scholarly journals Contactless Liquid Height and Property Estimation Using Surface Acoustic Waves

Acoustics ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 366-381
Author(s):  
Hani Alhazmi ◽  
Rasim Guldiken
Keyword(s):  
Acoustic Waves ◽  
Wave Amplitude ◽  
Surface Acoustic Waves ◽  
Experimental Studies ◽  
Wave Mode ◽  
Propagation Path ◽  
Liquid Volume ◽  
Time Frequency ◽  
Reflected Wave ◽  
Solid Plate

The propagation of surface acoustic waves over a solid plate is highly influenced by the presence of liquid media on the surface. At the solid–liquid interface, a leaky Rayleigh wave radiates energy into the liquid, causing a signification attenuation of the surface acoustic wave amplitude. In this study, we take advantage of this spurious wave mode to predict the characteristics of the media, including the volume or height. In this study, the surface acoustic waves were generated on a thick 1018 steel surface via a 5 MHz transducer coupled through an angle beam wedge. A 3D-printed container was inserted on the propagation path. The pulse-echo time-domain responses of the signal were recorded at five different volumes (0, 400, 600, 1000, and 1800 µL). With the aid of parametric CAD analysis, both the position and distance of the entire traveling wave in the liquid layer were modeled and verified with experimental studies. The results indicated that the average drop in the reflected wave amplitude due to liquid loading is −62.5% compared to the empty container, with a percentage of error within 10% for all cases. The localized-time frequency components of the reflected wave were obtained via a Short-Time Fourier Transform technique. Up to 10% reduction (500 KHz) in the central frequency was observed due to the liquid volume increasing. The method discussed herein could be useful for many applications, where some of the liquid’s parameters or the ultrasonic wave behavior in the liquid need to be assessed.

scholarly journals Visualization of Surface Acoustic Waves in Thin Liquid Films

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
R. W. Rambach ◽  
J. Taiber ◽  
C. M. L. Scheck ◽  
C. Meyer ◽  
J. Reboud ◽  
...  
Keyword(s):  
Liquid Film ◽  
Acoustic Waves ◽  
Low Cost ◽  
Thin Liquid Film ◽  
Surface Acoustic Waves ◽  
Liquid Films ◽  
Theoretical Description ◽  
Propagation Path ◽  
Microfluidic Channels ◽  
Potential Applications

Abstract We demonstrate that the propagation path of a surface acoustic wave (SAW), excited with an interdigitated transducer (IDT), can be visualized using a thin liquid film dispensed onto a lithium niobate (LiNbO3) substrate. The practical advantages of this visualization method are its rapid and simple implementation, with many potential applications including in characterising acoustic pumping within microfluidic channels. It also enables low-cost characterisation of IDT designs thereby allowing the determination of anisotropy and orientation of the piezoelectric substrate without the requirement for sophisticated and expensive equipment. Here, we show that the optical visibility of the sound path critically depends on the physical properties of the liquid film and identify heptane and methanol as most contrast rich solvents for visualization of SAW. We also provide a detailed theoretical description of this effect.

scholarly journals Quantification of Bolt Tension by Surface Acoustic Waves: An Experimentally Verified Simulation Study

Acoustics ◽  
2019 ◽  
Vol 1 (4) ◽  
pp. 794-807 ◽  
Author(s):  
Alhazmi ◽  
Guldiken
Keyword(s):  
Acoustic Waves ◽  
Large Scale ◽  
Surface Acoustic Waves ◽  
Bolted Joint ◽  
Civil Infrastructures ◽  
Reflected Wave ◽  
Real Area Of Contact ◽  
Central Hypothesis ◽  
Good Agreement ◽  
Real Area

Quantifying bolt tension and ensuring that bolts are appropriately tightened for large-scale civil infrastructures are crucial. This study investigated the feasibility of employing the surface acoustic wave (SAW) for quantifying the bolt tension via finite element modeling. The central hypothesis is that the real area of contact in a bolted joint increases as the tension or preload is increased, causing an acoustical signature change. The experimentally verified 3-D simulations were carried out in two steps: A preload was first applied to the bolt body to simulate the realistic behavior of bolted joint; and the SAW propagation was then excited on the top surface of the plate to reflect from the bolted joint. The bolt tension value was varied between 4 and 24 kN (properly tightened bolt) in the steps of 4 kN to study the effect of the bolt tension. The results indicate an increased reflected wave amplitude and a gradual phase shift, up to 0.5 µs, as the bolt tension increased. Furthermore, the result shows that the distance between the first reflected wave and the source becomes shorter as the preload increases, as hypothesized. A 1.9 mm difference in the distance between the maximum and minimum preload was observed. As part of this study, the simulation results were also compared with the experimental results, and a good agreement between the simulation and experiments was demonstrated.

