Functionality of Surface Acoustic Wave (SAW) transducer for palladium-platinum-based hydrogen sensor

The nanostructured palladium-platinum (PdPt) catalyst and the Surface Acoustic Wave device offers functional possibilities for developing an innovative hydrogen sensor. Since the catalysis between hydrogen and oxygen in ambient air releases heat, an electrical signal correlated with hydrogen concentration can be obtained by transferring PdPt heat over the SAW delay path. This scheme of detection has never been performed up to now and special attention is given in this article to prove its feasibility. In this purpose, we report an alternative SAW model that incorporates representations for interdigital transducers and delay path, and can reproduce changes in temperature. This model can be used to design an optimized temperature-sensitive SAW taking into account the effects of temperature over the delay path. We report as well the choice of the phase signal for temperature variation measurements (phase as a function of temperature) of a SAW made of LiNb03 128° YX (128°, rot Y cut, X prop.). We consider that an optimized SAW device can detect the slight PdPt temperature increase.