The sensor, which is smaller than a dime and paper thin, is based on the same theory behind plastic security tags used in stores to prevent shoplifting. The device, which will be described in the July 15 edition of Analytical Chemistry, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society, also shows promise for monitoring environmental toxins and terrorism agents like ricin.
"The vision of our work is a passive sensor of virtually unlimited lifetime that could be placed in the tissue of the skin," says Craig Grimes, Ph.D., a professor of electrical engineering at Penn State University and lead author of the paper.
Designed as an inexpensive device to continually monitor the blood glucose levels of people with diabetes, the passive sensor requires no internal power supply and no connections outside the body, according to Grimes and his associates. "Whenever a reading is needed, a person can wave their hand or arm in front of a reader that will automatically detect the sensor," Grimes says.
The sensor is based on "magnetoelastic" technology, just like the plastic security tags on store merchandise, which are sensed wirelessly as they pass through an exit.
"The cost of these anti-theft markers is a penny," Grimes says. "We've leveraged off that same premise, so the material cost associated with the sensors is effectively zero." The electronics used in the reader, which is about the size of a wristwatch, cost approximately $50, the researcher estimates.
"Magnetoelastic sensors can be considered the magnetic analog of an acoustic bell," Grimes explains. "If you hit a bell with a hammer, the bell rings at a characteristic frequency. If you coat the bell with a layer of paint, the frequency ch
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Contact: Michael Bernstein
m_bernstein@acs.org
202-872-6042
American Chemical Society
28-Jun-2004