Defective metal oxides as the next generation of lead-free piezoelectrics for ultrasonic actuators

Electromechanical smart materials are like muscles that change their size and exert forces under electrical stimuli. They are in sensors and medical devices and are essential for future technologies. Despite their importance, the best-performing material is an old technology: lead-based piezoelectrics, which is highly toxic. A new class of materials, non-classical electrostrictors, have been discovered. These outperform lead-based piezoelectrics and are biocompatible and inexpensive. However, we still need to assess them for “fast” ultrasounds.