Performance and Robustness Improvements in Ultrasonic Transportation Against Large-Scale Streaming

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Kun Jia ◽  
Ke-ji Yang ◽  
Bing-Feng Ju
Keyword(s):  
Elastic Constant ◽  
Lead Zirconate Titanate ◽  
Large Scale ◽  
Acoustic Radiation ◽  
Plane Waves ◽  
Acoustic Streaming ◽  
Sound Field ◽  
Radiation Force ◽  
Lead Zirconate ◽  
Potential Well

Acoustic streaming generated from the traveling-wave component of a synthesized sound field often has considerable influence on ultrasonic manipulations, in which the behavior of microparticles may be disturbed. In this work, the large-scale streaming pattern in a chamber with three incident plane waves is simulated, illustrating a directional traveling stream pattern and several vortical structures. Based on the numerical results, the trapping capability of an acoustic potential well is quantitatively characterized according to several evaluation criteria: the boundary and elastic constant of the acoustic potential well, the acoustic radiation force offset ratio, and the elastic constant offset ratio. By optimizing these parameters, the constraint of the acoustic potential well can be strengthened to promote the performance and robustness of the ultrasonic transportation. An ultrasonic manipulation device employing three 1.67-MHz lead zirconate titanate (PZT) transducers with rectangular radiation surface is prototyped and performance tested. The experimental results show that the average fluctuations of a microparticle during transportation have been suppressed into a region less than 0.01 times the wavelength. Particle displacement from equilibrium is no longer observed.

scholarly journals Mathematical modeling and experimental study on solid–liquid suspension separation in ultrasonic standing wave field

2021 ◽  
pp. 146134842110229
Author(s):  
Yajing Wang ◽  
Liqun Wu ◽  
Yaxing Wang ◽  
Yafei Fan
Keyword(s):  
Standing Wave ◽  
Sound Pressure ◽  
Acoustic Radiation ◽  
Sound Field ◽  
Radiation Force ◽  
High Energy ◽  
Factors Affecting ◽  
Liquid Suspension ◽  
Ultrasonic Standing Wave ◽  
Solid Liquid

A new method of removing waste chips is proposed by focusing on the key factors affecting the processing quality and efficiency of high energy beams. Firstly, a mathematical model has been established to provide the theoretical basis for the separation of solid–liquid suspension under ultrasonic standing wave. Secondly, the distribution of sound field with and without droplet has been simulated. Thirdly, the deformation and movement of droplets are simulated and tested. It is found that the sound pressure around the droplet is greater than the sound pressure in the droplet, which can promote the separation of droplets and provide theoretical support for the ultrasonic suspension separation of droplet; under the interaction of acoustic radiation force, surface tension, adhesion, and static pressure, the droplet is deformed so that the gas fluid around the droplet is concentrated in the center to achieve droplet separation, and the droplet just as a flat ball with a central sag is stably suspended in the acoustic wave node.

On the Calculation of Radiation Force on Spheres Due to Arbitrary Spatially Distributed Acoustic Beams

2005 ◽  
Author(s):  
Glauber T. Silva ◽  
Mostafa Fatemi
Keyword(s):  
Acoustic Radiation ◽  
Scattering Problem ◽  
Plane Waves ◽  
Acoustic Scattering ◽  
Radiation Force ◽  
Solid Sphere ◽  
Force Function ◽  
Cross Section Area ◽  
Spatially Distributed ◽  
Sphere Radius

This work presents a theory for the acoustic radiation force exerted on a solid sphere by an arbitrary spatially distributed beam. The theory is developed for an sphere suspended in an ideal fluid. We assume that the acoustic beam can be decomposed in a set of plane waves with same frequency, propagating in different directions. The sphere radius is considered to be much smaller than the wavelength of the beam. Bulk properties of the sphere such as shear and compressional sound speed are taken into account. The radiation force is obtained by solving the linear acoustic scattering problem for the sphere. Theoretically, the radiation force depends on the sphere cross section area, the radiation force function, and the vector energy flux upon the sphere. The radiation force function is related to the sphere scattering properties. We apply the developed theory to study the radiation force produced by an spherical concave transducer. The generated radiation force can be decomposed into two components, namely, axial and transverse with respect to the wave propagation direction. The ratio between the transverse and axial components of the force depends on the transducer F-number and wave frequency. Results show that this ratio for a 2 MHz transducer with 3.5 F-number on the focal plane is less than 5%.

scholarly journals Measurement of the acoustic streaming pattern in a standing surface acoustic wave field

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Sebastian Sachs ◽  
Christian Cierpka ◽  
Jörg König
Keyword(s):  
Wave Field ◽  
Acoustic Waves ◽  
Acoustic Radiation ◽  
Electrical Power ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Radiation Force ◽  
Flow Measurements

The application of standing surface acoustic waves (sSAW) has enabled the development of many flexible and easily scalable concepts for the fractionation of particle solutions in the field of microfluidic lab-ona-chip devices. In this context, the acoustic radiation force (ARF) is often employed for the targeted manipulation of particle trajectories, whereas acoustically induced flows complicate efficient fractionation in many systems [Sehgal and Kirby (2017)]. Therefore, a characterization of the superimposed fluid motion is essential for the design of such devices. The present work focuses on a structural analysis of the acousticallyexcited flow, both in the center and in the outer regions of the standing wave field. For this, experimental flow measurements were conducted using astigmatism particle tracking velocimetry (APTV) [Cierpka et al. (2010)]. Through multiple approaches, we address the specific challenges for reliable velocity measurements in sSAW due to limited optical access, the influence of the ARF on particle motion, and regions of particle depletion caused by multiple pressure nodes along the channel width and height. Variations in frequency, channel geometry, and electrical power allow for conclusions to be drawn on the formation of a complex, three-dimensional vortex structure at the beginning and end of the sSAW.

