Investigation of the propagation of the wave in SAW sensors is a basis for the research and design of the sensors. With the advance of the sensor, both the effect of environment on the surface ply and the geometry of ...Investigation of the propagation of the wave in SAW sensors is a basis for the research and design of the sensors. With the advance of the sensor, both the effect of environment on the surface ply and the geometry of waveguide are complicated. To consider the complication, a model with gradient surface ply and multilayer waveguide of SH wave propagation in sensor is proposed. The equation of wave velocity is derived by a transfer matrix method. Through the equation, the function of wave velocity increment via the change of parameters in the surface ply is obtained. The effect of the inhomogeneity on the function is also studied. Finally, some influencing factors of the behavior of the sensor are discussed.展开更多
In this paper,general principle of the Surface Acoustic Wave(SAW) sensor in wired and wireless con-figurations will be developed and a review of recent works concerning the field of high temperature applications will ...In this paper,general principle of the Surface Acoustic Wave(SAW) sensor in wired and wireless con-figurations will be developed and a review of recent works concerning the field of high temperature applications will be presented.The first part will be devoted to aspects of data transmission and processing.Both configurations of SAW de-vice,delay line and resonator,will be discussed as well as the remote interrogation techniques used to collect and to proc-ess signal.The second part will be devoted to the material aspects.Indeed,knowing that the conventional piezoelectric substrates such as quartz or lithium niobate cannot be used at high temperature,the choice of the material constituting the SAW device(substrate & electrodes) is one of the challenges to face.We will focus our discussion on the Langasite,the current reference for high temperature applications,and on the AlN/Sapphire structure,the very promising alternative for application where the use of high frequency is required.展开更多
This paper presents a FEM analysis of a membrane-based Surface Acoustic Wave(SAW)sensor.The sensor is a 2.45GHz Reflective Delay Line(R-DL)based on Lithium Niobate(LiNbO_(3)).As the wave propagation time is much small...This paper presents a FEM analysis of a membrane-based Surface Acoustic Wave(SAW)sensor.The sensor is a 2.45GHz Reflective Delay Line(R-DL)based on Lithium Niobate(LiNbO_(3)).As the wave propagation time is much smaller than the typical time constant of the phenomena to be monitored(deformation,temperature change etc.),the analysis can be performed in three successive steps.First,a static FEM study of the complete sensor(housing included)is carried out,to compute the temperature,stress and strain fields generated in the sensitive area by the measured parameters(pressure,temperature,etc.).Then,a dynamic electro-mechanical study of the R-DL is performed.The simulation takes the previously computed fields into account,which makes it possible to compute the sensor sensitivity to the measured parameters.The model takes advantage of the periodicity of the components of the R-DL to compute phenomenological parameters(Coupling-of-Mode parameters),which can later on be used to compute the electrical response of the sensor(step 3).In this paper,we focus on the first two steps.The COM parameters are extracted,under simultaneous thermal and mechanical stresses.Especially,the sensor sensitivity is obtained from the evolution of the velocity,under various stress configurations.展开更多
Layered Surface Acoustic Wave (SAW) devices with an InO_x/SiN_u/36°YX LiTaO_3 structure were investigated for sensing low concentrations of hydrogen (H_2) and ozone (O_3) at different operating temperatures.The s...Layered Surface Acoustic Wave (SAW) devices with an InO_x/SiN_u/36°YX LiTaO_3 structure were investigated for sensing low concentrations of hydrogen (H_2) and ozone (O_3) at different operating temperatures.The sensor consists of a 1μm thick silicon nitride (SiN_y) intermediate layer deposited by electron beam evaporation on a 36°Y-cut X-propagating piezoelectric lithium tantalate (LiTaO_3) substrate and a 100 nm thin indium oxide (InO_x) sensing layer deposited by R.F.magnetron sputtering.The device fabrication is described and the performance of the sensor is analyzed in terms of response magnitude as a function of operating temperature.Large frequency shifts of 360 kHz for 600μg/g of H_2 and 92 kHz for 40 ng/g O_3 were recorded.In addition,the surface morphology of the deposited films were investigated by Atomic Force Microscopy (AFM) and the chemical composition by X-Ray Photoelectron Spectroscopy (XPS) to correlate gas-sensing behavior to structural characteristics of the thin film.展开更多
Decane is one of the volatile organic compounds （VOCs） in human breath. Successful detection of decane in human breath has vast prospects for early lung cancer diagnosis. In this paper, a novel detecting device base...Decane is one of the volatile organic compounds （VOCs） in human breath. Successful detection of decane in human breath has vast prospects for early lung cancer diagnosis. In this paper, a novel detecting device based on a filter surface acoustic wave （SAW） gas sensor is presented. SAW sensors coated with a thin oxidized graphene film were used to detect decane in parts per million （ppm） concentrations. Control and signal detection circuits were designed using a vector network analyzer with a detection resolution of insertion loss down to 0.0001 dB. The results showed that the SAW sensor could respond quickly with great sensitivity when exposed to 0.2 ppm decane. This device shows tremendous potential in medical diagnosis and environmental assessment.展开更多
基金This study was supported by the National Natural Science Foundation of China (No. 59635140)the Doctoral Education Foundation of the Ministry of Education of ChinaAeronautics Foundation of China.
