1
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Huang D, Huang E, Cai D, Chen Z, Wen H, Wang Y, Ma D, Lu Y, Liu X, Liu D. Automated Droplet Ejection from a Digital Microfluidics Sample Pretreatment Device Enables Batch-Mode Chemiluminescence Immunoassay. Anal Chem 2024. [PMID: 39103289 DOI: 10.1021/acs.analchem.4c02217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2024]
Abstract
Digital microfluidics (DMF) features programmed manipulation of fluids in multiple steps, making it a valuable tool for sample pretreatment. However, the integration of sample pretreatment with its downstream reaction and detection requires transferring droplets from the DMF device to the outside world. To address this issue, the present study developed a modified DMF device that allows automated droplet ejection out of the chip, facilitated by a tailor-designed interface. A double-layered DMF microchip with an oil-filled medium was flipped over, with a liquid infusion port and a liquid expulsion port accommodated on the top working PCB plate and the bottom grounded ITO plate, respectively, to facilitate chip-to-world delivery of droplets. Using chemiluminescent immunoassay (CLIA) as an illustrative application, the sample pretreatment was programmed on the DMF device, and CLIA droplets were ejected from the chip for signal reading. In our workflow, CLIA droplets can be ejected from the DMF device through the chip-to-world interface, freeing up otherwise occupied electrodes for more sample pretreatment and enabling streamlined droplet microreactions and batch-mode operation for bioanalysis. Integrated with these interfacing portals, the DMF system achieved a single-channel throughput of 17 samples per hour, which can be further upscaled for more productive applications by parallelizing the DMF modules. The results of this study demonstrate that the droplet ejection function that is innovated in a DMF sample pretreatment microsystem can significantly improve analytical throughput, providing an approach to establishing an automated but decentralized biochemical sample preparation workstation for large-scale and continuous bioanalysis.
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Affiliation(s)
- Dezhi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen 518116, China
| | - Enqi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China
| | - Dongyang Cai
- Department of Laboratory Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China
- Guangdong Engineering Technology Research Center of Microfluidic Chip Medical Diagnosis, Guangzhou 510180, China
| | - Zhenhua Chen
- Department of Laboratory Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China
- Guangdong Engineering Technology Research Center of Microfluidic Chip Medical Diagnosis, Guangzhou 510180, China
| | - Hongting Wen
- Department of Laboratory Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China
| | - Yu Wang
- Department of Laboratory Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China
| | - Dachuan Ma
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
| | - Yao Lu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
| | - Xianming Liu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
| | - Dayu Liu
- Department of Laboratory Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510180, China
- Guangdong Engineering Technology Research Center of Microfluidic Chip Medical Diagnosis, Guangzhou 510180, China
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2
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Xu M, Vidler C, Wang J, Chen X, Pan Z, Harley WS, Lee PVS, Collins DJ. Micro-Acoustic Holograms for Detachable Microfluidic Devices. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2307529. [PMID: 38174594 DOI: 10.1002/smll.202307529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/24/2023] [Indexed: 01/05/2024]
Abstract
Acoustic microfluidic devices have advantages for diagnostic applications, therapeutic solutions, and fundamental research due to their contactless operation, simple design, and biocompatibility. However, most acoustofluidic approaches are limited to forming simple and fixed acoustic patterns, or have limited resolution. In this study,a detachable microfluidic device is demonstrated employing miniature acoustic holograms to create reconfigurable, flexible, and high-resolution acoustic fields in microfluidic channels, where the introduction of a solid coupling layer makes these holograms easy to fabricate and integrate. The application of this method to generate flexible acoustic fields, including shapes, characters, and arbitrarily rotated patterns, within microfluidic channels, is demonstrated.
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Affiliation(s)
- Mingxin Xu
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Callum Vidler
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Jizhen Wang
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Xi Chen
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Zijian Pan
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - William S Harley
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Peter V S Lee
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
- Graeme Clarke Institute, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - David J Collins
- Department of Biomedical Engineering, University of Melbourne, Melbourne, Victoria, 3010, Australia
- Graeme Clarke Institute, University of Melbourne, Parkville, Victoria, 3052, Australia
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3
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Bai YH, Chiu SY, Jiang HR. Deflection of sliding droplets by dielectrophoresis force on a superhydrophobic surface. Sci Rep 2024; 14:12458. [PMID: 38816437 PMCID: PMC11139917 DOI: 10.1038/s41598-024-62925-z] [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: 03/01/2024] [Accepted: 05/22/2024] [Indexed: 06/01/2024] Open
Abstract
In this study, we experimentally identify the effect of liquid dielectrophoresis (LDEP) force on a superhydrophobic surface in directing the trajectory of moving water droplets across designed interdigitated electrodes and show that this method is capable of rapidly selecting droplets at a high speed (200 mm/s). As the droplets traverse down the surface by the electric field, their deflection on the edge of these electrodes is achieved successively, allowing for the selective manipulation of discrete droplets. A series of experiments were conducted to validate the relationships among droplet deflections, applied electric fields, and dynamic contact angles. Our findings reveal that the principal driving force behind the droplet deflections is the LDEP force, which can provide instant manipulation of moving droplets rather than a variation in contact angles brought about by electrowetting. This study presents a proof-of-concept experiment utilizing LDEP for high-throughput droplet selection and also highlights the potential applications of this mechanism in high-speed digital microfluidics (DMF) and biological separation methodologies.
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Affiliation(s)
- Yun-Han Bai
- Institute of Applied Mechanics, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Da'an Dist., Taipei City, 106, Taiwan (R.O.C.)
| | - Shih-Yuan Chiu
- Department of Electrical Engineering, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Da'an Dist., Taipei City, 106, Taiwan (R.O.C.)
| | - Hong-Ren Jiang
- Institute of Applied Mechanics, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Da'an Dist., Taipei City, 106, Taiwan (R.O.C.).
