共查询到20条相似文献,搜索用时 31 毫秒
1.
Yu. V. Gulyaev V. E. Zemlyakov R. G. Kryshtal’ A. V. Medved’ Khoang van Fong V. V. Shemet 《Acoustical Physics》2001,47(1):42-44
A tunable gas sensor using surface acoustic waves (SAW) is described. It is designed on the basis of a waveguide delay line fabricated on a piezoelectric substrate made of 128° Y-cut LiNbO3. A voltage applied between the waveguide and two electrodes causes a local change in the properties of the substrate near the waveguide and differently affects the sensor’s response to the vapors of various analytes. Some results of the experimental study of the sensor, which show the change in the selectivity under the effect of voltage, are presented. The analytes used for testing include a number of alcohols and deionized water. The possibilities for employing such a sensor in the sensor arrays of gas analyzers of the electronic nose type are discussed. 相似文献
2.
从传感器核心元件及无线测温雷达的优化设计出发,研制了一种集成电子标签的高性能声表面波(SAW)无线无源测温系统。基于耦合模(COM)理论对作为传感元件的反射型SAW延迟线进行了优化设计,基于仿真结果,实验研制了采用YZ LiNbO_3石英基片的434 MHz反射型SAW延迟线,该器件是由一个换能器与8个反射器构成的反射型延迟线,其中3个反射器用于温度检测,另外5个反射器则用于采用相位编码的电子标签。测试结果显示所研制的反射型SAW延迟线具有良好的时域特性与较高的信噪比,并与理论仿真结果极为吻合。设计并研制了采用步进调频(FSCW)模式的测温雷达,利用高精度高低温箱对所研制的无线无源SAW测温系统进行了无线测试,系统表现出良好的线性特性,测温准确度达到了士1℃以内。 相似文献
3.
Simplified relations for the changes in SAW velocity and attenuation due to thin polymer coatings and vapor sorption are presented by making analytic approximations to the complex theoretical model developed earlier by Martin et al. [Anal. Chem. 66 (14) (1994) 2201–2219]. The approximate velocity relation is accurate within 4% for the film thicknesses up to 20% of the acoustic wavelength in the polymer film, and is useful for analyzing the mass loading, swelling and viscoelastic effects in SAW vapor sensors. The approximate attenuation relation is accurate within 20% for very thin films, (less than 2% of the acoustic wavelength in the film). Based on these relations, a new procedure for determination of polymer viscoelastic properties is described that exploits the frequency dependence of the velocity and attenuation perturbations, and employs multifrequency measurement on the same SAW platform. Expressions for individual contributions from the mass loading, film swelling and viscoelastic effects in SAW vapor sensors are derived, and their implications for the sensor design and operation are discussed. Also, a new SAW comb filter design is proposed that offers possibility for multimode SAW oscillator operation over a decade of frequency variation, and illustrates feasibility for experimental realization of wide bandwidth multifrequency SAW platforms. 相似文献
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E. E. Kornienko D. O. Mul’ O. A. Rubtsova S. P. Vaschenko V. I. Kuzmin I. P. Gulyaev D. V. Sergachev 《Thermophysics and Aeromechanics》2016,23(6):919-927
The structure and tribological properties of coatings made of PN85YU15 powder were studied. The coatings were deposited on the mild steel blanks by the technology of air-plasma spraying using a unit of annular input and gas-dynamic powder focusing. Efficiency of heating and acceleration of powder particles was studied preliminarily. Measurement results on temperature and velocity distributions of particles at a certain spraying distance by the method of spectral pyrometry and time-of-flight method are presented. The effect of plasmatorch arc current and amount of propane-butane in the plasma flow on the structure and properties of coatings is analyzed in this paper. It is determined that the phase composition of coatings and initial powder is the same: the main phase is Ni3Al compound; moreover, the structure contains Ni5Al3 phase. It is shown that an increase in the amount of propane-butane increases coatings porosity. The densest coatings (5.77%) were obtained at the plasmatorch arc current of 200 A with the reduced amount of propane-butane. The coatings obtained at the minimal arc current of 100 A with an increased amount of propane-butane are characterized by maximal porosity (20.38%). The results of tribological testing of the coatings under the conditions of sliding friction with a lubricant by the disc-plane scheme are presented. From the standpoint of obtaining the densest coatings with high performance, the optimal regimes of plasma spraying of PN85YU15 powder are the current from 140 A to 200 and using the air and propane-butane mixture only as the shielding gas (anode curtain). 相似文献
6.
