1
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Mika T, Kalnins M, Spalvins K. The use of droplet-based microfluidic technologies for accelerated selection of Yarrowia lipolytica and Phaffia rhodozyma yeast mutants. Biol Methods Protoc 2024; 9:bpae049. [PMID: 39114747 PMCID: PMC11303513 DOI: 10.1093/biomethods/bpae049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/24/2024] [Accepted: 07/09/2024] [Indexed: 08/10/2024] Open
Abstract
Microorganisms are widely used for the industrial production of various valuable products, such as pharmaceuticals, food and beverages, biofuels, enzymes, amino acids, vaccines, etc. Research is constantly carried out to improve their properties, mainly to increase their productivity and efficiency and reduce the cost of the processes. The selection of microorganisms with improved qualities takes a lot of time and resources (both human and material); therefore, this process itself needs optimization. In the last two decades, microfluidics technology appeared in bioengineering, which allows for manipulating small particles (from tens of microns to nanometre scale) in the flow of liquid in microchannels. The technology is based on small-volume objects (microdroplets from nano to femtolitres), which are manipulated using a microchip. The chip is made of an optically transparent inert to liquid medium material and contains a series of channels of small size (<1 mm) of certain geometry. Based on the physical and chemical properties of microparticles (like size, weight, optical density, dielectric constant, etc.), they are separated using microsensors. The idea of accelerated selection of microorganisms is the application of microfluidic technologies to separate mutants with improved qualities after mutagenesis. This article discusses the possible application and practical implementation of microfluidic separation of mutants, including yeasts like Yarrowia lipolytica and Phaffia rhodozyma after chemical mutagenesis will be discussed.
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Affiliation(s)
- Taras Mika
- Institute of Energy Systems and Environment, Riga Technical University, 12 – K1 Āzene street, Riga, LV-1048, Latvia
| | - Martins Kalnins
- Institute of Energy Systems and Environment, Riga Technical University, 12 – K1 Āzene street, Riga, LV-1048, Latvia
| | - Kriss Spalvins
- Institute of Energy Systems and Environment, Riga Technical University, 12 – K1 Āzene street, Riga, LV-1048, Latvia
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2
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Tang Q, Song C, Wang Y, Zhang JH, Liu M, Xu Y, Wang C, Cui X. Drop-On-Demand Microdroplet Generation under Charge Injection by Corona Discharge. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:11966-11973. [PMID: 38809418 DOI: 10.1021/acs.langmuir.4c00403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
In printing, microreactors, and bioassays, the precise control of micrometer-scale droplet generation is essential but challenging, often restricted by the equipment and nozzles used in traditional methods. We introduce a needle-plate electrode corona discharge technique that injects charges into an oil layer, enabling the precise manipulation of droplet polarization and splitting. This method allows for meticulous adjustment of microdroplet formation regarding location, size, and quantity by modulating the discharge voltage, discharge time, and electrode positioning. It enables the immediate initiation and cessation of droplet production, thereby facilitating on-demand droplet generation. Our study on the voltage-dependent droplet stretch coefficient shows that as the voltage increases, the droplets transition from controlled splitting to regular Taylor cone-like ejections, eventually reaching the Rayleigh limit and fully breaking apart. These advancements significantly improve microfluidic droplet manipulation, offering considerable benefits for applications in targeted drug delivery, rapid disease diagnostics, and precise environmental monitoring.
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Affiliation(s)
- Qiang Tang
- Base for Innovative Methods Promotion Application and Demonstration of Anhui Province, Anhui University of Science and Technology, Huainan 232000, Anhui, China
- School of Artificial Intelligence, Anhui University of Science and Technology, Huainan 232000, Anhui, China
| | - Chengcheng Song
- School of Artificial Intelligence, Anhui University of Science and Technology, Huainan 232000, Anhui, China
| | - Yan Wang
- School of Artificial Intelligence, Anhui University of Science and Technology, Huainan 232000, Anhui, China
| | - Jia-Han Zhang
- School of Electronic Information Engineering, Inner Mongolia University, Hohhot 010021, China
- Collaborative Innovation Center of Advanced Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
| | - Manfei Liu
- School of Artificial Intelligence, Anhui University of Science and Technology, Huainan 232000, Anhui, China
| | - Yunshan Xu
- School of Artificial Intelligence, Anhui University of Science and Technology, Huainan 232000, Anhui, China
| | - Chengjun Wang
- Base for Innovative Methods Promotion Application and Demonstration of Anhui Province, Anhui University of Science and Technology, Huainan 232000, Anhui, China
- School of Artificial Intelligence, Anhui University of Science and Technology, Huainan 232000, Anhui, China
| | - Xiaxia Cui
- Base for Innovative Methods Promotion Application and Demonstration of Anhui Province, Anhui University of Science and Technology, Huainan 232000, Anhui, China
- School of Artificial Intelligence, Anhui University of Science and Technology, Huainan 232000, Anhui, China
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3
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Santos FP, Tryggvason G, Ferreira GGS. Droplet-based logic gates simulation of viscoelastic fluids under electric field. Sci Rep 2024; 14:1771. [PMID: 38245567 PMCID: PMC10799872 DOI: 10.1038/s41598-024-52139-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 01/14/2024] [Indexed: 01/22/2024] Open
Abstract
Nano and microfluidic technologies have shown great promise in the development of controlled drug delivery systems and the creation of microfluidic devices with logic-like functionalities. Here, we focused on investigating a droplet-based logic gate that can be used for automating medical diagnostic assays. This logic gate uses viscoelastic fluids, which are particularly relevant since bio-fluids exhibit viscoelastic properties. The operation of the logic gate is determined by evaluating various parameters, including the Weissenberg number, the Capillary number, and geometric factors. To effectively classify the logic gates operational conditions, we employed a deep learning classification to develop a reduced-order model. This approach accelerates the prediction of operating conditions, eliminating the need for complex simulations. Moreover, the deep learning model allows for the combination of different AND/OR branches, further enhancing the versatility of the logic gate. We also found that non-operating regions, where the logic gate does not function properly, can be transformed into operational regions by applying an external force. By utilizing an electrical induction technique, we demonstrated that the application of an electric field can repel or attract droplets, thereby improving the performance of the logic gate. Overall, our research shows the potential of the droplet-based logic gates in the field of medical diagnostics. The integration of deep learning classification algorithms enables rapid evaluation of operational conditions and facilitates the design of complex logic circuits. Additionally, the introduction of external forces and electrical induction techniques opens up new possibilities for enhancing the functionality and reliability of these logic gates.
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Affiliation(s)
- F P Santos
- Systems Engineering and Computer Science Program, Federal University of Rio de Janeiro, 21941-909, Rio de Janeiro, Brazil.
| | - G Tryggvason
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MA, 21218, USA
| | - G G S Ferreira
- Chemical Engineering Program, Federal University of Rio de Janeiro, 21941-972, Rio de Janeiro, Brazil
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4
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Fang W, Tao Z, Li H, Yin S, Xu T, Huang Y, Wong T. AC-electric-field-controlled multi-component droplet coalescence at microscale. LAB ON A CHIP 2023; 23:2341-2355. [PMID: 37078784 DOI: 10.1039/d3lc00086a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Droplet coalescence with fast response, high controllability and monodispersity has been widely investigated in industrial production and bioengineering. Especially for droplets with multiple components, programmable manipulation of such droplets is crucial for practical applications. However, precise control of the dynamics can be challenging, owing to the complex boundaries and the interfacial and fluidic properties. AC electric fields, with their fast response and high flexibility, have attracted our interest. We design and fabricate an improved flow-focusing microchannel configuration together with a non-contact type of electrode featuring asymmetric geometries, based on which we conduct systematic investigations of the AC-electric-field-controlled coalescence of multi-component droplets at the microscale. Parameters such as flow rates, component ratio, surface tension, electric permittivity and conductivity were given our attention. The results show that droplet coalescence in different flow parameters can be achieved in milliseconds by adjusting the electrical conditions, which shows high controllability. Specifically, both the coalescence region and reaction time can be adjusted by a combination of applied voltage and frequency, and unique merging phenomena have appeared. One is contact coalescence with the approach of paired droplets, while the other is squeezing coalescence, which occurs in the start position and promotes the merging process. The fluid properties, such as the electric permittivity, conductivity and surface tension, present a significant influence on merging behavior. The increasing relative dielectric constant leads to a dramatic reduction of the start merging voltage from the original 250 V to 30 V. The range of effective voltage for coalescence decreases with the addition of surfactant, offering a stricter and yet higher selectivity on electrical conditions, about 1500 V. The conductivity presents a negative correlation with the start merging voltage due to the reduction of the dielectric stress, from 400 V to 1500 V. Finally, we achieve the precise fabrication process of the Janus droplet via implementation of the proposed method, where the components of the droplets and the coalescence conditions are well controlled. Our results can serve as a potent methodology to decipher the physics of multi-component droplet electro-coalescence and contribute to applications in chemical synthesis, bioassay and material synthesis.
