GENERATION AND DETECTION OF RAYLEIGH-WAVES WITH IMPROVED ATTENUATION USING A PIEZOCOPOLYMER TRANSDUCER P(VDF-TRFE)

Efficient elastic Rayleigh waves have been launched and detected on a non-piezoelectric substrate (duraluminium) with identical longitudinal wave transducers made of a piezoelectric copolymer film P(VDF-TrFE). We have improved the attenuation of Rayleigh waves by more than 20 dB, by fixing the electrode spatial period in accordance with the frequen cy of excitation for which the elastic power transfer to the medium of propagation is at a maximum, and by electrical impedance matching at emission and reception. We also report the effect of the coupling laye r thickness on the elastic power and electrical impedance of the trans ducer.