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4
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Zeng X, Jiang S, Zhong Z, Yang X, Chen Q, Li J, Zhu Z, Song J, Yang C. DIRECT: Digital Microfluidics for Isolation-Free Shared Library Construction of Single-Cell DNA Methylome and Transcriptome. SMALL METHODS 2024; 8:e2301075. [PMID: 37772685 DOI: 10.1002/smtd.202301075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/04/2023] [Indexed: 09/30/2023]
Abstract
Simultaneous profiling of DNA methylation and gene expression within single cells is a powerful technology to dissect complex gene regulatory network of cells. However, existing methods are based on picking a single-cell in a tube and split single-cell lysate into two parts for transcriptome and methylome library construction, respectively, which is costly and cumbersome. Here, DIRECT is proposed, a digital microfluidics-based method for high-efficiency single-cell isolation and simultaneous analysis of the methylome and transcriptome in a single library construction. The accuracy of DIRECT is demonstrated in comparison with bulk and single-omics data, and the high CpG site coverage of DIRECT allows for precise analysis of copy number variation information, enabling expansion of single cell analysis from two- to three-omics. By applying DIRECT to monitor the dynamics of mouse embryonic stem cell differentiation, the relationship between DNA methylation and changes in gene expression during differentiation is revealed. DIRECT enables accurate, robust, and reproducible single-cell DNA methylation and gene expression co-analysis in a more cost-effective, simpler library preparation and automated manner, broadening the application scenarios of single-cell multi-omics analysis and revealing a more comprehensive and fine-grained map of cellular regulatory landscapes.
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Affiliation(s)
- Xi Zeng
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Shaowei Jiang
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Zhixing Zhong
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Xiaoping Yang
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Qiuyue Chen
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Jin Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200433, P. R. China
| | - Zhi Zhu
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Jia Song
- Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200120, P. R. China
| | - Chaoyong Yang
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
- Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200120, P. R. China
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5
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Tang Y, Duan F, Zhou A, Kanitthamniyom P, Luo S, Hu X, Jiang X, Vasoo S, Zhang X, Zhang Y. Image-based real-time feedback control of magnetic digital microfluidics by artificial intelligence-empowered rapid object detector for automated in vitro diagnostics. Bioeng Transl Med 2023; 8:e10428. [PMID: 37476053 PMCID: PMC10354763 DOI: 10.1002/btm2.10428] [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: 03/25/2022] [Revised: 09/19/2022] [Accepted: 10/03/2022] [Indexed: 11/12/2022] Open
Abstract
In vitro diagnostics (IVD) plays a critical role in healthcare and public health management. Magnetic digital microfluidics (MDM) perform IVD assays by manipulating droplets on an open substrate with magnetic particles. Automated IVD based on MDM could reduce the risk of accidental exposure to contagious pathogens among healthcare workers. However, it remains challenging to create a fully automated IVD platform based on the MDM technology because of a lack of effective feedback control system to ensure the successful execution of various droplet operations required for IVD. In this work, an artificial intelligence (AI)-empowered MDM platform with image-based real-time feedback control is presented. The AI is trained to recognize droplets and magnetic particles, measure their size, and determine their location and relationship in real time; it shows the ability to rectify failed droplet operations based on the feedback information, a function that is unattainable by conventional MDM platforms, thereby ensuring that the entire IVD process is not interrupted due to the failure of liquid handling. We demonstrate fundamental droplet operations, which include droplet transport, particle extraction, droplet merging and droplet mixing, on the MDM platform and show how the AI rectify failed droplet operations by acting upon the feedback information. Protein quantification and antibiotic resistance detection are performed on this AI-empowered MDM platform, and the results obtained agree well with the benchmarks. We envision that this AI-based feedback approach will be widely adopted not only by MDM but also by other types of digital microfluidic platforms to offer precise and error-free droplet operations for a wide range of automated IVD applications.
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Affiliation(s)
- Yuxuan Tang
- School of Mechanical and Aerospace EngineeringNanyang Technological UniversitySingaporeSingapore
| | - Fei Duan
- School of Mechanical and Aerospace EngineeringNanyang Technological UniversitySingaporeSingapore
| | - Aiwu Zhou
- Singapore Center for 3D Printing, School of Mechanical and Aerospace EngineeringNanyang Technological UniversitySingaporeSingapore
| | - Pojchanun Kanitthamniyom
- School of Mechanical and Aerospace EngineeringNanyang Technological UniversitySingaporeSingapore
| | - Shaobo Luo
- School of MicroelectronicsSouthern University of Science and TechnologyShenzhenChina
| | - Xuyang Hu
- China‐Singapore International Joint Research InstituteGuangzhouChina
| | - Xudong Jiang
- School of Electronic and Electrical EngineeringNanyang Technological UniversitySingaporeSingapore
| | - Shawn Vasoo
- National Center for Infectious DiseaseTan Tock Seng HospitalSingaporeSingapore
| | - Xiaosheng Zhang
- School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Yi Zhang
- School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengduChina
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6
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Wang X, Hong XZ, Li YW, Li Y, Wang J, Chen P, Liu BF. Microfluidics-based strategies for molecular diagnostics of infectious diseases. Mil Med Res 2022; 9:11. [PMID: 35300739 PMCID: PMC8930194 DOI: 10.1186/s40779-022-00374-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 03/10/2022] [Indexed: 02/08/2023] Open
Abstract
Traditional diagnostic strategies for infectious disease detection require benchtop instruments that are inappropriate for point-of-care testing (POCT). Emerging microfluidics, a highly miniaturized, automatic, and integrated technology, are a potential substitute for traditional methods in performing rapid, low-cost, accurate, and on-site diagnoses. Molecular diagnostics are widely used in microfluidic devices as the most effective approaches for pathogen detection. This review summarizes the latest advances in microfluidics-based molecular diagnostics for infectious diseases from academic perspectives and industrial outlooks. First, we introduce the typical on-chip nucleic acid processes, including sample preprocessing, amplification, and signal read-out. Then, four categories of microfluidic platforms are compared with respect to features, merits, and demerits. We further discuss application of the digital assay in absolute nucleic acid quantification. Both the classic and recent microfluidics-based commercial molecular diagnostic devices are summarized as proof of the current market status. Finally, we propose future directions for microfluidics-based infectious disease diagnosis.