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Affiliation(s)
- Weidong Fang
- National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, Research Institute of Aero-Engine, Beihang University, Beijing, 100191, China.
| | - Zhi Tao
- National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, Research Institute of Aero-Engine, Beihang University, Beijing, 100191, China.
| | - Haiwang Li
- National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, Research Institute of Aero-Engine, Beihang University, Beijing, 100191, China.
| | - Shuai Yin
- School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Tiantong Xu
- National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, Research Institute of Aero-Engine, Beihang University, Beijing, 100191, China.
| | - Yi Huang
- National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, Research Institute of Aero-Engine, Beihang University, Beijing, 100191, China.
| | - Teckneng Wong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore
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5
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Liu F, Ge A, Li C, Gao W, Wu F, Kan L, Xu J, Ma B. Auto Flow-Focusing Droplet Reinjection Chip-Based Integrated Portable Droplet System (iPODs). Anal Chem 2023; 95:6672-6680. [PMID: 37053544 DOI: 10.1021/acs.analchem.3c00239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Droplet microfluidics provides powerful tools for biochemical applications. However, precise fluid control is usually required in the process of droplet generation and detection, which hinders droplet-based applications in point-of-care testing (POCT). Here, we present a droplet reinjection method capable of droplet distribution without precise fluid control and external pumps by which the droplets can be passively aligned and detected one by one at intervals. By further integrating the surface-wetting-based droplet generation chip, an integrated POrtable Droplet system (iPODs) is developed. The iPODs integrates multiple functions such as droplet generation, online reaction, and serial reading. Using the iPODs, monodisperse droplets can be generated at a flow rate of 800 Hz with a narrow size distribution (CV <2.2%). Droplets are kept stable, and the fluorescence signal can be significantly identified after the reaction. The spaced droplet efficiency in the reinjection chip is nearly 100%. In addition, we validate digital loop-mediated isothermal amplification (dLAMP) within 80 min with a simple operation workflow. The results show that iPODs has good linearity (R2 = 0.999) at concentrations ranging from 101 to 104 copies/μL. Thus, the developed iPODs highlights its potential to be a portable, low-cost, and easy-to-deploy toolbox for droplet-based applications.
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Affiliation(s)
- Fengyi Liu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anle Ge
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Chunyu Li
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Wei Gao
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Fei Wu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Lingyan Kan
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bo Ma
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
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6
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Luo Y, Cao Z, Liu Y, Zhang R, Yang S, Wang N, Shi Q, Li J, Dong S, Fan C, Zhao J. The emerging landscape of microfluidic applications in DNA data storage. LAB ON A CHIP 2023; 23:1981-2004. [PMID: 36946437 DOI: 10.1039/d2lc00972b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
DNA has been considered a promising alternative to the current solid-state devices for digital information storage. The past decade has witnessed tremendous progress in the field of DNA data storage contributed by researchers from various disciplines. However, the current development status of DNA storage is still far from practical use, mainly due to its high material cost and time consumption for data reading/writing, as well as the lack of a comprehensive, automated, and integrated system. Microfluidics, being capable of handling and processing micro-scale fluid samples in a massively paralleled and highly integrated manner, has gradually been recognized as a promising candidate for addressing the aforementioned issues. In this review, we provide a discussion on recent efforts of applying microfluidics to advance the development of DNA data storage. Moreover, to showcase the tremendous potential that microfluidics can contribute to this field, we will further highlight the recent advancements of applying microfluidics to the key functional modules within the DNA data storage workflow. Finally, we share our perspectives on future directions for how to continue the infusion of microfluidics with DNA data storage and how to advance toward a truly integrated system and reach real-life applications.
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Affiliation(s)
- Yuan Luo
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Cao
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
- International Joint Innovation Center, Zhejiang University, Haining 314400, China
| | - Yifan Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
- Shanghai Clinical Research and Trial Center, Shanghai, 201210, China
| | - Rong Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Shijia Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ning Wang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingyuan Shi
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Jie Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Shurong Dong
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
- International Joint Innovation Center, Zhejiang University, Haining 314400, China
| | - Chunhai Fan
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jianlong Zhao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, P.R. China
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7
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Wu J, Fang H, Zhang J, Yan S. Modular microfluidics for life sciences. J Nanobiotechnology 2023; 21:85. [PMID: 36906553 PMCID: PMC10008080 DOI: 10.1186/s12951-023-01846-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023] Open
Abstract
The advancement of microfluidics has enabled numerous discoveries and technologies in life sciences. However, due to the lack of industry standards and configurability, the design and fabrication of microfluidic devices require highly skilled technicians. The diversity of microfluidic devices discourages biologists and chemists from applying this technique in their laboratories. Modular microfluidics, which integrates the standardized microfluidic modules into a whole, complex platform, brings the capability of configurability to conventional microfluidics. The exciting features, including portability, on-site deployability, and high customization motivate us to review the state-of-the-art modular microfluidics and discuss future perspectives. In this review, we first introduce the working mechanisms of the basic microfluidic modules and evaluate their feasibility as modular microfluidic components. Next, we explain the connection approaches among these microfluidic modules, and summarize the advantages of modular microfluidics over integrated microfluidics in biological applications. Finally, we discuss the challenge and future perspectives of modular microfluidics.
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Affiliation(s)
- Jialin Wu
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
- Nanophotonics Research Center, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, China
| | - Hui Fang
- Nanophotonics Research Center, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, China
| | - Jun Zhang
- Queensland Micro and Nanotechnology Centre, Griffith University, Brisbane, QLD, 4111, Australia
| | - Sheng Yan
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
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8
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Huang C, Jiang Y, Li Y, Zhang H. Droplet Detection and Sorting System in Microfluidics: A Review. MICROMACHINES 2022; 14:mi14010103. [PMID: 36677164 PMCID: PMC9867185 DOI: 10.3390/mi14010103] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/23/2022] [Accepted: 12/26/2022] [Indexed: 05/26/2023]
Abstract
Since being invented, droplet microfluidic technologies have been proven to be perfect tools for high-throughput chemical and biological functional screening applications, and they have been heavily studied and improved through the past two decades. Each droplet can be used as one single bioreactor to compartmentalize a big material or biological population, so millions of droplets can be individually screened based on demand, while the sorting function could extract the droplets of interest to a separate pool from the main droplet library. In this paper, we reviewed droplet detection and active sorting methods that are currently still being widely used for high-through screening applications in microfluidic systems, including the latest updates regarding each technology. We analyze and summarize the merits and drawbacks of each presented technology and conclude, with our perspectives, on future direction of development.
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Affiliation(s)
- Can Huang
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77842, USA
| | - Yuqian Jiang
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yuwen Li
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77842, USA
| | - Han Zhang
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77842, USA
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9
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Artificial neural network-based predictions of surface electrocoalescence of water droplets in hydrocarbon media. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.09.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Yin S, Huang Y, Li H, Wong TN. Dynamics of alternating current electric field–assisted non‐Newtonian droplet formation with geometry confinement. Electrophoresis 2022; 43:2120-2129. [DOI: 10.1002/elps.202200056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/06/2022] [Accepted: 04/22/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Shuai Yin
- School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore Singapore
| | - Yi Huang
- School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore Singapore
- Research Institute of Aero‐Engine Beihang University Beijing P. R. China
| | - Haiwang Li
- Research Institute of Aero‐Engine Beihang University Beijing P. R. China
| | - Teck Neng Wong
- School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore Singapore
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11
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Fallah K, Fattahi E. Splitting of droplet with different sizes inside a symmetric T-junction microchannel using an electric field. Sci Rep 2022; 12:3226. [PMID: 35217700 PMCID: PMC8881490 DOI: 10.1038/s41598-022-07130-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/14/2022] [Indexed: 01/09/2023] Open
Abstract
In the current study, droplets dynamics under an asymmetric electric field in a T-junction are numerically studied using COMSOL Multi-physics software. The effect of different factors such as dimensionless length of mother droplet (L*), Capillary number (Ca), and electric capillary number (Cae) are investigated on the breakup process in symmetric T-junctions. Two novel patterns of droplets, namely, hybrid asymmetric splitting mode and sorting patterns, have been observed by imposing an electric field in one branch of the microchannel. It is also concluded that using an electric field is a promising strategy to reach droplets with arbitrary sizes and control over the splitting ratio of daughter droplets precisely in a T- junction by adjusting the electric field strength. After a certain electric capillary number (\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
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\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\left. {Ca_{e} } \right|_{Sorting}$$\end{document}CaeSorting), the mother droplet does not breakup and is sorted on the side of the branch that the electric field imposes. Furthermore, \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
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\usepackage{amssymb}
\usepackage{amsbsy}
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\begin{document}$$\left. {Ca_{e} } \right|_{Sorting}$$\end{document}CaeSorting increases with the increment of L* and Ca.
