• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1787-1788
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• 2006

In this paper, a noisy passive telemetry sensor system using Unscented Kalman Filter (UKF) is proposed. To overcome these trouble problems such as a power limitation and a estimation complexity that the general passive telemetry sensor system including IC chip has, the principle of inductive coupling was applied to the modelling of a passive telemetry sensor system (PTSS) and its noisy capacitive parameter was estimated by the UKF algorithm. Specialty, to show the effective tracking performance of the UKF, we compared with the tracking performance of Recursive Least Square Estimation (RLSE) using linearization

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.12
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• pp.809-813
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• 2016

We investigated a SiC-based hydrogen gas sensor with MIS (metal-insulator-semiconductor) structure for high temperature applications. The sensor was fabricated by $Pd/TiO_2/SiC$ structure, and a thin titanium dioxide ($TiO_2$) layer was exploited for sensitivity improvement. In the experiment, dependences of I-V characteristics and capacitance response properties on hydrogen gas concentrations from 0 to 2,000 ppm were analyzed at room temperature to $400^{\circ}C$. As the result, our sensor using $TiO_2$ dielectric layer showed possibilities with regard to use in hydrogen gas sensors for high-temperature applications.

• Transactions on Electrical and Electronic Materials
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• v.7 no.4
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• pp.184-188
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• 2006

This work describes efforts in the fabrication and testing of robust microelectromechanical systems (MEMS). Robustness is typically achieved by investigating non-silicon substrates and materials for MEMS fabrication. Some of the traditional MEMS fabrication techniques are applicable to robust MEMS, while other techniques are drawn from other technology areas, such as electronic packaging. The fabrication technologies appropriate for robust MEMS are illustrated through laminated polymer membrane based pressure sensor arrays. Each array uses a stainless steel substrate, a laminated polymer film as a suspended movable plate, and a fixed, surface micromachined back electrode of electroplated nickel. Over an applied pressure range from 0 to 34 kPa, the net capacitance change was approximately 0.14 pF. An important attribute of this design is that only the steel substrate and the pressure sensor inlet is exposed to the flow; i.e., the sensor is self-packaged.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.178-183
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• 2002

In this paper, the capacitive sensor which can detect the continuous position of liquid is proposed. The proposed sensor make up copper rod's defect which are oxidized in liquid and float switch's defect which are tired of continuous movements. This sensor make use of what capacitance is varying due to quantity and kind of dielectric in the plane gap. The operating principle of the sensor and the amplifying methode of detecting signal and the methode of apply in computer control system are presented in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04a
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• pp.637-642
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• 1995

For measuring the error motion of ultra-precision spindle, eliminating the geometric errors is a must. Unless it is achieved, geometric errors will be dominant in data. Here, the roundness error and alignment error between spindle and sensor are to be removed. That's because typical error range of such spindle is muchless than geometric one. A capacitive transducer of cylidricalshape was developed, which takes full advantage of the spatial-averaging effect by using large area compared tpo the geometric error. This idea was first proposed by Chapman and here it is modified for better performance with nomical gap of 50 .mu. m and with newly designed guards which encompass the respective sensor to rectify the electrical field distribution in good shape. The measurement system is made to get the orbit of Ultra-Precision Air Spindle which is supposed to have its runout under 1 .mu. m. The Calibration data of this sensor is presented and the spindle orbit from 2000rpm to 5500rpm is showed. It is quite reasonable to use this sensor in the range of 60 .mu. m with an accuracy of several tens of nm.

• Journal of Sensor Science and Technology
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• v.28 no.1
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• pp.1-6
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• 2019

This paper presents an air flow sensor (AFS) based on a polymer thin film. This AFS primarily consists of a polymer membrane attached to a metal-patterned glass substrate and a temperature-sensing element composed of NiCr. These two components were integrated on a single glass substrate. The AFS measures changes in capacitance caused by deformation of the polymer membrane based on the air flow and simultaneously detects the temperature of the surrounding environment. A readout integrated circuit (ROIC) was also fabricated for signal processing, and an ROIC chip, 1.8 mm by 1.9 mm in size, was packaged with an AFS in the form of a system-in-package module. The total size of the AFS is 1 by 1 cm, and the diameter and thickness of the circular-shaped polymer membrane are 4 mm and $15{\mu}m$, respectively. The rate of change of the capacitance is approximately 11.2% for air flows ranging between 0 and 40 m/s.

• Journal of Mechanical Science and Technology
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• v.17 no.11
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• pp.1650-1658
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• 2003

This paper deals with a novel shunt circuit, which is capable of suppressing multimode vibration amplitudes by using a pair of piezoceramic patches. In order to describe the characteristic behaviors of a piezoelectric damper connected with a series and a parallel resistor-negative capacitor branch circuit, the stiffness ratio and loss factor with respect to the non-dimensional frequency are considered. The mechanism of the shunt damper is also described by considering a shunt voltage constrained by shunt impedance. To obtain a guideline model of the piezo/beam system with a negative capacitive shunting, the governing equations of motion are derived through the Hamilton's principle and a piezo sensor equation as well as a shunt-damping matrix is developed. The theoretical analysis shows that the piezo/beam system combined with a series and a parallel resistor-negative capacitor branch circuit developed in this study can significantly reduce the multiple-mode vibration amplitudes over the whole structural frequency range.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.795-797
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• 2013

This paper describes a charge sharing capacitive-sensing circuit technique that improves the quality of images captured with fingerprint sensor LSIs. When the finger is dry, the electrical resistance of a finger surface is high. It leads to poor image quality. To capture clear images even when the finger is dry, the modified capacitive detection circuit improves the image quality using an enhancement plate at the finger surface and a voltage control circuit. The test circuit is analyzed on $0.35{\mu}m$ CMOS process.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1369-1371
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• 2015

본 논문은 전도성섬유 압력센서로 보행신호를 획득하고 걷기, 서기, 앉기, 계단오르기, 계단내려오기 등 총 5가지 행동을 인식하는 시스템을 개발하는 것이 목적이다. 시스템은 Capacitive pressure 센서, CDC(Capacitive to Digital Converter), 마이크로프로세서, 블루투스 모듈, 스마트 폰으로 구성되고 획득한 데이터 패턴을 분류한 결과 평균 99.5%의 높은 인식률을 보였다. 각 발당 한 개의 채널만을 이용해 행동패턴을 인지함으로써 적은 수의 채널로도 행동인지의 가능함을 확인할 수 있었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.5
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• pp.506-513
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• 2015

In this paper, we proposed a novel ethanol concentration sensor using microfluidic metamaterial absorber. The metamaterial absorber comprises a split-ring-cross resonator(SRCR) and a microfluidic channel. The SRCR can generate LC resonance that is very sensitive to changes in the effective dielectric constant around the capacitive gap. In addition, microfluidic channels can change the effective dielectric constant of the dielectric substrate by using an infinitesimal quantity of a liquid on the order of microliters. The proposed absorber can detect the electrical properties of different concentration of ethanol. The performance of the proposed absorber is demonstrated using the absorption measurements of a fabricated prototype sample with waveguides. In addition, the simulated results and measurement results show good agreement.