Modeling of MEMS Transducers with Perforated Moving Electrodes

Area of Science:

• Acoustics
• Microelectromechanical Systems (MEMS)
• Transducer Technology

Background:

• Microfabricated electroacoustic transducers with perforated moving plates are emerging for audio applications.
• Optimization for audio frequencies necessitates precise theoretical modeling.
• Existing models may lack the detail required for high-precision parameter tuning.

Purpose of the Study:

• To develop a high-precision analytical model for miniature electroacoustic transducers.
• To model transducers featuring a perforated moving plate electrode within an air gap and cavity.
• To enable optimization of transducer parameters for the audio frequency range.

Main Methods:

• Formulation of the acoustic pressure field within the air gap.
• Coupling the acoustic field to the moving plate's displacement and incident acoustic pressure.
• Incorporation of damping effects from thermal and viscous boundary layers in the air gap, cavity, and plate perforations.

Main Results:

• An analytical model for miniature electroacoustic transducers with perforated moving plates was successfully derived.
• The model accounts for acoustic-mechanical coupling and various damping mechanisms.
• Acoustic pressure sensitivity results were obtained and compared favorably with Finite Element Method (FEM) numerical results.

Conclusions:

• The developed analytical model provides a high-precision tool for optimizing microfabricated electroacoustic transducers.
• The model's accuracy is validated by comparison with numerical simulations.
• This work facilitates the design and improvement of miniature microphones and acoustic sources.