scholarly journals Acoustic tweezers via sub–time-of-flight regime surface acoustic waves

2016 ◽  
Vol 2 (7) ◽  
pp. e1600089 ◽  
Author(s):  
David J. Collins ◽  
Citsabehsan Devendran ◽  
Zhichao Ma ◽  
Jia Wei Ng ◽  
Adrian Neild ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Acoustic Waves ◽  
Optical Waveguides ◽  
Surface Acoustic Waves ◽  
Time Of Flight ◽  
Microfluidic Channel ◽  
Two Dimensions ◽  
Acoustic Standing Wave ◽  
Spatial Dimensions ◽  
Acoustic Tweezers

Micrometer-scale acoustic waves are highly useful for refined optomechanical and acoustofluidic manipulation, where these fields are spatially localized along the transducer aperture but not along the acoustic propagation direction. In the case of acoustic tweezers, such a conventional acoustic standing wave results in particle and cell patterning across the entire width of a microfluidic channel, preventing selective trapping. We demonstrate the use of nanosecond-scale pulsed surface acoustic waves (SAWs) with a pulse period that is less than the time of flight between opposing transducers to generate localized time-averaged patterning regions while using conventional electrode structures. These nodal positions can be readily and arbitrarily positioned in two dimensions and within the patterning region itself through the imposition of pulse delays, frequency modulation, and phase shifts. This straightforward concept adds new spatial dimensions to which acoustic fields can be localized in SAW applications in a manner analogous to optical tweezers, including spatially selective acoustic tweezers and optical waveguides.

scholarly journals Acoustophoretic Control of Microparticle Transport Using Dual-Wavelength Surface Acoustic Wave Devices

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 52 ◽  
Author(s):  
Jin-Chen Hsu ◽  
Chih-Hsun Hsu ◽  
Yeo-Wei Huang
Keyword(s):  
Particle Motion ◽  
Acoustic Waves ◽  
Acoustic Pressure ◽  
Acoustic Radiation ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Radiation Force ◽  
Dual Wavelength ◽  
Single Frequency ◽  
Motion Trajectories

We present a numerical and experimental study of acoustophoretic manipulation in a microfluidic channel using dual-wavelength standing surface acoustic waves (SSAWs) to transport microparticles into different outlets. The SSAW fields were excited by interdigital transducers (IDTs) composed of two different pitches connected in parallel and series on a lithium niobate substrate such that it yielded spatially superimposed and separated dual-wavelength SSAWs, respectively. SSAWs of a singltablee target wavelength can be efficiently excited by giving an RF voltage of frequency determined by the ratio of the velocity of the SAW to the target IDT pitch (i.e., f = cSAW/p). However, the two-pitch IDTs with similar pitches excite, less efficiently, non-target SSAWs with the wavelength associated with the non-target pitch in addition to target SSAWs by giving the target single-frequency RF voltage. As a result, dual-wavelength SSAWs can be formed. Simulated results revealed variations of acoustic pressure fields induced by the dual-wavelength SSAWs and corresponding influences on the particle motion. The acoustic radiation force in the acoustic pressure field was calculated to pinpoint zero-force positions and simulate particle motion trajectories. Then, dual-wavelength SSAW acoustofluidic devices were fabricated in accordance with the simulation results to experimentally demonstrate switching of SSAW fields as a means of transporting particles. The effects of non-target SSAWs on pre-actuating particles were predicted and observed. The study provides the design considerations needed for the fabrication of acoustofluidic devices with IDT-excited multi-wavelength SSAWs for acoustophoresis of microparticles.

scholarly journals Reusable acoustic tweezers for disposable devices

Lab on a Chip ◽  
2015 ◽  
Vol 15 (24) ◽  
pp. 4517-4523 ◽  
Author(s):  
Feng Guo ◽  
Yuliang Xie ◽  
Sixing Li ◽  
James Lata ◽  
Liqiang Ren ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Tweezers

Reusable acoustic tweezers used for disposable devices are demonstrated using locally transmitted standing surface acoustic waves.

Continuous separation of particles in a PDMS microfluidic channel via travelling surface acoustic waves (TSAW)

Lab on a Chip ◽  
2013 ◽  
Vol 13 (21) ◽  
pp. 4210 ◽  
Author(s):  
Ghulam Destgeer ◽  
Kyung Heon Lee ◽  
Jin Ho Jung ◽  
Anas Alazzam ◽  
Hyung Jin Sung
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Continuous Separation

scholarly journals Unsteady particle motion in an acoustic standing wave field

2019 ◽  
Author(s):  
S. Wanga ◽  
J. S. Allen ◽  
A. M. Ardekani
Keyword(s):  
Wave Field ◽  
Standing Wave ◽  
Particle Motion ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Particle Interaction ◽  
Inertial Force ◽  
Radiation Force ◽  
Acoustic Standing Wave ◽  
Standing Wave Field