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Affiliation(s)
- Xin Wang
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Xian-Zhe Hong
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Yi-Wei Li
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Ying Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan National Laboratory for Optoelectronics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences - Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430071 China
| | - Jie Wang
- Department of Radiology, Canary Center at Stanford for Cancer Early Detection, School of Medicine, Stanford University, Palo Alto, CA 94304 USA
| | - Peng Chen
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Bi-Feng Liu
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
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7
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Perdigones F, Quero JM. Printed Circuit Boards: The Layers' Functions for Electronic and Biomedical Engineering. MICROMACHINES 2022; 13:460. [PMID: 35334752 PMCID: PMC8952574 DOI: 10.3390/mi13030460] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/08/2022] [Accepted: 03/14/2022] [Indexed: 01/25/2023]
Abstract
This paper describes the fabrication opportunities that Printed Circuit Boards (PCBs) offer for electronic and biomedical engineering. Historically, PCB substrates have been used to support the components of the electronic devices, linking them using copper lines, and providing input and output pads to connect the rest of the system. In addition, this kind of substrate is an emerging material for biomedical engineering thanks to its many interesting characteristics, such as its commercial availability at a low cost with very good tolerance and versatility, due to its multilayer characteristics; that is, the possibility of using several metals and substrate layers. The alternative uses of copper, gold, Flame Retardant 4 (FR4) and silver layers, together with the use of vias, solder masks and a rigid and flexible substrate, are noted. Among other uses, these characteristics have been using to develop many sensors, biosensors and actuators, and PCB-based lab-on chips; for example, deoxyribonucleic acid (DNA) amplification devices for Polymerase Chain Reaction (PCR). In addition, several applications of these devices are going to be noted in this paper, and two tables summarizing the layers' functions are included in the discussion: the first one for metallic layers, and the second one for the vias, solder mask, flexible and rigid substrate functions.
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8
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Enel A, Vial J, Thiébaut D, Bourlon B. Gas Digital Microfluidic Platform: Application to Highly Volatile Compound Preconcentration. Anal Chem 2022; 94:4359-4365. [PMID: 35235299 DOI: 10.1021/acs.analchem.1c05128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Digital microfluidics platforms (DMFPs) have shown their efficiency in sample handling, using elementary operations that may be combined to perform complex applications. In this article, we present a new platform for gaseous samples handling involving a two-step digital preconcentration using the miniaturized preconcentrators of the DMFP. Choosing n-pentane at very low concentrations as a model for highly volatile compounds, poorly retained on the sorbent, the DMFP allowed bypassing the limit set by the breakthrough volume by repeating an elementary operation. It enabled a 5-fold increase of preconcentration factors in comparison to a single preconcentration step and an easier monitoring of the model compound. Promising applications are expected, as this system could be adapted to most volatile compound analysis devices, including micro gas chromatographs, to replace the current single-step preconcentration systems. By switching to two-step preconcentration with a DMFP, i.e., a digital preconcentration, it would be possible to get more concentrated samples through the column for easier trace analysis.
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Affiliation(s)
- Antoine Enel
- Université Grenoble Alpes, CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38000 Grenoble, France.,UMR8231 CBI, LSABM, ESPCI Paris-CNRS, PSL Institute, 10 rue Vauquelin, 75005 Paris, France
| | - Jérôme Vial
- UMR8231 CBI, LSABM, ESPCI Paris-CNRS, PSL Institute, 10 rue Vauquelin, 75005 Paris, France
| | - Didier Thiébaut
- UMR8231 CBI, LSABM, ESPCI Paris-CNRS, PSL Institute, 10 rue Vauquelin, 75005 Paris, France
| | - Bertrand Bourlon
- Université Grenoble Alpes, CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38000 Grenoble, France
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9
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Li H, Jiao L, Chen R, Zhu X, Yang Y, Ye D, Wang H, Yang Y, Liao Q. Upper Limit of Light-Levitated Droplet Motion. Anal Chem 2021; 93:16008-16016. [PMID: 34797649 DOI: 10.1021/acs.analchem.1c03512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The light-enabled droplet levitation shows promising potential in applications in biotechnology, clinical medicine, and nanomaterials. In particular, light-levitated droplets have good followability with a moving laser beam, resulting in flexibility in manipulating their motion. However, it is still unclear whether there exists an upper limit to the light-levitated droplet motion with a moving laser beam. Therefore, the motion of light-levitated droplets above the free interface is studied to determine the upper limit of motions of the droplets with a moving laser beam. We demonstrate that an inefficient interface temperature response because of a very high moving speed of the laser beam and the resultant small upward vertical component of vapor flow are responsible for the existence of an upper-limit velocity. Above the upper limit, the light-levitated droplets are unable to stably move with the laser beam and finally disappear. By contrast, the droplets can stably move with the laser beam in a wide range at or below this upper limit. In addition, an almost linear relationship between the upper-limit velocity of the light-levitated droplets and the input laser power is presented. The findings of the present study are informative for the implementation of this light levitation technology.
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Affiliation(s)
- Haonan Li
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Long Jiao
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Rong Chen
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Xun Zhu
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Yang Yang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Dingding Ye
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Hong Wang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Yijing Yang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
| | - Qiang Liao
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China.,Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China
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10
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Chen YY, Ting IJ, Wang SC. Using office inkjet printer to develop paper-based electrowetting-on-dielectric micromixer based on capillary wave-induced droplet vibration mixing for the reproducibility improvement of chemiluminescence assays. J Taiwan Inst Chem Eng 2021. [DOI: 10.1016/j.jtice.2021.07.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Yang YT, Ho TY. Conquering the Tyranny of Number With Digital Microfluidics. Front Chem 2021; 9:676365. [PMID: 34124004 PMCID: PMC8187867 DOI: 10.3389/fchem.2021.676365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/07/2021] [Indexed: 11/25/2022] Open
Abstract
The development of large-scale integration based on soft lithography has ushered a new revolution in microfluidics. This technology, however, relies inherently on pneumatic control of micromechanical valves that require air pressure to operate, while digital microfluidics uses a purely electrical signal on an electrode for droplet manipulation. In this article, we discuss the prospect and current challenges of digital microfluidics to solve the problem of the tyranny of numbers in arbitrary fluidic manipulation. We distill the fundamental physics governing electrowetting and their implications for specifications of the control electronics. We survey existing control electronics in digital microfluidics and detail the improvements needed to realize a low-power, programmable digital microfluidic system. Such an instrument would attract wide interest in both professional and non-professional (hobbyist) communities.
