Thick-film Piezoelectric Actuators for Micropositioning

Driven by the versatility of conventional thick-film technology, this work was aimed at investigating the application chances of the electric field induced strains in ferroelectric (thick-film) material layers. To this end an experimental investigation is described, which concerns the piezoelectric potential of PZT thick-films, screen-printed and fired on ceramic substrates, for applications in actuator development. It was carried out on a structure consisting of an alumina plate, clamped as a cantilever beam, the faces of which were supporting two symmetrically placed ferroelectric layers. An interdigital electrode system, created inside them, enabled a polarization parallel to the substrate, hence bending occurred in the regions of the beam that were covered by the films when opposite driving voltages were applied. The deflection measurements and their voltage dependence are shown, together with: structure design and realization, a deformation analysis and the performance highlighted as a micro-displacements actuator.