• 세라미스트
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• 제22권1호
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• pp.27-35
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• 2019

Research on ultraviolet (UV) light detection has attracted considerable attention from scientific researchers in related fields. It can be said that it is a very important time to accurately monitor the UV irradiation amount according to the wavelength region in real time. The oxide is very diverse in its kind and has the advantage of being able to efficiently control the band gap through band gap engineering. In addition, it is very stable in response to heat and atmospheric oxygen when UV is absorbed. Also, there is a known method that can effectively manufacture oxide nanoparticles and nanorods through various synthesis methods, and researches for improving the sensitivity of UV sensors have been carried out using this method. In this paper, we introduce the materials that can be used as UV sensors among various wide band oxide materials, and review the results of researches of various UV sensors using nano materials.

• 한국세라믹학회지
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• 제37권9호
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• pp.871-878
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• 2000

본 연구는 3mol% Pb(Sb$_{1}$2/Nb$_{1}$2/)O$_3$가 첨가된 상경계 영역의 Pb(Zr,Ti)O$_3$(PSN-PZT) 세라믹스에 대하여 RT66A와 광섬유센서를 이용하여, 교류강전계 하에서 압전 및 유전특성을 조사하였다. PSN-PZT 세라믹스의 압전 및 유전 특성에 미치는 non-180$^{\circ}$분역 재배열의 영향을 평가하기 위하여 RT66A와 MTI-2000 Fotonic$^{TM}$ sensor를 이용하여 인가전계와 주파수의 함수로 전계유기변위를 측정하였다. 그 결과, 교류강전계 하에서 전계유기변위는 강전계, 저주파수에서 큰 이력현상을 나타내고, 전계유기변위로부터 결정된 유효압전상수는 주파수가 감소할수록 증가하는 거동을 나타내고 있으며, 이러한 거동은 non-180$^{\circ}$분역 재배열의 영향으로 해석되었다.

• 한국세라믹학회지
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• 제32권12호
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• pp.1369-1376
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• 1995

The WO3 thin-film NOx sensor which is of practical use and includes the heater and the temperature sensor was fabricated. The WO3 thin films as a gas-sensing layer was deposited at ambient temperature in a high-vacuum resistance heated evaporator. The highest sensitivity of the WO3 thin-film sensor to NOx was obtained under the condition of the annealing temperature of 50$0^{\circ}C$ and the operating temperature of 30$0^{\circ}C$. The gas sensing characteristics of this sensor was excellent, i.e. high sensitivity (Rgas/Rair in 3 ppm NO2=53) and fast response time (4 seconds).

• 한국세라믹학회지
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• 제36권5호
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• pp.465-470
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• 1999

Sensing properties of $\alpha$-Fe2O3 thin film to reducing gases such as CHx and CO were systematically examined after deposition on Al2O3 substrate by PECVD(Plasma Enhanced Chemical Vapor Deposition)technique. Microstructure of deposited $\alpha$-Fe2O3 thin film showed the porous island structure. This specimen was annealed at 450, 550, $650^{\circ}C$ to enhance the gas sensing properties and investigated in terms of CO and C4H10 concentration from 500ppm to 3,000 ppm at operating temperature of 35$0^{\circ}C$ The gas sensitivity(%) to C4H10 measured at the operating temperature of 35$0^{\circ}C$ was 98.24 (highest sensitivity) 69.51 to CO and 2% to CH4 respectviely.

• 한국세라믹학회지
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• 제35권8호
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• pp.795-800
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• 1998

• 한국표면공학회지
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• 제52권5호
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• pp.239-245
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• 2019

To increase the throughput of tip-based nanolithography (TBN), one approach is to use a large array of such tips working in parallel. It is important to maintain co-planarity between the tip array and the writing surface. A slight misalignment can cause large discrepancies of contact force and feature sizes. We report a capacitive proximity sensor built-in with the TBN array for leveling an arrayed polymer pen array. The device allows alignment between an array of writing tips and the writing substrate without contact and contamination. The angular sensitivity of the sensor is $0.05^{\circ}$ for an array with maximum tip-to-tip separation of 100 mm.

• 한국인터넷방송통신학회논문지
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• 제11권2호
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• pp.225-229
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• 2011

본 연구에서는 환경 모니터링을 위한 정전용량형 압력센서를 저온동시소성세라믹 (LTCC) 기술을 이용하여 제작하였다. LTCC 기술은 실리콘 기반의 기술에 비하여 낮은 생산 단가, 높은 수율, 3차원 구조물의 용이한 제작성 등으로 인하여 센서 응용분야에서 중요한 역할을 담당하고 있으며, 특히 열악한 외부환경에 적합한 물질이다. 400 ${\mu}m$ 두께 삼차원 구조의 LTCC 다이어프램은 NEG사의 MLS 22C 상용 파우더를 이용하여 100 ${\mu}m$ 두께의 그린쉬트를 적층하고 동시소결하여 제작하였다. 제작한 다이어프램은 공동의 면적에 따른 센싱특성을 평가하기 위하여 각각 25, 49 $mm^2$의 두 종류를 제작하였다. 정전용량형 압력센서를 구현하기 위하여 상부에는 열증착기를 이용하여 Au 금속박막을 증착하였고 하부에는 상용 알루미늄막을 압착하였다. 압력에 따른 센싱특성을 평가하기 위하여 제작된 측정시스템을 이용하여 0~30 psi의 압력을 가변하여 압력센서의 정전용량 변화를 측정한 결과 두 센서 모두에서 선형적인 센싱 특성을 나타냄을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.207-210
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• 2002

This paper is concerned with the experiments on the active vibration control of a plate with piezoceramic sensors and actuators. The natural frequencies of the composite plate featured by a piezo-film sensor and piezo-ceramic actuator are calculated by using the modal analysis method. Modal coordinates are introduced to obtain the state equations of the structural system. Six natural frequencies were considered in the modelling, because robust control theory which has inherent robustness to structured uncertainty is adopted to suppress the transients vibrations of a glass fiber reinforced(GFR) composite beam. A robust controller satisfying the nominal performance and robust performance is designed using robust theory based on the structured singular value. Simulations were carried out with the designed controller and effectiveness of the robust control strategy was verified by results.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
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• pp.107-110
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• 1992

We investigate the influence of individual properties of piezoceramics such as elastic, dielectric, piezoelectric constants, and the coupling factor on the performance of the transducer operating in thickness mode oscillation. The investigation employs equivalent circuit analysis techniques. Appropriate transfer functions are obtained and discussed which suggest optimum selection guides of piezoelectric ceramics for each purpose, i.e. a transmitter, a receiver, and a pulse-echo transducer. The guides can help ceramic scientists find the direction to proceed in new material development.

• 한국전기전자재료학회논문지
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• 제14권12호
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• pp.987-993
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• 2001

In this paper, we presents the construction details and output characteristics of a thick film piezoresistive strain gage. The thick film was printed on the ceramic diaphragm back side by screen printing and cured at 850$^{\circ}C$. The strain distribution and deflection on ceramic diaphragm were performed with finite-element method(FEM tool ANSYS-5.3). Various thick film strain gage characteristics were analysed, including nonlinearity, hysteresis, stability and sensitivity of thick film strain gages.