A novel optimal sensitivity design scheme for yarn tension sensor using surface acoustic wave device
In this paper, we propose a novel optimal sensitivity design scheme for the yarn tension sensor using surface acoustic wave (SAW) device. In order to obtain the best sensitivity, the regression model between the size of the SAW yarn tension sensor substrate and the sensitivity of the SAW yarn tension sensor was established using the least square method. The model was validated too. Through analyzing the correspondence between the regression function monotonicity and its partial derivative sign, the effect of the SAW yarn tension sensor substrate size on the sensitivity of the SAW yarn tension sensor was investigated. Based on the regression model, a linear programming model was established to gain the optimal sensitivity of the SAW yarn tension sensor. The linear programming result shows that the maximum sensitivity will be achieved when the SAW yarn tension sensor substrate length is equal to 15 mm and its width is equal to 3 mm within a fixed interval of the substrate size. An experiment of SAW yarn tension sensor about 15 mm long and 3 mm wide was presented. Experimental results show that the maximum sensitivity 1982.39 Hz/g was accomplished, which confirms that the optimal sensitivity design scheme is useful and effective. 相似文献
7.
The surface acoustic wave (SAW) chemical agents sensors
usually operate in the oscillator feed-back configuration. It converts a
molecular interactions between SAW surface and chemisensitive layer placed
on it to relative easy to measurement electrical quantities (most often it
is an operating frequency or phase change). Although in the SAW sensors the
key role play chemisensitive coatings but nearly as important as the
coatings are electronic circuits cooperating with SAW devices. The results
of theoretical calculations show that the SAW sensors operating frequency
increasing is profitable from the sensitivity point of view. Unfortunately,
an advantageous sensitivity-frequency dependence is hard to apply because of
decreasing of SAW device dimensions and thereby the area of the
chemisensitive layer with the operating frequency. The smaller area of the
layer, the smaller amount of detecting gas particles sorbed and the weakest
response of the sensor. It is possible to avoid the problem using special
constructions of SAW stabilised oscillators. In the paper such constructions
have been described. 相似文献
8.
A promising approach to apply the Love wave concept to commercially available low-loss surface acoustic wave (SAW) devices of the type Murata SAF 380 is presented. Thin wave-guiding layers of variable thickness are coated on the piezoelectric substrate of the devices. Two different layer materials were used: sputtered SiO2 and a new polymer in this field, parylene C (poly-[2-chloro-p-xylylene]). Insertion loss, resonance frequency, frequency changes during protein precipitation and noise of the devices are discussed as a function of the thickness of the wave-guiding layer. It is demonstrated that the application of an optimized wave-guiding layer increases the sensitivity. When using SiO2 as wave-guiding layer, an optimum layer thickness of 4 μm leads to a detection limit of 1.7 pg/mm2. Therefore, the detection limit is improved by factor 7.7 as compared to uncoated SAW devices. Parylene-coated devices reach a detection limit of 2.9 pg/mm2 at an optimum layer thickness of 0.5 μm. This corresponds to an improvement by factor 4.3. As the SAW devices used in this study are commercially available at low costs, applying appropriate wave-guiding layers permits an application as chemical or biochemical sensors with excellent sensitivities. Moreover, parylene-coated devices combine the sensitivity increase by excitation of Love waves with an excellent protective effect against corrosive attacks by the surrounding medium. Therefore, these sensors are most suitable for biosensing in conducting buffer solutions. 相似文献
9.
为改善气体传感器性能,通过器件优化设计获得了一种应用于气体传感器的具有低损耗、高品质因子(Q)的单模式两端对声表面波(SAW)谐振器。该谐振器由两个换能器、分置于换能器两边的短路栅反射器以及在换能器之间分布的用于敏感膜镀膜的约2.5mm金属薄层构成。谐振器采用铝/金双层电极以降低测试气体环境的腐蚀影响。利用经典耦合模(COM)理论对器件性能进行了仿真以提取优化的结构设计参数。基于仿真结果,实验研制了基于300MHz频率的新型铝/金电极SAW两端对谐振器,测试结果显示所研制器件具有较低损耗(〈7dB),较高Q值(-3000)以及单一谐振模式的特点,并且,以所研制的新型谐振器为频率控制单元的谐振器型振荡器表现出良好的频率稳定度(t15Hz/h),这对于改善气体传感器的检测下限及稳定性等性能指标具有重要意义。 相似文献
10.
