Despite their miniature design, the MEMS loudspeakers impress with their high fidelity and low energy consumption, which is of particular relevance for battery-powered devices. Last but not least, the production with silicon technology enables cost-efficient chip production and assembly at a large scale.
MEMS loudspeakers use piezoelectric thin films as active elements that deform when electrical voltage is applied. This mechanical deflection displaces the surrounding air and thus generates sound waves. The use of silicon for the development of MEMS loudspeakers has proven its worth. Thanks to modern chip manufacturing technologies, the semiconductor material silicon can be processed in its smallest structures and is ideal for this electromechanical application. And it is also a very cost-effective material.
In the future, the transmission bandwidth is to be expanded to beyond 20 kHz by combining several miniature loudspeakers to form a multi-way system. "This puts us in a position to meet the high quality demands of the HD headphone market," says Daniel Beer, project manager at the IDMT.
Semiconductor expert Bernhard Wagner of Fraunhofer ISIT sees important development opportunities for the manufacture of MEMS loudspeakers:"We want to use new piezoelectric materials that are more energy-efficient and IC-compatible in the future. This will further reduce power consumption and enable mass production of MEMS loudspeakers in all major semiconductor factories".
The two Fraunhofer Institutes will present their achievements to the public for the first time at the annual conference of the German Society for Acoustics (DAGA) in Munich from March 19 to 22.