Monday, January 31, 2005

"CHIPS: plastic chips tap IR, solar power"

Development of a low-cost plastic infrared photovoltaic material by a group at the University of Toronto could herald a major step forward for solar power, its creators believe, by enabling solar-powered systems to also harvest infrared emissions. The material embeds various-size nanoparticles-or quantum dots-in a polymer suspension. "We have designed a plastic device that is physically flexible-you could even paint it onto things by putting it in a solution," said Toronto EE professor Ted Sargent. "However you deposit it, after drying you have a nice, thin, smooth film that provides the basis for an electronic device." Sargent's group had already demonstrated plastic infrared emitter chips, but the new results are detectors. Sargent believes large-area plastic infrared photovoltaics could become a major marketplace within 10 years, depending on how low their cost goes.

"OPTICS: Guiding light for optical circuits"

Cornell professor Michal Lipson heads a research group of a dozen EEs pursuing nanoscale photonics. The team has created silicon photonic chips that confine light in very small cavities that can slow down, enhance and otherwise manipulate the optical properties of light. These pioneering nanostructures enhance the light-matter interaction in silicon by orders of magnitude, Lipson claims, enabling a material's optical properties to be controlled externally � either electrically or with another optical signal. Lipson aims to provide the basic building blocks for electro-optical and all-optical circuits that include all necessary passive and active photonic components on a single CMOS chip. The daughter of two U.S. physicists, Lipson speaks English with a charming accent that reflects her upbringing in Brazil and Israel. She spoke recently with EE Times contributor R. Colin Johnson.

Wednesday, January 26, 2005

"CHIPS: international team boosts thin films"

The United States, Italy and China are cooperating to develop superior thin-film technologies that could endow future devices with properties not possible in today's processing. A group of scientists in the United States and Italy has described transparent organic thin films that use self-assembly to create ultrathin layers with superior electro-optical properties. A cooperating group in the United States and China has demonstrated that superconductivity can be precisely controlled in ultrathin films. Professors Tobin Marks and Antonio Facchetti at Northwestern University collaborated with professor Giorgio Pagani of the University of Milano-Bicocca to demonstrate a vapor-deposition technique for fabricating transparent organic thin films that self-assemble. The group reports a hundredfold increase in the self-assembled material's electro-optical responses at both the 1.3- and the 1.55-micron communications wavelengths.

Friday, January 21, 2005

"SENSORS: Sandia partners on sensor tech"

Defense contractor Custom Electronics has partnered with Sandia National Laboratories to develop a commercial sensor that will warn a driver the car's battery will fail a few days down the road. Custom Electronics (Oneonta, N.Y.) decided to join Sandia's new Mission Centric Venturing program after seeing a benchtop demonstration of its sensor, which will make a light blink on a car's dashboard. The warning system was developed by Sandia researcher Jonathan Weiss. "Since our mission here now includes economic competitiveness, I have adapted optic sensors for low-cost solutions to commercial sensor problems," said Weiss.

Thursday, January 20, 2005

"CHIPS: clock technique resonates for nixing jitter"

Details about a resonant clock distribution circuit jointly developed by IBM Corp. and Columbia University will be revealed at the IEEE's International Solid-State Circuits Conference next month. The second-generation design builds on last year's IBM-Columbia paper, but this time with a bottom-up approach that is one step away from possible commercialization. Last year, by canceling capacitive loading with integrated inductors, IBM and Columbia solved the jitter and skew problems of distributing gigahertz to terahertz clock signals in a prototype chip that retrofitted IBM's current clock distribution circuitry. This year, the IBM-Columbia design will feature a resonant oscillator solution that, if successful, will redefine the way clock distribution is done on high-end IBM processors. "I can't tell you the details of our new design before the ISSCC paper, except to say that we looked at everybody's resonant clocking techniques and have come up with a solution which we think will change the way clock signals are distributed on high-end processor chips," said Steven Chan, an EE at Columbia University. Chan works under EE and professor Ken Shepard in cooperation with physicist Phillip Restle at IBM's T.J. Watson Research Center (Yorktown Heights, N.Y.)

Thursday, January 13, 2005

"SENSORS: tiny magnetometer ups sensitivity at NIST"

The National Institute of Standards and Technology has developed a chip-scale atomic magnetometer, the size of a grain of rice, that can sense magnetic fields as weak as 50 picoteslas, or a million times weaker than Earth's magnetic field. Said to be far more sensitive and accurate for its size than existing designs, the tiny instrument could find use in handhelds that would sense unexploded ordnance, perform precise navigation or create geophysical maps (for locating minerals or oil). It could also enable medical instruments to be downsized. NIST's Peter Schwindt, architect of the mini magnetometer, called it "sensitive enough to detect a concealed rifle at 12 meters or a 6-inch-diameter steel pipeline as much as 35 meters underground."

"SENSORS: $200 sensor detected South Asia quake"

A novel electronics architecture enabled a seismic sensor costing nearly one-fiftieth that of more elaborate ones to detect the recent tsunami-causing earthquake in South Asia. While today's seismic detectors cost upward of $10,000 each, making them impractical to deploy in poor or rural areas such as those devastated by the recent tsunami, the new detector can be built for under $200. "My detector does not replace those expensive seismic detectors, which have many more functions than my sensor. But my design can sense earthquakes and volcanic activity much less expensively," said Randall Peters, chairman of the physics department at Mercer University (Macon, Georgia). "Right now my detector is set up to try to sense the Earth's acceleration to test a theory of James Shirley's [a scientist at NASA's Jet Propulsion Laboratory]. I was monitoring the instrument for that purpose when it jumped significantly and continued above the background noise for a period of more than two hours." By checking the exact timing, Peters confirmed that even though his sensor was almost halfway around the world, the device provided early warning just before the Indian Ocean earthquake that caused the region's devastating tsunami. His sensor, based on a precision pendulum-like architecture, moved two thousandths of an inch, with a period of oscillation of 30 seconds for two hours.

Monday, January 10, 2005

"OPTICS: laser demos silicon-opto convergence"

Intel Corp. claims to have developed the world's first all-silicon laser chip. The team foiled silicon's indirect bandgap, which ordinarily prevents lasers from emitting light efficiently, by using stimulated Raman scattering to generate enough optical gain to allow lasing. By pumping 0.4 microwatt into an on-chip silicon waveguide, the team achieved sufficient gain to initiate 100-nanosecond laser pulses at the 1,669.5-nm wavelength. "We are reporting Raman lasing in a compact, all-silicon waveguide cavity on a single silicon chip. With devices like this we are demonstrating the true convergence of silicon and optoelectronics," said Mario Paniccia, director of Intel's Photonic Technology Lab.