3. Conclusion and outlook

The introduction of restrictions on the use of lead has enabled the synthesis and development of a large number of lead-free piezoelectric materials with more or less complex compositions and with piezoelectric properties close to, or even superior to, some PZTs.

In contrast to materials with lead from the PZT family, lead-free materials are divided into different families, BaTiO ₃ , KNN, BNT and BFO, which have their own specific characteristics in terms of piezoelectric properties. Thanks to rapid improvements in their performance, the effectiveness of lead-free piezoelectric materials has been demonstrated in various devices and prototypes in the field of sensors, actuators and ultrasonic devices. Although their overall performance is still inferior to that of PZT-based devices, these prototypes reveal the strategic...