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Affiliation(s)
- Ya-Tang Yang
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - Tsung-Yi Ho
- Department of Computer Science, National Tsing Hua University, Hsinchu, Taiwan
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12
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Wang FM, Lu IP, Lin CT, Lu SS, Fan SK. Field-effect pump: liquid dielectrophoresis along a virtual microchannel with source-gate-drain electric fields. LAB ON A CHIP 2021; 21:2372-2382. [PMID: 34128001 DOI: 10.1039/d0lc01268h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We investigate liquid dielectrophoresis (LDEP) to implement field-effect pumps (FEPs) that drive liquids from source, via gate, toward drain electric fields between parallel plates without external pumps or the problem of dead volume. The appropriate gate electric field establishes a wall-less virtual microchannel to transfer the liquid from source to drain with an adjustable flow rate (Q) controlled by the difference of the square of the electric field strength (ΔE2DS). Analogous to field-effect transistors (FETs), the FEPs can operate in a "linear", "transition" or "saturation" region depending on ΔE2GD and ΔE2DS. With a sufficient ΔE2GD and a small ΔE2DS, the FEPs operated in the linear region where Q was linearly proportional to ΔE2DS and inversely proportional to the flow resistance R that was mainly determined by the length (L), width (W) and height (H) of a stable and fully-occupied virtual microchannel. With an insufficient ΔE2GD and a moderate to large ΔE2DS, narrowing, tapering and even pinch-off of virtual microchannels were observed, which increased R and changed the operation into the transition or saturation region. A field-effect stream merger regulating two streams was built based on two FEPs with shared gate and drain electrodes. The versatility of FEPs was demonstrated with preliminary studies on whole blood and particle solutions.
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Affiliation(s)
- Fu-Min Wang
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - I-Pei Lu
- Institute of Nanotechnology, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Chih-Ting Lin
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Shey-Shi Lu
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Shih-Kang Fan
- Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506, USA.
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Perdigones F. Lab-on-PCB and Flow Driving: A Critical Review. MICROMACHINES 2021; 12:175. [PMID: 33578984 PMCID: PMC7916810 DOI: 10.3390/mi12020175] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/30/2021] [Accepted: 02/05/2021] [Indexed: 12/25/2022]
Abstract
Lab-on-PCB devices have been developed for many biomedical and biochemical applications. However, much work has to be done towards commercial applications. Even so, the research on devices of this kind is rapidly increasing. The reason for this lies in the great potential of lab-on-PCB devices to provide marketable devices. This review describes the active flow driving methods for lab-on-PCB devices, while commenting on their main characteristics. Among others, the methods described are the typical external impulsion devices, that is, syringe or peristaltic pumps; pressurized microchambers for precise displacement of liquid samples; electrowetting on dielectrics; and electroosmotic and phase-change-based flow driving, to name a few. In general, there is not a perfect method because all of them have drawbacks. The main problems with regard to marketable devices are the complex fabrication processes, the integration of many materials, the sealing process, and the use of many facilities for the PCB-chips. The larger the numbers of integrated sensors and actuators in the PCB-chip, the more complex the fabrication. In addition, the flow driving-integrated devices increase that difficulty. Moreover, the biological applications are demanding. They require transparency, biocompatibility, and specific ambient conditions. All the problems have to be solved when trying to reach repetitiveness and reliability, for both the fabrication process and the working of the lab-on-PCB, including the flow driving system.
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Affiliation(s)
- Francisco Perdigones
- Electronic Engineering Department, Higher Technical School of Engineering, University of Seville, 41092 Seville, Spain
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14
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Subramanian S, Huiszoon RC, Chu S, Bentley WE, Ghodssi R. Microsystems for biofilm characterization and sensing - A review. Biofilm 2020; 2:100015. [PMID: 33447801 PMCID: PMC7798443 DOI: 10.1016/j.bioflm.2019.100015] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/11/2019] [Accepted: 11/26/2019] [Indexed: 11/30/2022] Open
Abstract
Biofilms are the primary cause of clinical bacterial infections and are impervious to typical amounts of antibiotics, necessitating very high doses for elimination. Therefore, it is imperative to have suitable methods for characterization to develop novel methods of treatment that can complement or replace existing approaches using significantly lower doses of antibiotics. This review presents some of the current developments in microsystems for characterization and sensing of bacterial biofilms. Initially, we review current standards for studying biofilms that are based on invasive and destructive end-point biofilm characterization. Additionally, biofilm formation and growth is extremely sensitive to various growth and environmental parameters that cause large variability in biofilms between repeated experiments, making it very difficult to compare experimental repeats and characterize the temporal characteristics of these organisms. To address these challenges, recent developments in the field have moved toward systems and miniature devices that can aid in the non-invasive characterization of bacterial biofilms. Our review focuses on several types of microsystems for biofilm evaluation including optical, electrochemical, and mechanical systems. This review will show how these devices can lead to better understanding of the physiology and function of these communities of bacteria, which can eventually lead to the development of novel treatments that do not rely on high-dosage antibiotics.
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Affiliation(s)
- Sowmya Subramanian
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
| | - Ryan C. Huiszoon
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
| | - Sangwook Chu
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
| | - William E. Bentley
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
| | - Reza Ghodssi
- MEMS Sensors and Actuators Laboratory, University of Maryland, College Park, MD, USA
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, USA
- Institute for Systems Research, University of Maryland, College Park, MD, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD, USA
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Washburn J, Millington DS. Digital Microfluidics in Newborn Screening for Mucopolysaccharidoses: A Progress Report. Int J Neonatal Screen 2020; 6:ijns6040078. [PMID: 33124616 PMCID: PMC7711648 DOI: 10.3390/ijns6040078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 09/29/2020] [Accepted: 10/04/2020] [Indexed: 11/16/2022] Open
Abstract
Newborn screening (NBS) for mucopolysaccharidosis type I (MPS I, Hurler syndrome) is currently conducted in about two-fifths of the NBS programs in the United States and in a few other countries. Screening is performed by measurement of residual activity of the enzyme alpha-l-iduronidase in dried blood spots using either tandem mass spectrometry or digital microfluidic fluorometry (DMF). In this article, we focus on the development and practical experience of using DMF to screen for MPS I in the USA. By means of their responses to a questionnaire, we determined for each responding program that is screening for MPS I using DMF the screen positive rate, follow-up methods, and classification of confirmed cases as either severe or attenuated. Overall, the results show that at the time of reporting, over 1.3 million newborns in the US were screened for MPS I using DMF, 2094 (0.173%) of whom were screen positive. Of these, severe MPS I was confirmed in five cases, attenuated MPS I was confirmed in two cases, and undetermined phenotype was reported in one case. We conclude that DMF is an effective and economical method to screen for MPS I and recommend second-tier testing owing to high screen positive rates. Preliminary results of NBS for MPS II and MPS III using DMF are discussed.
