Acoustic Actuators

Acoustic actuators generate sound, ultrasound, or mechanical motion in highly compact devices. At Fraunhofer IPMS, these technologies are based on micromechanical operating principles, with a particular focus on Nanoscopic Electrostatic Drives (NED) and Lateral Capacitive Micromachined Ultrasonic Transducers (L-CMUTs).

NED actuators utilize beam-shaped electrode structures with extremely narrow electrode gaps. Electrostatic forces are converted into lateral or vertical motion, enabling low driving voltages, minimal power consumption, and compatibility with standard CMOS silicon technologies. L-CMUTs employ microscopic bending beams within acoustic cavities to generate ultrasound. Unlike conventional ultrasonic transducers, sound is produced without a traditional membrane, allowing highly miniaturized devices with application-specific form factors, operating frequencies, and acoustic radiation characteristics.

Typical applications include MEMS-based headphones, micro-positioning platforms, distance measurement, and gesture recognition. The technologies are also well suited for collision detection, tactile short-range sensing, robotics, and non-destructive material testing. Fraunhofer IPMS supports industrial and research partners in the development of customized MEMS actuators, technology demonstrators, and integrated ultrasonic solutions for systems with limited installation space and low power requirements. These technologies are also suitable for acoustic spectroscopy and ultrasonic characterization of flowing gases, where compact, highly integrated actuator structures are essential.