Development of SH-SAW sensors for underwater measurement 总被引:3,自引:0,他引:3
We developed SH (shear horizontal) surface acoustic wave (SAW) sensors to detect protein molecules in liquid solutions applying a particular antibody thin film on the delay line of transverse SAW devices. The antibody investigated was human-immuno-globulin G (HigG) to hold the antigens (anti-HigG) in the protein solution to be measured. The sensor showed stable response to the mass loading effects of the anti-HigG molecules with the sensitivity up to 10.8 ng/ml/Hz. 相似文献
11.
提出了一种基于热声转换的高灵敏声表面波(SAW)电压传感机制并开展实验验证。从传热角度以及微扰理论出发建立了基于热声转换机制的SAW电压传感理论模型,探索了结构参数以及环境因素对SAW电压传感器灵敏度的影响规律。为了验证理论模型,在Y切石英基底上同芯片集成设计MEMS微型加热器与200 MHz声表面波器件以制备SAW电压传感器件,并搭建电压测试平台对传感器件开展性能测试。实验结果表明所制备的SAW传感器件电压与频率响应之间具有二次线性关系且在室温(20℃)下具有与理论相近的电压灵敏度(22.4 kHz/V),此外实验获得的环境温度对电压灵敏度的影响规律与理论相符。基于热声转换机制的SAW电压传感器能够显著的提高电压检测灵敏度。 相似文献
12.
Simple and efficient surface acoustic wave(SAW)two-port resonators with low insertion loss and high Q-values on ST-X quartz substrate using a corrosion-proof A1/Au-stripe electrode structure are developed for gas sensing.It was composed of two shorted grating reflectors and adjacent intedigital transducers(IDT),and an active metal film in the cavity between the IDTs for the sensitive film coating.The devices are expected to provide good protection towards metal electrode for gas sensors application in chemically reactive environments.Excellent device performance as low insertion loss,high Q factor and single-mode are achieved by carefully selecting the metallic electrode thickness,cavity length and acoustic aperture.Prior to fabrication,the coupling of modes(COM)model was performed for device simulation to determine the optimal design parameters.The fabricated single-mode SAW resonator at operation frequency of 300 MHz range exhibits matched insertion loss of~6.5 dB and loaded Q factor in the 3000 range.Using the fabricated resonator as the feedback element,a dualresonator-oscillator with excellent frequency stability(0.1 ppm)was developed and evaluated experimentally,and it is significant for performance improvement of SAW gas sensor. 相似文献
13.
Silicon sensors have been used in High Energy Physics for about 25 years. They have been continuously improved to meet new requirements and challenges. Based on a simple detection principle many different types of silicon sensors have been developed. This article gives an introduction to the basic properties of silicon sensors and the related readout electronics. Then several silicon sensor types are described, which are the building blocks of detectors for tracking and scintillator readout. Besides reviewing state of the art sensor types some new developments will be discussed. This includes extremely radiation hard sensors, novel sensors for photon counting and especially trends to integrate sensor and readout electronics into monolithic devices. Finally some selected examples of large detector systems in existing or planned experiments will be reviewed. 相似文献
14.
