2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications最新文献

{"title":"A novel temperature stable composite substrates for surface acoustic wave applications","authors":"Xun Gong, De Zhang","doi":"10.1109/SPAWDA.2008.4775850","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775850","url":null,"abstract":"The temperature coefficient of delay (TCD) of the surface acoustic wave (SAW) on the amorphous TeO2 /36deg to 46deg Y-X LiTaO3 layered substrates have been investigated. Other characteristics important for SAW applications such as wave modes, electromechanical coupling coefficient (K2) have also been calculated. It is found that they simultaneously have a very high K2 around 8%, a pure transverse surface wave mode and a zero TCD. The TCD can reach zero when the thickness of amorphous TeO2 film is much less than that of conventional SiO2 film, which means SAW devices on such substrates can be fabricated easily.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"541 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116592124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on property and wet etch of ZnO films grown by radio-frequency magnetron sputtering","authors":"Rui Chen, Xu-ming Bian, B. Fan, Chun-he He, Li Li","doi":"10.1109/SPAWDA.2008.4775769","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775769","url":null,"abstract":"ZnO is a wide band gap semiconductor material and has a large electromechanical coupling coefficient. ZnO has great potential for photoelectronic devices, acousto-optic devices and SAW devices. In this paper, ZnO films were deposited on quartz substrates by RF magnetron sputtering, with depositing and annealing parameters optimized through the orthogonality method. High-purity (99.999%) ZnO target, O2 and Ar were used in the deposition process. Base pressure was 3times10-5 mTorr and sputtering pressure was 10~15 mTorr, O2 and Ar partial pressure ratio was changed according to the flow rate. The influence of substrate temperature, grown atmosphere and annealing on the crystallization of ZnO films were investigated by X-ray diffraction (XRD). Results show that substrate temperature and annealing efficiently reduce FWHM of ZnO (002) peak. In the deposition period of ZnO film, larger O2 partial pressure is availed to improve the crystallization of the films. Deposition parameters for preferred c-axis orientation are: O2 and Ar partial pressure ratio, 1:9; substrate temperature, 400square; sputtering power, 200 W; and deposition time, 30 minutes. ZnO film was annealed in air at 900square for 1.5 hours. Three ZnO diffraction peaks were found: (002), (004) and (103). The intensity of (002) diffraction peak was 2477. Wet etch of ZnO film was also investigated. The proposed etch solution provided a rational etch rate, and a good selectivity between ZnO and resist was observed. Etch profile was measured by Alpha-step 500 profiler. Result shows that etch profile was moderate with little lateral etching activity, according to the request.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134405907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crop water stress measurement system based on acoustical emission technology","authors":"Shifeng Yang, Xiuqing Wang, Ji-min Zhao, Jian-ying Guo","doi":"10.1109/SPAWDA.2008.4775821","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775821","url":null,"abstract":"A microcomputer-based system of continuously measures water stress in crop in a non-destructive testing method was developed. Produced by cohesion between water molecules or adhesion to the conduit wall, the crop xylem cavitation was accompanied by the vessel walls vibration which is the indicator of the water stress. The physics of ultrasonic acoustic emissions (AEs) were used to measure the crop xylem cavitation events which were the transmission of vibration. The acoustic emissions could be measured both in the audio frequencies and in ultrasonic frequencies between 0.1 and 1 MHz. To optimize the cavitation measurement precision, the PCI-2 data acquisition equipment (DAQ) and R15 sensors, the Physical Acoustics Corp. (PAC), were adopted. The data recorded by the DAQ transferred the microcomputer to be processed and analysis. Some conclusions can be draw: cavitation induce AEs tend to shift to higher frequency when crop wood dehydration phenomena produces; the strongest frequencies of AEs in the range of 100-300 KHz; to some extend, the frequencies and counts changed gradually with the environment of the temperature, illumination, humidity, concentration of carbon dioxide, transpiration; an interruption of water supply or over-irrigation can easily result in changing of the AEs Frequency and counts. The system could be useful for agronomists testing irrigation regulation and in search of non-destructive of recording the water stress under the greenhouse conditions.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132622888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A mixed noise filtering algorithm based on the genetic algorithm and L-filter","authors":"Jinshuai Zhao","doi":"10.1109/SPAWDA.2008.4775759","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775759","url":null,"abstract":"A novel algorithm for mixed noise filtering in image processing is presented, combing the genetic algorithm and L-filter. The algorithm based on central limit theorem estimates mixed noise model through inter-selecting region of interest in the image, and adds this mixed noise model to a small test image for rebuilding degraded process. Aiming at this test image, the genetic algorithm is used to optimize the weight coefficients of L-filter. Then the optimized weight coefficients are used in combination with image edge information to execute L-filter to the image. Experiments demonstrate that this method is better than Laplacian filter and median filter.