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Affiliation(s)
| | - David S. Millington
- Duke University Hospital Biochemical Genetics Lab, Durham, NC 27709, USA
- Correspondence: ; Tel.: +1-919-448-8221
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16
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Kremers T, Thelen S, Bosbach N, Schnakenberg U. PortaDrop: A portable digital microfluidic platform providing versatile opportunities for Lab-On-A-Chip applications. PLoS One 2020; 15:e0238581. [PMID: 32881948 PMCID: PMC7470335 DOI: 10.1371/journal.pone.0238581] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/19/2020] [Indexed: 01/24/2023] Open
Abstract
Electrowetting-on-dielectric is a decent technique to manipulate discrete volumes of liquid in form of droplets. In the last decade, electrowetting-on-dielectric systems, also called digital microfluidic systems, became more frequently used for a variety of applications because of their high flexibility and reconfigurability. Thus, one design can be adapted to different assays by only reprogramming. However, this flexibility can only be useful if the entire system is portable and easy to use. This paper presents the development of a portable, stand-alone digital microfluidic system based on a Linux-based operating system running on a Raspberry Pi, which is unique. We present "PortaDrop" exhibiting the following key features: (1) an "all-in-one box" approach, (2) a user-friendly, self-explaining graphical user interface and easy handling, (3) the ability of integrated electrochemical measurements, (4) the ease to implement additional lab equipment via Universal Serial Bus and the General Purpose Interface Bus as well as (5) a standardized experiment documentation. We propose that PortaDrop can be used to carry out experiments in different applications, where small sample volumes in the nanoliter to picoliter range need to be handled an analyzed automatically. As a first application, we present a protocol, where a droplet is consequently exchanged by droplets of another medium using passive dispensing. The exchange is monitored by electrical impedance spectroscopy. It is the first time, the media exchange caused by passive dispensing is characterized by electrochemical impedance spectroscopy. Summarizing, PortaDrop allows easy combination of fluid handling by means of electrowetting and additional sensing.
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Affiliation(s)
- Tom Kremers
- Chair of Micro- and Nanosystems and Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Aachen, Germany
| | - Sarah Thelen
- Chair of Micro- and Nanosystems and Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Aachen, Germany
| | - Nils Bosbach
- Chair of Micro- and Nanosystems and Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Aachen, Germany
| | - Uwe Schnakenberg
- Chair of Micro- and Nanosystems and Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Aachen, Germany
- * E-mail:
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17
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Kothamachu VB, Zaini S, Muffatto F. Role of Digital Microfluidics in Enabling Access to Laboratory Automation and Making Biology Programmable. SLAS Technol 2020; 25:411-426. [PMID: 32584152 DOI: 10.1177/2472630320931794] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Digital microfluidics (DMF) is a liquid handling technique that has been demonstrated to automate biological experimentation in a low-cost, rapid, and programmable manner. This review discusses the role of DMF as a "digital bioconverter"-a tool to connect the digital aspects of the design-build-learn cycle with the physical execution of experiments. Several applications are reviewed to demonstrate the utility of DMF as a digital bioconverter, namely, genetic engineering, sample preparation for sequencing and mass spectrometry, and enzyme-, immuno-, and cell-based screening assays. These applications show that DMF has great potential in the role of a centralized execution platform in a fully integrated pipeline for the production of novel organisms and biomolecules. In this paper, we discuss how the function of a DMF device within such a pipeline is highly dependent on integration with different sensing techniques and methodologies from machine learning and big data. In addition to that, we examine how the capacity of DMF can in some cases be limited by known technical and operational challenges and how consolidated efforts in overcoming these challenges will be key to the development of DMF as a major enabling technology in the computer-aided biology framework.
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18
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Enel A, Bourrelier A, Vial J, Thiébaut D, Bourlon B. A microfluidic device for digital manipulation of gaseous samples. LAB ON A CHIP 2020; 20:1290-1297. [PMID: 32159188 DOI: 10.1039/c9lc01163c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Digital microfluidics is known for fine manipulation of sub-millimeter samples, with applications from biological sample preparation to diagnostic testing. Unfortunately, until now, it has been only limited to liquid phases. In this paper, we present a new system based on a digital microfluidic platform (DMFP), which is able to digitally manipulate gaseous samples, such as alkanes from n-hexane to n-nonane. The DMFP relies mostly on interconnected micropreconcentrators (μPCs) to trap and release the samples depending on their controlled temperature. We show that the DMFP is capable of performing all basic operations of digital microfluidics: trapping/releasing and moving samples, adding samples and separating samples. As a first example of a more complex programmable use of our DMFP, we measured the breakthrough volume of alkanes on a Tenax TA adsorbent. The results were consistent with tabulated values obtained with standard laboratory instruments. This DMFP promises great possibilities for more complex programmable gas microfluidics digital devices and the development of new digital gas sample preparation and analysis methods.
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Affiliation(s)
- A Enel
- Univ. Grenoble Alpes, CEA, LETI, MINATEC Campus, F-38000 Grenoble, France.
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Kubaski F, de Oliveira Poswar F, Michelin-Tirelli K, Matte UDS, Horovitz DD, Barth AL, Baldo G, Vairo F, Giugliani R. Mucopolysaccharidosis Type I. Diagnostics (Basel) 2020; 10:E161. [PMID: 32188113 PMCID: PMC7151028 DOI: 10.3390/diagnostics10030161] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 12/31/2022] Open
Abstract
Mucopolysaccharidosis type I (MPS I) is caused by the deficiency of α-l-iduronidase, leading to the storage of dermatan and heparan sulfate. There is a broad phenotypical spectrum with the presence or absence of neurological impairment. The classical form is known as Hurler syndrome, the intermediate form as Hurler-Scheie, and the most attenuated form is known as Scheie syndrome. Phenotype seems to be largely influenced by genotype. Patients usually develop several somatic symptoms such as abdominal hernias, extensive dermal melanocytosis, thoracolumbar kyphosis odontoid dysplasia, arthropathy, coxa valga and genu valgum, coarse facial features, respiratory and cardiac impairment. The diagnosis is based on the quantification of α-l-iduronidase coupled with glycosaminoglycan analysis and gene sequencing. Guidelines for treatment recommend hematopoietic stem cell transplantation for young Hurler patients (usually at less than 30 months of age). Intravenous enzyme replacement is approved and is the standard of care for attenuated-Hurler-Scheie and Scheie-forms (without cognitive impairment) and for the late-diagnosed severe-Hurler-cases. Intrathecal enzyme replacement therapy is under evaluation, but it seems to be safe and effective. Other therapeutic approaches such as gene therapy, gene editing, stop codon read through, and therapy with small molecules are under development. Newborn screening is now allowing the early identification of MPS I patients, who can then be treated within their first days of life, potentially leading to a dramatic change in the disease's progression. Supportive care is very important to improve quality of life and might include several surgeries throughout the life course.
