Ultrasound Transducers

Sound pressure level of a piezoelectric MEMS loudspeaker in free field
© Fraunhofer ISIT / photocompany, Itzehoe
Piezoelectric ultrasonic arrays with 80 MHz

For many years, ISIT has worked together with partners from research and industry in the field of acoustic microsystems. A focal point is the development of a new generation of loudspeakers. Unlike conventional electrodynamic microspeakers, the new chip speakers are based on powerful MEMS drives. These are manufactured using silicon technology and are characterized by extremely low manufacturing tolerances. Further advantages are the reduced size and the high energy efficiency, which makes the sounder particularly attractive for mobile communication devices such as tablets, smartphones and headphones. In addition to the MEMS speakers, miniaturized ultrasonic transducers are another research focus. Depending on the frequency range, the transducers at ISIT are usually designed as piezoelectric thickness or membrane transducers, with AlN, ScAIN and PZT as drive materials. In this way, efficient ultrasonic transducers with center frequencies of a few kHz up to several hundred MHz can be realized. The developed components include ultrasonic arrays for medical technology, non-destructive testing and gesture recognition.