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
Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 52 ◽  
Author(s):  
Jin-Chen Hsu ◽  
Chih-Hsun Hsu ◽  
Yeo-Wei Huang

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.


2016 ◽  
Vol 2 (7) ◽  
pp. e1600089 ◽  
Author(s):  
David J. Collins ◽  
Citsabehsan Devendran ◽  
Zhichao Ma ◽  
Jia Wei Ng ◽  
Adrian Neild ◽  
...  

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.


Author(s):  
Ghulam Destgeer ◽  
Anas Alazzam ◽  
Hyung Jin Sung

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.


Lab on a Chip ◽  
2009 ◽  
Vol 9 (23) ◽  
pp. 3354 ◽  
Author(s):  
Jinjie Shi ◽  
Hua Huang ◽  
Zak Stratton ◽  
Yiping Huang ◽  
Tony Jun Huang

2019 ◽  
Author(s):  
Ahmad Ahsan Nawaz ◽  
Marta Urbanska ◽  
Maik Herbig ◽  
Martin Nötzel ◽  
Martin Kräter ◽  
...  

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.


Lab on a Chip ◽  
2011 ◽  
Vol 11 (14) ◽  
pp. 2319 ◽  
Author(s):  
Jinjie Shi ◽  
Shahrzad Yazdi ◽  
Sz-Chin Steven Lin ◽  
Xiaoyun Ding ◽  
I-Kao Chiang ◽  
...  

Lab on a Chip ◽  
2008 ◽  
Vol 8 (2) ◽  
pp. 221-223 ◽  
Author(s):  
Jinjie Shi ◽  
Xiaole Mao ◽  
Daniel Ahmed ◽  
Ashley Colletti ◽  
Tony Jun Huang

RSC Advances ◽  
2019 ◽  
Vol 9 (14) ◽  
pp. 7916-7921 ◽  
Author(s):  
Ghulam Destgeer ◽  
Ali Hashmi ◽  
Jinsoo Park ◽  
Husnain Ahmed ◽  
Muhammad Afzal ◽  
...  

We present an acoustofluidic method based on travelling surface acoustic waves (TSAWs) for the self-assembly of microparticles inside a microfluidic channel.


2019 ◽  
Vol 317 (2) ◽  
pp. E212-E233 ◽  
Author(s):  
Günter A. Müller ◽  
Andreas W. Herling ◽  
Kerstin Stemmer ◽  
Andreas Lechner ◽  
Matthias H. Tschöp

To study the possibility that certain components of eukaryotic plasma membranes are released under certain (patho)physiological conditions, a chip-based sensor was developed for the detection of cell surface proteins, which are anchored at the outer leaflet of eukaryotic plasma membranes by a covalently attached glycolipid, exclusively, and might be prone to spontaneous or regulated release on the basis of their amphiphilic character. For this, unprocessed, full-length glycosylphosphatidylinositol-anchored proteins (GPI-AP), together with associated phospholipids, were specifically captured and detected by a chip- and microfluidic channel-based sensor, leading to changes in phase and amplitude of surface acoustic waves (SAW) propagating over the chip surface. Unprocessed GPI-AP in complex with lipids were found to be released from rat adipocyte plasma membranes immobilized on the chip, which was dependent on the flow rate and composition of the buffer stream. The complexes were identified in the incubation medium of primary rat adipocytes, in correlation to the cell size, and in rat as well as human serum. With rats, the measured changes in SAW phase shift, reflecting specific mass/size or amount of the unprocessed GPI-AP in complex with lipids, and SAW amplitude, reflecting their viscoelasticity, enabled the differentiation between the lean and obese (high-fat diet) state, and the normal (Wistar) and hyperinsulinemic (Zucker fatty) as well as hyperinsulinemic hyperglycemic (Zucker diabetic fatty) state. Thus chip-based sensing for complexes of unprocessed GPI-AP and lipids reveals the inherently labile anchorage of GPI-AP at plasma membranes and their susceptibility for release in response to (intrinsic/extrinsic) cues of metabolic relevance and may, therefore, be useful for monitoring of (pre-)diabetic disease states.


Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn

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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