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Affiliation(s)
- Francyne Kubaski
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501970, Brazil; (F.K.); (F.d.O.P.); (U.d.S.M.); (G.B.)
- Medical Genetics Service, HCPA, Porto Alegre 90035903, Brazil;
- INAGEMP, Porto Alegre 90035903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035903, Brazil
| | - Fabiano de Oliveira Poswar
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501970, Brazil; (F.K.); (F.d.O.P.); (U.d.S.M.); (G.B.)
- Medical Genetics Service, HCPA, Porto Alegre 90035903, Brazil;
| | - Kristiane Michelin-Tirelli
- Medical Genetics Service, HCPA, Porto Alegre 90035903, Brazil;
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035903, Brazil
| | - Ursula da Silveira Matte
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501970, Brazil; (F.K.); (F.d.O.P.); (U.d.S.M.); (G.B.)
- INAGEMP, Porto Alegre 90035903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035903, Brazil
- Gene Therapy Center, HCPA, Porto Alegre 90035903, Brazil
- Department of Genetics, UFRGS, Porto Alegre 91501970, Brazil
| | - Dafne D. Horovitz
- Medical Genetics Department, National Institute of Women, Children, and Adolescent Health, Oswaldo Cruz Foundation, Rio de Janeiro 21040900, Brazil; (D.D.H.); (A.L.B.)
| | - Anneliese Lopes Barth
- Medical Genetics Department, National Institute of Women, Children, and Adolescent Health, Oswaldo Cruz Foundation, Rio de Janeiro 21040900, Brazil; (D.D.H.); (A.L.B.)
| | - Guilherme Baldo
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501970, Brazil; (F.K.); (F.d.O.P.); (U.d.S.M.); (G.B.)
- INAGEMP, Porto Alegre 90035903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035903, Brazil
- Gene Therapy Center, HCPA, Porto Alegre 90035903, Brazil
- Department of Physiology, UFRGS, Porto Alegre 90050170, Brazil
| | - Filippo Vairo
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA;
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Roberto Giugliani
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501970, Brazil; (F.K.); (F.d.O.P.); (U.d.S.M.); (G.B.)
- Medical Genetics Service, HCPA, Porto Alegre 90035903, Brazil;
- INAGEMP, Porto Alegre 90035903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035903, Brazil
- Gene Therapy Center, HCPA, Porto Alegre 90035903, Brazil
- Department of Genetics, UFRGS, Porto Alegre 91501970, Brazil
- Postgraduation Program in Medicine, Clinical Sciences, UFRGS, Porto Alegre 90035003, Brazil
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Digital Microfluidic Platform to Maximize Diagnostic Tests with Low Sample Volumes from Newborns and Pediatric Patients. Diagnostics (Basel) 2020; 10:diagnostics10010021. [PMID: 31906315 PMCID: PMC7169462 DOI: 10.3390/diagnostics10010021] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 12/29/2019] [Accepted: 12/30/2019] [Indexed: 11/17/2022] Open
Abstract
"Children are not tiny adults" is an adage commonly used in pediatrics to emphasize the fact that children often have different physiological responses to sickness and trauma compared to adults. However, despite widespread acceptance of this concept, diagnostic blood testing is an excellent example of clinical care that is not yet customized to the needs of children, especially newborns. Cumulative blood loss resulting from clinical testing does not typically impact critically ill adult patients, but can quickly escalate in children, leading to iatrogenic anemia and related comorbidities. Moreover, the tests prioritized for rapid, near-patient testing in adults are not always the most clinically relevant tests for children or newborns. This report describes the development of a digital microfluidic testing platform and associated clinical assays purposely curated to address current shortcomings in pediatric laboratory testing by using microliter volumes (<50 µL) of samples. The automated platform consists of a small instrument and single-use cartridges, which contain all reagents necessary to prepare the sample and perform the assay. Electrowetting technology is used to precisely manipulate nanoliter-sized droplets of samples and reagents inside the cartridge. To date, we have automated three disparate types of assays (biochemical assays, immunoassays, and molecular assays) on the platform and have developed over two dozen unique tests, each with important clinical application to newborns and pediatric patients. Cell lysis, plasma preparation, magnetic bead washing, thermocycling, incubation, and many other essential functions were all performed on the cartridge without any user intervention. The resulting assays demonstrate performance comparable to standard clinical laboratory assays and are economical due to the reduced hands-on effort required for each assay and lower overall reagent consumption. These capabilities allow a wide range of assays to be run simultaneously on the same cartridge using significantly reduced sample volumes with results in minutes.
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21
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Tang B, Shao W, Groenewold J, Li H, Feng Y, Xu X, Shui L, Barman J, Zhou G. Transition of interfacial capacitors in electrowetting on a graphite surface by ion intercalation. Phys Chem Chem Phys 2019; 21:26284-26291. [PMID: 31602437 DOI: 10.1039/c9cp04436a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The low voltage electrowetting response of a LiCl aqueous solution on a freshly cleaved surface of highly oriented pyrolytic graphite (HOPG) is presented. For applied voltages below 1 V, the energy stored in the electrical double layer (EDL) is insufficient to drive the spreading of the drop due to the pinning of the three phase contact line at the step edges. Electrochemical impedance spectroscopy shows a dramatic increase in capacitance above 1 V, which provides a sufficient electrowetting force for depinning the contact line, resulting in a subsequent decrease of the contact angle. The transition of the interfacial capacitance from the EDL to the many-fold high capacitance of the pseudocapacitor drives the electrowetting transition on the HOPG surface. The observed changes in the capacitances above 1 V are correlated with the cyclic voltammetry and atomic force microscopy results, which show that the Cl- ions intercalate into the graphite galleries upon acquiring sufficient energy to overcome the van der Waals attraction between the graphene layers through the side of the step edge of the basal planes. To the best of our knowledge, this is the first study on the voltage dependent intercalation mediated transition of interfacial capacitance driving the spreading of an aqueous electrolyte drop on the HOPG surface, which provides a fundamental understanding of the mechanism and opens up potential applications in microfluidics and charge storage technologies.
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Affiliation(s)
- Biao Tang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper Displays South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China.
