Guiding Light

With the Internet helping push the capacity needed for moving data to unprecedented levels, telecommunications firms depend more than ever on fiber-optic networks. Yet while optical systems can handle far bigger loads than their electronic cousins, all-optical systems have, until recently, been impractical. Why? Light is tough to manipulate in certain situations–for example, when it needs to change directions in an extremely small space. Now, though, an MIT-Sandia National Laboratory group has come up with a technology that should help solve the problem. The researchers have developed what they call a photonic crystal, which can guide light through a 90-degree turn in the space of about a square micrometer. (A micrometer’s one-millionth of a meter.) That’s small enough to let manufacturers integrate the devices into electronic chips–a key advantage in today’s miniaturized world. But Pierre Villeneuve, a research scientist at the MIT Research Laboratory of Electronics and one of the crystal’s inventors, notes that while all-optical transmission systems aren’t far off, computer processors based on all-optical technologies probably won’t be developed for years. “There are still staggering obstacles to be overcome,” he notes.

North Pole, Mars-Style

Mars and Earth share key features, including large, cold polar caps. In recent analyses of topographic data from the Mars Global Surveyor spacecraft, researchers from MIT and elsewhere obtained striking new information about Mars’ north polar region. The group found the ice cap’s about 750 miles across and nearly two miles thick. The researchers also showed it sits in a three-mile-deep, hemispheric-scale depression. This supports the theory that early in Mars’ history, when liquid water flowed on the planet, it migrated to high northern latitudes and froze there, helping form that era’s polar cap. “We’ve now established that there was a surface route for the water to get to the pole,” says Maria Zuber, professor of geophysics and planetary sciences. Zuber was one of five MIT researchers on the team, which also included scientists from NASA, Caltech, Brown, the Carnegie Institution of Washington, Washington University and the U.S. Jet Propulsion Laboratory.

Soft Shoe

For those who’ve come from a jog, tennis game or long day at the office with aching feet, relief may be in sight. MIT senior Ronald Demon has invented an all-purpose shoe that automatically adjusts to the wearer’s needs, adding extra cushioning in areas facing the greatest pressure. Demon, who started the project five years ago while attending high school in Palmetto, Fla., began with computer studies. He designed footwear in which fluid in small bladders within the heel and sole shifts from one area to another based on information from computer chip-based pressure sensors. Demon, who has now created prototypes of the shoes, has received extensive media coverage. He has also been hearing from footwear firms interested in looking at his invention.

Safer Drugs?

Like gloves and shoes, a lot of molecules–including many used in pharmaceuticals–come in matched sets structurally. Usually that’s not a problem, but in selected drugs the “good” variant of the chemical may be matched with one that can have ill effects in certain circumstances. That was true of thalidomide, the agent which caused the birth of deformed infants in the ’50s. One form of paired molecules in the drug was blameless; all the damage was done by its “mirror image,” which became biologically active in pregnant women. The concerns are significant enough that the U.S. Food and Drug Administration now considers the non-active half of a paired pharmaceutical ingredient an impurity unless it’s proven harmless. MIT’s Gregory Fu, though, may be on the way to helping eliminate the unneeded halves of molecular pairs. Using specially designed chemical catalysts, he’s succeeded in “reacting one form away” in certain paired, mirror-image molecules. The American Chemical Society recently conferred one of its major awards on Fu for this achievement.