Surface Acoustic Wave 915 MHz resonator oscillator gas sensors using SnO2 nanowires-based nanocomposite layer

In this paper we report on Surface Acoustic Wave (SAW) gas sensors based on quartz two-port resonators configured as oscillators at resonant frequency of 915 MHz. Nanowires (NW) of semiconducting tin dioxide (SnO₂) have been grown by Vapor Phase (VP) process and used as filler in a nanocomposite layer to fabricate a highly-sensitive nanomaterial for gas detection, at room temperature. The nanocomposite layer consisting of an organic host-matrix of cadmium arachidate (CdA) and a weight-tailored filler of SnO₂ NW has been deposited as thin film onto SAW resonators by means of the molecular engineering Langmuir-Blodgett (LB) technique. SAW gas sensors performance was investigated in presence of ppm-level of ethanol, methanol, ethylacetate, toluene, at room temperature. The results demonstrate good sensitivity to vapors under test at ppm-level and a SAW gas response tuned by the weight-content of filler of SnO₂ NW in the LB nanocomposite layer.