The sound of joy in your ear

Find the Latest SoC Solutions
for... Automotive... IoT... Security... Audio... Video

Push-pull principle for loudspeaker concept

ipms.fraunhofer.de, Dec. 12, 2022 – 

We want modern technology to become smaller and more energy-efficient without losing quality. Technical innovation is needed to achieve this. For several years, the Fraunhofer Institute for Photonic Microsystems IPMS has been researching a novel energy-efficient actuator system for micro loudspeakers. The prototype now presented has surpassed expectations: High volume and excellent sound quality meet high energy efficiency in practical tests. The results were now presented in the Nature Journal Microsystems & Nanoengineering.

View of the speaker chips from above, showing the otherwise hidden arrangement of the actuators. The research team led by Bert Kaiser, Manager Business Unit Monolithically Integrated Actuator and Sensor Systems at Fraunhofer IPMS, has been conducting research for years on a unique actuator system for wireless micro loudspeakers. With an arrangement of three electrodes in a common movable configuration on a beam, the Fraunhofer Institute presented for the first time a symmetrical bending transducer that embodies the push-pull principle and operates at low voltages. A first modeling approach was already presented in the journal Microsystems and Nanoengineering last year. The new paper now shows test results of the first prototype, which have confirmed the predictions from the theoretical approaches.

Bert Kaiser reports: "By implementing our novel push-pull actuators in a MEMS micro loudspeaker, we have in particular demonstrated the feasibility of a commercially highly attractive application." The first balanced micro loudspeaker shows excellent audio reproduction over a wide frequency range of more than nine octaves (10 Hz to 6:3 kHz) with a distortion factor of less than 1.2 %. "We therefore expect that this electrode configuration will stimulate the development of innovative electrostatic actuators for a wide range of applications. In this context, it is also important to mention that the silicon fabrication technology is compatible with the complementary metal-oxide semiconductor technology," Bert Kaiser added.

click here to read more...

 Back