In this paper the development of a capacitive microphone with integrated preamplifier is described. The condenser microphone is made by micromachining of polyimide on silicon, and is compatible with CMOS technology. Therefore, the structure can be realised by post processing on substrates containing integrated circuits, independently of the IC process. Microphones with a required DC bias voltag...

Capacitive micromachined transducers have long been used as generators and detectors of ultrasound both in air and immersion applications [l-31. Typically, the frequency of operation has been in the MHz range. However, they can still be operated at very low frequencies, where their mechanical sensitivity is poor, but the frequency response is flat. In this paper we show that, together with the ...

This article deals with effects of thermal stresses on stability and frequency response of a fully clamped circular microplate, which acts as the diaphragm of a capacitive MEMS microphone. Static and dynamic pull-in phenomena limit the stable regions of a capacitive MEMS microphone. The results show that the non-dimensional static pull-in voltage of the studied case is about 5.23 (38.6 V). On t...

The paper presents the performance optimization of a MEMS accelerometer based microphone for the fully implantable hearing application. A genetic algorithm is employed to optimize the device geometry parameters satisfying the design constraints. The analytical model run on MATLAB and the simulation model implemented in COMSOL MULTIPHYSICS 4.2 show good agreement. Optimization with Genetic algor...

A continuous-time (CT) sigma-delta modulator (SDM) for condenser microphone readout interfaces is presented in this paper. The CT SDM can accommodate a single-ended input and has high input impedance, so that it can be directly driven by a single-ended condenser microphone. A current-sensing boosted OTA-C integrator with capacitive feedforward compensation is employed in the CT SDM to achieve h...

This paper presents the analysis, design, fabrication, and testing of a condenser microphone utilizing a thin low-stress polycrystalline silicon diaphragm suspended above a p+ perforated back plate. The microphone is fabricated using a combination of surface and bulk micromachining techniques in a single wafer process without the need of wafer bonding. The device shows sensitivities of -34 dB (...

In this paper the effect of corrugated diaphragm on performance of MEMS microphone is described. The corrugated diaphragm is modeled in order to improve the sensitivity of micromachined silicon acoustic sensor. Analytical analyzes have been carried out to derive mathematic expressions for the mechanical sensitivity and displacement of corrugated diaphragm with residual stress. It is shown that ...

A microphone is a transducer that converts acoustic energy into electrical energy. Microphones are widely used in voice communications devices, hearing aids, surveillance and military aims, ultrasonic and acoustic distinction under water, and noise and vibration control (Ma et al. 2002). Micromachining technology has been used to design and fabricate various silicon microphones. Among them, the...