Germanium speeds silicon circuits 2 to
IBM says it's found a way to increase semiconductor speed between two- and
four-fold: add germanium to a silicon transistor's base. The germanium builds in
an electric field, changing the physics of a device and accelerating electrons
across the transistor, explains IBM Fellow Bernard Meyerson. In addition, the
SiGe transistors are precisely "grown" layer by layer, instead of firing atoms
into silicon, making it possible to boost circuit-design accuracy up to
100-fold. And, because the technology uses mostly conventional silicon, it can
be produced in "regular" semiconductor-fabrication facilities, making it
dramatically less expensive than specialty materials such as gallium arsenide.
Hughes Electronics, which has been working with IBM on the technology, predicts
"availability as early as 1997 of the fastest silicon ICs used in communications
applications to date," according to Hughes spokesman Ron Finnila. For more
information, e-mail email@example.com, visit http://www.research.ibm.com/sigetech/.
Calculating weld safety
Pipelines, reactors, agitators, boilers, exhaust systems, and more need to be repaired or replaced because welded joints fail to reach the end of their anticipated fatigue life. The reason: calculation procedures for ductile steel are inadequate because they cannot take into account the complex multi-axial stresses to which welded joints are exposed. Many designers react by using more and stronger welds than necessary to ensure the safety of the finished product. In an attempt to overcome both problems, Professor Cetin Morris Sonsino at the Fraunhofer Institute, Darmstadt, Germany, has developed the calculation method "hypothesis of effective equivalent stress." The method recognizes that it is local shear strains or stresses that are responsible for the failure of critical component sectors. Based on Sonsino's findings, the Institute has developed software that allows designers to use the calculations in their day-to-day work. The project's success should let designers optimize their plans without having to make allowances for undefined safety factors, leading to considerable materials savings. FAX C.M. Sonsino at (+49) 6151 705 214.
Kiddie video camera uses CMOS chip
VISION, a Scottish electronic imaging company, has linked
with U.S. toy manufacturer Tyco to develop a video camera just for kids. The
Tyco "VideoCam" provides black and white video pictures, which will be relayed
directly into a television via a standard VCR player. The technology combines
both image sensing and image processing on the same CMOS chip. VISION's CMOS
imaging technology has resulted in a lightweight, sturdy, simple to operate, and
cost-effective to make video camera. Advantages include reduced cost, size, and
power requirements. For details, FAX (408) 374-4722, e-mail firstname.lastname@example.org .
ATM switch accelerates data to 5 Gbps
Toshiba Corp. of Japan has developed a prototype switching device for an asynchronous-transfer-mode (ATM) system, a next-generation high-speed data-transmission network, that attains a data exchange speed of 5 gigabits per second (Gbps). This is the fastest rate achieved by a single CMOS chip to date, say company sources. Today, the transmission speed of commercial-level ATM switch ICs ranges from 1 to 2.5 Gbps. The 8-input/8-output (622 Mbps per port) switching IC meets specifications proposed by the ATM Forum, the U.S.-based international consortium of ATM equipment manufacturers. ATM networks use high-speed switching to transmit multiple data types, such as audio signals, image signals, text, and voice. Data flows are broken down into cells made up of 48 bytes of information and 5 bytes of address data. High-speed switching transmits cells individually in a prioritized order. "ATM networks are among the most promising of advanced communication networks. I believe this new switching device will put us in the forefront of ATM innovations," says Kenshi Manabe, technology executive of Toshiba's semiconductor group. For more information, phone (800) 879-4963.
Save images in a crystal
Scientists at Israel's Technion R&D Foundation Ltd. have developed novel techniques for storing and retrieving information in crystal media--and for the application of light patterns and electric fields to crystals. These techniques induce controllable domain structures for data storage. They provide both method and apparatus for fixing images, holograms, and domain gratings by applying an electric field on a crystal and simultaneously illuminating it with a light pattern. The method also provides for reversibly fixing images and holograms in a crystal. The development can overcome the problems that present photo-refractive techniques have encountered, such as the nonpermanency of the light patterns in a crystal, which make them unsuitable for storing data. FAX (972) 4-8320845.
