PASCO, Wash., June 18 -- Interest in "smart" materials that can sense and respond to changes in their environment has increased with new advances in the 20-year-old science, according to a report presented here today at the Northwest Regional Meeting of the American Chemical Society, the world's largest scientific society.
Smart materials are being developed that could be used to mimic biologic systems, notably in artificial limbs--in which they could sense and adjust to changes in temperature, pressure, electrical current, pH balance and magnetic field, according to James A. Harvey, who is an adjunct professor at Oregon Graduate Institute and a researcher at Hewlett Packard Company in Corvallis, Oregon.
This could make it possible for an artificial limb to perform basic limb functions, among them, the ability to pick up objects. Also in development are gel implants containing smart materials that would signal the gel to release drugs, such as blood pressure medications, as the body needs them.
Smart materials may also save lives by preventing accidents. Demonstration models of bridges containing smart materials have been built in San Diego and other cities. Embedded in the structure of the bridges, these materials can sense changes in pressure, and signal that structural damage may occur.
Perhaps the most futuristic applications in development are "smart cars" and "smart highways" that would work in combination to prevent collisions by monitoring the distance between cars and adjusting their speed or direction when they get too close. Experimental models could be ready by 2002, says Dr. Harvey.
Smart materials are designed to receive a stimulus, transmit or process it, and then respond by producing a useful effect, such as a signal showing that the smart material is working. The stimuli may include stress, strain, incident photons, small molecules, an electric or magnetic field, hydrostatic pressure, or the like. The useful effects produced may include changes in color, volume, stress distribution, and index of refraction.
A nonprofit organization with a membership of more than 155,000 chemists and chemical engineers as its members, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.