LOS ANGELES -- Rescue workers amid the rubble of the bomb-ravaged federal office building in Oklahoma City last year expressed their anguish at not knowing where to dig for victims.
Only an army of crawling insects could have quickly searched the rubble without risking further death or injury. And what could insects do to help?
Plenty, if they could be commanded by people, said Kristofer S. J. Pister, an electrical engineer at the University of California at Los Angeles. What those rescuers needed was a swarm of mechanical "crickets" capable of penetrating the wreckage until they sensed the warmth, the cries or the movements of the victims. Then they could signal locations of the victims by chirping or sending radio signals.
"Within the next few years," Pister said, "we will build the first synthetic insects." Eventually, they will be made smart enough to do rescue work or military reconnaissance. And they'll be cheap enough to scatter by the dozens across a collapsed building or a battlefield and to discard when their work is done.
In laboratories across the country, engineers, physicists and chemists are developing the kinds of sensors, motors, gears and miniaturized communications needed to build such "microcyborgs."
But they are just a hint of the miniature marvels being developed or now in production:
High-tech factories are producing millions of microscopic accelerometers, tiny silicon sensors that detect the rapid deceleration of a car as it crashes and that deploy air bags before the occupants slam into the steering wheel and dashboard.
Military researchers are developing micro-gyroscopes so small and cheap that they may be used one day to guide common tank shells to their targets as accurately as the electronics in today's million-dollar guided missiles do.
Engineers are creating tweezers and other surgical tools the size of a human hair, small enough to be threaded into the brain to repair life-threatening defects in blood vessels.
Scientists are developing micro-sensors and other components for inexpensive, hand-held analytical devices. Doctors will get lab results more quickly, law enforcement will get on-the-scene DNA profiles from smaller samples, and homebuyers will learn the lead content of house paint in seconds.
Some researchers are pushing even deeper into microscopic realms, dimensions where the width of a human hair becomes a clumsy yardstick, and atoms and molecules are the bricks and mortar. Their work could lead to computers with vastly increased memory and to new metals with unique and valuable properties.
It is an international competition with an economic payoff worth billions of dollars to the nations and corporations that master the technologies first. The university, corporate and defense researchers involved compare what they are doing to the early work that launched the current boom in computers and microelectronics.
In 1946, ENIAC, the world's first electronic computer, weighed 30 tons, contained 17,000 vacuum tubes and filled a 30-by-50-foot room. It cost $486,000 and required six people to run it.
No one would have predicted then that, after 50 years of miniaturization, desktop computers 50,000 times faster than ENIAC would be running in millions of American homes. Computer chips -- the micro-circuitry at the heart of those advances -- are now nearly everywhere in our lives, controlling our cars, our watches, our kitchen appliances, our toys and our televisions.
"Microfabrication has made possible the information age as we see it today," said Marvin H. White, program director for microstructures at the National Science Foundation. In the next century, scientists and engineers believe, those who command microfabrication most effectively "will be at the cornerstone of all our industry," he said.
Why is smaller so much better?
There are several reasons, scientists say. Smaller electronics are faster because electronic signals don't have to travel as far to do their work. They also need less electricity to operate, making them more portable and useful in more varied applications.
And, thanks to physical properties unique to such tiny dimensions, many micro-mechanical devices are far more sensitive and durable than their full-size counterparts.
The scientists involved say they are developing products that will provide greater productivity, a higher standard of living and a stronger national defense.
Modern navigation and targeting systems -- the "smart" weapons that helped win the Persian Gulf war -- demand "enormous computing power and a tiny amount of space to put it in," said Larry Dalton, a chemist at the University of Southern California. "Stealth aircraft wouldn't be possible without the advent of the miniaturization of electronics."
But the real engine driving these technological advances is profit.
The photo-lithographic technology used to manufacture computer chips makes it possible to produce hundreds of intricate devices on a single silicon wafer, driving down the per-unit cost.