A tunable gas sensor using an acoustic waveguide

A tunable gas sensor using surface acoustic waves (SAW) is described. It is designed on the basis of a waveguide delay line fabricated on a piezoelect ric substrate made of 128 degrees Y-cut LiNbO3. A voltage applied between t he waveguide and two electrodes causes a local change in the properties of the substrate near the waveguide and differently affects the sensor's respo nse to the vapors of various analytes. Some results of the experimental stu dy of the sensor, which show the change in the selectivity under the effect of voltage, are presented. The analytes used for testing include a number of alcohols and deionized water. The possibilities for employing such a sen sor in the sensor arrays of gas analyzers of the electronic nose type are d iscussed. (C) 2001 MAIK "Nauka/Interperiodica".