Non-Linear Behavioral Modeling of Capacitive MEMS Microphones

Anzinger, Sebastian; Wasisto, Hutomo Suryo; Basavanna, Abhiraj; Fueldner, Marc; Dehe, A.

doi:10.1109/mems49605.2023.10052386

Cited by 7 publications

(1 citation statement)

References 7 publications

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“…Similar models are presented in [101,102]. In [103,104], a non-linear electrical circuit of a capacitive microphone is presented. This research focuses on a proper derivation of equations for the variation of the capacitance including the deformation of the membrane and the capacitance due to electrical fringing fields.…”

Section: Non Linear Extensionmentioning

confidence: 97%

Equivalent electrical circuits for electroacoustic MEMS design: a review

Liechti

2024

J. Micromech. Microeng.

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At the era of powerful computers, it’s tempting to employ finite element models early in the design phase of a device. However, especially for MEMS devices, the dimensional ratios and short wavelengths compared to the device’s dimensions, along with the involvement of multiple physics, can necessitate complex and computationally intensive models, making them impractical for optimization processes. Hence, reduced order models, like the lumped element model, are often preferred as they accurately represent complex system behavior within a defined frequency range. This review explores the use of lumped element models and their corresponding electrical equivalent circuits for simulating MEMS electro-acoustic devices, offering insights into their diverse applications within this specific domain.

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Section: Non Linear Extensionmentioning

confidence: 97%

Equivalent electrical circuits for electroacoustic MEMS design: a review

Liechti

2024

J. Micromech. Microeng.

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A behavioral nonlinear modeling implementation for MEMS capacitive microphones

Shubham,

Nawaz,

Song

et al. 2024

Sensors and Actuators A: Physical

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Piezoelectric MEMS microphones based on rib structures and single crystal PZT thin film

You,

Gan,

Yang

et al. 2024

Microsyst Nanoeng

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In this study, a controllable mass‒frequency tuning method is presented using the etching of rib structures on a single-crystal PZT membrane. The rib structures were optimized to reduce the membrane mass while maintaining the stiffness; therefore, the center frequency could be increased to improve the low-frequency bandwidth of microphones. Additionally, this methodology could reduce the modulus and improve the sensitivity for the same resonant frequency, which typically indicates the maximum acoustic overload point (AOP). The PZT film was chosen because of its greater density; the simulation results showed that PZT could provide a greater frequency tuning (24.9%) compared to that of the AlN film (5.8%), and its large dielectric constant enabled the optimal design to have small electrodes at the maximum stress location while mitigating the sacrificial capacitance effect on electrical gain. An analytical model of rib-structure microphones was established and greatly reduced the computing time. The experimental results of the impedance tests revealed that the center frequencies of the six microphones shifted from 74.6 kHz to 106.3 kHz with rib-structure inner radii ranging from 0 μm to 340 μm; this result was in good agreement with the those of the analytical analysis and finite element modeling. While the center frequency greatly varied, the measured sensitivities at 1 kHz only varied within a small range from 22.3 mV/Pa to 25.7 mV/Pa; thus, the membrane stiffness minimally changed. Moreover, a single-crystal PZT film with a (100) crystal orientation and 0.24-degree full width at half maximum (FWHM) was used to enable differential sensing and a low possibility of undesirable polarization. Paired with a two-stage differential charge amplifier, a differential sensing microphone was experimentally demonstrated to improve the sensitivity from 25.7 mV/Pa to 36.1 mV/Pa and reduce the noise from −68.2 dBV to −82.8 dBV.

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Non-Linear Behavioral Modeling of Capacitive MEMS Microphones

Cited by 7 publications

References 7 publications

Equivalent electrical circuits for electroacoustic MEMS design: a review

Equivalent electrical circuits for electroacoustic MEMS design: a review

A behavioral nonlinear modeling implementation for MEMS capacitive microphones

Piezoelectric MEMS microphones based on rib structures and single crystal PZT thin film

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