A multifrequency composite ultrasonic transducer system is described. The transducer consists of lead zirconate titanate (PZT) piezoelectric ceramic cylinders embedded in a vinylidene fluoride/trifluoroethylene (P(VDF-TrFE)) copolymer matrix. Both phases are piezoelectrically active. By selecting an appropriate height to diameter ratio for the ceramic cylinders, the transducer can be made to resonate at a number of frequencies. The frequency of the resonance arising from the copolymer matrix depends on the composite thickness. The other resonance frequencies are determined by the height to diameter ratio of the ceramic cylinders. A number of multifrequency transducers have been constructed and the observed resonance frequencies agree well with the predictions, based on the mode coupling theory.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics