The converging-surface-acoustic-wave technique: anaylsis and applications to nondestructive evaluation

1986 ◽  
Vol 64 (9) ◽  
pp. 1324-1329 ◽  
Author(s):  
P. Cielo ◽  
C. K. Jen ◽  
X. Maldague
Keyword(s):  
Acoustic Waves ◽  
Laser Interferometer ◽  
Surface Acoustic Waves ◽  
Pulsed Laser ◽  
Ultrasonic Pulse ◽  
Planar Defects ◽  
Wave Technique ◽  
Pulse Arrival ◽  
Pulsed Laser Beam

Converging surface-acoustic waves (SAW) are generated by irradiating the inspected material with an annular-shaped pulsed laser beam. The converging-SAW pulse arrival is detected by a laser interferometer focused on the center of the annulus, where the converging effect produces a strong amplification of the ultrasonic pulse. This technique can be applied either to the detection of defects or to the characterization of the material by measuring the SAW velocity or attenuation. In this paper we present an analysis of the converging-wave propagation in order to explain some features of the detected signal, such as its shape and amplitude for different positions of the probing beam. A comparison with the signal intensities expected for a diverging as well as a collimated SAW is also presented. Applications of this technique to the characterization of anisotropic materials as well as to the detection of subsurface planar defects are presented and discussed.

Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 86-87
Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn
Keyword(s):  
Integrated Circuit ◽  
Acoustic Waves ◽  
New Technology ◽  
Surface Acoustic Waves ◽  
Electromechanical Properties ◽  
Leading Role ◽  
Saw Devices ◽  
Transmission Electron ◽  
High Degree

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.

scholarly journals Highly Sensitive Surface Acoustic Wave Magnetic Field Sensor Using Multilayered TbCo2/FeCo Thin Film

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 902 ◽  
Author(s):  
Aurelien Mazzamurro ◽  
Abdelkrim Talbi ◽  
Yannick Dusch ◽  
Omar Elmazria ◽  
Philippe Pernod ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Magnetic Field Sensor ◽  
Nanostructured Thin Film ◽  
Highly Sensitive ◽  
Magnetic Model ◽  
Field Sensor

Over the last decades, the use of Surface Acoustic Waves (SAW) has emerged as a promising technology in many applications such as filters, signal processing but also sensors. We report the fabrication and the characterization of a SAW delay line magnetic field sensor using uniaxial multi-layered 14×[TbCo2(3.7nm)/FeCo(4nm)] nanostructured thin film deposited on Y36° Lithium Niobate (Figure 1a). The sensor shows an interesting dependency to a tunable bias magnetic field with different orientations relative to the easy axis. The obtained results are well explained using an equivalent piezo-magnetic model described in a previous work.

scholarly journals Characterization of Ablated Bone and Muscle for Long-Pulsed Laser Ablation in Dry and Wet Conditions

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1338 ◽  
Author(s):  
Nguendon Kenhagho ◽  
Shevchik ◽  
Saeidi ◽  
Faivre ◽  
Meylan ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Thermal Damage ◽  
Pulsed Laser ◽  
Principal Component ◽  
Classification Error ◽  
Ablation Efficiency ◽  
Mahalanobis Distances ◽  
Dry Conditions ◽  
Fast Healing

Smart laser technologies are desired that can accurately cut and characterize tissues, such as bone and muscle, with minimal thermal damage and fast healing. Using a long-pulsed laser with a 0.5–10  ms pulse width at a wavelength of 1.07  µm, we investigated the optimum laser parameters for producing craters with minimal thermal damage under both wet and dry conditions. In different tissues (bone and muscle), we analyzed craters of various morphologies, depths, and volumes. We used a two-way Analysis of Variance (ANOVA) test to investigate whether there are significant differences in the ablation efficiency in wet versus dry conditions at each level of the pulse energy. We found that bone and muscle tissue ablated under wet conditions produced fewer cracks and less thermal damage around the craters than under dry conditions. In contrast to muscle, the ablation efficiency of bone under wet conditions was not higher than under dry conditions. Tissue differentiation was carried out based on measured acoustic waves. A Principal Component Analysis of the measured acoustic waves and Mahalanobis distances were used to differentiate bone and muscle under wet conditions. Bone and muscle ablated in wet conditions demonstrated a classification error of less than 6.66 % and 3.33 %, when measured by a microphone and a fiber Bragg grating, respectively.

scholarly journals Controlling cell–cell interactions using surface acoustic waves

2014 ◽  
Vol 112 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Feng Guo ◽  
Peng Li ◽  
Jarrod B. French ◽  
Zhangming Mao ◽  
Hong Zhao ◽  
...  
Keyword(s):  
Intercellular Communication ◽  
Acoustic Waves ◽  
Cancer Metastasis ◽  
Surface Acoustic Waves ◽  
Spatial Arrangement ◽  
Gap Junctional Intercellular Communication ◽  
Wave Technique ◽  
Immunological Reactions ◽  
Gap Junctional

The interactions between pairs of cells and within multicellular assemblies are critical to many biological processes such as intercellular communication, tissue and organ formation, immunological reactions, and cancer metastasis. The ability to precisely control the position of cells relative to one another and within larger cellular assemblies will enable the investigation and characterization of phenomena not currently accessible by conventional in vitro methods. We present a versatile surface acoustic wave technique that is capable of controlling the intercellular distance and spatial arrangement of cells with micrometer level resolution. This technique is, to our knowledge, among the first of its kind to marry high precision and high throughput into a single extremely versatile and wholly biocompatible technology. We demonstrated the capabilities of the system to precisely control intercellular distance, assemble cells with defined geometries, maintain cellular assemblies in suspension, and translate these suspended assemblies to adherent states, all in a contactless, biocompatible manner. As an example of the power of this system, this technology was used to quantitatively investigate the gap junctional intercellular communication in several homotypic and heterotypic populations by visualizing the transfer of fluorescent dye between cells.

Laser-Generated Surface Acoustic Wave Technique for Crack Monitoring – A Review

2013 ◽  
Vol 7 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Kun Chen ◽  
◽  
Xing Fu ◽  
Dante J. Dorantes-Gonzalez ◽  
Yanning Li ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Numerical Models ◽  
Surface Acoustic Waves ◽  
Detection Methods ◽  
Quantitative Detection ◽  
Quantitative Monitoring ◽  
Crack Monitoring ◽  
Wave Technique

In this paper, the principle of surface acoustic wave techniques and their application to the monitoring of cracks are presented and compared to other classic non-destructive techniques. A practical classification of methods regarding the excitation and detection of surface acoustic waves is enumerated, among them, laser-generated surface acoustic wave technique is carefully analyzed as a prospective technique, and two important detection methods using piezoelectric and light deflection are described. Then, the strategies and variables used in crack monitoring based on laser-generated surface acoustic wave technique are reviewed. To achieve the goal of quantitative detection of cracks, most researchers use numerical models and experiments to characterize main crack features. Discussions and prospective approaches for further quantitative monitoring of cracks are provided.

Pulsed laser-stimulated surface acoustic waves in p-CdTe crystals

2001 ◽  
Vol 35 (8) ◽  
pp. 924-926 ◽  
Author(s):  
A. Baidullaeva ◽  
A. I. Vlasenko ◽  
É. I. Kuznetsov ◽  
A. V. Lomovtsev ◽  
P. E. Mozol’ ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Pulsed Laser
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