Smart Materials
They will soon be in everything
from computers to concrete bridges.
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.
W. Wayt Gibbs
writer
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