• 정보저장시스템학회논문집
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• 제8권1호
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• pp.16-21
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• 2012

SAW device is widely used as filters, sensors, actuators in various technologies. And capacitive sensor is tremendously used to measure pressure, gap, etc. The application of SAW device as signal conditioner of capacitive sensor reduces noise level and enables high precision measurement. The response increase of SAW based capacitive sensor is produced just before the two capacitive electrode contacts by the existence of parasitic resistance of capacitive electrode. In this paper, we analyze the effects of parasitic resistance and propose the calibrating method using lumped component and execute the high precision gap measurement using calibrated system. And xx nm resolution and yy ${\mu}m$ stroke was attained.

• 센서학회지
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• 제19권5호
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• pp.337-341
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• 2010

In this work, the nanocrystalline ZnO/polycrystalline(poly) aluminum nitride(AlN)/ Si-layered structure was fabricated for humidity sensor applications based on surface acoustic wave(SAW). The ZnO film was used as a sensitive material layer. The ZnO and AlN(0002) were deposited by a sol-gel process and a pulse reactive magnetron sputtering, respectively. The ZnO sensitive films coated on AlN have a hexagonal wurtzite structure after the thin films annealed at $400^{\circ}C$, $500^{\circ}C$ and $600^{\circ}C$. The surface of the film exhibits sponginess and a nanometer particle size(below 50 nm). The largest shift in the frequency response was at approximately 200 kHz(the relative humidity: 10 %~90 %) for the structure annealed at $400^{\circ}C$. The effect of the change in the environmental temperature on the frequency response of the SAW humidity sensor was also investigated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.557-558
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• 2010

• International Journal of Korean Welding Society
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• 제1권1호
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• pp.1-6
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• 2001

This paper describes several advances in sensor and process control techniques for applications in Submerged Arc Welding (SAW), which combine to give a fully automatic system capable of controlling and adapting the overall welding process. This technology has been applied in longitudinal and spiral pipe mills and in pressure vessel production.

• 한국음향학회지
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• 제35권6호
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• pp.473-479
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• 2016

본 연구는 센서 표면에 고정된 티오에스터 분자와 금 나노입자를 이용하여 수용액 중의 시안화이온(cyanide)을 선택적이고, 고민감도로 검출할 수 있는 200 MHz 표면음향파(Surface Acoustic Wave, SAW) 센서의 개발에 관한 것이다. SAW 센서표면에 형성된 티오에스터 단분자막은 시안화이온의 친핵성 첨가반응에 의해 가수분해되어 티올(thiol)이 만들어지고, 티올 분자는 다시 금 나노입자와 반응에 의해 티올-금 나노입자 복합체를 형성한다. 이후 신호증폭을 위해, gold(III) chloride trihydrate와 hydroxylamine hydrochloride 조합에 의한 금 나노입자의 사이즈 확대반응을 수행하였다. SAW 센서는 수용액 중에서 시안화이온에 대한 검출 능력이 17.7 uM이었으며, 공진주파수 변화량은 시안화이온의 농도가 커지면서 포화되는 현상을 보여주었다. 한편, 제작된 SAW 센서는 시안화이온 이외의 플루오라이드(fluoride), 아세테이트(acetate), 그리고 설페이트(sulfate) 이온 등의 다른 음이온에는 전혀 반응성이 없었으며, 다른 음이온에 의한 간섭현상도 나타나지 않았다. 끝으로 모든 실험은 재현성 있는 실험 결과를 얻기 위해서 자체 제작한 유체제어 모듈과 센서를 이용하여 진행하였다.

• 전기학회논문지
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• 제63권4호
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• pp.495-501
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• 2014

Piezoresistive-type, capacitive-type, and optical-type sensors have mainly been used for measuring a strain. However, in building a sensor network for remote monitoring using these conventional sensors there are disadvantages such as the complexity of a measuring system including wireless communication circuitry and high cost. In this paper, we demonstrates a highly-sensitive surface acoustic wave (SAW) strain sensor which is advantageous to harsh environments and wireless network. We designed and fabricated the SAW strain sensor. The SAW strain sensor attached on a specimen was tested with a tensile tester. The strain on the sensor surface was measured with a commercial strain gauge and compared with that obtained from strain analysis. The central frequency shift of the SAW sensor was measured with a network analyzer. The sensitivity of the SAW strain sensor is 134 $Hz/{\mu}{\varepsilon}$ which is high compared to previous results.

• 한국정밀공학회지
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• 제23권4호
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• pp.139-145
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• 2006

This paper presents the design and manufacturing of a sensor using SAW and delay line in order to measure temperature. SAW sensors having single and double electrodes are manufactured on the $128^{\circ}YX-LiNbO_3$ substrate, and its process is addressed. Before manufacturing, the device is simulated using a commercial finite element program. The frequency responses of the saw sensor on the temperature change is measured. Since the center frequency on the temperature change from $-30^{\circ}C$ to $80^{\circ}C$ is linearly changed, the saw sensor is applicable to measure the temperature change or strain variation.

• 한국항행학회논문지
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• 제27권4호
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• pp.469-472
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• 2023

If temperature management is required in factory or environmental monitoring, temperature can be measured by connecting various sensors wired or wirelessly. Surface acoustic wave sensors measure temperature using changes in acoustic waves on the sensor surface according to temperature, and are useful for wireless networks. In this paper, in order to build a wireless temperature measurement system in the 900 MHz frequency band, the temperature characteristics of the passive SAW sensor were measured, and the analysis and removal of multipath reflection wave effect inside the high temperature chamber were conducted. The resonant frequency of the SAW sensor was measured, and radio transmission/reception and multipath reflected wave removal techniques were proposed in the shielded chamber.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.537-537
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• 2010

High precision sensing is very important in various technologies. Especially, it is more important when it were applied to nano/micro meter level's sensing like AFM, storage, etc. And capacitive sensing is widely used method. To improve the measurement efficiency, many signal conditioners were studied and one of them was surface acoustic wave (SAW) device. SAW device is very widely used as a high frequency bandwidth filter. Due to the reflective characteristic of high frequency, the response of SAW device contains both propagative and reflective signal at the external impedance. In this paper, we used SAW device as signal conditioner of capacitive sensor. And high precision gap measurement was executed using capacitive load. Reference signal was reflective SAW response and the magnitude at the center frequency of SAW device by the change of impedance was checked. Finally, the attainable gap resolution was determined.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.251-252
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• 2006

A development of surface acoustic wave gas sensor to detecting volatile gas has been observed by monitoring output signal as function of time onto the network analyzer. The SAW sensor with a center frequency of 200MHz was fabricated on $42^{\circ}$ S-T Quartz substrates. Using the gas chromatography column has been selectivity. Experimental results, which show the phase change of output signal under the absorption of volatile gas onto sensors, were 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.