Monday, September 26, 2005

"NANOTECH: Construction plan for the nanozone"

Nanotechnology-tool maker FEI Co. (Hillsboro, Ore.) broke the angstrom barrier this year, announcing imaging features as small as half an angstrom (1/20 of a nanometer). It did so under the leadership of chairman, president and CEO Vahé Sarkissian, a chip industry veteran and cofounder of AMD's processor business, who took on day-to-day oversight when he joined FEI in 1998. Sarkissian shared his opinions on what it will take for nanotechnology pioneers in semiconductors, materials and the life sciences — FEI's customers — to travel the learning curve in the uncharted territory he calls the "nanozone."

EE Times: You are an EE, like most of our readers, and you helped found Advanced Micro Devices' memory and microprocessor businesses. Most of the companies you have been a part of have done chip-related work, from wafer lithography to electron-beam metrology. How did you go from there to building nanotechnology tools?

Vahé Sarkissian: I actually started in physics. A professor at MIT pointed me in the right direction; I took a physics course from him one semester, and it was almost all about semiconductors. After that I switched my major to EE.

What drove semiconductors originally was physics, but the convergence with chemistry and now mechanical engineering, with MEMS [microelectromechanical systems], is even more multidisciplinary. And the nanozone is where it's all converging. I joined FEI because it provides tools for pioneers in that area.

"CHIPS: Semiconductors from algae? It's no fish tale"

Using chemical deposition and other techniques, Georgia Institute of Technology researchers have demonstrated that microscopic algae — silicon-dioxide diatoms — can be converted into semiconductors without changing the intricate structure of the organism's shell. The ability to mass-produce the shellfish easily and form thin films of them in uniform arrays prompted the researchers to convert them into semiconductors. Nearly 20 percent of living things are 10-micron-diameter unicellular algae called diatoms — microscopic silicon-dioxide shellfish that float in every sea, lake, river and stream. Diatoms, which eat carbon dioxide and give off oxygen, generate 40 percent of the 50 billion tons of organic carbon in the sea. They multiply by doubling, enabling enormous populations to grow quickly. By doubling their number every generation, diatoms can be grown in almost any amount necessary — 40 reproduction cycles yield 1 trillion replicas. Sandhage's method first evicts the tenants, leaving only the intricately patterned silicon-dioxide shell with thousands of compartments inside, measured in nanometers. Ideally, the internal structure would be programmed by genetic engineering so that each 10-micron diatom shell would be about as smart as a microprocessor.

"ALGORITHMS: 'Rational' geometry simplifies EE toolbox staple"

Engineers today model alternating current, magnetic flux and other quantities using trigonometric calculations that require the use of a computer, calculator or, at the least, lookup tables. Now mathematician Norman Wildberger proposes scrapping the angle representation in geometry in favor of a "rational" system. By beginning with simpler definitions, all the familiar engineering calculations that currently require tables or a calculator can be done with simple arithmetic, argues Wildberger, whose "rational trigonometry" uses ratios of whole numbers in place of the sine, cosine and tangent functions. Wildberger says his concepts of divine proportions, rational trigonometry and universal geometry will benefit EEs and anyone else whose work involves trigonometry.

Tuesday, September 20, 2005

"WIRELESS: Virginia Tech to smarten up cognitive radio"

Virginia Tech hopes to smarten up experimental cognitive radios so that ad hoc communications networks can adapt to aid in disaster relief, battlefield communications, consumer Wi-Fi and other cognitive radio applications.
By sharing a distributed knowledge base, Virginia Tech's "cognitive engine" will serve as the communication system's "brain" by sensing unused bandwidth, avoiding interference, adapting to changing circumstances and optimizing network performance. At the same time, the engine will help maintain the autonomy of individual cognitive-radio nodes. Virginia Tech researchers have applied for a patent on their cognitive engine, which will also work with existing hardware, said Charles Bostian, director of Virginia Tech's Center for Wireless Telecommunications. "We are going to see if we can use vacant TV channels for Wi-Fi-like services without interfering with other emergency services that are already operating there." Cognitive engines allow radios to share a distributed knowledge base that parcels out individual and collective reasoning tasks to network nodes as a way to automate adaptation and learning. Cognitive radios have surpassed software-defined radio as the focus of radio design because they give radios the ability to decide which bands to use based on availability, location and experience. Cognitive radios may not autoconfigure by themselves, but under the supervision of a cognitive engine a network can be optimized.

