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De Lora JA, Aubermann F, Frey C, Jahnke T, Wang Y, Weber S, Platzman I, Spatz JP. Evaluation of Acoustophoretic and Dielectrophoretic Forces for Droplet Injection in Droplet-Based Microfluidic Devices. ACS OMEGA 2024; 9:16097-16105. [PMID: 38617618 PMCID: PMC11007716 DOI: 10.1021/acsomega.3c09881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/05/2024] [Accepted: 03/18/2024] [Indexed: 04/16/2024]
Abstract
Acoustophoretic forces have been successfully implemented into droplet-based microfluidic devices to manipulate droplets. These acoustophoretic forces in droplet microfluidic devices are typically generated as in acoustofluidic devices through transducer actuation of a piezoelectric substrate such as lithium niobate (LiNbO3), which is inherently accompanied by the emergence of electrical fields. Understanding acoustophoretic versus dielectrophoretic forces produced by electrodes and transducers within active microfluidic devices is important for the optimization of device performance during design iterations. In this case study, we design microfluidic devices with a droplet injection module and report an experimental strategy to deduce the respective contribution of the acoustophoretic versus dielectrophoretic forces for the observed droplet injection. Our PDMS-based devices comprise a standard oil-in-water droplet-generating module connected to a T-junction injection module featuring actuating electrodes. We use two different electrode geometries produced within the same PDMS slab as the droplet production/injection channels by filling low-melting-point metal alloy into channels that template the electrode geometries. When these electrodes are constructed on LiNbO3 as the substrate, they have a dual function as a piezoelectric transducer, which we call embedded liquid metal interdigitated transducers (elmIDTs). To decipher the contribution of acoustophoretic versus dielectrophoretic forces, we build the same devices on either piezoelectric LiNbO3 or nonpiezo active glass substrates with different combinations of physical device characteristics (i.e., elmIDT geometry and alignment) and operate in a range of phase spaces (i.e., frequency, voltage, and transducer polarity). We characterize devices using techniques such as laser Doppler vibrometry (LDV) and infrared imaging, along with evaluating droplet injection for our series of device designs, constructions, and operating parameters. Although we find that LiNbO3 device designs generate acoustic fields, we demonstrate that droplet injection occurs only due to dielectrophoretic forces. We deduce that droplet injection is caused by the coupled dielectrophoretic forces arising from the operation of elmIDTs rather than by acoustophoretic forces for this specific device design. We arrive at this conclusion because equivalent droplet injection occurs without the presence of an acoustic field using the same electrode designs on nonpiezo active glass substrate devices. This work establishes a methodology to pinpoint the major contributing force of droplet manipulation in droplet-based acoustomicrofluidics.
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Affiliation(s)
- Jacqueline A. De Lora
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Florian Aubermann
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
- Max
Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
| | - Christoph Frey
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Timotheus Jahnke
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Yuanzhen Wang
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Sebastian Weber
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Ilia Platzman
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Joachim P. Spatz
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
- Max
Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
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Rich J, Cole B, Li T, Lu B, Fu H, Smith BN, Xia J, Yang S, Zhong R, Doherty JL, Kaneko K, Suzuki H, Tian Z, Franklin AD, Huang TJ. Aerosol jet printing of surface acoustic wave microfluidic devices. MICROSYSTEMS & NANOENGINEERING 2024; 10:2. [PMID: 38169478 PMCID: PMC10757899 DOI: 10.1038/s41378-023-00606-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/17/2023] [Accepted: 09/06/2023] [Indexed: 01/05/2024]
Abstract
The addition of surface acoustic wave (SAW) technologies to microfluidics has greatly advanced lab-on-a-chip applications due to their unique and powerful attributes, including high-precision manipulation, versatility, integrability, biocompatibility, contactless nature, and rapid actuation. However, the development of SAW microfluidic devices is limited by complex and time-consuming micro/nanofabrication techniques and access to cleanroom facilities for multistep photolithography and vacuum-based processing. To simplify the fabrication of SAW microfluidic devices with customizable dimensions and functions, we utilized the additive manufacturing technique of aerosol jet printing. We successfully fabricated customized SAW microfluidic devices of varying materials, including silver nanowires, graphene, and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). To characterize and compare the acoustic actuation performance of these aerosol jet printed SAW microfluidic devices with their cleanroom-fabricated counterparts, the wave displacements and resonant frequencies of the different fabricated devices were directly measured through scanning laser Doppler vibrometry. Finally, to exhibit the capability of the aerosol jet printed devices for lab-on-a-chip applications, we successfully conducted acoustic streaming and particle concentration experiments. Overall, we demonstrated a novel solution-based, direct-write, single-step, cleanroom-free additive manufacturing technique to rapidly develop SAW microfluidic devices that shows viability for applications in the fields of biology, chemistry, engineering, and medicine.
