SAW Gas Sensors with Nb-doped Titania Nanoparticles Layers

A surface acoustic wave (SAW) gas sensor with Nb-doped titania nanoparticles layers as chemically interactive material is presented. A SAW two-port resonator integrated on ST-cut quartz substrate has been functionally characterized as oscillator in dual differential mode at the resonant frequency of 433.92 MHz. Solvent-casting coatings based on Nb-doped titania nanoparticles have been prepared to coat the SAW microdevices for roomtemperature detection of Volatile Organic Compounds (VOCs) such as methanol, acetone and m-xylene. The results demonstrate the potential of these SAW high frequency gas microsensors at high sensitivity with a typical response of 18.9 kHz/61 ppm methanol for a SAW 433 MHz sensor coated by a 5 at% Nb-doped Ti02 nanoparticles layer, at room temperature