Forget dumb old bricks and mortar: engineers are designing future devices from exotic materials that incorporate chemical switches or mechanical sensors to improve their performance. These "smart materials" are just starting to emerge from the laboratory, but soon you can expect to find them in everything from laptop computers to concrete bridges.

At a recent conference in San Diego, attendees were allowed a glimpse of a smart future still under construction. A hodgepodge group of physicists, chemists, computer scientists, civil engineers and even washing machine makers gathered to compare notes and to demonstrate for one another a host of inventions that stretch, twist, measure or respond in novel ways (the diversity is readily apparent from a quick glance at the conference program). Meanwhile, the conference's keynote speakers--most notably James S. Sirkis of the University of Maryland--wrangled over just how to define this new cross-discipline.

Unifying the field, the doyens concluded, is a shared goal to enhance ordinary objects or to create extraordinary ones by embedding sensors, processors or actuators into larger things. An alternative explanation, however, might be that the all-embracing label of smart materials provides an excuse for playful engineers to do cool things with polymers, fiber optics and microprocessors.

Certainly there was no lack of creativity in San Diego. Applications for smart materials covered a broad gamut. Jeff M. Melzak's group at Case Western Reserve University is embedding silicon pressure sensors into Goodyear tires to improve fuel economy and reduce wear. Army researchers are placing piezoelectric crystals inside helicopter rotor blades; the crystals produce a feedback response intended to reduce the vibration and noise inside the cockpit.

Philip R. Troyk of the Illinois Institute of Technology has constructed wireless sensors no larger than a Rice Krispie. Implanted in a patient's muscle, the devices could relay information on local nerve activity via radio to an external computer. The devices could also receive power through magnetic induction and send out mild shocks that stimulate the muscle into action.

A few inventions demonstrated at the conference appear to offer considerable promise. Consider:

• Advanced liquid crystal displays may soon improve the quality of life of anyone who uses laptop and hand-held computers. A team at Kent State University was touting a new kind of liquid crystal technology; it should lead to flat color display panels that have much better resolution and lower cost than current state-of-the-art LCDs. The smart-crystal displays will also consume far less battery power, allowing portables to come closer to living up to their name.
• Artificial muscles that expand and contract in a controllable way could find numerous applications in robotics, medical implants, even virtual reality. At the smart materials conference, researchers at the University of New Mexico showed off an artificial muscle substance that is twice as strong as human muscles and contracts nearly as fast.
• Embedded sensors offer a way to monitor the health of structures that undergo a lot of wear and tear--concrete bridges and icebreaker propellers, to name just two examples. Engineers hope to save both money and lives with smart structures that warn their operators when the load becomes more than they can bear.

These projects may seem to have little in common with one another. But new areas of technology always emerge through chaos and confusion over their mission. Smart material researchers can at least take heart in the rapid changes in their field; it will probably take only years, rather than decades, before their work starts yielding useful products.

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