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Affiliation(s)
- Keivan Fallah
- Department of Mechanical Engineering, Sari Branch, Islamic Azad University, Sari, Iran.
| | - Ehsan Fattahi
- Brewing and beverage technology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
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12
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Yin M, Alexander Kim Z, Xu B. Micro/Nanofluidic‐Enabled Biomedical Devices: Integration of Structural Design and Manufacturing. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Mengtian Yin
- Department of Mechanical and Aerospace Engineering University of Virginia Charlottesville VA 22904 USA
| | - Zachary Alexander Kim
- Department of Mechanical and Aerospace Engineering University of Virginia Charlottesville VA 22904 USA
| | - Baoxing Xu
- Department of Mechanical and Aerospace Engineering University of Virginia Charlottesville VA 22904 USA
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13
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Chaudhuri J. Magnetic-field- and thermal-radiation-induced entropy generation in a multiphase nonisothermal plane Poiseuille flow. Phys Rev E 2021; 104:065105. [PMID: 35030912 DOI: 10.1103/physreve.104.065105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 11/23/2021] [Indexed: 12/28/2022]
Abstract
The effect of radiative heat transfer on the entropy generation in a two-phase nonisothermal fluid flow between two infinite horizontal parallel plates under the influence of a constant pressure gradient and transverse noninvasive magnetic field have been explored. Both fluids are considered to be viscous, incompressible, immiscible, Newtonian, and electrically conducting. The governing equations in Cartesian coordinates are solved analytically with appropriate boundary conditions to obtain the velocity and temperature profile inside the channel. Application of a transverse magnetic field is found to reduce the throughput and the temperature distribution of the fluids in a pressure-driven flow. The temperature and fluid flow inside the channel can also be noninvasively altered by tuning the magnetic field intensity, temperature difference between the channel walls and the fluids, and several intrinsic fluid properties. The entropy generation due to the heat transfer, magnetic field, and fluid flow irreversibilities can be controlled by altering the Hartmann number, radiation parameter, Brinkmann number, filling ratio, and ratios of fluid viscosities and thermal and electrical conductivities. The surfaces of the channel wall are found to act as a strong source of entropy generation and heat transfer irreversibility. The rate of heat transfer at the channel walls can also be tweaked by the magnetic field intensity, temperature differences, and fluid properties. The proposed strategies in the present study can be of significance in the design and development of next-generation microscale reactors, micro-heat exchangers, and energy-harvesting devices.
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Affiliation(s)
- Joydip Chaudhuri
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
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14
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Le TNQ, Tran NN, Escribà-Gelonch M, Serra CA, Fisk I, McClements DJ, Hessel V. Microfluidic encapsulation for controlled release and its potential for nanofertilisers. Chem Soc Rev 2021; 50:11979-12012. [PMID: 34515721 DOI: 10.1039/d1cs00465d] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nanotechnology is increasingly being utilized to create advanced materials with improved or new functional attributes. Converting fertilizers into a nanoparticle-form has been shown to improve their efficacy but the current procedures used to fabricate nanofertilisers often have poor reproducibility and flexibility. Microfluidic systems, on the other hand, have advantages over traditional nanoparticle fabrication methods in terms of energy and materials consumption, versatility, and controllability. The increased controllability can result in the formation of nanoparticles with precise and complex morphologies (e.g., tuneable sizes, low polydispersity, and multi-core structures). As a result, their functional performance can be tailored to specific applications. This paper reviews the principles, formation, and applications of nano-enabled delivery systems fabricated using microfluidic approaches for the encapsulation, protection, and release of fertilizers. Controlled release can be achieved using two main routes: (i) nutrients adsorbed on nanosupports and (ii) nutrients encapsulated inside nanostructures. We aim to highlight the opportunities for preparing a new generation of highly versatile nanofertilisers using microfluidic systems. We will explore several main characteristics of microfluidically prepared nanofertilisers, including droplet formation, shell fine-tuning, adsorbate fine-tuning, and sustained/triggered release behavior.
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Affiliation(s)
- Tu Nguyen Quang Le
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia. .,Faculty of Chemical Engineering, Ho Chi Minh City University of Technology, Ho Chi Minh City, Vietnam
| | - Nam Nghiep Tran
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia. .,School of Chemical Engineering, Can Tho University, Can Tho City, Vietnam
| | - Marc Escribà-Gelonch
- Higher Polytechnic Engineering School, University of Lleida, Igualada (Barcelona), 08700, Spain
| | - Christophe A Serra
- Université de Strasbourg, CNRS, Institut Charles Sadron UPR 22, F-67000 Strasbourg, France
| | - Ian Fisk
- Division of Food, Nutrition and Dietetics, School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK.,The University of Adelaide, North Terrace, Adelaide, South Australia, Australia
| | | | - Volker Hessel
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia. .,School of Engineering, University of Warwick, Library Rd, Coventry, UK
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15
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Hemachandran E, Hoque SZ, Laurell T, Sen AK. Reversible Stream Drop Transition in a Microfluidic Coflow System via On Demand Exposure to Acoustic Standing Waves. PHYSICAL REVIEW LETTERS 2021; 127:134501. [PMID: 34623851 DOI: 10.1103/physrevlett.127.134501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 07/16/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
Transition between stream and droplet regimes in a coflow is typically achieved by adjusting the capillary numbers (Ca) of the phases. Remarkably, we experimentally evidence a reversible transition between the two regimes by controlling exposure of the system to acoustic standing waves, with Ca fixed. By satisfying the ratio of acoustic radiation force to the interfacial tension force, Ca_{ac}>1, experiments reveal a reversible stream drop transition for Ca<1, and stream relocation for Ca≥1. We explain the phenomenon in terms of the pinching, advection, and relocation timescales and a transition between convective and absolute instability from a linear stability analysis [P. Guillot et al., Phys. Rev. Lett. 99, 104502 (2007)PRLTAO0031-900710.1103/PhysRevLett.99.104502].
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Affiliation(s)
- E Hemachandran
- Fluid Systems Lab, Department of Mechanical Engineering, Indian Institute of Technology Madras, 600036 Chennai, India
| | - S Z Hoque
- Fluid Systems Lab, Department of Mechanical Engineering, Indian Institute of Technology Madras, 600036 Chennai, India
| | - T Laurell
- Division of Nanobiotechnology, Department of Biomedical Engineering, Lund University, 22363 Lund, Sweden
| | - A K Sen
- Fluid Systems Lab, Department of Mechanical Engineering, Indian Institute of Technology Madras, 600036 Chennai, India
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16
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Shi N, Mohibullah M, Easley CJ. Active Flow Control and Dynamic Analysis in Droplet Microfluidics. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2021; 14:133-153. [PMID: 33979546 PMCID: PMC8956363 DOI: 10.1146/annurev-anchem-122120-042627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Droplet-based microfluidics has emerged as an important subfield within the microfluidic and general analytical communities. Indeed, several unique applications such as digital assay readout and single-cell sequencing now have commercial systems based on droplet microfluidics. Yet there remains room for this research area to grow. To date, most analytical readouts are optical in nature, relatively few studies have integrated sample preparation, and passive means for droplet formation and manipulation have dominated the field. Analytical scientists continue to expand capabilities by developing droplet-compatible method adaptations, for example, by interfacing to mass spectrometers or automating droplet sampling for temporally resolved analysis. In this review, we highlight recently developed fluidic control techniques and unique integrations of analytical methodology with droplet microfluidics-focusing on automation and the connections to analog/digital domains-and we conclude by offering a perspective on current challenges and future applications.
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Affiliation(s)
- Nan Shi
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA;
| | - Md Mohibullah
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA;
| | - Christopher J Easley
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA;
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17
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Yin S, Huang Y, Wong TN. Critical conditions for organic thread cutting under electric fields. SOFT MATTER 2021; 17:2913-2919. [PMID: 33587082 DOI: 10.1039/d0sm02078h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Conditions for triggering the cutting of organic samples under an AC electric field are investigated in a microchannel to explore the strategy for organic sample manipulation. Based on the nature of triggering and developing instability at liquid interfaces, in combination with an equivalent electric circuit model, a novel electric capillary number method is proposed as a comprehensive critical condition for the cutting. We uncover the physics behind cutting and non-cutting of an organic thread for different electric frequencies, electric properties of fluid, and width of the organic thread. The critical time required and the critical cutting position are studied to offer guidelines for accurate cutting. Higher electric frequency and higher permittivity of the aqueous phase surrounding the organic phase can reduce the voltage required for cutting. In summary, the newly defined electric capillary number is proved to be a comprehensive criterion for determining the cutting phenomena, which is capable of considering the interfacial tension, the electric permittivity and the electric field strength applied. The results offer applicable references for achieving efficient and accurate cutting of organic samples in practical applications.
