004

"WIRELESS: smaller antenna design said to boost efficiency"
A four-year skunk works effort at the University of Rhode Island in Kingston has cut the size of an antenna by as much as one-third for any frequency from the KHz to the GHz range. Using conventional components the four-part antenna design cancels out normal inductive loading, thereby linearizing the energy radiation along its mast and enabling the smaller size. "The DLM [distributed load monopole] antenna is based on a lot of things that currently exist," said the researcher who invented the smaller antenna, Robert Vincent of the university's physics department, "but I've been able to put a combination of them together to create a revolutionary way of building antennas. It uses basically a helix plus a load coil." The patent-pending design could transform every antenna-from the GHz models for cell phones to the giant, KHz AM antennas that stud the high ground of metropolitan areas-Vincent said.
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Friday, June 04, 2004

"Heads-up display promises to help near-blind to navigate"
University of Washington students have turned a pair of Elvis Costello-style eyeglasses and a backpack into a system that helps the near-blind navigate around stationary objects. Their Wearable Low Vision Aid projects icons on top of obstacles seen in a heads-up display, using a laser diode and a vibrating crystal fiber made from components that cost less than $1. The system projects a bright warning icon � visible even to the legally blind � into the eye so as to illuminate just the part of the retina where the approaching obstacle is imaged. As a consequence, approaching obstacles are brightly highlighted, making them easy for the blind person to avoid (even if his or her vision is too poor to discern what they are).Audio Interviews / Text:

Thursday, May 27, 2004

"Chip diffusion modeling yields better maps"
Diffusion modeling similar to the technique used to design semiconductors has helped solve a long-standing problem in information display � the cartogram. The classic example of a cartogram is a U.S. map with the size of each state proportional to its population. Computerized rendering of cartograms was invented at the University of Michigan in the 1960s, but the technique has since languished because even the fastest computers take an inordinate amount of time to render a well-drawn cartogram using traditional algorithms. Using diffusion modeling, University of Michigan researcher Mark Newman solved the problem with almost instantaneous renderings of accurate, computerized cartograms. Cartograms are made by modeling how populations would migrate if they were evenly distributed. Most are hand- drawn to maintain proper proportions such as keeping cities in the right states.
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Tuesday, May 25, 2004

"VIDEO: tracking software enters the game"
Segmentation and object recognition software used in video applications such as facial recognition in security cameras is being applied to sports programming. Researchers at the University of Calgary (Alberta) are investigating whether automatic recognition and tracking software can "watch" a sporting event for a viewer, keep track of who did what and when, then diagrammatically represent the highlights or even live action using icons instead of raw video. "Once we extract the moving objects in a scene, we can transform that data and present it in all sorts of formats. We can even make a little schematic of a sports game which is good for viewing on a small handheld device like a cellphone," said researcher Jeffrey Boyd.
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Monday, May 24, 2004

"ANTI-TERROR: Sticky sensor may keep troops out of harm's way"
Using sensor circuitry, a paintball gun and a "big glob of sticky polymer," undergraduate students at the University of Florida (Gainesville) have invented a device that may save the lives of U.S. soldiers in Iraq and Afghanistan whom agitators continue to ambush with roadside explosives. The students devised a projectile with an electronic sensor that can be shot at suspicious objects up to 65 feet away. The sensor sends back its analysis of the targeted object to soldiers using a 450-MHz wireless transmitter.
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"CHIPS: Dopants stabilize materials at the nanoscale level"
Downsizing to the nanoscale theoretically endows materials with greater strength, enabling copper interconnects, for example, to remain reliable even when line widths shrink to the nanoscale. But critics predict that high temperatures during use might cause the nanometer-sized grains to merge back into micron-sized grains, thereby making the material more brittle and prone to failure. Now a University of Arkansas professor contends that his simulations foretell a day when nanoscale copper will be doped, just as silicon semiconductors are today, thereby stabilizing the metal and preventing it from becoming brittle at high temperatures.
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Monday, May 17, 2004

"NANOTECH: Team exploits electromigration to build nanosystems"
Chip designers usually take pains to avoid electromigration, an effect that plagues metal layers, especially aluminum. But now, researchers at Lawrence Berkeley National Laboratory have harnessed electromigration down carbon nanotube "pipelines" to deliver a constant stream of indium atoms to nanoelectromechanical systems (NEMS).
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Thursday, May 13, 2004

