The Cutting Edge: COMPUTING / TECHNOLOGY / INNOVATION : Fiber-Optics That Work More, Labor Less
High-speed fiber-optic communication systems depend on movable mirrors that steer laser beams of light to the right spot along the glass fiber. But these fiber-optic “couplings” are very labor intensive, since the mirrors must be adjusted by hand before packaging. Coupling efficiencies--the percentage of the laser light power actually transmitted into the fiber--are considered good at only 50%. And if the couplings are heavily jarred or subjected to extreme temperature variations, the efficiency is reduced to the point that the coupler must be discarded.
Now researchers at UC Berkeley have built a microscopic version of these mirrors, with mirror adjustments made by a micromotor not much larger than the cross-section of a human hair. The entire movable micromirror, motor and all, fits within an area four-hundredths of an inch square. The micromirrors are built by a technique known as surface micromachining, which evolved from the processes and materials developed to make integrated circuits. The microscopic motors move a slider back and forth by repeatedly striking it with a battering ram of silicon.
Miniature hinges allow the mirror to tip at varying angles. The slider moves in tiny steps--about one-hundred-thousandth of an inch--and by acting in concert with a twin, the motor can adjust the angle of the gold-plated micromirror. The researchers have shown that 45% coupling efficiencies can routinely be achieved. And owing to their small mass, these micromirror systems can survive even a six-foot fall without going out of alignment. The overall goal of the Berkeley program, which has been supported by Hewlett-Packard Co., is to build complete micro-optical systems that can be used not only in communication systems but also for medical and environmental sensing applications.
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Smarter Than the Average Bear: Yogi Bear was expert at stealing picnic baskets from unsuspecting visitors to Jellystone Park. But Yogi’s creators at Hanna-Barbera don’t want anyone stealing their intellectual property by forging their limited-edition and production cel animation. (Art is the second-most frequently “forged” form.) So in a first for animation studios, Hanna-Barbera is using the DNA of studio founder Joseph Barbera in the transparent registration mark on the art as well as in the ink in the pen he uses to autograph the art.
Utilizing the services of the Los Angeles firm Art Guard International Inc., the studio created a gene chemistry ink using DNA extracted from strands of Barbera’s hair. The seal of authenticity features an oval Fred Flintstone logo and carries its own number. Art Guard International takes a follicle of hair and separates out a single DNA sequence. A forger trying to replicate the inks containing the DNA would have to know exactly which sequence has been used. The company believes its technology could also be used to prevent forgeries of rare coins, stamps, and even credit cards.
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Deadly Diet: Like death and taxes, cockroaches are one of the constants of life. People spend half a billion dollars a year on insecticides trying to rid their homes and businesses of these disease-carrying and seemingly indestructible insects.
But regular spraying always leaves a few resistant roaches who survive and produce offspring who inherit the resistance.
However, something better may be on the way. Heather Wren, a research scientist in Virginia Tech’s entomology department, has discovered a combination of natural substances that prevents cockroaches from reproducing: The females’ own bodies sabotage themselves as eggs develop, so the females die and the eggs are never laid.
The insects eat the bait because it contains a nutrient they require. But the mixture also contains an inhibitor that interferes with the way the cockroach is able to metabolize certain nutrients. Separately, the substances are not lethal, but in combination they deprive the insects of nutrients they need for survival.
Previous insect growth regulators sought to kill young cockroaches; Wren’s compound is the only one to kill adults. Dominion BioSciences, based in Virginia Tech’s Research Center in Blacksburg, Va., has licensed the technology and will apply for international patents in the near future.
EPA-required testing will start next year and a commercial product is expected by 1997.
In the meantime, to have an environmentally friendly product, Dominion is trying to create a biodegradable bait station. The company expects the bait stations to be no more expensive than those currently on the market. Research is also going on to see if the same approach can be applied to termites and ants.