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Affiliation(s)
- Shuai Yin
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
| | - Yi Huang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. and Research Institute of Aero-Engine, Beihang University, No. 37 XueYuan Road, Haidian District, Beijing, 100083, China
| | - Teck Neng Wong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
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18
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Liu H, Singh RP, Zhang Z, Han X, Liu Y, Hu L. Microfluidic Assembly: An Innovative Tool for the Encapsulation, Protection, and Controlled Release of Nutraceuticals. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:2936-2949. [PMID: 33683870 DOI: 10.1021/acs.jafc.0c05395] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nutraceuticals have been gradually accepted as food ingredients that can offer health benefits and provide protection against several diseases. It is widely accepted due to potential nutritional benefits, safety, and therapeutic effects. Most nutraceuticals are vulnerable to the changes in the external environment, which leads to poor physical and chemical stability and absorption. Several researchers have designed various encapsulation technologies to promote the use of nutraceuticals. Microfluidic technology is an emerging approach which can be used for nutraceutical delivery with precise control. The delivery systems using microfluidic technology have obtained much interest in recent years. In this review article, we have summarized the recently introduced nutraceutical delivery platforms including emulsions, liposomes, microspheres, microgels, and polymer nanoparticles based on microfluidic techniques. Emphasis has been made to discuss the advantages, preparations, characterizations, and applications of nutraceutical delivery systems. Finally, the challenges, several up-scaling methods, and future expectations are discussed.
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Affiliation(s)
- Haofan Liu
- College of Quality and Technical Supervision, Hebei University, Baoding 071002, China
| | - Rahul Pratap Singh
- Department of Pharmacy, School of Medical & Allied Sciences, G.D. Goenka University, Sohna, Gurgaon, India, 122103
| | - Zhengyu Zhang
- Key Laboratory of Pharmaceutical Quality Control of Hebei Province, College of Pharmaceutical Sciences, Hebei University, Baoding 071002, China
| | - Xiao Han
- Key Laboratory of Pharmaceutical Quality Control of Hebei Province, College of Pharmaceutical Sciences, Hebei University, Baoding 071002, China
| | - Yang Liu
- School of Pharmaceutical Sciences, Zhengzhou University, No. 100, Kexue Avenue, Zhengzhou 450001, China
| | - Liandong Hu
- College of Quality and Technical Supervision, Hebei University, Baoding 071002, China
- Key Laboratory of Pharmaceutical Quality Control of Hebei Province, College of Pharmaceutical Sciences, Hebei University, Baoding 071002, China
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19
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Li D, Cao Y, Huang B, Han M, Wu X, Sun Q, Zheng C, Zhao L, Ma C, Jin H, Wang X, Liu Y, Zhang Y. Active Femtoliter Droplet Generation in Microfluidics by Confined Interface Vibration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1297-1305. [PMID: 33428403 DOI: 10.1021/acs.langmuir.0c03368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The precise and effective generation of micron-sized droplets is one of the most common and important issues for droplet-based microfluidics. Active droplet generation makes use of additional energy input in promoting interfacial instabilities for droplet generation. Here, we report a new technique for the active generation of femtoliter droplets in microfluidic systems using confined interfacial vibration (CIV). The CIV is formed at the orifice of a traditional inkjet nozzle first by pushing the liquid out and then pulling it back. Droplets are pinched off during the withdrawal process, and this is different from the current active droplet generation techniques, which only monodirectionally push the liquid out. Droplets with radius ranging from ca. 1 to 28 μm can be actively generated by CIV at an orifice with radius 30 μm, distinguishing from conventional active generation techniques in which the droplets are always comparable or slightly bigger than the orifice. Experimental results showed that the droplet volume can be customized by controlling the intensity of the CIV. The inherent digital nature of the inkjet technique enables easy and precise regulating of the droplet volume, making it seamlessly compatible with the digital microfluidic systems.
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Affiliation(s)
- Dege Li
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Yi Cao
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Bingfang Huang
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Molong Han
- Centre of Micro-photonics, Swinburne University of Technology, Melbourne 3122, Australia
| | - Xinlei Wu
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Qiang Sun
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Chao Zheng
- Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, U.K
| | - Lilong Zhao
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Chi Ma
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Hui Jin
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Xiaolong Wang
- Dongying Science and Technology Bureau, Dongying 257000, China
| | - Yonghong Liu
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Yanzhen Zhang
- College of Mechanical and Electronic Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Centre of Micro-photonics, Swinburne University of Technology, Melbourne 3122, Australia
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20
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Liu F, Xu T, Liu W, Zheng X, Xu J, Ma B. Spontaneous droplet generation via surface wetting. LAB ON A CHIP 2020; 20:3544-3551. [PMID: 32895671 DOI: 10.1039/d0lc00641f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A surface wetting-driven droplet generation microfluidic chip was developed, and could produce droplets spontaneously once adding a drop of oil and an aqueous sample on the chip without any power source and equipment. The chip is simply composed of three drilled holes connected by a single microchannel. The aqueous sample dropped in the middle hole could be converged and segmented into monodispersed droplets spontaneously by preloading oil in the side hole, and then flow into the other side hole through the microchannel. To address the high throughput and stability in practical applications, a siphon pump was further integrated into the microfluidic chip by simply connecting oil-filled tubing also acting as a collector. In this way, droplets can be generated spontaneously with a high uniformity (CV < 3.5%) and adjustable size (30-80 μm). Higher throughput (280 Hz) and multi-sample emulsification are achieved by parallel integration of a multi-channel structure. Based on that, the microfluidic chip was used as the droplet generator for the ddPCR to absolutely quantify S. mutans DNA. This is the first time that the feasibility of droplet generation driven only by oil wettability on hydrophobic surfaces is demonstrated. It offers great opportunity for self-sufficient and portable W/O droplet generation in biomedical samples, thus holding the potential for point-of-care testing (POCT).
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Affiliation(s)
- Fengyi Liu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, P.R. China.
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21
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Qi C, Li Y, Liu Z, Kong T. Electrohydrodynamics of droplets and jets in multiphase microsystems. SOFT MATTER 2020; 16:8526-8546. [PMID: 32945331 DOI: 10.1039/d0sm01357a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Electrohydrodynamics is among the most promising techniques for manipulating liquids in microsystems. The electric stress actuates, generates, and coalesces droplets of small sizes; it also accelerates, focuses, and controls the motion of fine jets. In this review, the current understanding of dynamic regimes of electrically driven drops and jets in multiphase microsystems is summarized. The experimental description and underlying mechanism of force interplay and instabilities are discussed. Conditions for controlled transitions among different regimes are also provided. Emerging new phenomena either due to special interfacial properties or geometric confinement are emphasized, and simple scaling arguments proposed in the literature are introduced. The review provides useful perspectives for investigations involving electrically driven droplets and jets.
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Affiliation(s)
- Cheng Qi
- College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen 518000, Guangdong, China
| | - Yao Li
- College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen 518000, Guangdong, China
| | - Zhou Liu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518000, Guangdong, China.
| | - Tiantian Kong
- Department of Biomedical Engineering, School of Medicine, Shenzhen University, Shenzhen 518000, Guangdong, China.
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22
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Li HT, Wang HF, Wang Y, Pan JZ, Fang Q. A minimalist approach for generating picoliter to nanoliter droplets based on an asymmetrical beveled capillary and its application in digital PCR assay. Talanta 2020; 217:120997. [DOI: 10.1016/j.talanta.2020.120997] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 12/22/2022]
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23
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Yin Z, Huang Z, Lin X, Gao X, Bao F. Droplet Generation in a Flow-Focusing Microfluidic Device with External Mechanical Vibration. MICROMACHINES 2020; 11:mi11080743. [PMID: 32751579 PMCID: PMC7463860 DOI: 10.3390/mi11080743] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/23/2020] [Accepted: 07/28/2020] [Indexed: 12/30/2022]
Abstract
The demand for highly controllable droplet generation methods is very urgent in the medical, materials, and food industries. The droplet generation in a flow-focusing microfluidic device with external mechanical vibration, as a controllable droplet generation method, is experimentally studied. The effects of vibration frequency and acceleration amplitude on the droplet generation are characterized. The linear correlation between the droplet generation frequency and the external vibration frequency and the critical vibration amplitude corresponding to the imposing vibration frequency are observed. The droplet generation frequency with external mechanical vibration is affected by the natural generation frequency, vibration frequency, and vibration amplitude. The droplet generation frequency in a certain microfluidic device with external vibration is able to vary from the natural generation frequency to the imposed vibration frequency at different vibration conditions. The evolution of dispersed phase thread with vibration is remarkably different with the process without vibration. Distinct stages of expansion, shrinkage, and collapse are observed in the droplet formation with vibration, and the occurrence number of expansion–shrinkage process is relevant with the linear correlation coefficient.