"SUPERCOMPUTERS: U.S. targets fastest supercomputer"
Winning back the title of world's fastest supercomputer is the goal of a new $25 million contract awarded by the Energy Department to Oak Ridge National Laboratory's Center for Computational Science. The award, announced Wednesday (May 12) by Energy Secretary Spencer Abraham, seeks a sustained capacity of 50 trillion calculations per second (teraflops) and a peak capacity of over 250 teraflops. Japan's Earth Simulator holds the record at nearly 40 teraflops. Abraham said the National Leadership Computing Facility (NLCF) would be a five-year program that pools the partnership's computational resources to create the world's fastest supercomputer. Along with regaining the speed title, officials said weather prediction, biological protein folding as well as battlefield and nanoscale simulations could all benefit from faster supercomputers.
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Thursday, May 06, 2004

"QUANTUM: entanglement demo of quantum gate, computer could be next"
The world's first proof of concept for quantum entanglement within a semiconductor was reported recently by Albert Chang, an adjunct professor at Purdue University who recently moved to Duke University. Chang next plans to build the world's first quantum gate in an electronically controlled semiconductor device, enabling the creation of a key building block in quantum computation. "We were able to obtain the first direct evidence for spin entanglement in a coupled double-quantum-dot system," said Chang. "This is why we are so excited about this new result." Chang was a 12-year veteran of AT&T Bell Laboratories' Microstructure Physics Research Department before joining Purdue University. While a professor at Purdue University in 2001, Chang demonstrated a serial quantum-dot system and predicted he would demonstrate quantum entanglement in two to five years � a promise he fulfilled with his recent demonstration. Next, Chang predicts he will demonstrate the world's first electronically controlled semiconductor quantum gate within two years. This prediction is based on his new parallel configuration of two gallium arsenide quantum-dot transistors with a common source and drain.
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"NANOPARTICLES: in orderly arrays, serve thin-film role"
All the fuss over nanoparticles might lead one to assume they are routinely being used to prepare thin films. But insolubility and the clumping it causes thwarted early attempts to turn nanoparticle laboratory results into usable devices. Now, researchers at Sandia National Laboratories and the University of New Mexico say they've perfected a commercially feasible way for orderly arrays of nanoparticles to self-assemble, each insulated from the others by silicon dioxide. The technique will not only enable new devices, the researchers said, but could also solve one of the longest-standing problems with nanoparticles: forming orderly connections between micro- and nanoscale.
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Monday, May 03, 2004

"NANOTECH: self-assembled nanoparticles are insulated"
Researchers at Sandia National Laboratories and the University of New Mexico say they've perfected a commercially feasible way for orderly arrays of nanoparticles to self-assemble, each insulated from the others by silicon dioxide. The technique will not only enable new devices, the researchers said, but could also solve one of the longest-standing problems with nanoparticles: forming orderly connections between the microscale and the nanoscale. "We are showing engineers how to make use of the nanoparticles that physicists have only been able to measure in the lab," said Jeff Brinker, Sandia National Laboratories fellow as well as an engineering professor at the University of New Mexico. "With our self-assembly technique, you can stop nanoparticles from clumping plus they are insulated from each other with silicon dioxide."
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Friday, April 30, 2004

"ANTI-TERROR: Pentagon tests toxin detection and forecast system"
Scott Swerdlin describes how the blimp with the 23-foot-long sensor-studded tether that is now hovering over the Pentagon is about to conduct novel tests of simulated airborne toxins. As the blimp releases a faux poison over the course of the next two weeks, a real-time system designed for first responders will gauge how much of the toxin has been discharged and where, and then predict where the plume will drift and how it will disperse. Results of the effort, which is sponsored by the Defense Advanced Research Projects Agency, will be incorporated into an umbrella protection regime against chemical, biological and radiological toxins that can be adapted to all Defense Department facilities and foreign embassies. "What we think is really novel about this system, making it the only one in the world, is that it uses what we call multiscale forecasting," said project leader Swerdlin, a software engineer at the National Center for Atmospheric Research (NCAR).
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Thursday, April 29, 2004

