• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.559-560
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• 2006

The paper presents solutions of conventional piezoresistive pressure sensors. Deflection of diaphragm by external stress causes some problems, because the electrode is deposited on the diaphragm formed piezoresistors. To solve these problems, piezoresistors is formed by two implantation steps. To fabricate diaphragm, the backside silicon etching step is done by immersing the wafer into TMAH solution. $30{\mu}m$ thick diaphragm is obtained. Sensitivity of the piezoresistive pressure sensor fabricated is 48.6 mV/V-psi.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3328-3330
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• 1999

In this paper, the fabrication of a micro actuator with a micro electromagnet and an actuator diaphragm is presented. The micro electromagnet consists of a magnetic core and a micro inductive planar coil. The actuator diaphragm is the p+ silicon diaphragm on both sides of which magnetostrictive materials are deposited by sputtering. The micro electromagnet is fabricated by sputtering, evaporating, etching and electroplating. The magnetic flux density of the micro electromagnet is measured by using the gauss meter. The deflection of the actuator diaphragm is measured by using the laser vibrometer and optic microscope.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1655-1657
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• 2000

본 논문에서는 세라믹 다이어프램식 압력센서를 설계하기 전에 세라믹 다이어프램의 변위에 대한 최적 조건을 확립하기 위해 세라믹의 기계적 특성, 다이어프램의 두께와 직경 등을 변화시키면서 중심부와 변곡점 부근에서 압력에 대한 다이어프램의 변위를 시뮬레이션 하였다.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.2
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• pp.87-94
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• 2009

There are several types of compressors which are appropriate for hydrogen gas station. Diaphragm type of compressor is the one of them and it satisfies the requirements for that purpose in terms of maintaining gas purity and making high pressure over 700 bar. The objective of this study is to find an optimal design of oil distribution hole configuration. The number of holes is changed maintaining total cross-sectional area of holes. Five cases(1 hole, 4, 8,16 and 24 holes) were studied through Fluid Structure Interaction(FSI) analysis method. Gas and oil pressure, the deflection and stress of the diaphragm were analysed during compression and suction process respectively. There is no specific difference among the cases during compression. An additional deflection due to the existence of hole was found during suction for all case. But the highest deflection and stress were found in the 1 hole case. It was seen that 60% decrease of stress in magnitude in 24 hole case compare to the 1 hole case.

• Journal of Sensor Science and Technology
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• v.12 no.6
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• pp.265-272
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• 2003

This paper describes anodic bonding characteristics of MLCA (Multi Layer Ceramic Actuator) to Si-wafer using evaporated Pyrex #7740 glass thin-films for MEMS applications. Pyrex #7740 glass thin-films with same properties were deposited on MLCA under optimum RF magneto conditions(Ar 100%, input power $1\;W/cm^2$). After annealing in $450^{\circ}C$ for 1 hr, the anodic bonding of MLCA and Si-wafer was successfully performed at 600 V, $400^{\circ}C$ in - 760 mmHg. Then, the MLCA/Si bonded interface and fabricated Si diaphragm deflection characteristics were analyzed through the actuation test. It is possible to control with accurate deflection of Si diaphragm according to its geometries and its maximum non-linearity is 0.05-0.08 %FS. Moreover, any damages or separation of MLCA/Si bonded interfaces do not occur during actuation test. Therefore, it is expected that anodic bonding technology of MLCA/Si wafers could be usefully applied for the fabrication process of high-performance piezoelectric MEMS devices.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.6
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• pp.471-478
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• 2009

The specific some types of compressors are appropriate for a use in hydrogen gas station. Metal diaphragm type of hydrogen compressor is one of them, which can satisfy the critical requirements of maintaining gas purity and producing high pressure over 850 bar. The objective of this study is to investigate an characteristics of compression through two-way Fluid-Structure-Interaction (FSI) analysis as bulk modulus and initial volume of oil independently varies. Deflection of diaphragm, oil density, gas and oil pressure were analyzed during a certain period of compression process. According to the analysis results, bulk modulus and initial volume remarkably affected deflection of diaphragm, oil density, gas and oil pressure. The highest gas pressure were attained with the highest bulk modulus of $7e^9\;N/m^2$ and the lowest initial oil volume of 80 cc.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.1017-1019
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• 1998

In this paper, the fabrication of a micropump with two giant magnetostrictive films of Sm-Fe and Tb-Fe is presented. The pump consist of one silicon wafer and one cover glass. The micropump consists of an actuator diaphragm, a paired nozzle and diffuser, and two through holes. The Structure of the micropump is fabricated by the chemical vapor deposition, the etching and the sputtering of the magnetostrictive films. The deflection of the actuator measured diaphragm is measured by using the laser vibrometer and the flow rate of the micro pump is observed by using a video microscope.

• Steel and Composite Structures
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• v.7 no.1
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• pp.35-52
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• 2007

The cold formed light-gauge profiled steel sheeting can offer considerable shear resistance acting in the steel building frame. This paper conducted the full-scale test on the shear behavior of stressed skin diaphragm using profiled sheeting connected by the self-tapping screws. A three-dimensional finite element model that simulates the stressed skin diaphragm was developed. The sheet was modeled using thin element model while the supporting members were simulated using beam elements. Fasteners were represented in the numerical model as equivalent springs. A joint test program was conducted to characterize the properties of these springs and results were reported in this study. Finite element model of the full-scale test was analyzed by use of the ANSYS package, considering nonlinearity caused by the large deflection and slip of fasteners. The experimental data was compared with the results acquired by the EUR formulas and finite element analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.97-103
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• 2002

Vibration isolation technology using an air spring and laminated rubber bearing is widely used because it has excellent vibration isolation characteristics. In the part of that, we usually make use of the self-damped air suing. It is occupied two chambers, restrictor, diaphragm and load plate. Two chambers contain compressed air and the volume of chambers and the area of load plate give a definition of stiffness and load. The restrictor and the volume ratio of two chambers give a definition of damping ratio. The conventional model of restrictor is made of one orifice and it causes turbulent flow in the orifice at the region of large deflection. The stillness of air suing is larger and the damping is lower in the region of large deflection. In the multi-orifice case, the stiffness is similar to air spring with one orifice but damping ratio is larger than conventional air spring. And damping ratio is smaller than conventional air suing in small deflection region. Deflection is small in the region of high frequency so small damping is better than large damping. As a result, we can reduce the storage stiffness of air suing in the wide region of deflection and increase the damping ratio in the region of large deflection. After this, we will try to and the relation of Reynolds Number and Flow Resistance then we are going to make another restrictor for air spring to improve damping ratio and stiffness.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.140.1-140.1
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• 2005