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114352803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contact acoustic nonlinearity phenomenon caused by the acoustic wave propagating in the composite material","authors":"Jian-jun Chen, D. Zhang, Y. Mao","doi":"10.1109/SPAWDA.2008.4775762","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775762","url":null,"abstract":"Due to the massive applications of multilayered composite materials (for example carbon fiber material, glass fiber material etc.) in material industry, aviation industry, medical enterprise and other consumer industries, it becomes an important work to carry on the non-destructive evaluation to the long-term characteristic and the security of the composite materials in use. The reliability of a composite material is mainly decided by the quality of its bonded interfaces. In the bonded interface, the weak bonding region is possibly the initial spot of the entire equipment's failure. Therefore the examination technology of the bonding state at the interface becomes the hot spot of the current research and application. Actually, in the bonded interface, micro-cracks or micro-flaws will be formed during the solidification of bonding material or after the composite material have been used for a period of time. When a longitudinal acoustic wave propagates through the interface with micro-cracks, it will drive the two surfaces of the micro-cracks to pop each other and the contact acoustic nonlinearity (CAN) phenomenon will happen. In this paper, we analysis the CAN phenomenon in the interface and propose a CAN parameter to describe the bonding state. Also an experiment is stated in the paper to scan the bonding state at the interface using the CAN parameter. The results show that the region with weak bonding strength can be easily distinguished from the scanning contour.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132911037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scattering of SH-waves by an interacting circular cavity and crack near the bimaterial interface","authors":"Zai-lin Yang, B. Sun, Chao Liu","doi":"10.1109/SPAWDA.2008.4775782","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775782","url":null,"abstract":"The problems of SH-wave scattering, which is caused by half-space circular cavity near the bimaterial interface and crack of arbitrary length and arbitrary position, are studied in this paper based on the field of elastodynamics, and the methods of Green's Function, complex variables function, the method of crack-division and multi-polar coordinates are used here. Firstly, a suitable Green's function is constructed, which is the key technology of this problem. Two Green's functions are needed here: The first one is an essential solution of the displacement field for the elastic half-space containing a circular cavity and crack with arbitrary length and arbitrary position under the out-of-plane harmonic line-loads at an arbitrary point; The second Green' function is an essential solution of the displacement field for the elastic half space subjected to the out-of-plane harmonic line source loads at half space surface arbitrary point. The scattering of SH-wave by the crack at an arbitrary position and a circular cavity near the bimaterial interface is investigated, the problem can be regarded as harmony model: the bimaterial media is divided into two parts along the horizontal interface, one is an elastic half space with a circular cavity and a crack, and the other is a complete elastic half space. The horizontal surfaces of the two parts are loaded with unknown anti-plane forces in order to satisfy at the linking section. A series of Fredholm integral equations can be set up through continuity conditions. Then, the solution of the problem can be reduced to a series of algebraic equations and solved numerically by truncating the finite terms of the infinite integral equations, the analytical solution of displacement field and stress field of scattering of SH-wave by the crack and circular cavity near the bimaterial interface are given. Numerical examples are provided to show the influences of wave numbers, incident angle, the distance between the center of the circular cavity and horizontal surfaces, the distance between the center of the circular cavity and crack, the angle of crack, the length of crack, and parameter combinations of different media upon dynamic stress concentration factor (DSCF).","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134185064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of multilayered acoustic wave devices with the method of reverberation-ray matrix","authors":"Yong-qiang Guo, Wei-qiu Chen","doi":"10.1109/SPAWDA.2008.4775758","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775758","url":null,"abstract":"The method of reverberation-ray matrix (MRRM) are modified and extended to the analysis of wave propagation in multilayered acoustic wave devices based on three-dimensional linear piezoelectricity. By