文摘Investigation of the propagation of the wave in SAW sensors is a basis for the research and design of the sensors. With the advance of the sensor, both the effect of environment on the surface ply and the geometry of waveguide are complicated. To consider the complication, a model with gradient surface ply and multilayer waveguide of SH wave propagation in sensor is proposed. The equation of wave velocity is derived by a transfer matrix method. Through the equation, the function of wave velocity increment via the change of parameters in the surface ply is obtained. The effect of the inhomogeneity on the function is also studied. Finally, some influencing factors of the behavior of the sensor are discussed.
基金supported by the REGION LORRAINE,Contrat Projet Etat Région 2007~2013Ple de Recherche Scientifique et Technologique.Matériaux,Energie,Procédés,Produits:Matériaux fonctionnels micro-et nanostructurés pour la réalisation de micro-et nanosystèmes."
文摘In this paper,general principle of the Surface Acoustic Wave(SAW) sensor in wired and wireless con-figurations will be developed and a review of recent works concerning the field of high temperature applications will be presented.The first part will be devoted to aspects of data transmission and processing.Both configurations of SAW de-vice,delay line and resonator,will be discussed as well as the remote interrogation techniques used to collect and to proc-ess signal.The second part will be devoted to the material aspects.Indeed,knowing that the conventional piezoelectric substrates such as quartz or lithium niobate cannot be used at high temperature,the choice of the material constituting the SAW device(substrate & electrodes) is one of the challenges to face.We will focus our discussion on the Langasite,the current reference for high temperature applications,and on the AlN/Sapphire structure,the very promising alternative for application where the use of high frequency is required.
基金This project has been partly supported by the COMET K1 center ASSIC Austrian Smart Systems Integration Research Center.The COMET‘Competence Centers for Excellent Technologies’program is supported by BMVIT,BMWFW and the federal provinces of Carinthia and Styria.
文摘This paper presents a FEM analysis of a membrane-based Surface Acoustic Wave(SAW)sensor.The sensor is a 2.45GHz Reflective Delay Line(R-DL)based on Lithium Niobate(LiNbO_(3)).As the wave propagation time is much smaller than the typical time constant of the phenomena to be monitored(deformation,temperature change etc.),the analysis can be performed in three successive steps.First,a static FEM study of the complete sensor(housing included)is carried out,to compute the temperature,stress and strain fields generated in the sensitive area by the measured parameters(pressure,temperature,etc.).Then,a dynamic electro-mechanical study of the R-DL is performed.The simulation takes the previously computed fields into account,which makes it possible to compute the sensor sensitivity to the measured parameters.The model takes advantage of the periodicity of the components of the R-DL to compute phenomenological parameters(Coupling-of-Mode parameters),which can later on be used to compute the electrical response of the sensor(step 3).In this paper,we focus on the first two steps.The COM parameters are extracted,under simultaneous thermal and mechanical stresses.Especially,the sensor sensitivity is obtained from the evolution of the velocity,under various stress configurations.
文摘Layered Surface Acoustic Wave (SAW) devices with an InO_x/SiN_u/36°YX LiTaO_3 structure were investigated for sensing low concentrations of hydrogen (H_2) and ozone (O_3) at different operating temperatures.The sensor consists of a 1μm thick silicon nitride (SiN_y) intermediate layer deposited by electron beam evaporation on a 36°Y-cut X-propagating piezoelectric lithium tantalate (LiTaO_3) substrate and a 100 nm thin indium oxide (InO_x) sensing layer deposited by R.F.magnetron sputtering.The device fabrication is described and the performance of the sensor is analyzed in terms of response magnitude as a function of operating temperature.Large frequency shifts of 360 kHz for 600μg/g of H_2 and 92 kHz for 40 ng/g O_3 were recorded.In addition,the surface morphology of the deposited films were investigated by Atomic Force Microscopy (AFM) and the chemical composition by X-Ray Photoelectron Spectroscopy (XPS) to correlate gas-sensing behavior to structural characteristics of the thin film.
文摘Decane is one of the volatile organic compounds （VOCs） in human breath. Successful detection of decane in human breath has vast prospects for early lung cancer diagnosis. In this paper, a novel detecting device based on a filter surface acoustic wave （SAW） gas sensor is presented. SAW sensors coated with a thin oxidized graphene film were used to detect decane in parts per million （ppm） concentrations. Control and signal detection circuits were designed using a vector network analyzer with a detection resolution of insertion loss down to 0.0001 dB. The results showed that the SAW sensor could respond quickly with great sensitivity when exposed to 0.2 ppm decane. This device shows tremendous potential in medical diagnosis and environmental assessment.
