• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.4
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• pp.280-287
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• 2002

We present technical issues involved in the development of actuators and sensors for applications to high-precision Micro Electro Mechanical System (MEMS). The technical issues include fabrication uncertainty and noise disturbance, causing major difficulties for MEMS to achieve high-precision actuation and detection functions. For nano-precision actuators, we solve the fabrication instability and electrical noise problems using digital actuators coupled with nonlinear mechanical modulators. For the high-precision capacitive sensors, we present a branched finger electrodes using high-amplitude anti-phase sensing signals. We also demonstrate the potential applications of the nanoactuators and nanodetectors to high-precision positioning MEMS.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.39.1-39
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• 2002

We present nanoactuators and nanodetectors for high-precision Micro Electro Mechanical System (MEMS) applications. Major technical difficulties in the high-precision MEMS are arising from the fabrication uncertainty and electrical noise problems. In this paper, we present high-precision actuators and detectors, overcoming the technical limitations placed by the conventional MEMS technology. For the nano-precision actuation, we present a nonlinearly modulated digital actuator (NMDA). NMDA composed of a digital microactuator and a nonlinear micromechanical modulator. The nonlinear micromechanical modulator is intended to purify the actuation errors in the stroke of the digital a...

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.11
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• pp.1364-1370
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• 2019

Tilt sensors are mainly used to measure the collapse of structures such as buildings, bridges and tunnels. Recently, due to the ease of use and low price, many tilt sensors using MEMS sensors have been used, but the measurement angle range is limited, and thus, they do not have high precision for 360 degree. This is due to the inherent offset and scale errors of MEMS sensors. In this paper, we proposed an algorithm for the calculation of precision angles to reduce the mechanical error of MEMS sensors, and produced a MEMS sensor module and a transmission module to compare the angle accuracy of sensor modules before calibration and the angle measurement accuracy after calibration. Experimental results show that the proposed technique has a precision of ± 0.015 degrees for all 360-degree.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.379-382
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• 2007

The MEMS (Micro Electro Mechanical Systems) process is used in a micro/nano pattern manufacturing method. This method is based on the lithography technology. But the MEMS process has some problems such as complicated process, long processing time and high production costs. Many researchers are doing research in substitute manufacturing method to work out a solution to these problems. In this paper, we apply a dieless incremental forming technology to a substitute method of MEMS process. This dieless forming technology is using in the commercial scale sheet forming such as a prototype of automobile sheet parts. 5-axes CNC (Computerized Numeric Control) method are applied in this system to get a micro-scale dieless forming results. These 5-axes system are composed of precision AC servo motor stages (4-axes) and PZT actuator (1-axis). A PZT actuator is used in a precision actuating axis because it can be operated in the nano scale stroke resolution. This micro dieless incremental forming system has the advantage of minimization in manipulating distance and working space. As equipment and tools become smaller in size, minute inertia force and high natural frequency can be obtained. Therefore, high precision forming performance can be obtained. This allows the factory to quickly provide the customer with goods because the manufacturing system and process are reduced. To construct this micro manufacturing system, many technologies are necessary such as high stiffness frame, high precision actuating part, structural analysis, high precision tools and system control. To achieve the optimal forming quality, the micro dieless forming system is designed and made with high stiffness characteristic.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.376-377
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• 2006

Chemical Mechanical Planarization (CMP) has emerged as an enabling technology for the manufacturing of multi-level metal interconnects used in high-density Integrated Circuits (IC). Recently, multi-level structures have been also widely used m the MEMS device such as micro engines, pressure sensors, micromechanical fluid pumps, micro mirrors and micro lenses. Especially, among the thin films available in IC technologies, polysilicon has probably found the widest range of uses in silicon technology based MEMS. This paper presents the characteristic of polysilicon CMP for multi-level MEMS structures. Two-step CMP process verifies that is possible to decrease dishing amount with two type of slurries characteristics. This approach is attractive because two-step CMP process can be decreased dishing amount considerably more then just one CMP process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.23-24
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.318-321
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• 2005

FIB (Focused ion Beam) milling on a 500-nm-thick silicon nitride membrane was studied in order to fabricate a high-resolution shadow mask, or called a nanostencil. The silicon nitride membrane was fabricated by MEMS processes of LPCVD, photolithography, ICP etching and bulk silicon etching. The apertures made by FIB milling and normal photolithography were compared. The square metal pattern deposited through FIB milled shadow mask showed 6 times smaller comer radius than the case of photolithography. The results show high resolution patterning could be achieved by local deposition through FIB milled shadow-mask.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.10
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• pp.3554-3570
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• 2021

With the rapid development of the Chinese water project, the safety monitoring of dams is urgently needed. Many drawbacks exist in dams, such as high monitoring costs, a limited equipment service life, long-term monitoring difficulties. MEMS sensors have the advantages of low cost, high precision, easy installation, and simplicity, so they have broad application prospects in engineering measurements. This paper designs intelligent monitoring based on the collaborative measurement of dual MEMS sensors. The system first determines the endpoint coordinates of the sensor array by the coordinate transformation relationship in the monitoring system and then obtains the dam settlement according to the endpoint coordinates. Next, this paper proposes a dual-MEMS sensor collaborative measurement algorithm that builds a mathematical model of the dual-sensor measurement. The monitoring system realizes mutual compensation between sensor measurement data by calculating the motion constraint matrix between the two sensors. Compared with the single-sensor measurement, the dual-sensor measurement algorithm is more accurate and can improve the reliability of long-term monitoring data. Finally, the experimental results show that the dam subsidence monitoring system proposed in this paper fully meets the engineering monitoring accuracy needs, and the dual-sensor collaborative measurement system is more stable than the single-sensor monitoring system.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.292.1-292.1
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.221.2-221.2
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• 2007