Expanding the application space for piezoelectric materials

The long history of innovation in the field of piezoelectric devices has, over the last 65 years, been predominantly rooted in a single material, the Pb(Zr, Ti)O3 ceramic, known as lead zirconate titanate (PZT). Despite enormous resources being dedicated in the last 20 years to identifying lead-free alternatives to PZT and developing a thriving, but limited, market in PbTiO3-relaxor single crystals, most device developments are still PZT based. However, more recently, solid solutions based on BiFeO3 have opened up new applications for active piezoelectric devices at high temperatures (to 600 ○C) and under high stress (exceeding 250 MPa), with applications in industrial ultrasound, aerospace, automotive, and micro-actuators. This perspective article examines how new materials are expanding the application space for piezoelectric materials.