At the end of the 19th century, the Curie brothers demonstrated that by applying stress to naturally occurring crystalline materials such as quartz, an electric charge will be produced. This phenomenon is called the piezoelectric effect and can be used in various sensors and microphones, as well as ultrasonic receiver types of applications. There is also an inverse effect where applying an electric field to a material with piezoelectric properties will cause a physical distortion, resulting in the displacement of a few microns; in short, converting electrical energy into mechanical energy. This can be used for ultrasonic source types of applications such as speakers, but in this training the focus will be on how this anti-piezo effect is used for actuator products.