• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.114-117
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• 2011

A thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated and then thin 1.6 ${\mu}m$ thickness P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated also. These thick and thin P(VDF/TrFE) film pyroelectric infrared ray sensor was mounted in TO-5 housing to detect infrared light of 5.5 ~ 14 ${\mu}m$ wavelength for human body detecting with each other. The noise output voltage of the thick P(VDF/TrFE) film pyroelectric infrared ray sensor were 380 mV and NEP(noise equivalent power) is $3.95{\times}10^{-7}$ W which is the similar value with the commercial pyroelectric infrared ray sensor using ceramic materials as a sensing material. The NEP and specific detectivity $D^*$ of the thin P(VDF/TrFE) film pyroelectric infrared ray sensor were $2.13{\times}10^{-8}$ W and $9.37{\times}106$ cm/W under emission energy of 13 ${\mu}W/cm^2$ respectively. These result caused by lower thermal diffusion coefficient of a thin 1.6 ${\mu}m$ thickness PVDF/TrFE film than the thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor.

• Journal of Sensor Science and Technology
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• v.19 no.1
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• pp.58-61
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• 2010

This paper describes the fabrication and characteristics of NO sensor using ZnO thin film by RF magnetron sputter system. The sensitivity, working temperature, and response time of sputtered pure ZnO thin film and added catalysts such as Pt, Pd, Al, Ti on those films were measured and analyzed. The sensitivity of pure ZnO thin film at working temperature of $300^{\circ}C$ is 0.875 in NO gas concentration of 0.046 ppm. At same volume of the gas in chamber, measuring sensitivity of 1.87 at $250^{\circ}C$ was the case of Pt/ZnO thin film. The ZnO thin films added with catalyst materials were showed higher sensitivity, lower working temperature and faster adsorption characteristics to NO gas than pure ZnO thin film.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.409-410
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• 2002

In order to measure the oil-film pressure in sliding surface of machinery, we have developed a piezo-resistive type thin-film pressure sensor. To reduce the measurement error due to temperature and strain, the constituent of the pressure sensitive alloy was optimized and a new sensor shape was devised. In this study, we present the measurement results of the oil-film pressure distribution in engine connecting rod big-end bearing and piston pin- bosses with 3 different pin-boss shapes using the newly developed thin-film pressure sensor.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.176.2-176.2
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• 2014

In this work, we demonstrated that the fabrication of flexible graphene-based chemical sensor with heaters by soft lithographic patterning method [1]. First, monolayer and multilayer graphene were prepared by thermal chemical vapor deposition transferred onto SiO2 / Si substrate in order to fabrication of patterned-sensor and -heater. Second, patterned-monolayer and multilayer graphene were detached through soft lithography process, which was transferred on top and bottom sides of PET film. Third, Au / Ti (Thickness : 100/30 nm) electrodes were deposited end of the patterned-graphene line by sputtering system. Finally, we measured sensor properties through injection of NO2 and CO2 gas on different temperature with voltage change of graphene heater.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.3
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• pp.37-41
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• 2002

In this research, we investigate the properties of membrane and thin film sensor which is using magnetic resonance properties. we expect to $Si_xN_y$ and SiC materials as membrane materials, we measured thin film stress and properties to find the best membrane fabrication condition. Of the two membrane, $Si_xN_y$ thin film is the better than SiC thin film. because of an adequate tensile stress and lower thermal expansion coefficient as sensor structure layer. After performing deposition and patterning thin film sensor material on $Si_xN_y$, we analyzed the magnetic hysteresis and magnetic resonance frequency of sensor. If the magnetic field which is applied in sensor material is removed, magnetization made by magnetic field is transited to elastic mode. moreover. energy radiation is induced during the transition and voltage generates in sensor by energy radiation. At this moment, If voltage generation period is longer, mechanical vibration is induced and signal is generated by mechanical vibration. we also see that as the increase of thin film sensor' length and width, magnetic resonance frequency is decreased.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.2
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• pp.91-95
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• 2012

ZnO thin films were deposited on p-type 4H-SiC substrate by pulsed laser deposition. ZnO nanowires were formed on p-type 4H-SiC substrate by furnace. Ti/Au electrodes were deposited on ZnO thin film/SiC and ZnO nanowire/SiC structures, respectively. Structural and crystallographical properties of the fabricated ZnO thin film/SiC and ZnO nanowire/SiC structures were investigated by field emission scanning electron microscope and X-ray diffraction. In this work, resistance and sensitivity of ZnO thin film/SiC gas sensor and ZnO nanowire/SiC gas sensor were measured at $300^{\circ}C$ with various CO gas concentrations (0%, 90%, 70%, and 50%). Resistance of gas sensor decreases at CO gas atmosphere. Sensitivity of ZnO nanowire/SiC gas sensor is twice as big as sensitivity of ZnO thin film/SiC gas sensor.

• Journal of Sensor Science and Technology
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• v.14 no.3
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• pp.186-190
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• 2005

This paper describes the development of a surface acoustic wave gas sensor that is designed to detect volatile gas by monitering phase change of output signal as a function of time. The sensor consists of SAW oscillators with a center frequency of 100 MHz fabricated on $128^{\circ}$ Y-Z $LiNbO_{3}$ substrates. Experimental results, which show the phase change of output signal under the absorption of volatile gas onto sensors, are presented. The proposed sensor has the properties of high sensitivity compare to the conventional SAW gas sensor and chemical selectivity. Thus, it is thought these results are applicable for use in sensor array of an high performance electronic nose system.

• Electrical & Electronic Materials
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• v.10 no.10
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• pp.1022-1028
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• 1997

In this paper we present the construction details and output characteristics of a diaphragm-type pressure sensor with Cu-Ni(53:47) thin-film strain gauges. In order to improve the sensitivity and the temperature compensation two circumferential gauges are placed near the center of the diaphragm and two radial gauges are located near the edge. For all the gauges the relative change in resistance ΔR/R with pressure is of the order 10$^{-3}$ for the maximum pressure. The output is found to be linear over the entire pressure range(0-30kfg/cm$^2$)and the output sensitivity obtained is 1.6mV/V. The maximum nonlinearity observed in output characteristics is 0.35%FS for 5V excitation and the hysteresis is less than 0.1%FS.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1080-1086
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• 2007

The aim of this paper is to establish the optimum fabrication condition of specimens, using the Vapor Deposition Polymerization Method(VDPM), which is one of modesto prepare functional organic thin films using a dry process, and to develop a thin film type humidity sensor which has good humidity sensitive characteristics. The inner part of the film became denser and roughness of the film surface eased as curing temperature increased so that thickness of the film could be made uniform. This also shows the appropriate curing temperature was $250^{\circ}C$. The basic structure of the humidity sensor is a parallel capacitor which consists of three layers of Aluminum/Polyimide/Aluminum. The result of SEM and AFM measurement shows that the thickness of PI thin films decreased and the refraction increased as curing temperature increased, which indicates that a capacitance-type humidity sensor utilizing polyimide thin film is fabricated on a glass substrate. The characteristics of fabricated samples were measured under various conditions, and the samples had linear characteristics in the range of 20-80 %RH, independent of temperature change, and low hysteresis characteristic.

• Journal of the Korean Ceramic Society
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• v.32 no.12
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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).