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Magnetic-Responsive Bendable Nozzles for Open Surface Droplet Manipulation. Polymers (Basel) 2019; 11:polym11111792. [PMID: 31683935 PMCID: PMC6918237 DOI: 10.3390/polym11111792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/18/2019] [Accepted: 10/28/2019] [Indexed: 01/23/2023] Open
Abstract
The handling of droplets in a controlled manner is essential to numerous technological and scientific applications. In this work, we present a new open-surface platform for droplet manipulation based on an array of bendable nozzles that are dynamically controlled by a magnetic field. The actuation of these nozzles is possible thanks to the magnetically responsive elastomeric composite which forms the tips of the nozzles; this is fabricated with Fe3O4 microparticles embedded in a polydimethylsiloxane matrix. The transport, mixing, and splitting of droplets can be controlled by bringing together and separating the tips of these nozzles under the action of a magnet. Additionally, the characteristic configuration for droplet mixing in this platform harnesses the kinetic energy from the feeding streams; this provided a remarkable reduction of 80% in the mixing time between drops of liquids about eight times more viscous than water, i.e., 6.5 mPa/s, when compared against the mixing between sessile drops of the same fluids.
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Tohgha UN, Alvino EL, Jarnagin CC, Iacono ST, Godman NP. Electrowetting Behavior and Digital Microfluidic Applications of Fluorescent, Polymer-Encapsulated Quantum Dot Nanofluids. ACS APPLIED MATERIALS & INTERFACES 2019; 11:28487-28498. [PMID: 31290307 DOI: 10.1021/acsami.9b07983] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Digital microfluidics is a liquid-handling technology capable of rapidly and autonomously controlling multiple discrete droplets across an array of electrodes and has seen continual growth in the fields of chemistry, biology, and optics. This technology is enabled by rapidly switching the wettability of a surface through the application of an electric field: a phenomenon known as electrowetting-on-dielectric. The results reported here elucidate the wetting behavior of fluorescent quantum dot nanofluids by varying the aqueous-solubilizing polymers, changing the size of the nanocrystals, and the addition of surfactants. Nanofluid droplets were demonstrated to have very large changes in contact angle (>100°) by employing alternating current voltage to aqueous droplets within a dodecane medium. The stability of quantum dot nanofluids is also evaluated within a digital microfluidics platform, and the optical properties are not perturbed even under high voltages (250 V). Multiple fluorescent droplets with varying emission can be simultaneously actuated and rapidly mixed (<10 s) to generate a new nanofluid with optical properties different from the parent solutions.
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Affiliation(s)
- Urice N Tohgha
- Air Force Research Laboratory, Materials and Manufacturing Directorate , Wright-Patterson Air Force Base , Dayton , Ohio 45433-7750 , United States
- Azimuth Corporation , 4027 Colonel Glenn Highway , Beavercreek , Ohio 45431 , United States
| | - Ernest L Alvino
- Department of Chemistry and Chemistry Research Center , United States Air Force Academy , Colorado Springs , Colorado 80840 , United States
| | - Clark C Jarnagin
- Air Force Research Laboratory, Materials and Manufacturing Directorate , Wright-Patterson Air Force Base , Dayton , Ohio 45433-7750 , United States
- Azimuth Corporation , 4027 Colonel Glenn Highway , Beavercreek , Ohio 45431 , United States
| | - Scott T Iacono
- Department of Chemistry and Chemistry Research Center , United States Air Force Academy , Colorado Springs , Colorado 80840 , United States
| | - Nicholas P Godman
- Air Force Research Laboratory, Materials and Manufacturing Directorate , Wright-Patterson Air Force Base , Dayton , Ohio 45433-7750 , United States
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Zhong Z, Li Z, Chakrabarty K, Ho TY, Lee CY. Micro-Electrode-Dot-Array Digital Microfluidic Biochips: Technology, Design Automation, and Test Techniques. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2019; 13:292-313. [PMID: 30571645 DOI: 10.1109/tbcas.2018.2886952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Digital microfluidic biochips (DMFBs) are being increasingly used for DNA sequencing, point-of-care clinical diagnostics, and immunoassays. DMFBs based on a micro-electrode-dot-array (MEDA) architecture have recently been proposed, and fundamental droplet manipulations, e.g., droplet mixing and splitting, have also been experimentally demonstrated on MEDA biochips. There can be thousands of microelectrodes on a single MEDA biochip, and the fine-grained control of nanoliter volumes of biochemical samples and reagents is also enabled by this technology. MEDA biochips offer the benefits of real-time sensitivity, lower cost, easy system integration with CMOS modules, and full automation. This review paper first describes recent design tools for high-level synthesis and optimization of map bioassay protocols on a MEDA biochip. It then presents recent advances in scheduling of fluidic operations, placement of fluidic modules, droplet-size-aware routing, adaptive error recovery, sample preparation, and various testing techniques. With the help of these tools, biochip users can concentrate on the development of nanoscale bioassays, leaving details of chip optimization and implementation to software tools.
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Kanitthamniyom P, Zhang Y. Magnetic digital microfluidics on a bioinspired surface for point-of-care diagnostics of infectious disease. Electrophoresis 2019; 40:1178-1185. [PMID: 30770588 DOI: 10.1002/elps.201900074] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/09/2019] [Accepted: 02/09/2019] [Indexed: 12/13/2022]
Abstract
Magnetic digital microfluidics uses magnetic force to manipulate droplets on a Teflon-coated substrate through the added magnetic particles. To achieve a wide range of droplet manipulation, hydrophilic patterns, known as surface energy traps, are introduced onto the Teflon-coated hydrophobic substrate. However, the Teflon-coated substrate is difficult to modify because it is nonwettable, and existing techniques for patterning surface energy traps have many limitations. Inspired by the mussel adhesion mechanism, we use polydopamine, a bioinspired substance that adheres strongly to almost any materials, to pattern surface energy traps on the Teflon-coated substrate with a great ease. We have optimized the polydopamine coating protocol and characterized the surface properties of the polydopamine surface energy traps. Droplet operations including particle extraction, liquid dispensing, liquid shaping, and cross-platform transfer have been demonstrated on the polydopamine surface energy trap-enabled magnetic digital microfluidic platform in both single-plate and two-plate configurations. Furthermore, the detection of hepatitis B surface antigen using ELISA has been demonstrated on the new magnetic dgitial microfluidic platform. This new bioinspired magnetic digital microfluidic platform is easy to fabricate and operate, showing a great potential for point-of-care applications.
