MEMS Speaker Modeling

Loudspeaker is the common terms to identify an electroacoustic transducer, a device which converts an electrical audio signal into a corresponding sound. Despite in the last decades the consumer electronics industry has been able to shrink and digitize most components and functions, the micro speakers for portable applications are still bulky, heavy and difficult to integrate in to digital systems. Voice Coil Magnet (VCM) or Balanced Armature (BA) concepts are de facto industry standards. This article describes the MEMS and semiconductor technology latest efforts to answer the need for smaller, less power hungry, scalable, easy to integrate micro speaker devices. In particular, the article illustrates in detail the approach developed and commercialized by USound GmbH. The introduction outlines the micro speaker market landscape and major technical specifications. The article outlines the building blocks for designing a MEMS piezo speaker and the analytical model and results. As in the case of miniaturized microphones and many other sensors and actuators, silicon micro speakers have the potential to challenge the status quo of the incumbent technologies and establish a new standard.