The acoustic-based separation has attracted considerable attention in biomedical research, such as sorting of cells and particles. Current design principles used for acoustic systems are based on the steady Stokes theory, equating the Stokes drag with the primary radiation force. However, this approach is not valid for large cells/particles or in the presence of particle–particle interaction. In this work,we analytically examine unsteady inertial affects and particle–particle hydrodynamic interaction on the particle motion in a viscous fluid in the presence of an acoustic standing wave field. Comparing our results to the steady Stokes theory, we find that the unsteady inertial force decreases the particle’s velocity, while particle–particle interaction enhances it. For a particular acoustic-based separation approach ‘tilted-angle standing surface acoustic waves (taSSAW)’, we find that both effects of unsteady inertial force and particle–particle interaction are evident and should be considered for O(10μm) particles or larger. Our study improves the current predictions of particle trajectory in acoustic-based separation devices.

Ultra-High Frequency Sound Waves for Microparticle Separation

2015 ◽  
Author(s):  
Ghulam Destgeer ◽  
Anas Alazzam ◽  
Hyung Jin Sung
Keyword(s):  
Acoustic Waves ◽  
High Frequency ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Sound Waves ◽  
Ultra High Frequency ◽  
High Frequency Sound ◽  
Frequency Sound ◽  
Sheath Fluid ◽  
Order Of Magnitude

In this study, we have demonstrated a particle separation device taking advantage of the ultra-high frequency sound waves. The sound waves, in the form of surface acoustic waves, are produced by an acoustofluidic platform build on top of a piezoelectric substrate bonded to a microfluidic channel. The particles’ mixture, pumped through the microchannel, is focused using a sheath fluid. A travelling surface acoustic wave (TSAW), propagating normal to the flow, interacts with the particles and deflect them from their original path to induce size-based separation in a continuous flow. We initially started the experiment with 40 MHz TSAWs for deflecting 10 μm diameter polystyrene particles but failed. However, larger diameter particles (∼ 30 μm) were successfully deflected from their streamlines and separated from the smaller particles (∼ 10 μm) using TSAWs with 40 MHz frequency. The separation of smaller diameter particles (3, 5 and 7 μm) was also achieved using an order of magnitude higher-frequency (∼ 133 MHz) TSAWs.

Continuous particle separation in a microfluidic channel via standing surface acoustic waves (SSAW)

Lab on a Chip ◽  
2009 ◽  
Vol 9 (23) ◽  
pp. 3354 ◽  
Author(s):  
Jinjie Shi ◽  
Hua Huang ◽  
Zak Stratton ◽  
Yiping Huang ◽  
Tony Jun Huang
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Particle Separation ◽  
Continuous Particle

scholarly journals Using real-time fluorescence and deformability cytometry and deep learning to transfer molecular specificity to label-free sorting

2019 ◽  
Author(s):  
Ahmad Ahsan Nawaz ◽  
Marta Urbanska ◽  
Maik Herbig ◽  
Martin Nötzel ◽  
Martin Kräter ◽  
...  
Keyword(s):  
Real Time ◽  
Acoustic Waves ◽  
Blood Cells ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Cell Types ◽  
Biological Research ◽  
Label Free ◽  
Molecular Specificity ◽  
Deformability Cytometry

The identification and separation of specific cells from heterogeneous populations is an essential prerequisite for further analysis or use. Conventional passive and active separation approaches rely on fluorescent or magnetic tags introduced to the cells of interest through molecular markers. Such labeling is time- and cost-intensive, can alter cellular properties, and might be incompatible with subsequent use, for example, in transplantation. Alternative label-free approaches utilizing morphological or mechanical features are attractive, but lack molecular specificity. Here we combine image-based real-time fluorescence and deformability cytometry (RT-FDC) with downstream cell sorting using standing surface acoustic waves (SSAW). We demonstrate basic sorting capabilities of the device by separating cell mimics and blood cell types based on fluorescence as well as deformability and other image parameters. The identification of blood sub-populations is enhanced by flow alignment and deformation of cells in the microfluidic channel constriction. In addition, the classification of blood cells using established fluorescence-based markers provides hundreds of thousands of labeled cell images used to train a deep neural network. The trained algorithm, with latency optimized to below 1 ms, is then used to identify and sort unlabeled blood cells at rates of 100 cells/sec. This approach transfers molecular specificity into label-free sorting and opens up new possibilities for basic biological research and clinical therapeutic applications.

Acoustic tweezers: patterning cells and microparticles using standing surface acoustic waves (SSAW)

Lab on a Chip ◽  
2009 ◽  
Vol 9 (20) ◽  
pp. 2890 ◽  
Author(s):  
Jinjie Shi ◽  
Daniel Ahmed ◽  
Xiaole Mao ◽  
Sz-Chin Steven Lin ◽  
Aitan Lawit ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Tweezers
Sign in / Sign up

Export Citation Format

Share Document