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Affiliation(s)
| | | | | | | | - Fubing Bao
- Correspondence: ; Tel.: +86-571-87676345
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24
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Azimi-Boulali J, Madadelahi M, Madou MJ, Martinez-Chapa SO. Droplet and Particle Generation on Centrifugal Microfluidic Platforms: A Review. MICROMACHINES 2020; 11:mi11060603. [PMID: 32580516 PMCID: PMC7344714 DOI: 10.3390/mi11060603] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 01/09/2023]
Abstract
The use of multiphase flows in microfluidics to carry dispersed phase material (droplets, particles, bubbles, or fibers) has many applications. In this review paper, we focus on such flows on centrifugal microfluidic platforms and present different methods of dispersed phase material generation. These methods are classified into three specific categories, i.e., step emulsification, crossflow, and dispenser nozzle. Previous works on these topics are discussed and related parameters and specifications, including the size, material, production rate, and rotational speed are explicitly mentioned. In addition, the associated theories and important dimensionless numbers are presented. Finally, we discuss the commercialization of these devices and show a comparison to unveil the pros and cons of the different methods so that researchers can select the centrifugal droplet/particle generation method which better suits their needs.
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Affiliation(s)
- Javid Azimi-Boulali
- School of Engineering and Sciences, Tecnológico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey 64849, NL, Mexico;
| | - Masoud Madadelahi
- School of Engineering and Sciences, Tecnológico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey 64849, NL, Mexico;
- Correspondence: (M.M.); (S.O.M.-C.)
| | - Marc J. Madou
- Department of Mechanical and Aerospace Engineering, University of California Irvine, Irvine, CA 92697, USA;
| | - Sergio O. Martinez-Chapa
- School of Engineering and Sciences, Tecnológico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey 64849, NL, Mexico;
- Correspondence: (M.M.); (S.O.M.-C.)
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25
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Wu S, Chen J, Liu X, Yao F. Experimental study of droplet formation in the cross-junction. J DISPER SCI TECHNOL 2020. [DOI: 10.1080/01932691.2020.1736092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Suchen Wu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Juan Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Xiangdong Liu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, China
- College of Electrical, Energy and Power Engineering, Yangzhou University, Yangzhou, China
| | - Feng Yao
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, China
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26
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Li L, Zhang C. Electro-hydrodynamics of droplet generation in a co-flowing microfluidic device under electric control. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124258] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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A Liquid-Metal-Based Dielectrophoretic Microdroplet Generator. MICROMACHINES 2019; 10:mi10110769. [PMID: 31718029 PMCID: PMC6915379 DOI: 10.3390/mi10110769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 02/06/2023]
Abstract
This paper proposes a novel microdroplet generator based on the dielectrophoretic (DEP) force. Unlike the conventional continuous microfluidic droplet generator, this droplet generator is more like “invisible electric scissors”. It can cut the droplet off from the fluid matrix and modify droplets’ length precisely by controlling the electrodes’ length and position. These electrodes are made of liquid metal by injection. By applying a certain voltage on the liquid-metal electrodes, the electrodes generate an uneven electric field inside the main microfluidic channel. Then, the uneven electric field generates DEP force inside the fluid. The DEP force shears off part from the main matrix, in order to generate droplets. To reveal the mechanism, numerical simulations were performed to analyze the DEP force. A detailed experimental parametric study was also performed. Unlike the traditional droplet generators, the main separating force of this work is DEP force only, which can produce one droplet at a time in a more precise way.
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Zhang JM, Ji Q, Duan H. Three-Dimensional Printed Devices in Droplet Microfluidics. MICROMACHINES 2019; 10:E754. [PMID: 31690055 PMCID: PMC6915402 DOI: 10.3390/mi10110754] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 12/18/2022]
Abstract
Droplet microfluidics has become the most promising subcategory of microfluidics since it contributes numerous applications to diverse fields. However, fabrication of microfluidic devices for droplet formation, manipulation and applications is usually complicated and expensive. Three-dimensional printing (3DP) provides an exciting alternative to conventional techniques by simplifying the process and reducing the cost of fabrication. Complex and novel structures can be achieved via 3DP in a simple and rapid manner, enabling droplet microfluidics accessible to more extensive users. In this article, we review and discuss current development, opportunities and challenges of applications of 3DP to droplet microfluidics.
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Affiliation(s)
- Jia Ming Zhang
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China.
| | - Qinglei Ji
- Department of Production Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
- Department of Machine Design, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Huiling Duan
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China.
- CAPT, HEDPS and IFSA Collaborative Innovation Center of MoE, Peking University, Beijing 100871, China.
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29
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Azarmanesh M, Bawazeer S, Mohamad AA, Sanati-Nezhad A. Rapid and Highly Controlled Generation of Monodisperse Multiple Emulsions via a One-Step Hybrid Microfluidic Device. Sci Rep 2019; 9:12694. [PMID: 31481702 PMCID: PMC6722102 DOI: 10.1038/s41598-019-49136-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/20/2019] [Indexed: 02/07/2023] Open
Abstract
Multiple Emulsions (MEs) contain a drop laden with many micro-droplets. A single-step microfluidic-based synthesis process of MEs is presented to provide a rapid and controlled generation of monodisperse MEs. The design relies on the interaction of three immiscible fluids with each other in subsequent droplet formation steps to generate monodisperse ME constructs. The design is within a microchannel consists of two compartments of cross-junction and T-junction. The high shear stress at the cross-junction creates a stagnation point that splits the first immiscible phase to four jet streams each of which are sprayed to micrometer droplets surrounded by the second phase. The resulted structure is then supported by the third phase at the T-junction to generate and transport MEs. The ME formation within microfluidics is numerically simulated and the effects of several key parameters on properties of MEs are investigated. The dimensionless modeling of ME formation enables to change only one parameter at the time and analyze the sensitivity of the system to each parameter. The results demonstrate the capability of highly controlled and high-throughput MEs formation in a one-step synthesis process. The consecutive MEs are monodisperse in size which open avenues for the generation of controlled MEs for different applications.
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Affiliation(s)
- Milad Azarmanesh
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Saleh Bawazeer
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Abdulmajeed A Mohamad
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
| | - Amir Sanati-Nezhad
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada. .,Center for Bioengineering Research and Education, Biomedical Engineering Program, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
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30
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Huang Y, Yin S, Chong WH, Wong TN, Ooi KT. Precise morphology control and fast merging of a complex multi-emulsion system: the effects of AC electric fields. SOFT MATTER 2019; 15:5614-5625. [PMID: 31166359 DOI: 10.1039/c9sm00430k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We showed that an AC electric field can be effectively used to control the full morphology of a multi-emulsion system (oil/water/oil, O/W/O and water/oil/water, W/O/W); specifically, the size of outer droplets and the number of inner droplets (from 5 to 0) could be controlled. In our system, such control was achieved by adopting non-contact type of electrodes together with double-flow-focusing geometry to apply an AC electric field during the formation of complex droplets. As such, the AC electric field could be used without contamination. In addition to morphology control, we also achieved both one-step and two-step merging of the core droplets in the W/O/W droplet system within 100 milliseconds, which is by far the fastest merging in double emulsion droplets ever reported. To the best of our knowledge, this paper is the first article to report the control of core droplets in an O/W/O system by matching the frequency of the AC electric field with that of the core production rate. In this article, we adopted the electric capillary number CaE to analyze the effectiveness of the AC electric field applied at a high frequency, which offers a guideline for practical applications. Furthermore, the merging phenomena among various droplet systems discovered could add extra dimensions for the manipulation of double emulsions. Our findings reveal new physical insights that bring about a better understanding of the interfacial phenomena and electrohydrodynamics of droplets, which is of great importance for practical applications involving the complex interactions of multiple droplets.
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Affiliation(s)
- Yi Huang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang, Avenue, 639798, Singapore.
| | - Shuai Yin
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang, Avenue, 639798, Singapore.
| | - Wen Han Chong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang, Avenue, 639798, Singapore.
| | - Teck Neng Wong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang, Avenue, 639798, Singapore.
| | - Kim Tiow Ooi
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang, Avenue, 639798, Singapore.