Rechargeable batteries charge research effort
Current battery technology leaves a lot to be desired when it comes to long life and energy output. One new venture addressing these needs has been formed by BC Research Inc., DynaMotive Technologies Corp, and Moli Energy, all of Vancouver, Canada. The R&D venture will develop high-capacity carbons for rechargeable lithium batteries. The partners will characterize material properties, and develop applications for the new carbon forms. Lithium ion batteries have high energy density and good cycle life. The partners anticipate that battery anodes made with the new carbon forms will permit smaller and more powerful batteries with longer times between recharges than current technologies. FAX (604) 222-5545.
Scientists ponder outer-space bubble trouble
Put a pot of water on a hot stove, and you'll soon see
steam bubbles scurrying toward the surface. But if you try to boil water aboard
an orbiting space shuttle, something else will happen: One huge bubble will form
along the heated surface and stay there, refusing to carry heat away. Soon,
portions of the heated container will dry out, and it may crack. However, by
using sound waves, electric fields, and forced-liquid currents, three scientists
at The Johns Hopkins University's Whiting School of Engineering hope to make
bubbles behave in more productive ways in the absence of gravity. The research,
important because bubbles play a major role in cooling and water purification,
will prove crucial as space vessels spend more time in weightless conditions. In
normal gravity, gas bubbles are lighter than the surrounding liquid. Thus, they
detach and float upward, stirring the liquid, and condensing and transferring
some of their heat to the cooler water. In space, however, the bubbles don't
rise because they are no longer lighter than the water around them. Mechanical
engineers Andrea Prosperetti, Cila Herman, and Hasan N. Oguz will study ways to
dislodge the giant bubbles that form during gravity-free boiling. The research
is sponsored by a multi-year grant from NASA's Microgravity and Science
Applications Div. For details, e-mail email@example.com , FAX (410) 516-5251.
Novel needle helps characterize tissue
MIT researchers have developed a needle embedded with
microchips that could replace several probes doctors currently use to
characterize human tissue such as tumors. The needle could also be less
expensive than current probes and is 30% smaller in diameter--a fact that
patients are sure to appreciate. The researchers, led by Kenneth S. Szajda of
the Harvard-MIT Division of Health Sciences and Technology, have built a
prototype device that measures temperature. The ultimate goal: a needle that
also measures such parameters as pH, oxygen concentration, and radiation dosage.
The needle was originally developed for use in the hyperthermic treatment of
cancer, where heat is used to improve the effectiveness of radiation and
chemotherapy. "Characterization of the tumor environment is essential to
planning and evaluating hyperthermic treatments," says Dr. Szajda. Though
conventional temperature probes for this purpose "work very well," he said,
"they do have limitations. Our idea was to build something that would work even
better." For details, e-mail Elizabeth Thomson at firstname.lastname@example.org .
Polymer could insulate circuits
Researchers at Rensselaer Polytechnic Institute have
discovered an effective way to coat surfaces with polynaphthalene, a long-chain
polymer that has a very low dielectric constant. As a result, the polymer could
find application in insulating high-speed, high-density microelectronic
circuits. The problem with using long-chain polymers as insulating materials for
multilevel chips has been finding an effective and environmentally safe way to
apply them as thin-film coatings. Traditional spin coating relies on using
dissolved materials, and some thermally stable long-chain polymers, such as
polynaphthalene, do not easily dissolve. At Rensselaer, Toh-Ming Lu and James
Moore evaporated ortho-diethynyl-benzene, a monomer precursor, and deposited it
on a heated silicon wafer in the university's clean room. The precursor
transformed into a very thin transparent coating of polynaphthalene. Tests show
the coating to have a dielectric constant of less than 2.6 and to be stable at
temperatures of 600C. For details visit http://www.rpi.edu/dept/NewsComm/tips/news_ideas.asp .
Parallel-processor architectures get flexible
Imagine connecting all the computers in a building so
that they can share resources, allowing a computer that is running a really big
program to borrow memory--and even processors--from idle computers nearby. Now
imagine that such a system would be comparable in cost and reliability to a
normal network. That is one of the possible results of FLASH--Flexible
Architecture for Shared Memory--a project being conducted at Stanford
University's Computer Systems Laboratory. Its goal: to develop a new and more
flexible type of parallel processor--a computer that uses more than one central
processing unit at once. The 46-member-plus research team expects to have a
prototype of the machine built and running by the end of the year. It is also
working on HIVE--an operating system that would allow the computer to run many
existing programs. The project, a cooperative effort with LSI Logic and Silicon
Graphics, is supported by the Department of Defense's Advanced Research Projects
Agency. For details, e-mail email@example.com .