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Affiliation(s)
- Joseph Rich
- Department of Biomedical Engineering, Duke University, Durham, NC 27708 USA
| | - Brian Cole
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708 USA
| | - Teng Li
- Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| | - Brandon Lu
- Department of Biomedical Engineering, Duke University, Durham, NC 27708 USA
| | - Hanyu Fu
- Department of Biomedical Engineering, Duke University, Durham, NC 27708 USA
| | - Brittany N. Smith
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708 USA
| | - Jianping Xia
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708 USA
| | - Shujie Yang
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708 USA
| | - Ruoyu Zhong
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708 USA
| | - James L. Doherty
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708 USA
| | - Kanji Kaneko
- Deptartment of Precision Mechanics, Faculty of Science and Engineering, Chuo University, Tokyo, 112-8551 Japan
| | - Hiroaki Suzuki
- Deptartment of Precision Mechanics, Faculty of Science and Engineering, Chuo University, Tokyo, 112-8551 Japan
| | - Zhenhua Tian
- Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| | - Aaron D. Franklin
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708 USA
- Department of Chemistry, Duke University, Durham, NC 27708 USA
| | - Tony Jun Huang
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708 USA
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Li Y, Wei X, Zhou Y, Wang J, You R. Research progress of electronic nose technology in exhaled breath disease analysis. MICROSYSTEMS & NANOENGINEERING 2023; 9:129. [PMID: 37829158 PMCID: PMC10564766 DOI: 10.1038/s41378-023-00594-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 10/14/2023]
Abstract
Exhaled breath analysis has attracted considerable attention as a noninvasive and portable health diagnosis method due to numerous advantages, such as convenience, safety, simplicity, and avoidance of discomfort. Based on many studies, exhaled breath analysis is a promising medical detection technology capable of diagnosing different diseases by analyzing the concentration, type and other characteristics of specific gases. In the existing gas analysis technology, the electronic nose (eNose) analysis method has great advantages of high sensitivity, rapid response, real-time monitoring, ease of use and portability. Herein, this review is intended to provide an overview of the application of human exhaled breath components in disease diagnosis, existing breath testing technologies and the development and research status of electronic nose technology. In the electronic nose technology section, the three aspects of sensors, algorithms and existing systems are summarized in detail. Moreover, the related challenges and limitations involved in the abovementioned technologies are also discussed. Finally, the conclusion and perspective of eNose technology are presented.
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Affiliation(s)
- Ying Li
- School of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University, Beijing, 100192 China
- Laboratory of Intelligent Microsystems, Beijing Information Science and Technology University, Beijing, 100192 China
| | - Xiangyang Wei
- School of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University, Beijing, 100192 China
- Laboratory of Intelligent Microsystems, Beijing Information Science and Technology University, Beijing, 100192 China
| | - Yumeng Zhou
- School of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University, Beijing, 100192 China
| | - Jing Wang
- School of Electronics and Information Engineering, Changchun University of Science and Technology, Changchun, 130022 China
| | - Rui You
- School of Instrument Science and Opto-Electronics Engineering, Beijing Information Science and Technology University, Beijing, 100192 China
- Laboratory of Intelligent Microsystems, Beijing Information Science and Technology University, Beijing, 100192 China
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Akther A, Walsh EP, Reineck P, Gibson BC, Ohshima T, Abe H, McColl G, Jenkins NL, Hall LT, Simpson DA, Rezk AR, Yeo LY. Acoustomicrofluidic Concentration and Signal Enhancement of Fluorescent Nanodiamond Sensors. Anal Chem 2021; 93:16133-16141. [PMID: 34813284 DOI: 10.1021/acs.analchem.1c03893] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Diamond nitrogen-vacancy (NV) centers constitute a promising class of quantum nanosensors owing to the unique magneto-optic properties associated with their spin states. The large surface area and photostability of diamond nanoparticles, together with their relatively low synthesis costs, make them a suitable platform for the detection of biologically relevant quantities such as paramagnetic ions and molecules in solution. Nevertheless, their sensing performance in solution is often hampered by poor signal-to-noise ratios and long acquisition times due to distribution inhomogeneities throughout the analyte sample. By concentrating the diamond nanoparticles through an intense microcentrifugation effect in an acoustomicrofluidic device, we show that the resultant dense NV ensembles within the diamond nanoparticles give rise to an order-of-magnitude improvement in the measured acquisition time. The ability to concentrate nanoparticles under surface acoustic wave (SAW) microcentrifugation in a sessile droplet is, in itself, surprising given the well-documented challenge of achieving such an effect for particles below 1 μm in dimension. In addition to a demonstration of their sensing performance, we thus reveal in this work that the reason why the diamond nanoparticles readily concentrate under the SAW-driven recirculatory flow can be attributed to their considerably higher density and hence larger acoustic contrast compared to those for typical particles and cells for which the SAW microcentrifugation flow has been shown to date.
