New piezoceramic films for high resolution medical imaging applications

The fabrication process of new PZT-PNN piezoelectric ceramics (Ferroperm Pz21) is first described. Thick films are obtained through a tape casting route with a thickness between 60 and 90 /spl mu/m. This material is designed essentially to be integrated in high frequency medical transducers where properties such as high permittivity and high coupling factor are required. The dielectric, elastic, piezoelectric and microstructure properties of this ceramic are characterized as a function of frequency and used to simulate the behavior of an imaging transducer operating around 30 MHz. The performance obtained shows that Pz21 ceramics are well adapted for high resolution medical imaging applications.