"MEMS: femtosecond pulsed laser sculpts nanoscale microelectromechanical systems"
Nanoscale sculpting of three-dimensional microelectromechanical systems has been enabled by careful characterization of a femtosecond laser's critical intensity. By varying a femtosecond pulsed laser's intensity, University of Michigan researchers report, materials can be selectively vaporized in 3-D, enabling MEMS ablation tolerances as small as 10 nanometers. "We have MEMS designers beating down our door," said Alan Hunt, an assistant professor in the department of biomedical engineering (Ann Arbor). "They bring us these structures they want to make but can't figure out how and we say, sure we can help you make that. We believe our technique will be a real enabler for MEMS."
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Wednesday, April 28, 2004

"ROBOTS: readied to take on search-and-rescue duties"
Microminiaturization has made possible swarms of autonomous robots using nothing more than off-the-shelf parts. But concentrating their wireless chatter and getting them to cooperate to solve problems may be five years away, the National Science Foundation cautions. It's putting $2.6 million into a five-year effort to turn multiple wireless robots into an emergency search-and-rescue team. "We want to help emergency response personnel by sending cooperative robots into an unknown site," said California Institute of Technology researcher Joel Burdick. "My team will be developing software that enables each of them to perform slightly different tasks that together accomplish the goal."
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Friday, April 23, 2004

"CHIPS: sharpened images reveal nature of atomic-scale structure of doping"
Stephen Pennycook describes a team of research scientists that have used an improved electron microscope to confirm a long-held theory concerning the structural nature of doped atomic-scale surfaces. The discovery also promises to give material designers the capability of predicting the composition of materials without having actually to fabricate samples. The scientists from Oak Ridge National Laboratory (ORNL), Pixon LLC and the Japan Society for the Promotion of Science recently produced images of an atom at resolutions as fine as 0.7 angstrom, a new world record. In doing so, they found out why trace amounts of dopants have such drastic effects on a material's properties. "It's been one of the world's long-standing unsolved mysteries, how the grains of ceramics form," said ORNL Fellow Stephen Pennycook about the surface of his silicon-nitride test material. "A tiny bit of dopant has a huge effect on a material's properties, but we did not know why."
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Wednesday, April 14, 2004

"POLYMER: conductive plastic could speed electronics manufacturing"
A conductive plastic that mixes electronics-functions into the material before it is cured could make possible products from disposable e-newspapers to large-scale organic LEDs that can be sprayed on walls. The patented plastic, Oligotron, was developed by TDA Research Inc. (Wheat Ridge, Colo.), under a National Science Foundation contract. Unlike earlier materials, it uses noncorrosive solvents to manufacture organic-polymer-based electronics products.
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Friday, April 09, 2004

"NANOSCALE: beads sniff tough-to-find toxins"
A biosensor that uses nanoshells � nanoscale hollow beads � may provide the long-sought technology U.S. homeland security officials have sought to sense arbitrary biotoxins. Researchers at the University of Arizona have continued the pioneering work of a colleague to create the biosensors. Made from cell membrane material with embedded ion channels, the biosensors transduce fluorescence in the presence of nearly any agent, from biotoxins to proteins to other difficult-to-sense organics, even those inside a living cell. Because the nanoshells are so small and can work inside a living cell without disrupting normal activities, as many as 100 can monitor as many as 100 different agents.
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Wednesday, April 07, 2004

"MEMS: friction study reveals nanoscale adhesive force"
As microelectromechanical systems scale down in size, common forces such as surface tension and friction become more dominant. At Sandia National Laboratories (Albuquerque), friction at the nanoscale is getting close scrutiny that has turned up some surprises, including the discovery of a previously undetected adhesive force. Sandia researcher Maarten de Boer recently announced the early results of a program that uses an "inchworm" (a common device for making precise measurements), downsized for MEMS, as a measuring stick to characterize friction between MEMS surfaces. De Boer found hitherto undetected adhesive forces that result from nanoscale features.
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Friday, April 02, 2004

