They're small, smart and vigilant, the sort of miniature technology that science fiction writers once dreamed of. But the battery-powered, wireless sensors sometimes known as "smart dust" are here, and they're making their way into the electronic fabric of our lives.
In the last few years, smart dust sensors smaller than a deck of cards have been deployed in research projects to monitor the vibration of manufacturing equipment, keep tabs on colonies of seabirds and measure fine variations in vineyard climates that can make or break a wine.
Now they're being sold for real. Dust Networks Inc., a chief developer, said this week that defense contractor Science Applications International Corp. of San Diego would become one of its first customers, using the technology for perimeter security systems. A grocery chain in Minnesota installed the sensors in August to monitor energy use. A competitor, Sensicast Systems Inc., just announced its own arrangement to provide sensors to monitor the environment at a nuclear generating station.
Those deals resonate in an industry that didn't exist until a few years ago. Industry analysts predict that micro-sensors -- which communicate via radio-linked networks like computers on the Internet -- will become as ubiquitous in their own way as personal computers on the World Wide Web.
To be sure, sensors have been around for decades, particularly in the manufacturing world. But they've been costly, relatively large and limited by the wires that connected them to centralized monitors. As a consequence, they were generally used by companies with deep pockets.
In recent years, as the cost of computing plummeted along with the size of computing machines, science fiction fantasy quietly morphed into technological fact. Starting in academic labs at the University of California at Berkeley and elsewhere, development of smart dust (a whimsical name that suggests where inventors hope the technology is headed) has spread to the government and private sectors.
The capabilities vary. Some take pictures. Others serve as sensitive thermometers. There are even tiny sensors that can detect the presence of gunmetal and tanks. Some analysts and researchers believe that networks of these diminutive monitors may eventually link refrigerators, printers, car keys and other everyday objects to the Internet, enabling observers and other machines to keep track of them remotely.
"It's vast, in terms of the possibilities," said Glen Allmendinger, president of Harbor Research Inc., who predicted that sales of smart dust and related technology would grow from about $10 million this year to billions by the end of the decade.
"Homeland security is going to be a big part of it, but there are so many other applications," said Craig Mathias, an analyst at the Farpoint Group, an advisory firm specializing in wireless communications and mobile computing. "Is it going to be a $1 billion business? Absolutely."
It's not just technology enthusiasts and executives at tiny companies who are excited. The Defense Department's research project agency has spent millions on university research. Earlier this year, the CIA's venture capital arm In-Q-Tel bought a stake in Dust Networks. Technology researchers at the Department of Homeland Security have made sensors a priority. Even computer chip giant Intel Corp. is working on wireless networks of sensors.