the plane wave solution assumption, state equations are established whose solutions are expressed with unknown wave amplitudes. Within the framework of MRRM, the phase and scattering relations are properly set up to determine the unknowns without involving exponentially growing functions and matrix inversion operations in an easy and uniform way. Thus the present MRRM is unconditionally stable and free from limitations to the frequency, the thickness of individual layers and the total number of layers. The surface waves, the interface waves and the bulk waves are all included in the formulation. Therefore, the present formulation applies to SAW devices as well as BAW devices. Numerical examples are given to illustrate the well performance of the proposed formulation of MRRM for the analysis of free waves in multilayered acoustic wave devices.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133352860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calibration of quartz tuning fork temperature sensors","authors":"Jun Xu, B. You, Hong-jun Wang, Jing Ma","doi":"10.1109/SPAWDA.2008.4775828","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775828","url":null,"abstract":"This paper presents the results from investigations of thermal sensitivity, thermal response time and long-term stability of a newly miniaturized design of thermal sensitive quartz tuning fork resonator working at flexural mode with ZY-cut at fundamental frequency of 32 kHz. Special attention is given to the methodology and equipment for calibration of quartz tuning fork temperature sensor. To obtain accuracy better than 0.05degC, quartz tuning temperature sensors require calibration. We have figured out that the single point calibration methodology of quartz tuning fork temperature sensor for some applications, where low cost calibrated sensors are necessary. By applying the smart sensor concept, the calibration curve can be stored in the Transducer Electronics Datasheet. After temperature calibration, the quartz tuning fork temperature sensor measurement accuracy can reach 0.05degC with a resolution of 0.01degC over an operating range of -40degC to 140 degC.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126960192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The finite element analysis of cylindrical overlapping piezoelectric transducers","authors":"T. Dong, Likun Wang, L. Qin, L. Li, Wei-wei Wu, G. Wang","doi":"10.1109/SPAWDA.2008.4775848","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775848","url":null,"abstract":"The cylindrical overlapping piezoelectric transducer is mainly composed of the three cylindrical piezoelectric ceramics, bracket, metal bolt, rubber, waterproof layer and output cable. The transducer model was established, separately in the air and water, with ANSYS to calculate the vibration frequency and conductance .The transmitting response and directivity in water were also calculated .The results showed that the overlapping structure effectively improved the sensitivity of the piezoelectric transducer.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125508435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Point defect states of bending waves in phononic crystal thin plates","authors":"Z. Yao, Gui-Lan Yu, Yuesheng Wang, Z. Shi","doi":"10.1109/SPAWDA.2008.4775773","DOIUrl":"https://doi.org/10.1109/SPAWDA.2008.4775773","url":null,"abstract":"The band structures of bending waves propagating in the phononic crystal thin plates with point defect are explored based on the supercell technique combined with the improved plane wave expansion method. The plate is composed of a periodic array of circular crystalline Al2O3 cylinders embedded in the epoxy matrix for square lattice. The point defect is introduced by changing one of the cylinders' radii. The results show that the defect modes exist in the first band gap, the frequencies and the numbers of the defect modes are strongly dependent on the defect filling fraction and the filling fraction. All the flat defect bands appearing in the first band gap are nondegenerate. For a given defect filling fraction, there are up to five nondegenerate defect bands emerging inside the first band gap, and the frequencies of defect bands increase with the filling fraction increases. The defect bands disappear at very low or very high filling fractions. For a given filling fraction, three nondegenerate defect bands appearing near the upper edge of the gap move to the middle as the defect filling fraction is reduced, and the edges of the first band gap remain hardly changed. The study of the displacement distributions associated with the three defect modes shows that the flat bands correspond to the special localized frequencies of the waves. For the two lower defect modes, the displacement amplitudes around the defect are much bigger than that at or far away from the defect. However, for the higher defect mode, the displacement amplitude reaches the maximum at the location of the defect and decays rapidly with the distance away from that. Obviously, the bending waves correspond to such three modes are so localized at or near the defect that they can not escape into the surrounding phononic crystals. That is, the point defect behaves like a resonant vacant.","PeriodicalId":190941,"journal":{"name":"2008 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126002669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}