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Affiliation(s)
- Asma Akther
- Micro/Nanophysics Research Laboratory, School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Ella P Walsh
- School of Physics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Philipp Reineck
- ARC Centre of Excellence for Nanoscale BioPhotonics & School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Brant C Gibson
- ARC Centre of Excellence for Nanoscale BioPhotonics & School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Takeshi Ohshima
- National Institutes for Quantum Science and Technology, Takasaki, Gunma 370-1292, Japan
| | - Hiroshi Abe
- National Institutes for Quantum Science and Technology, Takasaki, Gunma 370-1292, Japan
| | - Gawain McColl
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, Victoria 3010, Australia
| | - Nicole L Jenkins
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, Victoria 3010, Australia
| | - Liam T Hall
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - David A Simpson
- School of Physics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Amgad R Rezk
- Micro/Nanophysics Research Laboratory, School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Leslie Y Yeo
- Micro/Nanophysics Research Laboratory, School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
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Akkoyun F, Gucluer S, Ozcelik A. Potential of the acoustic micromanipulation technologies for biomedical research. BIOMICROFLUIDICS 2021; 15:061301. [PMID: 34849184 PMCID: PMC8616630 DOI: 10.1063/5.0073596] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 11/16/2021] [Indexed: 05/04/2023]
Abstract
Acoustic micromanipulation technologies are a set of versatile tools enabling unparalleled micromanipulation capabilities. Several characteristics put the acoustic micromanipulation technologies ahead of most of the other tweezing methods. For example, acoustic tweezers can be adapted as non-invasive platforms to handle single cells gently or as probes to stimulate or damage tissues. Besides, the nature of the interactions of acoustic waves with solids and liquids eliminates labeling requirements. Considering the importance of highly functional tools in biomedical research for empowering important discoveries, acoustic micromanipulation can be valuable for researchers in biology and medicine. Herein, we discuss the potential of acoustic micromanipulation technologies from technical and application points of view in biomedical research.
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Affiliation(s)
| | | | - Adem Ozcelik
- Author to whom correspondence should be addressed:
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Wong KS, Lim WTH, Ooi CW, Yeo LY, Tan MK. In situ generation of plasma-activated aerosols via surface acoustic wave nebulization for portable spray-based surface bacterial inactivation. LAB ON A CHIP 2020; 20:1856-1868. [PMID: 32342089 DOI: 10.1039/d0lc00001a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The presence of reactive species in plasma-activated water is known to induce oxidative stresses in bacterial species, which can result in their inactivation. By integrating a microfludic chipscale nebulizer driven by surface acoustic waves (SAWs) with a low-temperature atmospheric plasma source, we demonstrate an efficient technique for in situ production and application of plasma-activated aerosols for surface disinfection. Unlike bulk conventional systems wherein the water is separately batch-treated within a container, we show in this work the first demonstration of continuous plasma-treatment of water as it is transported through a paper strip from a reservoir onto the chipscale SAW device. The significantly larger surface area to volume ratio of the water within the paper strip leads to a significant reduction in the duration of the plasma-treatment, while maintaining the concentration of the reactive species. The subsequent nebulization of the plasma-activated water by the SAW then allows the generation of plasma-activated aerosols, which can be directly sprayed onto the contaminated surface, therefore eliminating the storage of the plasma-activated water and hence circumventing the typical limitation in conventional systems wherein the concentration of the reactive species diminishes over time during storage, resulting in a reduction in the efficacy of bacterial inactivation. In particular, we show up to 96% reduction in Escherichia coli colonies through direct spraying with the plasma-activated aerosols. This novel, low-cost, portable and energy-efficient hybrid system necessitates only minimal maintenance as it only requires the supply of tap water and battery power for operation, and is thus suitable for decontamination in home environments.