"NANOTECH: Oregon boosts nanotechnology funding"
Oregon Gov. Theodore Kulongoski said the state will boost nanotechnology research with $20 million in initial state funding to cover infrastructure costs at Oregon's Nanoscience and Microtechnologies Institute. Kulongoski laid out the state's four-year funding plan Thursday (April 1) at the Innotech 2004 conference here. The institute, also know as Onami, is a building block for even greater potential to be the leader in nanotechnology," Kulongoski said.
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Thursday, April 01, 2004

"SENSOR: tag may combat 'friendly fire' incidents"
Fratricide-the act of killing one's own soldiers, also called "blue-on-blue" incidents-can now be largely prevented through the use of a radar tag sensor developed at Sandia National Laboratories (Albuquerque, N.M.), according to engineers there. "We think we can help prevent friendly fire incidents with our sensor, but there are still many hurdles to get over before they become a part of the U.S. military procurement cycle," said engineer Lars Wells, leader of the group that invented the device. In some recent conflicts, the casualties from "friendly fire" incidents have been higher than those from enemy fire. During a recent test of the radar tag sensor, the Sandia National Laboratories engineers showed that it can return a synthetic radar echo when targeted by radar from U.S. aircraft, thereby alerting the aircraft not to target that "friendly" position. Properly installed on all U.S. and coalition military vehicles and eventually on individual soldiers themselves, the device's inventors believe it can virtually eliminate friendly fire from aircraft (but not artillery) during combat. The sensor is slated to make its debut before U.S. Army procurement officials this fall.
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Monday, March 29, 2004

"NANOTECH: microfluidic pump chases self-cooled chips"
Future chips may be self-ventilating, thanks to added microfluidic-like layers that pump heat-laden air off-chip using a classic "corona wind" effect. Purdue University has patented the technique at the nanoscale, and two team members have co-founded a company to commercialize aspects of the cooling system. The Purdue team recently demonstrated a chip that created ions between closely spaced carbon-nanotube electrodes and funneled the resulting air currents down microfluidic channels, allowing the resultant heat to squirt out the sides of the chip.
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Friday, March 26, 2004

"TERAHERTZ: research gains momentum
Already the first crude images from terahertz image chips have proven that Superman-style "X-ray vision" may soon be commonplace. Last year the European Space Agency's StarTiger R&D team showed a 16-pixel device that they claim produced the world's first terahertz picture of a human hand. The detector used a silicon photonic-bandgap material. Likewise, microelectromechanical systems are also being crafted to bridge the terahertz gap. At least one group has built a stack of silicon bars with a micromachined funnel that focuses terahertz signals of 1- to 10-micron wavelengths. Both traditional- and quantum-transistor experimenters have also reported progress. Intel Corp., for one, promises a "terahertz" transistor later in this decade using silicon-on-insulator technology, a fully depleted substrate and a high-k gate dielectric.
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"TERAHERTZ: Dj vu technology"
Vladimir Kozlov, president and co-founder of Microtech Instruments Inc., is building cutting-edge products out of technology that's almost 60 years old. "Our sources of terahertz [waves] are based on vacuum diodes, also known as backward-wave oscillators, which is fairly old technology, having been developed in Russia after World War II," said Kozlov, who helped found Eugene, Ore.-based Microtech in 1992. "We engineered Russian BWOs into a complete terahertz spectrometer for the experimenter, and we've continually upgraded it for about 12 years now." Kozlov claims today's solid-state researchers have a long way to go to catch up with Microtech's turnkey terahertz spectrometers, which offer high-power, high-resolution, spectroscopic imaging with broadband radiation from 30 GHz to 1.5 THz. Using BWOs as sources, the tabletop systems also include terahertz detectors with a 2-inch-square opto-acoustic sensor called a "golay cell." Both the BWOs and golay cells are manufactured exclusively in Russia.
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"TERAHERTZ: microwaves meet infrared at the final frontier"
With all the advances in solid-state communications � from long-wavelength, very low-frequency radio waves that talk to submerged submarines, to short-wavelength, very high-frequency light waves that communicate with lasers � you would think the whole electromagnetic spectrum was covered. You'd be wrong. There exists a gap, centered at 1 trillion cycles per second, that the solid-state era has only begun to bridge. The terahertz gap is the last frontier in the EM spectrum. Terahertz frequencies are where microwaves meet infrared light waves. Microwaves are "millimeter wavelengths" whereas infrared is "nanometer wavelength," leaving the terahertz gap nestled in between at "micron wavelengths."
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Monday, March 22, 2004