Monday, September 19, 2005

"MATERIALS: Inventor's 'recipe' makes polymers conductive"

A new type of conductive polymer created at Integral Technologies Inc. promises to offer a plastic material that can be used as a substitute for metal. While today's conductive polymers are more flexible and weigh less than metal, their higher impedance has made them suitable only for low-voltage, low-current applications. When polymers are doped enough to support high-current ac, for instance, they become too brittle. Now Integral Technologies (Bellingham, Wash.) claims to have melded polymers with micron-sized metal filaments to create a material with properties that are the best of both worlds, to form anything from copper wires to flexible interconnects to antennas. "Ours is the world's only highly conductive polymer," claimed Thomas Aisenbrey, inventor of the material and general manager and vice president of product development at Integral. "It's conductive enough that you can run heavy current through it, either ac or dc." Called ElectriPlast, the approach is derived from a material called Plastenna that Aisenbrey engineered to make moldable antennas for wireless telephone handsets. The company embedded metal filaments in the handsets' case to gather RF signals. Then it broadened the recipe for the material, so that now its process can be used to make nearly any currently available polymer conductive.

Tuesday, September 13, 2005

"ROBOTICS: NSF panel to assess U.S. robotics technology"

The World Technology Evaluation Center (WTEC) will release its International Study of Robotics on Friday (Sept. 16) at a National Science Foundation conference. During the NSF conference, “Robots: An Exhibition of U.S. Automatons from the Leading Edge of Research,” WTEC will compare Asian and European robotic technology with U.S. robots exhibited at an NSF workshop last year. Since then, a six-member panel has toured 50 robot facilities in Japan, South Korea and Western Europe to assess the status of international research.

Monday, September 12, 2005

"CHIPS: Conductive diamond/nanotubes promise ice chips"

Argonne National Laboratories has found a way to make diamond a conductor as well as an insulator and semiconductor, opening the door to a new era of all-diamond chips. A spin-off company, Advanced Diamond Technologies Inc., has licensed the technology and material for development. In general, diamond deposition yields high-performance, long-lasting, radiation-hard dielectric films that can be thin or thick, can be etched alongside silicon components and can be doped either as n- or p-type semiconductors. Diamond's stiffness yields faster resonators, its smoothness yields friction-free microelectromechanical systems and its chemical inertness makes it ideal for bioengineered devices such as human implants. Argonne's patented ultrananocrystalline-diamond deposition taps a plasma-enhanced chemical-vapor process that is seeded with 2- to 5-nanometer grains of diamond. Instead of growing layers of single-crystal diamond one atom at a time, Argonne's process grows the material from seeds to islands to film. By adjusting the ultrananocrystalline process, the lab's researchers have managed to grow nanotubes between the diamond islands, turning what would ordinarily be a dielectric that insulates as well as silicon dioxide into a conductor that conducts as well as aluminum or copper.

Monday, September 05, 2005

"OPTICS: Varying speed of light a fiber-optics plus?"

In an experiment at the Ecole Polytechnique Federale de Lausanne, researchers have been able to speed up or slow down light transmitted through an optical fiber with precise control. This capability could have application in telecommunications, optical switching and optical computing. The experiment, which uses stimulated Brillouin scattering, verifies a prediction of Arnold Sommerfeld and Leon Brillouin, who early in the 20th century theorized that narrowband amplification at a sharp spectral transition could enable the speed of light to become variable. "We are reporting the first demonstration of a wide optical control of the signal velocity in an optical fiber," said Luc Thevenaz, who leads the group. "The starting and ending points of a pulse carry the information and those still propagate at the normal velocity, but the peak of those same pulses propagates at a variable group velocity that can exceed c [the speed of light in a vacuum]. This is what we experimentally demonstrated and observed." Thevenaz performed the work with EEs Miguel Gonzalez-Herraez at the University of Alcala (Madrid, Spain) and Kwang-Yong Song at the University of Tokyo (Japan).