It looks iridescent when it captures the light, like tiny grains of abalone shell. But this slightly sparkly stuff — called smart dust — does more than look pretty — it can save lives. Some airborne substances that can kill — such as anthrax spores, or the nerve agent sarin — can’t be smelled or seen.
Over the past 10 years, chemist Michael Sailor and his colleagues at the University of California, San Diego have been working on a device — akin to a smoke detector — to sense these toxins in the air. This device is a lot smaller than a smoke detector — about the size of pepper. Dr. Sailor calls it “smart dust.”
Smart dust is made of silicon. Each of the separate silicon particles holds molecules that react when they come in contact with specific airborne chemicals. Here’s what makes the dust “smart” — different reactions cause the dust to turn different colors. The colors are read with a laser and a spectrometer.
You can imagine a multitude of uses — it could be painted on surfaces to detect TNT, gasoline or organic pollutants in minute concentrations — or the presence of a chemical or biological weapon. But Dr. Sailor can’t say when smart dust will be ready to use. He says we need a collaborative effort between chemists, engineers, biologists, and industry to produce the devices.
And smart dust needs more field tests — to find out how far away you can get and still accurately read the information it contains.