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Affiliation(s)
- Kiing S Wong
- School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia.
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Chatzimichail S, Supramaniam P, Ces O, Salehi-Reyhani A. Micropatterning of planar metal electrodes by vacuum filling microfluidic channel geometries. Sci Rep 2018; 8:14380. [PMID: 30258167 PMCID: PMC6158193 DOI: 10.1038/s41598-018-32706-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 09/13/2018] [Indexed: 11/09/2022] Open
Abstract
We present a simple, facile method to micropattern planar metal electrodes defined by the geometry of a microfluidic channel network template. By introducing aqueous solutions of metal into reversibly adhered PDMS devices by desiccation instead of flow, we are able to produce difficult to pattern "dead end" or discontinuous features with ease. We characterize electrodes fabricated using this method and perform electrical lysis of mammalian cancer cells and demonstrate their use as part of an antibody capture assay for GFP. Cell lysis in microwell arrays is achieved using the electrodes and the protein released is detected using an antibody microarray. We show how the template channels used as part of the workflow for patterning the electrodes may be produced using photolithography-free methods, such as laser micromachining and PDMS master moulding, and demonstrate how the use of an immiscible phase may be employed to create electrode spacings on the order of 25-50 μm, that overcome the current resolution limits of such methods. This work demonstrates how the rapid prototyping of electrodes for use in total analysis systems can be achieved on the bench with little or no need for centralized facilities.
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Affiliation(s)
- Stelios Chatzimichail
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK
- Institute of Chemical Biology, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK
| | - Pashiini Supramaniam
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK
- Institute of Chemical Biology, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK
| | - Oscar Ces
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK
- Institute of Chemical Biology, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK
- fabriCELL, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK
| | - Ali Salehi-Reyhani
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK.
- Institute of Chemical Biology, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK.
- fabriCELL, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, UK.
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Connacher W, Zhang N, Huang A, Mei J, Zhang S, Gopesh T, Friend J. Micro/nano acoustofluidics: materials, phenomena, design, devices, and applications. LAB ON A CHIP 2018; 18:1952-1996. [PMID: 29922774 DOI: 10.1039/c8lc00112j] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Acoustic actuation of fluids at small scales may finally enable a comprehensive lab-on-a-chip revolution in microfluidics, overcoming long-standing difficulties in fluid and particle manipulation on-chip. In this comprehensive review, we examine the fundamentals of piezoelectricity, piezoelectric materials, and transducers; revisit the basics of acoustofluidics; and give the reader a detailed look at recent technological advances and current scientific discussions in the discipline. Recent achievements are placed in the context of classic reports for the actuation of fluid and particles via acoustic waves, both within sessile drops and closed channels. Other aspects of micro/nano acoustofluidics are examined: atomization, translation, mixing, jetting, and particle manipulation in the context of sessile drops and fluid mixing and pumping, particle manipulation, and formation of droplets in the context of closed channels, plus the most recent results at the nanoscale. These achievements will enable applications across the disciplines of chemistry, biology, medicine, energy, manufacturing, and we suspect a number of others yet unimagined. Basic design concepts and illustrative applications are highlighted in each section, with an emphasis on lab-on-a-chip applications.
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Affiliation(s)
- William Connacher
- Medically Advanced Devices Laboratory, Center for Medical Devices and Instrumentation, Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093-0411, USA.
