Portable acoustic wave sensor systems

A portable acoustic wave chemical sensor system that has the unique advantage of providing two independent responses, doubling the amount of information provided by the sensor, is described. These sensors utilize surface acoustic wave (SAW) devices coated with viscoelastic polymers that absorb a wide variety of volatile organic species, including chlorinated hydrocarbons (CHCs). A comparison of the relative magnitudes of these two responses, specifically the wave velocity and the wave attenuation can be used to discriminate between different isolated chemical species. This allows species identification and quantification using a single SAW sensor. Tests of this portable acoustic wave sensor (PAWS) system using polymer-coated SAW devices show rapid, reversible detection of gas phase species, rapid reestablishment of sensor baseline using an activated carbon scrubber, and discrimination of species based on a comparison of the attenuation and velocity responses.<
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