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.

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 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.

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.

Acoustofluidic Simulations: Ultrasound Handling of Liquids and Particles in Microfluidic Systems

2008 ◽  
Author(s):  
Peder Skafte-Pedersen ◽  
Henrik Bruus
Keyword(s):  
Acoustic Radiation ◽  
Acoustic Streaming ◽  
Radiation Force ◽  
Second Order ◽  
Order Effects ◽  
Perturbation Approach ◽  
First Order ◽  
At Resonance ◽  
Liquid Flows ◽  
Second Order Equations

Within the field of lab-on-a-chip systems large efforts are devoted to the development of onchip tools for particle handling and mixing in viscosity-dominated liquid flows on the sub-mm scale. One technology involves ultrasound with frequencies in the MHz range, which leads to wavelengths of the order of 0.1–1 mm suitable for mm-sized microchambers. Due to the nonlinearity of the governing acoustofluidic equations, second-order effects will induce steady forces on fluids and suspended particles through the effects known as acoustic streaming and acoustic radiation force. We extend the basic perturbation approach for treating these effects in systems at resonance in various geometries. The first-order eigenmodes are used as source terms for the time-averaged viscous second-order equations. The theory is applied to explain experimental results on aqueous microbead solutions in silicon-glass microchips.

scholarly journals Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

Sensors ◽  
2017 ◽  
Vol 17 (7) ◽  
pp. 1664 ◽  
Author(s):  
Shilei Liu ◽  
Yanye Yang ◽  
Zhengyang Ni ◽  
Xiasheng Guo ◽  
Linjiao Luo ◽  
...  
Keyword(s):  
Standing Wave ◽  
Acoustic Radiation ◽  
Acoustic Streaming ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Wave Fields ◽  
Acoustic Standing Wave

Micro Cooling Based on Acoustic Streaming

2008 ◽  
Author(s):  
Hongming Sun ◽  
Hang Guo
Keyword(s):  
Heat Transfer ◽  
Analytical Study ◽  
Stokes Equations ◽  
Acoustic Radiation ◽  
Acoustic Streaming ◽  
Fluid Motion ◽  
Radiation Force ◽  
Cooling Effect ◽  
Navier Stokes ◽  
Navier Stokes Equations

Heat transfer due to forced convection caused by acoustic streaming in microfluidic devices is shown to have potential in cooling effect. However, few studies are made for theoretically studying the fluid motion induced by the acoustic field and forced heat transfer for micro cooling in microdevices. In this paper, Navier-Stokes equations are first employed to study acoustic radiation force and acoustic streaming in microchannel actuated by ultrasonic vibration. Then, an analytical study of fluid motion acoustically induced and the temperature field in microchannel is investigated to determine the enhancement of cooling effect in microchannel with acoustic streaming.

New applications of sonoelastography in rheumatology: where are we now?

Rheumatology ◽  
2018 ◽  
Vol 58 (5) ◽  
pp. 765-769 ◽  
Author(s):  
Teresa Martins-Rocha ◽  
Irene Azzolin ◽  
Teodora Serban ◽  
Giuseppe Massazza ◽  
Annamaria Iagnocco
Keyword(s):  
Potential Role ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Ultrasound Elastography ◽  
Acoustic Radiation Force Impulse ◽  
Lower Sensitivity ◽  
Imaging Method ◽  
Promising Tool ◽  
New Applications

Abstract Ultrasound elastography (UE) is a non-invasive imaging method that allows the assessment of tissue elastic property. Different UE techniques are currently available (i.e. strain UE and acoustic radiation force impulse UE), with several potential clinical applications. Recent studies investigated the role of UE in two systemic rheumatic diseases and psoriasis. This research added interesting information to the already known applications of UE in the assessment of tendinopathies. In SS, acoustic radiation force impulse UE has shown a potential role in the diagnosis of the disease, with lower sensitivity than and similar specificity to salivary gland histology. In SSc, a potential use of UE in screening pre-clinical disease has been reported. In psoriasis, the use of strain UE in evaluating treatment response has been highlighted. UE is a promising tool in rheumatology, with a potential role in the evaluation of various tissues and pathologies.

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