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Aydogan Gokturk P, Ulgut B, Suzer S. AC Electrowetting Modulation of Low-Volatile Liquids Probed by XPS: Dipolar vs Ionic Screening. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3319-3326. [PMID: 30768276 DOI: 10.1021/acs.langmuir.8b04099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
X-ray photoelectron spectroscopic (XPS) data have been recorded for a low-molecular-weight poly(ethylene glycol) microliter-sized sessile liquid drops sitting on a dielectric covered planar electrode while imposing a ±6 V square-wave actuation with varying frequencies between 10-1 and 105 Hz to tap into the information derivable from (AC) electrowetting. We show that this time-varying XPS spectra reveal two distinct behaviors of the device under investigation, below and above a critical frequency, measured as ∼70 Hz for the liquid poly(ethylene glycol) with a 600 Da molecular weight. Below the critical frequency, the liquid complies faithfully to the applied bias, as determined by the constant shift in the binding energy position of the XPS peaks representative of the liquid throughout its entire surface. The liquid completely screens the applied electrical field and the entire potential drop takes place at the liquid/dielectric interface. However, for frequencies above the critical value, the resistive component of the system dominates, resulting in the formation of equipotential surface contours, which are derived from the differences in the positions of the twinned O 1s peaks under AC application. This critical frequency is independent of the size of the liquid drop, and the amplitude of the excitation, but increases when ionic moieties are introduced. The XP spectra under AC actuation is also faithfully simulated using an equivalent circuit model consisting of only resistors and capacitors and using an electrical circuit simulation software. Moreover, a mimicking device is fabricated and its XP spectra are recorded using the Sn 3d peaks of the solder joints at different points on the circuit to confirm the reliability of the measured and simulated AC behaviors of the liquid. These new findings indicate that in contrast to direct current case, XPS measurements under variable frequency AC actuation reveal (through differences in the frequency response) information related to the chemical makeup of the liquid(s) and brings the laboratory-based XPS as a powerful complimentary arsenal to electrochemical analyses of liquids and their interfaces.
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Affiliation(s)
| | - Burak Ulgut
- Department of Chemistry , Bilkent University , Bilkent , 06800 Ankara , Turkey
| | - Sefik Suzer
- Department of Chemistry , Bilkent University , Bilkent , 06800 Ankara , Turkey
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Chen K, Sui C, Wu Y, Ao Z, Guo SS, Guo F. A digital acoustofluidic device for on-demand and oil-free droplet generation. NANOTECHNOLOGY 2019; 30:084001. [PMID: 30523921 DOI: 10.1088/1361-6528/aaf3fd] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report a digital acoustofluidic device for on-demand and oil-free droplet generation. By applying a programmed radio frequency signal to a circular interdigital transducer, the dynamic focused acoustic pressure profiles generated rise up and dispense sample liquids from a reservoir to dynamically eject the droplets into the air. Our device allows droplets to be dispensed on demand with precisely controlled generation time and sequence, and accurate droplet volume. Moreover, we also demonstrate the generation of a droplet with a volume of 24 pL within 10 ms, as well as the encapsulation of a single cell into droplets. This acoustofluidic droplet generation technique is simple, biocompatible, and enables the on-demand droplet generation and encapsulation of many different biological materials with precise control, which is promising for single cell sampling and analysis applications.
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Affiliation(s)
- Keke Chen
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China
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Maity S, Chaudhuri J, Mitra S, Rarotra S, Bandyopadhyay D. Electric field assisted multicomponent reaction in a microfluidic reactor for superior conversion and yield. Electrophoresis 2018; 40:401-409. [PMID: 30511476 DOI: 10.1002/elps.201800377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 11/22/2018] [Accepted: 11/22/2018] [Indexed: 11/11/2022]
Abstract
We explore the improvements in yield and conversion of a chemical reaction inside a two-phase microfluidic reactor when subjected to an externally applied alternating current (AC) electric field. A computational fluid dynamic (CFD) framework has been developed to incorporate the descriptions of the two-phase flow, multicomponent transport and reaction, and the Maxwell's stresses generated at oil-water interface owing to the presence of the externally applied electric field. The CFD model ensures that the reactants are flown into a microchannel together with the oil and water phases before the reaction takes place at the interface and products diffuse back to the bulk phases. The study unveils that the variation in the intensity of the AC field helps in converting a two-phase stratified flow into an oil-in-water microemulsion composed of oil slugs, plugs, or droplets. Importantly, the results also suggest that harnessing the vortices inside or outside these flow patterns helps in the improvement in mass transfer across the interface, which can be employed to improve the yield and conversion of a reaction. We have shown an example case of a pseudo-first order reaction for which the variation in frequency and intensity of AC field is found to form higher surface-to-volume-ratio flow patterns having a higher throughput. The convective recirculation in and around these miniaturized flow morphologies increase the rate of mass transfer, mixing of reactant and products, conversion of reactant, and yield of products. The results reported can be of significance in the design and development of future advanced-flow rector technologies.
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Affiliation(s)
- Surjendu Maity
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, India
| | - Joydip Chaudhuri
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India
| | - Shirsendu Mitra
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India
| | - Saptak Rarotra
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India
| | - Dipankar Bandyopadhyay
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, India.,Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India
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Pan Z, Men Y, Senapati S, Chang HC. Immersed AC electrospray (iACE) for monodispersed aqueous droplet generation. BIOMICROFLUIDICS 2018; 12:044113. [PMID: 30174772 PMCID: PMC6095705 DOI: 10.1063/1.5048307] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/07/2018] [Indexed: 05/16/2023]
Abstract
We report a new immersed alternating current (AC) electrospray droplet generation method that can generate monodispersed water-in-oil droplets, with diameters ranging from 5 μm to 150 μm, in a stationary oil phase. This method offers high through-put, easy size tuning, and droplets with a viscous aqueous phase at high ionic strengths (raw physiological samples). Yet, it does not require coordinated flows of the dispersed/continuous phases or even a microfluidic chip. The design relies on a small constant back pressure (less than 0.1 atm) to drive the water phase through a nozzle (glass micropipette) and a non-isotropic AC electric Maxwell pressure to eject it into the oil phase. Undesirable field-induced discharge and nanojet formation at the tip are suppressed with a biocompatible polymer, polyethylene oxide. Its viscoelastic property favors the monodispersed dripping mechanism, with a distinct neck forming at the capillary tip before pinch-off, such that the tip dimension is the only controlling length scale. Consecutive droplets are connected by a whipping filament that disperses the drops away from the high-field nozzle to prevent electro-coalescence. A scaling theory is developed to correlate the droplet size with the applied pressure, the most important tuning parameter, and to determine the optimum frequency. The potential applications of this technology to biological systems are demonstrated with a digital loop-mediated isothermal amplification experiment, with little damage to the nucleic acids and other biomolecules, but with easy adaptive tuning for the optimum droplet number for accurate quantification.
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Affiliation(s)
- Zehao Pan
- Center for Microfluidics and Medical Diagnostics, Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, 46556 Indiana, USA
| | - Yongfan Men
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Satyajyoti Senapati
- Center for Microfluidics and Medical Diagnostics, Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, 46556 Indiana, USA
| | - Hsueh-Chia Chang
- Center for Microfluidics and Medical Diagnostics, Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, 46556 Indiana, USA
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A stretchable conductive Polypyrrole Polydimethylsiloxane device fabricated by simple soft lithography and oxygen plasma treatment. Biomed Microdevices 2018; 20:30. [PMID: 29564563 DOI: 10.1007/s10544-018-0273-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
This paper reports a simple method used to fabricate a stretchable conductive polypyrrole (PPy) rough pore-shape polydimethylsiloxane (p-PDMS) device. An abrasive paper is first used to imprint rough micro-structures on the SU-8 micromold. The p-PDMS microchannel is then fabricated using a standard soft-lithography process. An oxygen plasma treatment is then applied to form an irreversible sealing between the microchannel and a blank cover PDMS. The conductive layer is formed by injecting the PPy mixture into the microchannel which polymerizes in the rough pore-shape micro-structures; The PPy/p-PDMS hybrid device shows good electrical property and stretchability. The electrical properties of different geometrical designs of the PPy/p-PDMS microchannel under stretching were investigated, including straight, curved, and serpentine. Mouse embryonic fibroblasts (NIH/3 T3) were also cultured inside the PPy/p-PDMS device to demonstrate good biocompatibility and feasibility using the conductive and stretchable microchannel in cell culture microfluidics applications. Finally, cyclic stretching and bending tests were performed to evaluate the reliability of PPy/p-PDMS microchannel.