Experimental Studies on Nonlinear Dispersive Surface Acoustic Waves for Solitons

1995 ◽  
Vol 34 (Part 1, No. 5B) ◽  
pp. 2653-2659 ◽  
Author(s):  
Vadim Kavalerov ◽  
Hideki Katoh ◽  
Naohito Kasaya ◽  
Mitsuteru Inoue ◽  
Toshitaka Fujii
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Experimental Studies

scholarly journals Microfluidic Jetting Deformation and Pinching-off Mechanism in Capillary Tubes by Using Traveling Surface Acoustic Waves

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 5 ◽  
Author(s):  
Yulin Lei ◽  
Hong Hu ◽  
Jian Chen ◽  
Peng Zhang
Keyword(s):  
Acoustic Waves ◽  
Capillary Tube ◽  
Surface Acoustic Waves ◽  
Liquid Volume ◽  
Rf Power ◽  
Single Droplet ◽  
Research Attention ◽  
Number Range ◽  
Drop On Demand ◽  
Resonance Frequencies

To date, there has been little research attention paid to jetting deformation and pinching-off of microfluidic flows induced by the surface acoustic wave (SAW) mechanism. Further, such studies were almost limited to one sessile drop actuation without any confinement mechanisms. Such a scenario is likely attributable to the mechanism’s relatively poor controllability, the difficulty of maintaining the fluid loading position and issues related to stability and repeatability. In this paper, a novel SAW-microfluidic jetting system with a vertical capillary tube was designed, accompanied by a large number of experiments investigating the single droplet jetting mechanism with different device dimensions, resonance frequencies and radio frequency (RF) power capabilities. The study began with the whole jetting deformation and droplet pinching off through the use of a microscope with a high-speed camera, after which the results were discussed to explain the droplet jetting mechanism in a vertical capillary tube. After that, the study continued with experimental and theoretical examinations for high-quality single droplet jetting conditions. Jetting characterization parameters, including threshold RF power, resonance frequency, liquid volume, pinching off droplet dimensions, were thoroughly analyzed. Lastly, the Weber number range, a significant parameter in SAW-microfluidic jetting, was verified, and the pinching off microdroplet dimension was analyzed and compared via experiments. The significance of this study lies in the realization of microfluidic drop-on-demand based on SAW technology.

scholarly journals Enhanced Sensitivity of a Hydrogen Sulfide Sensor Based on Surface Acoustic Waves at Room Temperature

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3796 ◽  
Author(s):  
Xueli Liu ◽  
Wen Wang ◽  
Yufeng Zhang ◽  
Yong Pan ◽  
Yong Liang ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Acoustic Waves ◽  
Room Temperature ◽  
Delay Line ◽  
Quartz Substrate ◽  
Surface Acoustic Waves ◽  
Van Der Waals Interactions ◽  
Propagation Path ◽  
Saw Sensor ◽  
Phase Discrimination

In this contribution, a new surface acoustic wave (SAW)-based sensor was proposed for sensing hydrogen sulfide (H2S) at room temperature (30 °C), which was composed of a phase discrimination circuit, a SAW-sensing device patterned with delay line, and a triethanolamine (TEA) coating along the SAW propagation path of the sensing device. The TEA was chosen as the sensitive interface for H2S sensing, owing to the high adsorption efficiency by van der Waals’ interactions and hydrogen bonds with H2S molecules at room temperature. The adsorption in TEA towards H2S modulates the SAW propagation, and the change in the corresponding phase was converted into voltage signal proportional to H2S concentration was collected as the sensor signal. A SAW delay line patterned on Y-cut quartz substrate with Al metallization was developed photographically, and lower insertion and excellent temperature stability were achieved thanks to the single-phase unidirectional transducers (SPUDTs) and lower cross-sensitivity of the piezoelectric substrate. The synthesized TEA by the reaction of ethylene oxide and ammonia was dropped into the SAW propagation path of the developed SAW device to build the H2S sensor. The developed SAW sensor was characterized by being collecting into the phase discrimination circuit. The gas experimental results appear that fast response (7 s at 4 ppm H2S), high sensitivity (0.152 mV/ppm) and lower detection limit (0.15 ppm) were achieved at room temperature. It means the proposed SAW sensor will be promising for H2S sensing.

scholarly journals Towards a Multi-Interdigital Transducer Configuration to Combine Focusing and Trapping of Microparticles within a Microfluidic Platform: A 3D Numerical Analysis

2021 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Gianluca Mezzanzanica ◽  
Olivier Français
Keyword(s):  
Numerical Analysis ◽  
Acoustic Waves ◽  
Wave Amplitude ◽  
Acoustic Pressure ◽  
Surface Acoustic Waves ◽  
Microfluidic Channels ◽  
Pressure Pattern ◽  
Focusing Effect ◽  
Particle Focusing ◽  
Micro Particles

In Lab-On-a-chip devices, the separation and manipulation of micro-particles within microfluidic channels are important operations in the process of biological analyses. In this study, the microfluidic flow is coupled with acoustic waves through a 3D multi-physics numerical solution in order to generate optimized acoustic pressure pattern. Exploiting interdigital transducers (IDTs), surface acoustic waves (SAWs) are generated on the surface of a piezoelectric substrate (lithium niobate). These waves interfere constructively to generate a standing pressure field within a fluid contained in a microchannel placed between them. Several studies and applications have been reported exploiting two facing IDTs, effective in particle focusing due to the acoustic radiation force developed by the acoustic pressure. In this work, a configuration made by four IDTs is investigated to enhance the focusing effect and provide trapping capabilities. A complex matrix of pressure wave nodes (zero wave amplitude) and antinodes (maximum wave amplitude) is generated and optimized to acquire the right acoustic pressure pattern. Results obtained show particle focusing effects but also trapping on specific sites depending on the distribution of waves. These innovative results, based on multiphysics 3D numerical analysis, highlight the versatility and the efficiency of this configuration depending on the design of the microfluidic structure implemented in the SAW-based platform. Applications towards biological cell sorting and assembling can be considered based on this principle.

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.

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