Another field of work of this business unit includes acoustic systems and the corresponding high-performance micro-actuators. Here a focus is on the development of MEMS microphones and speakers. These can be produced much more cost effectively and more miniaturized in at least the same acoustic quality as their conventional electrodynamic equivalents. The high energy efficiency of these components is another advantage. This makes the ISIT chip microphones and speakers especially attractive for mobile communication devices such as tablets, smartphones, headphones, and hearing aids that require high acoustic quality and low energy consumption while the component size has to keep shrinking. Miniaturized ultrasonic transducers are another focal point aside from the MEMS speakers. Depending on the frequency range, the transducers at ISIT are usually designed as thickness-mode or membrane transducers with AlN, AlScN, or PZT available as drive materials. Efficient ultrasound transducers with center frequencies of a few kHz to several hundred MHz can be realized this way. The developed components include ultrasound arrays for medical technology, non-destructive testing, and gesture recognition.