Ultrasonic transducer with silicon. A well known material with new applications

The vibrations of piezoelectric driven (ZnO) thin silicon membranes up to 200 kHz are studied. Non-linear vibrations with amplitudes of several micrometers for subharmonic frequency produce considerable ultrasonic radiation. The application of the discussed structure as a liquid nebulizer is investigated. A high-order mode vibration with large amplitude is a necessary condition for the generation of surface acoustic waves in the liquid film and drop formation.