ABSTRACT

Undoubtedly, one of the most exciting technological evolutions over the last decade of the twentieth century is in the field of microsystems (microelectromechanical systems (MEMS)). MEMS technology has been able to profit from the benefits and innovations created during the integrated circuit (IC) technology revolution in terms of processes, equipments and materials. The measurement of the pressure is certainly one of the most mature applications of MEMS technology. The following chapter will present an electromagnetic comprehensive study of a new micromachined microphone performed in MEMS technology. However, the main purpose of this chapter is not to introduce MEMS technology, but it will serve to develop an electromagnetic analysis theory that can serve as a model in several MEMS magnetic sensors based, for example, on the Hall effect or Lorentz force. Through different approaches, the magnetic field expression and shape, then subsequently the induced voltage, will be investigated and determined. Developed magnetic modelling techniques will be widely applied on a new electrodynamic MEMS microphone concept to prove its feasibility and interest in a purely arithmetical term. To our knowledge, the proposed electrodynamic principle has never been exploited in practice to realize silicon micromachined microphones. Therefore, the integration of the electrodynamic principle on a single chip and the realization technology choice are our two major pre-eminences.