CHEMICAL VAPOR SENSOR USING A SAW RESONATOR

A surface acoustic wave (SAW) device has been used as a chemical vapour sensor by coating phosphatidylethanolamine (PE) on to the device surface as an appropriate adsorptive coating. The characteristics of a PE-coated SAW resonator operating at 310 MHz, and capable of detecting chemical vapours, such as amyl acetate, citral, beta-ionone, menthone and other organic gases are described. The lowest concentration (by volume) of chemical vapours required to change the resonant frequency was different for each compound and the values were 0.1 ppm for beta-ionone, 0.5 pp for citral, 2 ppm for menthone, 10 ppm for amyl acetate and 100 ppm for alcohols, respectively. These data are in agreement with the results previously reported for olfactory cells and AT-cut crystal resonator devices. This study demonstrated that the SAW resonator device, coated with lipid, can be applied as a chemical vapour sensor.