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36
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Finite element modelling of non-faradic electric impedance spectroscopy through flexible polymer microchip. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2017.11.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Huang Y, Wang YL, Wong TN. AC electric field controlled non-Newtonian filament thinning and droplet formation on the microscale. LAB ON A CHIP 2017; 17:2969-2981. [PMID: 28745766 DOI: 10.1039/c7lc00420f] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Monodispersity and fast generation are innate advantages of microfluidic droplets. Other than the normally adopted simple Newtonian fluids such as a water/oil emulsion system, fluids with complex rheology, namely, non-Newtonian fluids, which are being widely adopted in industries and bioengineering, have gained increasing research interest on the microscale. However, challenges occur in controlling the dynamic behavior due to their complex properties. In this sense, the AC electric field with merits of fast response and easiness in fulfilling "Lab on a chip" has attracted our attention. We design and fabricate flow-focusing microchannels with non-contact types of electrodes for the investigation. We firstly compare the formation of a non-Newtonian droplet with that of a Newtonian one under an AC electric field and discover that viscoelasticity contributes to the discrepancies significantly. Then we explore the effect of AC electric fields on the filament thinning and droplet formation dynamics of one non-Newtonian fluid which has a similar rheological behavior to bio samples, such as DNA or blood samples. We investigate the dynamics of the thinning process of the non-Newtonian filament under the influence of an AC electric field and implement a systematic exploration of the non-Newtonian droplet generation influenced by parameters such as the flow conditions (flow rate Q, capillary number Ca), fluid property (Weissenberg number Wi), applied voltage (U) and frequency (f) of the AC electric field. We present the dependencies of the flow condition and electric field on the non-Newtonian droplet formation dynamics, and conclude with an operating diagram, taking into consideration all the above-mentioned parameters. Results show that the electric field plays a critical role in controlling the thinning process of the filament and the size of the generated droplet. Furthermore, for the first time, we quantitatively measure the flow field of the non-Newtonian droplet formation under the influence of an AC electric field, assisted by a high-speed micro particle imaging velocimetry (μPIV) system. The flow field distributions obtained using the correlation algorithm show that the electric field generated Maxwell stress deforms the interface, changes the flow recirculation pattern, stimulates the instability and hence reduces the size of the non-Newtonian droplet. Finally, we analyze the impact of Maxwell stress by means of the electric capillary number CaE. Our findings reveal the rich physics of non-Newtonian fluids and widen the applications of electric field in non-Newtonian environments, which could be critical for bioengineering.
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Affiliation(s)
- Y Huang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore.
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Abstract
In this work, we investigate the pulsation of an electrically charged jet surrounded by an immiscible dielectric liquid in flow-focusing capillary microfluidics. We have characterized a low-frequency large-amplitude pulsation and a high-frequency small-amplitude pulsation, respectively. The former, due to the unbalanced charge and fluid transportation is responsible for generating droplets with a broad size distribution. The latter is intrinsic and produces droplets with a relatively narrow size distribution. Moreover, the average size of the final droplets can be tuned via the intrinsic pulsating frequency through changing the diameter of the emitted liquid jet. Our results provide degree of control over the emulsion droplets with submicron sizes generated in microfluidic-electrospray platform.
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Abstract
Droplet microfluidics generates and manipulates discrete droplets through immiscible multiphase flows inside microchannels. Due to its remarkable advantages, droplet microfluidics bears significant value in an extremely wide range of area. In this review, we provide a comprehensive and in-depth insight into droplet microfluidics, covering fundamental research from microfluidic chip fabrication and droplet generation to the applications of droplets in bio(chemical) analysis and materials generation. The purpose of this review is to convey the fundamentals of droplet microfluidics, a critical analysis on its current status and challenges, and opinions on its future development. We believe this review will promote communications among biology, chemistry, physics, and materials science.
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Affiliation(s)
- Luoran Shang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yao Cheng
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yuanjin Zhao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
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Abstract
In the recent past, the field of optofluidics has thrived from the immense efforts of researchers from diverse communities. The concept of optofluidics combines optics and microfluidics to exploit novel properties and functionalities. In the very beginning, the unique properties of liquid, such as mobility, fungibility and deformability, initiated the motivation to develop optical elements or functions using fluid interfaces. Later on, the advancements of microelectromechanical system (MEMS) and microfluidic technologies enabled the realization of optofluidic components through the precise manipulation of fluids at microscale thus making it possible to streamline complex fabrication processes. The optofluidic system aims to fully integrate optical functions on a single chip instead of using external bulky optics, which can consequently lower the cost of system, downsize the system and make it promising for point-of-care diagnosis. This perspective gives an overview of the recent developments in the field of optofluidics. Firstly, the fundamental optofluidic components will be discussed and are categorized according to their basic working mechanisms, followed by the discussions on the functional instrumentations of the optofluidic components, as well as the current commercialization aspects of optofluidics. The paper concludes with the critical challenges that might hamper the transformation of optofluidic technologies from lab-based procedures to practical usages and commercialization.
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Xi HD, Zheng H, Guo W, Gañán-Calvo AM, Ai Y, Tsao CW, Zhou J, Li W, Huang Y, Nguyen NT, Tan SH. Active droplet sorting in microfluidics: a review. LAB ON A CHIP 2017; 17:751-771. [PMID: 28197601 DOI: 10.1039/c6lc01435f] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The ability to manipulate and sort droplets is a fundamental issue in droplet-based microfluidics. Various lab-on-a-chip applications can only be realized if droplets are systematically categorized and sorted. These micron-sized droplets act as ideal reactors which compartmentalize different biological and chemical reagents. Array processing of these droplets hinges on the competence of the sorting and integration into the fluidic system. Recent technological advances only allow droplets to be actively sorted at the rate of kilohertz or less. In this review, we present state-of-the-art technologies which are implemented to efficiently sort droplets. We classify the concepts according to the type of energy implemented into the system. We also discuss various key issues and provide insights into various systems.
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Affiliation(s)
- Heng-Dong Xi
- School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd., Xi'an, Shaanxi, China
| | - Hao Zheng
- School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd., Xi'an, Shaanxi, China
| | - Wei Guo
- School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd., Xi'an, Shaanxi, China and Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road, Brisbane, QLD 4111, Australia.
| | - Alfonso M Gañán-Calvo
- Depto. de Ingeniería Aeroespacial y Mecánica de Fluidos, Universidad de Sevilla, E-41092 Sevilla, Spain
| | - Ye Ai
- Pillar of Engineering Product Development, Singapore University of Technology and Design, Singapore
| | - Chia-Wen Tsao
- Department of Mechanical Engineering, National Central University, No. 300, Zhongda Rd, Taoyuan, Taiwan
| | - Jun Zhou
- School of Information and Communication Technology, Griffith University, Nathan, QLD 4111, Australia
| | - Weihua Li
- School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Yanyi Huang
- Biodynamic Optical Imaging Center, Peking University, Beijing 100871, China
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road, Brisbane, QLD 4111, Australia.
| | - Say Hwa Tan
- Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road, Brisbane, QLD 4111, Australia.
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Teo AJT, Li KHH, Nguyen NT, Guo W, Heere N, Xi HD, Tsao CW, Li W, Tan SH. Negative Pressure Induced Droplet Generation in a Microfluidic Flow-Focusing Device. Anal Chem 2017; 89:4387-4391. [DOI: 10.1021/acs.analchem.6b05053] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Adrian J. T. Teo
- Queensland
Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia
- School
of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore (639798)
| | - King-Ho Holden Li
- School
of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore (639798)
| | - Nam-Trung Nguyen
- Queensland
Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia
| | - Wei Guo
- Queensland
Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia
- School
of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd, Xi’an, Shaanxi China
| | - Nadine Heere
- Queensland
Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia
- Institute
of Cognitive Science, University of Osnabrück, 49069 Osnabrück, Germany
| | - Heng-Dong Xi
- School
of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd, Xi’an, Shaanxi China
| | - Chia-Wen Tsao
- Department
of Mechanical Engineering, National Central University, No. 300,
Zhongda Road, Taoyuan, Taiwan
| | - Weihua Li
- School
of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Say Hwa Tan
- Queensland
Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia
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Zhu P, Wang L. Passive and active droplet generation with microfluidics: a review. LAB ON A CHIP 2016; 17:34-75. [PMID: 27841886 DOI: 10.1039/c6lc01018k] [Citation(s) in RCA: 510] [Impact Index Per Article: 63.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Precise and effective control of droplet generation is critical for applications of droplet microfluidics ranging from materials synthesis to lab-on-a-chip systems. Methods for droplet generation can be either passive or active, where the former generates droplets without external actuation, and the latter makes use of additional energy input in promoting interfacial instabilities for droplet generation. A unified physical understanding of both passive and active droplet generation is beneficial for effectively developing new techniques meeting various demands arising from applications. Our review of passive approaches focuses on the characteristics and mechanisms of breakup modes of droplet generation occurring in microfluidic cross-flow, co-flow, flow-focusing, and step emulsification configurations. The review of active approaches covers the state-of-the-art techniques employing either external forces from electrical, magnetic and centrifugal fields or methods of modifying intrinsic properties of flows or fluids such as velocity, viscosity, interfacial tension, channel wettability, and fluid density, with a focus on their implementations and actuation mechanisms. Also included in this review is the contrast among different approaches of either passive or active nature.