scholarly journals Diversity of 2D Acoustofluidic Fields in an Ultrasonic Cavity Generated by Multiple Vibration Sources

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 803 ◽  
Author(s):  
Qiang Tang ◽  
Song Zhou ◽  
Liang Huang ◽  
Zhong Chen
Keyword(s):  
Particle Trajectory ◽  
Acoustic Radiation ◽  
Preliminary Investigation ◽  
Acoustic Streaming ◽  
Radiation Force ◽  
Structure Design ◽  
Microfluidic Mixing ◽  
Promising Tool ◽  
Induced Drag ◽  
Novel Method

Two-dimensional acoustofluidic fields in an ultrasonic chamber actuated by segmented ring-shaped vibration sources with different excitation phases are simulated by COMSOL Multiphysics. Diverse acoustic streaming patterns, including aggregation and rotational modes, can be feasibly generated by the excitation of several sessile ultrasonic sources which only vibrate along radial direction. Numerical simulation of particle trajectory driven by acoustic radiation force and streaming-induced drag force also demonstrates that micro-scale particles suspended in the acoustofluidic chamber can be trapped in the velocity potential well of fluid flow or can rotate around the cavity center with the circumferential acoustic streaming field. Preliminary investigation of simple Russian doll- or Matryoshka-type configurations (double-layer vibration sources) provide a novel method of multifarious structure design in future researches on the combination of phononic crystals and acoustic streaming fields. The implementation of multiple segmented ring-shaped vibration sources offers flexibility for the control of acoustic streaming fields in microfluidic devices for various applications. We believe that this kind of acoustofluidic design is expected to be a promising tool for the investigation of rapid microfluidic mixing on a chip and contactless rotational manipulation of biosamples, such as cells or nematodes.

Numerical Study on the Influence of Microchannel’s Geometry on Sub-Micron Particles Separation Using Acoustophoresis

2020 ◽  
Author(s):  
Tsz Wai Lai ◽  
Sau Chung Fu ◽  
Ka Chung Chan ◽  
Christopher Yu Hang Chao ◽  
Anthony Kwok Yung Law
Keyword(s):  
Acoustic Radiation ◽  
Numerical Study ◽  
Acoustic Streaming ◽  
Particle Separation ◽  
Radiation Force ◽  
Rectangular Microchannel ◽  
Cross Sectional ◽  
Fluid Medium ◽  
Particle Sorting ◽  
Micron Particle

Abstract Application of acoustophoresis to cell and particle separation in microchannel filled with fluid medium has been drawing increasing attention in many disciplines in the past decades due to its high precision and minimum damage to the matters of interest. Previous studies on particle separation often rely on the size-dependent feature of the acoustic radiation force (ARF), while the acoustic streaming effect (ASE) is a hurdle as the particle size goes down. Sub-micron particles circulate according to the streaming vortices and become inseparable from the particles settled on the pressure node. Instead of suppressing the ASE, this study intends to utilize the combined effect of ARF and ASE on sub-micron particle sorting by altering the microchannel’s cross-sectional shapes. The roles of ARF and ASE on particles with 0.2um and 2um in radius in various cross-sectional shapes are studied numerically. The studied geometries include 1. rectangular, 2. trapezoidal, and 3. triangular. The results show that changing the cross-sectional shapes affects the acoustic field’s magnitude and distribution, the streaming patterns, the magnitude of streaming velocity, and the movement of sub-micron particles. In non-rectangular microchannel, sub-micron particles circulate towards and settle at the center of the streaming vortices. This phenomenon shows the potential to manipulate the streaming-dominant particles, thereby enhancing the acoustophoretic particle sorting performance.

scholarly journals Active structural acoustic control of transmitted sound through a double panel partition by weighted sum of spatial gradients

2017 ◽  
Vol 36 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Kiran Chandra Sahu ◽  
Jukka Tuhkuri
Keyword(s):  
Lead Zirconate Titanate ◽  
Power Transmission ◽  
Acoustic Radiation ◽  
Lead Zirconate ◽  
Sound Attenuation ◽  
Sound Power ◽  
Weighted Sum ◽  
Spatial Gradients ◽  
Volume Velocity ◽  
Zirconate Titanate

Active control of harmonic sound transmission through an acoustically baffled, rectangular, simply supported double panel partition has been analytically studied. Velocity potential method is used for the vibro-acoustic modeling unlike the commonly used cavity mode method. It is very well-known that at high frequencies uncontrolled double panel partition mostly radiates sound due to the dipole-type motion of the radiating panel, which the volume velocity method can't be able to detect, therefore, weighted sum of spatial gradients is used to control these modes and achieves sound attenuation in a broad frequency band. A piezoceramic actuator (lead zirconate titanate) is attached on one side of the panel surface, and the optimal magnitude and phase of the voltage supplied to the lead zirconate titanate for minimizing the weighted sum of spatial gradients and volume velocity at the error sensor locations are calculated using a simple-gradient based algorithm. Numerical results of sound power transmission ratio and averaged quadratic velocity of panels indicate that lead zirconate titanate should be placed on the incident panel and minimization of the control quantities should be done on the radiating panel to achieve better sound attenuation. The acoustic radiation mode analysis shows that the weighted sum of spatial gradients is able to control multiple acoustic radiation modes and, thereby, accomplishes better reduction of sound power transmission compared to volume velocity.

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