Piezoelectric actuators

This first family of actuators exploits the inverse piezoelectric effect, identified by the Curie brothers in the 1880s. This effect enables mechanical deformation to be generated in a material by applying an electric field. A wide range of materials can be used to achieve this effect, including quartz and ceramics with perovskite or tungsten-bronze crystalline structures. For actuation, ferroelectric ceramics are widely preferred, in particular lead titano-zirconate (hereinafter conventionally referred to as PZT), and possibly lead titanate PbTiO3 or barium titanate BaTiO3. A semi-crystalline polymer such as PVDF also exhibits a piezoelectric effect, but its use as an actuator remains very limited.

Ferroelectric ceramics such as PZT are...