Developments to Watch
Butterflies Point the Way to Better Tanks
STUDIES OF THE IRIDESCENT SHADES OF BUTTERFLY wings could lead to coatings to make tanks and planes invisible. As implausible as that sounds, British defense officials think research by physicists Peter Vukusic and J. Roy Sambles at the University of Exeter in Britain could have important military uses--and lucrative ones for industry as well.
Under an electron microscope, the wings of some colorful butterflies look like gray slate roofs. That's because the color we see stems from structure, not pigments. The wings are covered by tiny overlapping "tiles" 50 times thinner than a human hair. Each tile consists of multiple layers of cells separated by air gaps. Light penetrates this complex structure and bounces off the layers in ways that can give colors a haunting iridescent sheen.
By deciphering how variations in structure affect colors, the research could provide a recipe for microscopic plastic flakes to regulate color. One result might be the blackest black ever--a coating so black it would block even infrared heat rays. That could make a tank undetectable by night-vision systems. And extending the concept to radio wavelengths could make planes invisible to radar. Similar particles in inks could produce security seals that would make credit cards and banknotes harder to forge.EDITED BY OTIS PORTReturn to top
A Jet Stream That Clears Out Blood Clots
BLOOD CLOTS IN CORONARY ARTERIES can cause chest pain and heart attacks--and can be deadly if not removed quickly. Standard treatment uses a drug, such as urokinase, to dissolve the clot. But it can take hours to work--too long for some patients. And many can't tolerate urokinase.
Three years ago, a new device proved effective at unclogging the arteries of dialysis patients. Now, the Food & Drug Administration has also approved it for chest pains and heart attacks. Developed by Minneapolis-based Possis Medical Inc., AngioJet is a tiny version of industrial water-jet tools used to slice steel and concrete. At the end of a thin stainless steel tube inside a plastic tube is a tiny showerhead that faces backward. Doctors guide it through an artery to the clot. Then, saline solution is pumped at great pressure through the showerhead. The jets rush back into the plastic tube, creating suction that breaks up the clot.
The FDA acted swiftly after AngioJet turned in sterling results. It clears clots in two minutes or less, causes far less internal bleeding, and is several thousand dollars cheaper than urokinase, says Dr. Stephen R. Ramee, a cardiac specialist at Osch-ner Clinic in New Orleans. After AngioJet, only 15% of patients suffered heart attacks, died, or required bypass operations within 30 days--vs. 33% of those treated with urokinase.EDITED BY OTIS PORTReturn to top
Digital Eyes on the Soccer Ball
LAST SEPTEMBER, BRITAIN'S BOLTON WANDERERS SOCCER CLUB LOST A CRUCIAL GAME to archrival Everton when the referee and linesman turned thumbs down on a goal by Gerry Taggart. News photos, however, proved the officials wrong. That inspired a Bolton company, Intelligent Sports Technology Ltd. (IST), to develop a computerized system for deciding with digital precision when a goal has been scored.
Eight miniature TV cameras are mounted around the goal's mouth--two on each corner post and four across the top bar. When something enters the goal, images from these cameras are used by a workstation to determine whether a goal has been scored. First, the computer looks for a soccer ball. If it finds a sphere of the proper size, the computer compares images from all the cameras to verify whether the ball crossed the goal line. When a goal is confirmed, the referee hears a signal in an earpiece receiver.
Outfitting a stadium will cost $165,000 to $200,000, but if that's too much, teams could also rent the set-up. "We are confident that the system will go ahead," says Adrian S. Carmichael, secretary of IST. Fans will demand it, he says, because they're fed up with officiating goofs. Britain's Football Assn. and FIFA (Federation Internationale de Football Association), however, have not yet decided whether they want to hand the job of goal-tallying to an electronic referee.EDITED BY OTIS PORTReturn to top