Piezoelectric membranes consisting of sputter deposited PbZrXTi1-XO3 (PZT) films on silicon diaphragms have been investigated for their resonance and piezoelectrical properties, in view of their application as stator of a micromotor. The behavior of resonance frequencies was studied as a function of membrane thickness and de-bias, in order to derive the total stress in the films and the piezoelectric coupling constant (d(31)approximate to 40 pm/V). The latter was also derived from the quasi-static deflections.