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Affiliation(s)
- Pingan Zhu
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. and HKU-Zhejiang Institute of Research and Innovation (HKU-ZIRI), 311300, Hangzhou, Zhejiang, China
| | - Liqiu Wang
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. and HKU-Zhejiang Institute of Research and Innovation (HKU-ZIRI), 311300, Hangzhou, Zhejiang, China
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Timung S, Chaudhuri J, Borthakur MP, Mandal TK, Biswas G, Bandyopadhyay D. Electric field mediated spraying of miniaturized droplets inside microchannel. Electrophoresis 2016; 38:1450-1457. [DOI: 10.1002/elps.201600311] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/27/2016] [Accepted: 09/11/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Seim Timung
- Department of Chemical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam India
| | - Joydip Chaudhuri
- Department of Chemical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam India
| | - Manash Pratim Borthakur
- Department of Mechanical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam India
| | - Tapas Kumar Mandal
- Department of Chemical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam India
- Centre for Nanotechnology; Indian Institute of Technology Guwahati; Guwahati Assam India
| | - Gautam Biswas
- Department of Mechanical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam India
| | - Dipankar Bandyopadhyay
- Department of Chemical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam India
- Centre for Nanotechnology; Indian Institute of Technology Guwahati; Guwahati Assam India
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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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Jia Y, Ren Y, Liu W, Hou L, Tao Y, Hu Q, Jiang H. Electrocoalescence of paired droplets encapsulated in double-emulsion drops. LAB ON A CHIP 2016; 16:4313-4318. [PMID: 27714017 DOI: 10.1039/c6lc01052k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We utilize an ac electric field to trigger the on-demand fusion of two aqueous cores inside water-in-oil-in-water (W/O/W) double-emulsion drops. We attribute the coalescence phenomenon to field-induced structural polarization and breakdown of the stress balance at interfaces. This method provides not only accurate control over the reaction time of coalescence but also protection of the reaction from cross contamination.
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Affiliation(s)
- Yankai Jia
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China. and State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Weiyu Liu
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Likai Hou
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Ye Tao
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Qingming Hu
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Hongyuan Jiang
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China. and State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
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48
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Chaudhuri J, Timung S, Dandamudi CB, Mandal TK, Bandyopadhyay D. Discrete electric field mediated droplet splitting in microchannels: Fission, Cascade, and Rayleigh modes. Electrophoresis 2016; 38:278-286. [PMID: 27436402 DOI: 10.1002/elps.201600276] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/10/2016] [Accepted: 07/11/2016] [Indexed: 01/24/2023]
Abstract
Numerical simulations supplemented by experiments together uncovered that strategic integration of discrete electric fields in a non-invasive manner could substantially miniaturize the droplets into smaller parts in a pressure driven oil-water flow inside microchannels. The Maxwell's stress generated from the electric field at the oil-water interface could deform, stretch, neck, pin, and disintegrate a droplet into many miniaturized daughter droplets, which eventually ushered a one-step method to form water-in-oil microemulsion employing microchannels. The interplay between electrostatic, inertial, capillary, and viscous forces led to various pathways of droplet breaking, namely, fission, cascade, or Rayleigh modes. While a localized electric field in the fission mode could split a droplet into a number of daughter droplets of smaller size, the cascade or the Rayleigh mode led to the formation of an array of miniaturized droplets when multiple electrodes generating different field intensities were ingeniously assembled around the microchannel. The droplets size and frequency could be tuned by varying the field intensity, channel diameter, electrode locations, interfacial tension, and flow ratio. The proposed methodology shows a simple methodology to transform a microdroplet into an array of miniaturized ones inside a straight microchannel for enhanced mass, energy, and momentum transfer, and higher throughput.
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Affiliation(s)
- Joydip Chaudhuri
- Department of Chemical Engineering, Indian Institute of Technology, Guwahati, India
| | - Seim Timung
- Department of Chemical Engineering, Indian Institute of Technology, Guwahati, India
| | | | - Tapas Kumar Mandal
- Department of Chemical Engineering, Indian Institute of Technology, Guwahati, India.,Centre for Nanotechnology, Indian Institute of Technology, Guwahati, India
| | - Dipankar Bandyopadhyay
- Department of Chemical Engineering, Indian Institute of Technology, Guwahati, India.,Centre for Nanotechnology, Indian Institute of Technology, Guwahati, India
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49
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Xi HD, Guo W, Leniart M, Chong ZZ, Tan SH. AC electric field induced droplet deformation in a microfluidic T-junction. LAB ON A CHIP 2016; 16:2982-2986. [PMID: 27173587 DOI: 10.1039/c6lc00448b] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present for the first time an experimental study on the droplet deformation induced by an AC electric field in droplet-based microfluidics. It is found that the deformation of the droplets becomes stronger with increasing electric field intensity and frequency. The measured electric field intensity dependence of the droplet deformation is consistent with an early theoretical prediction for stationary droplets. We also proposed a simple equivalent circuit model to account for the frequency dependence of the droplet deformation. The model well explains our experimental observations. In addition, we found that the droplets can be deformed repeatedly by applying an amplitude modulation (AM) signal.
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Affiliation(s)
- Heng-Dong Xi
- School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd, Xi'an, Shaanxi, China
| | - Wei Guo
- School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd, Xi'an, Shaanxi, China
| | - Michael Leniart
- University of Duisburg-Essen, University Street 2, Essen 45117, Germany and Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia.
| | - Zhuang Zhi Chong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore
| | - Say Hwa Tan
- Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia.
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50
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Castro-Hernández E, García-Sánchez P, Alzaga-Gimeno J, Tan SH, Baret JC, Ramos A. AC electrified jets in a flow-focusing device: Jet length scaling. BIOMICROFLUIDICS 2016; 10:043504. [PMID: 27375826 PMCID: PMC4912565 DOI: 10.1063/1.4954194] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/04/2016] [Indexed: 05/11/2023]
Abstract
We use a microfluidic flow-focusing device with integrated electrodes for controlling the production of water-in-oil drops. In a previous work, we reported that very long jets can be formed upon application of AC fields. We now study in detail the appearance of the long jets as a function of the electrical parameters, i.e., water conductivity, signal frequency, and voltage amplitude. For intermediate frequencies, we find a threshold voltage above which the jet length rapidly increases. Interestingly, this abrupt transition vanishes for high frequencies of the signal and the jet length grows smoothly with voltage. For frequencies below a threshold value, we previously reported a transition from a well-behaved uniform jet to highly unstable liquid structures in which axisymmetry is lost rather abruptly. These liquid filaments eventually break into droplets of different sizes. In this work, we characterize this transition with a diagram as a function of voltage and liquid conductivity. The electrical response of the long jets was studied via a distributed element circuit model. The model allows us to estimate the electric potential at the tip of the jet revealing that, for any combination of the electrical parameters, the breakup of the jet occurs at a critical value of this potential. We show that this voltage is around 550 V for our device geometry and choice of flow rates.
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Affiliation(s)
- Elena Castro-Hernández
- Área de Mecánica de Fluidos, Departamento de Ingeniería Aeroespacial y Mecánica de Fluidos, Universidad de Sevilla , Avenida de los Descubrimientos s/n, 41092 Sevilla, Spain
| | - Pablo García-Sánchez
- Departamento de Electrónica y Electromagnetismo, Facultad de Física, Universidad de Sevilla , Avenida de Reina Mercedes s/n, 41012 Sevilla, Spain
| | - Javier Alzaga-Gimeno
- Área de Mecánica de Fluidos, Departamento de Ingeniería Aeroespacial y Mecánica de Fluidos, Universidad de Sevilla , Avenida de los Descubrimientos s/n, 41092 Sevilla, Spain
| | - Say Hwa Tan
- Queensland Micro- and Nanotechnology Centre, Griffith University , Brisbane QLD 4111, Australia
| | - Jean-Christophe Baret
- CNRS, Univ. Bordeaux , CRPP, UPR 8641, Soft Micro Systems, 115 Avenue Schweitzer, 33600 Pessac, France and Max-Planck Institute for Dynamics and Self-Organization, Droplets, Membranes and Interfaces, Am Fassberg 17, DE-37077 Goettingen, Germany
| | - Antonio Ramos
- Departamento de Electrónica y Electromagnetismo, Facultad de Física, Universidad de Sevilla , Avenida de Reina Mercedes s/n, 41012 Sevilla, Spain
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