Magazine

A Chain Drive for the World's Tiniest Motors


Researchers at Sandia National Laboratories have fabricated the world's smallest chain. The tiny silicon gizmo looks just like the chain on your trusty bike--but with a big difference: Each link measures a mere 50 microns long--half of the diameter of a human hair.

Ed Vernon, the microchain's designer, believes the invention could one day be used to power tiny camera shutters. It could also provide various gear ratios and linkages among hundreds of motors on silicon chips. Such chips--known in industry as microelectromechanical systems (MEMS)--are really machines that integrate minuscule motors, sensors, and other mechanical devices with computer smarts on slivers of silicon.

To build the microchain, the Sandia scientists piled five layers of silicon onto a slice of wafer three by eight millimeters. In each layer, they used photolithography and other chipmaking techniques to print the next "floor" of the tiny high-rise structure. Two years ago, the big buzzword in biotech was genomics. In 2001, it was proteomics--a fancy way of saying protein analysis. This year, new technologies should move proteomics beyond hype to practical reality. Two biotech companies--Cellzome of Heidelberg, Germany, and MDS Proteomics of Toronto--have developed highly automated methods for fishing large clusters of proteins out of cells and body fluids. Their studies appear in two independent papers in the Jan. 10 issue of Nature.

Until recently, scientists have had trouble analyzing the function of most proteins. That's because in many cases these compounds are difficult to obtain in quantity, and because they tend to carry out their biological tasks in combinations, or "complexes," of as many as 80 proteins.

The two Nature papers describe different ways to isolate and extract these complexes. Working with yeast, both groups were able to uncover hundreds of proteins that had never before been scrutinized. Using powerful computer programs, the groups were able to predict the functions of these proteins based on the kinds of complexes in which they were found.

This has important implications for drug research, says Giulio Superti-Furga, vice-president of Cellzome. Knowing a molecule's precise function will allow pharmaceutical companies to design safer, less toxic medicines. The ballast water of international freighters is teeming with pesky critters such as green crabs from Europe and tubeworms from Australia. Once established in America's harbors, these invasive animals can quickly take over, killing many native species. Existing technologies to clean ballast water are expensive and potentially dangerous to crew members.

But a novel method devised to prevent ballast-tank corrosion appears to have the added benefit of thwarting hardy marine invaders. Because the technique promises to save shippers money, environmentalists hope it will be widely used throughout the industry. "It is a win-win solution," says Mario Tamburri, a marine ecologist at the Monterey Bay Aquarium Research Institute in Monterey, Calif.

Up until now, shipping companies have used expensive paints to prevent ballast tanks from rusting. The new approach, developed by Sumitomo Heavy Industries, is to bubble nitrogen gas into the ballast water. This removes most of the dissolved oxygen, resulting in less rust. Tamburri estimates that shippers could save as much as $100,000 per year per ship simply by switching over to this deoxygenation technique.

In the process, aquatic animals that are sensitive to oxygen levels are wiped out. Green crabs, for example, can survive only two or three days in low-oxygen containers, according to Tamburri's tests. That's well short of the time it takes a cargo vessel to cross the ocean. -- In the wake of September 11 and the anthrax attacks that followed, doctors and nurses are racing to educate themselves about the symptoms caused by microbes used as weapons. A Web site designed by researchers from the University of Alabama's Center for Disaster Preparedness may help. The site offers interactive classes on six potential biological weapons, including anthrax, smallpox, and plague. The courses, which are free of charge, use case-based scenarios and photos to teach clinicians how to diagnose these rare diseases during their early stages. The Web address is www.bioterrorism.uab.edu.

-- A new mathematical theory could pave the way for sharper digital images and superior music recordings. Developed by math professors Akram Aldroubi of Vanderbilt University and Karlheinz Gr?chenig of the University of Connecticut, the theory will help engineers come up with algorithms to convert analog waves--the sounds and sights of the world around us--into the zeros and ones of digital electronics.

With traditional techniques for translating analog to digital, the original signals must be "band-limited," meaning engineers must define and limit how much of an image or a sound they wish to capture. Digital audio recording, for example, discards high- and low-frequency sounds as part of a process called sampling. Aldroubi says their theory will enable recording devices to capture a richer palette and to reduce signal loss when the material is compressed.


Tim Cook's Reboot
LIMITED-TIME OFFER SUBSCRIBE NOW
 
blog comments powered by Disqus