• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.4
• /
• pp.766-771
• /
• 2008

As the practical range of SAW Device extended into various fields including physical sensor, chemical sensor and ID Tag, the platform for various SAW Devices is required more than ever. While SAW ID or Sensors advanced remarkably, the development of platform which applies to SAW Sensor left much to be desired. Therefore this paper represents the SAW platform in order to use SAW ID such as ID Tag or Sensors more conveniently. The SAW platform consists of a RF module which can recognize SAW ID and a main module which has a hish performance processor in order to process the response signal of SAW ID. The main module which has a high performance processor is designed by GUI environmental type to ensure that users are able to use the platform more easily. In this paper, the SAW platform, which is based on ARM9 core processor, used Windows Embedded CE 6.0 OS which brings friendly interface to users. Also the developers can make less effort to design various applications with sensors.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1457-1459
• /
• 1994

A surface acoustic wave(SAW) sensor for the detection of odorants has been constructed by depositing various phospholipids and fatty acids onto the surface of the SAW device. Applying the Langmuir-Blodgett technique, it was possible to deposit the optimal number of layers which was found to be between 10 and 20. Menthone, amylacetate, acetoin, and other organic gases showed different affinities to the coated lipids. An explanation is given for different odorant affinities based on the monolayer properties of phospholipids.

• Journal of Sensor Science and Technology
• /
• v.17 no.2
• /
• pp.143-146
• /
• 2008

Polymer-coated film SAW sensors have been fabricated and their sensing properties for toxic chemicals have been extensively investigated. Four types of the toxic chemical compounds of hydrogen cyanide(AC), carbonyl dichloride(CG), pinacolyl methylfluorophosphonate(GD), 2,2'-dichlorodiethylthio ether(HD) were used as target gases. SAW sensors using five different kinds of polymers were used to detect toxic chemicals and their gas sensing characteristics were investigated. The polymers used as the sensing materials were polyisobutylene(PIB), polyepichlorohydrin(PECH), polydimethylsiloxane(PDMS), polybutadiene(PBD) and polyisoprene(PIP). The recommendable mixing ratio of PIB, PECH, PDMS, PBD and PIP to solvents were 1:30, 1:40, 1:10, 1:30 and 1:30, respectively. The sensing characteristics of the SAW sensors were measured by using E-5061A network analyzer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.11a
• /
• pp.251-252
• /
• 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.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.5
• /
• pp.437-443
• /
• 2010

SAW device is widely used as band pass filters, chemical or physical sensors, and actuators. In this paper, we propose the capacitive gap measurement system with high precision using SAW device. The research process is mainly composed of theoretical and experimental part. In the theoretical part, equivalent circuit model was used to predict the SAW response by the change of load impedance. In the experimental part, commercialized capacitor was used to see the SAW response by the change of load capacitance to check the feasibility as a sensor unit. After that, experimental setup to measure and adjust the gap was made and the SAW response by the change of gap which caused the capacitance change was measured. Finally, resolution and stroke was decided compared with the signal change and basic measurement noise level.

• Proceedings of the KOSOMBE Conference
• /
• v.1991 no.05
• /
• pp.98-100
• /
• 1991

A sensitive surface acoustic wave (SAW) sensor for the detection of odorants has been constructed by depositing different phospholipids and fatty acids on the surface of the SAW device wi th the Langmuir-Blodgett technique. The characteristics of SAW device operating at 310 MHz deposited with phosphatidylcholine were analyzed. Amyl acetate, acetoin, menthone and other organic gases showed different affinities. The identification of odorants depending on the species of lipid used for coating is discussed in terms of the similarity of the normalized resonant frequency shift pattern. Using a number of different lipid-coated SAW devices, odorants could be identified by a neural-network pattern recognition with back-propagation algorithm.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.6
• /
• pp.473-479
• /
• 2016

We report a highly selective and sensitive 200 MHz Surface Acoustic Wave (SAW) sensor that can detect cyanide ion in aqueous solution using surface immobilized thioester molecules in combination with gold nanoparticles (AuNPs). To construct the sensor device, a monolayer of thioester compound was immobilized on the SAW sensor surface. At the sensor surface, hydrolysis of thioester group by nucleophilic addition of cyanide occurred and the resulting free thiol unit bound to AuNP to form thiol-AuNP conjugate. For the signal enhancement, gold staining signal amplification process was introduced subsequently with gold (III) chloride trihydrate and reducing agent, hydroxylamine hydrochloride. The SAW sensor showed a detection ability of $17.7{\mu}M$ for cyanide in aqueous solution and demonstrated a saturation behavior between the frequency shift and the concentration of cyanide ion. On the other hand, our SAW sensor had no activities for other anions such as fluoride ion, acetate ion and sulfate ion, moreover, no significant interference observed by other anions. Finally, all the experiments were carried out in-house developed sensor and fluidics modules to obtain highly reproducible results.

• Journal of Sensor Science and Technology
• /
• v.5 no.3
• /
• pp.41-48
• /
• 1996

We developed SAW gas sensor for monitoring SOx gas with high sensitivity. It was fabricated as a microsensor for detecting SOx gas by depositing sensing material on SAW device. As a detecting layer material, CdS was selected. Deposition of CdS in the form of thin films was carried out by the ultrasonic spray pyrolysis method using ultrasonic spray nozzle. Thin films with the uniform and large surface area for sensors were deposited. The stable pyrolysis environment provided by uniform and fine droplets formed by spray nozzle made it possible to obtain thin films with excellent quality. The minimum grain size of the CdS thin films was about 50 nm when deposited at $300^{\circ}C$. SAW gas sensors showed reasonable sensitivity and reproducibility. Further studies are required to investigate the interference of other gases to SOx gas detection.

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

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.376-380
• /
• 2009

Surface acoustic wave (SAW) device is widely used as a bandpass filter, a chemical or physical sensor, and an actuator. In this paper, we propose the capacitive gap measurement system with high precision through the signal processing using SAW device. The research process is mainly composed of theoretical part and experimental part. In theoretical part, equivalent circuit model was used to simulate the SAW response by the change of capacitance. In experimental part, commercialized capacitor was used to see the SAW response by the change of load capacitance. After that, gap adjustment system was made physically and the SAW response by the change of gap which caused the capacitance change was measured. And resolution and stroke was decided comparing the signal change and basic measurement noise level.