• Advances in Computational Design
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• v.2 no.2
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• pp.107-119
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• 2017

The Micro circular diaphragm (MCD) is the mechanical actuator part used in the micro electro-mechanical sensors (MEMS) that combine electrical and mechanical components. These actuators are working under harsh mechanical and thermal conditions, so it is very important to study the mechanical and thermal behaviors of these actuators, in order to do with its function successfully. The objective of this paper is to determine the thermo-mechanical behavior of MCD by developing the traditional bulge test technique to achieve the aims of this work. The specimen is first pre-stressed to ensure that is no initial deflection before applied the loads on diaphragm and then clamped between two plates, a differential pressure (P) and temperature ($T_b$) is leading to a deformation of the MCD. Analytical formulation of developed bulge test technique for MCD thermo-mechanical characterization was established with taking in-to account effect of the residual strength from pre-stressed loading. These makes the plane-strain bulge test ideal for studying the mechanical and thermal behavior of diaphragm in both the elastic and plastic regimes. The differential specimen thickness due to bulge effect to describe the mechanical behavior, and the temperature effect on the MCD material properties to study the thermal behavior under deformation were discussed. A finite element model (FEM) can be extended to apply for investigating the reliability of the proposed bulge test of MCD and compare between the FEM results and another one from analytical calculus. The results show that, the good convergence between the finite element model and analytical model.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.207-209
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• 1993

In this paper, an electrostatic silicon micro actuator has been designed and fabricated using the micro machining technology. The actuator consists of two counter electrodes. One is an Al film deposited on a pyrex glass, and the other is a circular corrugated diaphragm with boron doped. The diaphragm is fabricated by boron etch stop technique using an anisotropic etchant, EPW.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.8
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• pp.790-796
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• 2013

Micro-speaker diaphragms play an important role in generating a desired audio response. The diaphragm is generally a circular membrane, and the cross section is a double dome, with an inner dome and an outer dome. To improve the sound quality of the speaker, a number of corrugations may be included in the outer dome region. In this study, the role of these corrugations is investigated using two kinds of finite element method (FEM) calculations. Structural FEM modeling was carried out to investigate the change in stiffness of the diaphragm when the corrugations were included. Modal FEM modeling was then carried out to compare the natural frequencies and the resulting vibrational modes of the plain and corrugated diaphragms. The effects of the corrugations on the vibration characteristics of the diaphragm are discussed.

• Transactions of Materials Processing
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• v.23 no.1
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• pp.10-15
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• 2014

Recently, micro-speakers have attracted much attention due to their increasing demand in mobile devices. Micro-speakers use polymer diaphragms, which are manufactured from thin polymer film by the thermoforming process. The diaphragm is generally designed to be a circular membrane with a cross section consisting of a double dome structure, and a number of corrugations are located in the outer region to produce better sound quality. In the current study, a finite element (FE) analysis is performed for thermoforming, and the resulting thickness reduction in the corrugation regions is estimated. The estimated thickness distribution is used in further structural and modal FE analyses, from which the effects of local thickness reduction on the stiffness and vibration characteristics are determined.

• Journal of IKEEE
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• v.1 no.1 s.1
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• pp.1-10
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• 1997

It is well-known that rectangular bulk-Si sensors prepared by etch or epi etch-stop micromachining technology are already in practical use today, but the conventional bulk-Si sensor shows some drawbacks such as large chip size and limited applications as silicon sensor device is to be miniaturized. We consider a circular-shape SOI(Silicon-On-Insulator) micro-cavity technology to facilitate multiple sensors on very small chip, to make device easier to package than conventional sensor like pressure sensor and to provide very high over-pressure capability. This paper demonstrates the cross-functional results for stress analyses(targeting $5{\mu}m$ deflection and 100MPa stress as maximum at various applicable pressure ranges), for finding permissible diaphragm dimension by output sensitivity, and piezoresistive sensor theory from two-type SOI structures where the double SOI structure shows the most feasible deflection and small stress at various ambient pressures. Those results can be compared with the ones of circular-shape bulk-Si based sensor$^{[17]}. The SOI micro-cavity formed the sensors is promising to integrate with calibration, gain stage and controller unit plus high current/high voltage CMOS drivers onto monolithic chip.

• Current Optics and Photonics
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• v.4 no.4
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• pp.293-301
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• 2020

In this paper we propose and theoretically analyze a monolithic multiparametric sensor consisting of a superstructure of surface-relief waveguide Bragg gratings (WBGs), a micro-machined diaphragm, and a cantilever beam. Diaphragms of two different configurations, namely circular and square, are designed and analyzed separately for pressure measurement. The square diaphragm is then selected for further study, since it shows relatively higher sensitivity compared to the circular one, as it incurs more induced stress when any pressure is applied. The cantilever beam with a proof mass is designed to enhance the sensitivity for acceleration measurement. A unique mathematical method using coupled-mode theory and the transfer-matrix method is developed to design and analyze the shift in the Bragg wavelength of the superstructure configuration of the gratings, due to simultaneously applied pressure and acceleration. The effect of temperature on the wavelength shift is compensated by introducing another Bragg grating in the superstructure configuration. The measured sensitivities for pressure and acceleration are found to be 0.21 pm/Pa and 6.49 nm/g respectively.