Detection of volatile organic compounds using surface acoustic wave sensors with different polymer coatings

This paper compares the obtained experimental results with surface acoustic wave devices coated with three different polymers, polydimethylsiloxane (PDMS), polybutadiene (PBD) and polyetherurethane (PEUT), by detecting low concentrations of three volatile organic compounds (VOCs): octane, toluene and propanal. The polymer type and thickness and so as the test gas nature have a great influence on the sensitivity and selectivity of this sensor type. The different coatings have been prepared with the same thicknesses and they have been tested with the same gas concentrations. It has been possible to measure low concentrations of volatile organic compounds obtaining very good results of sensitivity and very short response and recovery times. There is difference of response among the different tested concentrations and the responses have been linear.