Developments to Watch
BRAIN AND BRAWN IN A SINGLE CHIP
LIKE THE SCARECROW IN The Wizard of Oz, micromachines want a brain. Current microelectromechanical (MEM) systems require two chips--one that functions as an ultra-teensy motor, gear, or sensor and another for the circuits to control it. That's true even though the same techniques are used to make both the machine and the brain.
Engineers at the Energy Dept.'s Sandia National Laboratories in New Mexico have found a way to put brawn and brain on one chip. According to experts at Analog Devices Inc. and the University of California at Berkeley, the breakthrough heralds all manner of smart MEM chips in medicine, communications, computers, and military hardware.
Heat is the hang-up in combining microcircuits and mechanical parts on a single silicon wafer. The machines must be tempered by heating them to around 900C--which melts any existing circuits. But if the machines are made first, the surface of the silicon wafer ends up too hilly to "print" control-circuit lines--it's like writing on sandpaper. So a Sandia team headed by Paul J. McWhorter developed a way to etch micromachines at the bottom of trenches, then fill in the trenches with silicon dioxide to make the wafer's surface smooth again. After the circuitry is formed around the trenches, the silicon dioxide is removed so the tiny gears can turn.EDITED BY PETER COY By Otis PortReturn to top
SHOCK ABSORBERS FOR IN-LINE SKATES
AFTER A FEW BUMPY HOURS in a pair of in-line skates, even seasoned athletes sometimes complain of leg pains. To the rescue comes Pavel Belogour, a Northeastern University economics student, who just received a patent on springlike shock absorbers that go beneath the heel.
Belogour, 25, a native of Belarus who won a gold medal in rowing with a Soviet junior team in the 1988 world championships, says the idea for shocks occurred to him while he was skating in New York's Central Park shortly after he immigrated to the U.S. in 1991. Belogour says he built his prototype from parts found in a hardware store. It's on loan, he says, to a "major producer" of in-line skates, and Belogour is fielding queries from several other manufacturers as well.EDITED BY PETER COY By Neil GrossReturn to top
ZAPPING STEEL TO FIGHT FRICTION
BENDING AND STRETCHING cold-rolled steel to make parts can rupture the metal--and the die as well. To lessen friction, some processors run the strips through a roller roughened by grinding or sandblasting. That gives the strips a matte surface that retains lubricant. Cold Metal Products Inc. of Youngstown, Ohio, roughens the rollers more uniformly by making millions of tiny craters with a laser. The technique, from Belgium's Metallurgical Research Center, is used in Europe and Japan. Cold Metal hopes to make it catch on in the U.S.EDITED BY PETER COYReturn to top
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MALE INFERTILITY: OF MICE AND MEN
A GENE DUBBED THE "DESERT HEDGEHOG" PLAYS A CENTRAL role in male fertility. The gene causes bristles to grow on fruit flies, making them look like hedgehogs under a microscope. But Harvard University scientists have discovered that the mouse version of it is a key regulator of sperm production. In mice that lack the gene, males have no mature sperm.
Scientists at Ontogeny Inc. in Cambridge, Mass., are trying to determine whether the gene is expressed the same way in humans. If so, they hope that injections of the protein produced by the gene could aid infertile men, says Thomas Ingolia, Ontogeny's research vice-president. He says the hedgehog gene protein appears to work somewhat like erythropoietin, a substance that boosts red blood cell levels. Both trigger the conversion of precursor cells into mature cells. Ontogeny hopes to determine in the next year whether the hedgehog gene protein is relevant to humans. If so, the company plans to begin clinical trials on a drug candidate the following year.EDITED BY PETER COY By Geoffrey SmithReturn to top