"AI: Sharp unit to license IP from U.S. labs"
Artificial-intelligence technology that could change the way busy sports fans get their fix will be among the licensable intellectual property unveiled here Tuesday (March 23) by the newly formed Sharp Technology Ventures. The venture's charter is to commercialize technologies developed at Sharp Laboratories of America Inc. that have languished here in the labs � "technologies that, for one reason or another, Sharp Corp. in Japan is not going to develop," said Jon Clemens, the leader of Sharp Technology Ventures. Clemens retired last year as director of Sharp Labs after getting permission from the $20 billion parent company in Osaka to form the tech venture company.
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Friday, March 19, 2004

"ANTI-TERROR: sensor net prototype being tested in Tennessee"
SensorNet, a first-alert anti-terrorist network, is being tested in Tennessee before it's delivered to Homeland Security for use nationwide. It is one more step toward outfitting U.S. weather stations to detect the release of toxins and predict where the winds will take them. The Tennessee prototype will be a good test of the national deployment plan, said John Strand, project manager for the SensorNet program. A cooperative effort by Oak Ridge and the National Oceanic and Atmospheric Administration (NOAA), the program now has working sites in New York, Washington and Fort Bragg, North Carolina, and Nashville, Knoxville and Oak Ridge, Tenn. SensorNet will span the state with sensors that can alert emergency responders and the public when they are in danger of being exposed to water- or airborne toxins from chemical, biological or radiological releases.
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Monday, March 15, 2004

"TERAHERTZ: SiGe process tapped for 'X-ray vision'"
Russian and U.S. academics are collaborating to develop terahertz silicon germanium chips for "X-ray vision" systems that could peer through suitcases and clothing to identify weapons, through clouds to guide aircraft and through skin to pinpoint cancer. The researchers foresee the chips' use in terahertz scanning spectrometers, just now coming over the technological horizon. "We are very excited about collaborating with our Russian colleagues. We will combine their work on the theoretical side with our work using SiGe to improve three different types of terahertz emitter chips we have designed," said James Kolodzey, professor of electrical and computer engineering at the University of Delaware (Newark). Kolodzey's counterpart in Russia is Miron Kagan, director of the Russian Academy's Institute of Radioengineering and Electronics (Moscow). That institute in turn collaborates with the Ioffe Physico-Technical Institute (St. Petersburg).
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Thursday, March 11, 2004

"NANOTECH: Oregon prof: Wires beat tubes in nano world"
With so many stories heralding the merits of carbon nanotubes as the channels of next-generation nanoscale transistors, you'd think the case was closed. Not so, say researchers here who claim nanowires can create better nanoscale transistors � ones that can be placed more accurately, can use application-specific doping and can be more easily integrated with traditional silicon processing. "Our most recent results show how to grow nanowires in precisely the places you want them on silicon wafers. Nanowires offer many advantages over nanotubes, such as the ability to dope them in different well-understood ways for different applications," said EE professor Rajendra Solanki at Oregon Health and Science University.
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"NANOTECH: Nanowires vie with carbon nanotubes for next-gen transistors"
With so many stories heralding the merits of carbon nanotubes as the channels of next-generation nanoscale transistors, you'd think the case was closed. Not so, say researchers here who claim nanowires can create better nanoscale transistors � ones that can be placed more accurately, can use application-specific doping and can be more easily integrated with traditional silicon processing. "Our most recent results show how to grow nanowires in precisely the places you want them on silicon wafers. Nanowires offer many advantages over nanotubes, such as the ability to dope them in different well-understood ways for different applications," said EE professor Rajendra Solanki at Oregon Health and Science University (
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Monday, March 08, 2004

"SONAR: renders ocean floor transparent"
A breakthrough in sonar technology may soon make it possible to more accurately detect and map underwater artifacts, such as mines, even when they are buried. "Our results are from simulations, but they show that some relatively simple changes to standard sonar equipment will result in a much simpler and effective means of detecting underwater mines," said David Pierson, a Johns Hopkins University scientist who invented the technique for his dissertation under professor David Aspnes at North Carolina State University.
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