When voltage is applied to piezoelectric materials, they flex, a property that can be used to generate sound. This is the principle behind the piezoelectric speaker. Leti recently developed a MEMS-based piezo speaker in which the piezo switch was made from a thin layer of PZT (lead zirconate titanate). “We used the sol-gel method to deposit the material—the best way to obtain the optimal crystalline structure and yields,” said a representative of Leti. The institute leverages a lab with state-of-the-art equipment dedicated to PZT research to analyze and gain insights into how the material works and enhance its performance.

And this is very good news for MEMS, where PZT could have many other uses. MEMS, which are playing an increasing role in our everyday lives, have to be coupled with sensors or switches for certain applications. And these sensors and switches can now potentially be made from PZT. The research will fuel advances in everything from RF components to medical systems, optical components, and haptic feedback systems for new human-machine interfaces.