I. N. Nikolaev R. R. Galiev 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2008,2(1):98-103
The morphological features of palladium thin films deposited on different substrates are described. Film deposition has been performed by means of the pulsed laser evaporation method. It is shown that the grain structure of palladium films is formed independently of the substrate roughness. Particular emphasis is placed on the correlation between gas-sensitive metal-insulator-semiconductor (MIS) sensor properties and the nanostructure of palladium films used as metal electrodes in these sensors. It is concluded that a change in the morphology of palladium films has no direct influence on the degradation of the hydrogen sulphide sensitivity of MIS sensors that arises after sensor annealing in air enriched with hydrogen. 相似文献
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The three-dimensional (3D) finite element (FE) simulation and analysis of Love wave sensors based on polyisobutylene (PIB) layers/SiO$_{2}$/ST-90$^\circ$X quartz structure are presented in this paper, as well as the investigation of coupled resonance effect on the acoustic properties of the devices. The mass sensitivity of the basic Love wave device with SiO$_{2}$ guiding layers is solved analytically. And the highest mass sensitivity of 128 m$^{2}$/kg is obtained as $h_{\rm s}/\lambda =0.175$. The sensitivity of the Love wave sensors for sensing volatile organic compounds (VOCs) is greatly improved due to the presence of coupled resonance induced by the PIB nanorods on the device surface. The frequency shifts of the sensor corresponding to CH$_{2}$Cl$_{2}$, CHCl$_{3}$, CCl$_{4}$, C$_{2}$Cl$_{4}$, CH$_{3}$Cl and C$_{2}$HCl$_{3}$ with the concentration of 100 ppm are 1.431 kHz, 5.507 kHz, 13.437 kHz, 85.948 kHz, 0.127 kHz and 17.879 kHz, respectively. The viscoelasticity influence of the sensitive material on the characteristics of SAW sensors is also studied. By taking account of the viscoelasticity of the PIB layers, the sensitivities of the SAW sensors with the PIB film and PIB nanorods decay in different degree. The gas sensing property of the Love wave sensor with PIB nanorods is superior to that of the PIB films. Meanwhile, the Love wave sensors with PIB sensitive layers show good selectivity to C$_{2}$Cl$_{4}$, making it an ideal selection for gas sensing applications. 相似文献
17.
The solid-state electrochemical principle has been a selective and accurate way of sensing chemical components in various
environments, including liquid metal, for an extended period of time. Since after Carl Wagner’s interpretation of zirconia,
there appeared many advances in chemical sensor applications. The electrochemical techniques for the chemical measurements
have, in general, several major advantages compared to other methods. The information of interest is directly converted into
electrical signal which may be employed in electronic circuits. Electrochemical measurements are always selective for the
quantities that undergo the electrochemical redox reaction. In most cases, reactions at equilibrium are considered, but techniques
have also been developed to be able to use kinetic limit. Furthermore, the signal is independent of materials properties,
such as the ionic conductivity or impurity as long as it is a predominant ionic conductor. Depending on the type of application,
voltage or current measurements are employed. While potentiometric method commonly allows measuring chemical species over
a wide range of concentration, amperometric sensors generally cover a quite limited range but have a much higher resolution.
In this paper, various principles of electrochemical techniques to measure the chemical quantities are introduced. And there
are many examples of the status of researches on electrochemical sensors, such as oxygen sensor, carbon dioxide sensor, NO
x
sensor, SO
x
sensor, and hydrogen sensor. 相似文献
18.
A c-axis orientated aluminium nitride (AlN) film on a 128° Y-X lithium niobate (LiNbO3) surface acoustic wave (SAW) device which exhibit a large electromechanical coupling coefficient (k2) and a high SAW velocity property, is needed for future communication applications. In this study, a c-axis orientated (B, Al)N film (with 2.6 at.% boron) was deposited on a 128° Y-X LiNbO3 substrate by a co-sputtering system to further boost SAW device properties. The XRD and TEM results show that the (B, Al)N films show highly aligned columns with the c-axis perpendicular to the substrate. The hardness and Young's modulus of (B, Al)N film on 128° Y-X LiNbO3 substrates are at least 17% and 7% larger than AlN films, respectively. From the SAW device measurement, the operation frequency characteristic of (B, Al)N film on 128° Y-X LiNbO3 is higher than pure AlN on it. The SAW velocity also increases as (B, Al)N film thickness increases (at fixed IDT wavelength). Furthermore, the k2 of (B, Al)N on the IDT/128° Y-X LiNbO3 SAW device shows a higher value than AlN on it. 相似文献
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光纤振动传感器探头的设计 总被引:2,自引:0,他引:2
提出和论述了一种光纤振动传感器的原理和探头设计方法。使用悬臂梁来遮挡反射回光纤的光 ,用光强度调制来实现振动信号的测量。这种传感探头只需一根光纤引出 ,紧凑小巧 ,易于安装调试。结果表明 ,这种光纤振动传感器传感头是可靠而耐用的 ,长时间工作稳定 ,抗外界干扰强 ,易制作 ,易安装。 相似文献