Gas sensors based on SAW narrow aperture devices

A new configuration of surface acoustic wave (SAW) gas sensors based on SAW waveguide devices with relatively narrow aperture of several wavelengths is suggested. This suggested configuration permits to impart to SAW sensor a new feature such as a certain electronic tuning of chemical selectivity (without sensitive coating) by applying electric voltage between this waveguide and two planar electrodes closely placed on the substrate aside the waveguide. Furthermore due to rather narrow aperture it permits to improve sensor's important characteristic such as threshold mass detectability. Sensors with this narrow waveguide configuration, by our opinion, are promising for application in modern gas analysis systems like electronic nose (E-nose) and portative chromatograph applications.