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Ahmed H, Destgeer G, Park J, Jung JH, Sung HJ. Vertical Hydrodynamic Focusing and Continuous Acoustofluidic Separation of Particles via Upward Migration. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1700285. [PMID: 29619294 PMCID: PMC5827645 DOI: 10.1002/advs.201700285] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 10/13/2017] [Indexed: 05/04/2023]
Abstract
A particle suspended in a fluid within a microfluidic channel experiences a direct acoustic radiation force (ARF) when traveling surface acoustic waves (TSAWs) couple with the fluid at the Rayleigh angle, thus producing two components of the ARF. Most SAW-based microfluidic devices rely on the horizontal component of the ARF to migrate prefocused particles laterally across a microchannel width. Although the magnitude of the vertical component of the ARF is more than twice the magnitude of the horizontal component, it is long ignored due to polydimethylsiloxane (PDMS) microchannel fabrication limitations and difficulties in particle focusing along the vertical direction. In the present work, a single-layered PDMS microfluidic chip is devised for hydrodynamically focusing particles in the vertical plane while explicitly taking advantage of the horizontal ARF component to slow down the selected particles and the stronger vertical ARF component to push the particles in the upward direction to realize continuous particle separation. The proposed particle separation device offers high-throughput operation with purity >97% and recovery rate >99%. It is simple in its fabrication and versatile due to the single-layered microchannel design, combined with vertical hydrodynamic focusing and the use of both the horizontal and vertical components of the ARF.
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Affiliation(s)
- Husnain Ahmed
- Department of Mechanical EngineeringKAISTDaejeon34141South Korea
| | - Ghulam Destgeer
- Department of Mechanical EngineeringKAISTDaejeon34141South Korea
| | - Jinsoo Park
- Department of Mechanical EngineeringKAISTDaejeon34141South Korea
| | - Jin Ho Jung
- Department of Mechanical EngineeringKAISTDaejeon34141South Korea
| | - Hyung Jin Sung
- Department of Mechanical EngineeringKAISTDaejeon34141South Korea
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Khoshmanesh K, Tang SY, Zhu JY, Schaefer S, Mitchell A, Kalantar-Zadeh K, Dickey MD. Liquid metal enabled microfluidics. LAB ON A CHIP 2017; 17:974-993. [PMID: 28225135 DOI: 10.1039/c7lc00046d] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Several gallium-based liquid metal alloys are liquid at room temperature. As 'liquid', such alloys have a low viscosity and a high surface tension while as 'metal', they have high thermal and electrical conductivities, similar to mercury. However, unlike mercury, these liquid metal alloys have low toxicity and a negligible vapor pressure, rendering them much safer. In comparison to mercury, the distinguishing feature of these alloys is the rapid formation of a self-limiting atomically thin layer of gallium oxide over their surface when exposed to oxygen. This oxide layer changes many physical and chemical properties of gallium alloys, including their interfacial and rheological properties, which can be employed and modulated for various applications in microfluidics. Injecting liquid metal into microfluidic structures has been extensively used to pattern and encapsulate highly deformable and reconfigurable electronic devices including electrodes, sensors, antennas, and interconnects. Likewise, the unique features of liquid metals have been employed for fabricating miniaturized microfluidic components including pumps, valves, heaters, and electrodes. In this review, we discuss liquid metal enabled microfluidic components, and highlight their desirable attributes including simple fabrication, facile integration, stretchability, reconfigurability, and low power consumption, with promising applications for highly integrated microfluidic systems.
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Affiliation(s)
| | - Shi-Yang Tang
- Department of Bioengineering and Therapeutic Sciences, Schools of Medicine and Pharmacy, University of California, San Francisco, California, USA
| | - Jiu Yang Zhu
- School of Engineering, RMIT University, Melbourne, Victoria, Australia.
| | - Samira Schaefer
- Department of Applied Chemistry, Reutlingen University, Reutlingen, Baden-Wuerttemberg, Germany
| | - Arnan Mitchell
- School of Engineering, RMIT University, Melbourne, Victoria, Australia.
| | | | - Michael D Dickey
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
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Self-Aligned Interdigitated Transducers for Acoustofluidics. MICROMACHINES 2016; 7:mi7120216. [PMID: 30404386 PMCID: PMC6189727 DOI: 10.3390/mi7120216] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 12/17/2022]
Abstract
The surface acoustic wave (SAW) is effective for the manipulation of fluids and particles at microscale. The current approach of integrating interdigitated transducers (IDTs) for SAW generation into microfluidic channels involves complex and laborious microfabrication steps. These steps often require full access to clean room facilities and hours to align the transducers to the precise location. This work presents an affordable and innovative method for fabricating SAW-based microfluidic devices without the need for clean room facilities and alignment. The IDTs and microfluidic channels are fabricated using the same process and thus are precisely self-aligned in accordance with the device design. With the use of the developed fabrication approach, a few types of different SAW-based microfluidic devices have been fabricated and demonstrated for particle separation and active droplet generation.
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