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Affiliation(s)
- Pojchanun Kanitthamniyom
- Singapore 3D Printing Center, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| | - Yi Zhang
- Singapore 3D Printing Center, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
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Development of Coplanar Electro-Wetting Based Microfluidic Sorter to Select Micro-Particles in High Volume Throughput at Milliliter Amount within Twenty Minutes. SENSORS 2018; 18:s18092941. [PMID: 30181484 PMCID: PMC6164432 DOI: 10.3390/s18092941] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 08/28/2018] [Accepted: 09/01/2018] [Indexed: 11/17/2022]
Abstract
This paper reports the work of developing one coplanar microfluidic sorter while using the electro-wetting on dielectrics (EWOD) technique. When connected with delivery capillary to receive sample solution containing micro-particles, this device can select about 10 micro-particles in high volume throughput of milliliter amount within 20 min, to potentially match the requirement of efficiently determining the low amounts of bacteria in concentrated food and environmental samples, of which the typical bacteria density is 10 colony forming unit or less, much smaller than that of clinical pathogen samples. This coplanar T-shape EWOD device contains two fluidic channels, one inlet channel and the other collection channel stemmed from the middle of inlet channel. When the solution droplet falls from the delivery capillary to the entrance end of inlet channel, the droplet is driven to the intersection of two channels. The droplet containing fluorescent particle will be diverted to the lower channel to collect. Otherwise, the non-fluorescent droplet keeps moving toward the other end of inlet channel to waste zone. The particle fluorescence is collected through microscope lens to detect with one photomultiplier tube. The detected signals trigger the personal computer control board to active each EWOD electrode to direct the droplet moving directions. When the solution of 1 mL containing about 10 fluorescent micro-particles is delivered into this sorting device, nearly all the particles were correctly directed into collection zone in 20 min.
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Millington D, Norton S, Singh R, Sista R, Srinivasan V, Pamula V. Digital microfluidics comes of age: high-throughput screening to bedside diagnostic testing for genetic disorders in newborns. Expert Rev Mol Diagn 2018; 18:701-712. [PMID: 30004274 PMCID: PMC6481615 DOI: 10.1080/14737159.2018.1495076] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Digital microfluidics (DMF) is an emerging technology with the appropriate metrics for application to newborn and high-risk screening for inherited metabolic disease and other conditions that benefit from early treatment. Areas covered: This review traces the development of electrowetting-based DMF technology toward the fulfillment of its promise to provide an inexpensive platform to conduct enzymatic assays and targeted biomarker assays at the bedside. The high-throughput DMF platform, referred to as SEEKER®, was recently authorized by the United States Food and Drug Administration to screen newborns for four lysosomal storage disorders (LSDs) and is deployed in newborn screening programs in the United States. The development of reagents and methods for LSD screening and results from screening centers are reviewed. Preliminary results from a more compact DMF device, to perform disease-specific test panels from small volumes of blood, are also reviewed. Literature for this review was sourced using principal author and subject searches in PubMed. Expert commentary: Newborn screening is a vital and highly successful public health program. DMF technology adds value to the current testing platforms that will benefit apparently healthy newborns with underlying genetic disorders and infants at-risk for conditions that present with symptoms in the newborn period.
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Affiliation(s)
- David Millington
- Department of Pediatrics, Duke University Medical Center, Durham, NC
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Emani S, Nelson LT, Norton S, Singh R, Pamula V, Emani S. Enzymatic Functional Assays of Coagulation Using Small Sample Volumes. Lab Med 2018; 49:47-54. [PMID: 29206934 DOI: 10.1093/labmed/lmx067] [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: 11/14/2022] Open
Abstract
Current laboratory methods for comprehensive thrombophilia status require large blood volumes and long turn-around times. We demonstrate the feasibility of performing thrombophilia panel testing of enzymatic functional assays on a microfluidic cartridge using low sample volume.Functional assays for Antithrombin III, Protein C, Factor VIII, and plasminogen were adapted on the digital microfluidic platform by developing novel fluorogenic substrates and establishing on-cartridge fluorescence (360/460 nm) detection. Cartridge vs. microtiter plate results were compared using samples obtained from pediatric patients. Linear regression and Bland-Altman plots were used to establish correlations. Results were not significantly different when performed on-cartridge compared to microtiter plates. Importantly, the sample volume required is significantly lower for all on-cartridge compared to microtiter plate assays (25 μL vs. 2 ml).This study demonstrates the feasibility of thrombophilia panel testing with high-fidelity using small plasma volume. The efficacy of this near-patient technology in clinical settings needs further investigation.
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Affiliation(s)
- Sirisha Emani
- Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA
| | | | | | | | | | - Sitaram Emani
- Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA
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Serra M, Ferraro D, Pereiro I, Viovy JL, Descroix S. The power of solid supports in multiphase and droplet-based microfluidics: towards clinical applications. LAB ON A CHIP 2017; 17:3979-3999. [PMID: 28948991 DOI: 10.1039/c7lc00582b] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Multiphase and droplet microfluidic systems are growing in relevance in bioanalytical-related fields, especially due to the increased sensitivity, faster reaction times and lower sample/reagent consumption of many of its derived bioassays. Often applied to homogeneous (liquid/liquid) reactions, innovative strategies for the implementation of heterogeneous (typically solid/liquid) processes have recently been proposed. These involve, for example, the extraction and purification of target analytes from complex matrices or the implementation of multi-step protocols requiring efficient washing steps. To achieve this, solid supports such as functionalized particles (micro or nanometric) presenting different physical properties (e.g. magnetic, optical or others) are used for the binding of specific entities. The manipulation of such supports with different microfluidic principles has both led to the miniaturization of existing biomedical protocols and the development of completely new strategies for diagnostics and research. In this review, multiphase and droplet-based microfluidic systems using solid suspensions are presented and discussed with a particular focus on: i) working principles and technological developments of the manipulation strategies and ii) applications, critically discussing the level of maturity of these systems, which can range from initial proofs of concept to real clinical validations.
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Affiliation(s)
- M Serra
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France.
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31
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Khalid N, Kobayashi I, Nakajima M. Recent lab-on-chip developments for novel drug discovery. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [DOI: 10.1002/wsbm.1381] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 12/11/2016] [Accepted: 12/20/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Nauman Khalid
- School of Food and Agricultural Sciences; University of Management and Technology; Lahore Pakistan
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences; Deakin University; Waurn Ponds Australia
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Japan
| | - Isao Kobayashi
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Japan
- Food Research Institute; NARO; Tsukuba Japan
| | - Mitsutoshi Nakajima
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Japan
- Food Research Institute; NARO; Tsukuba Japan
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Moore JA, Nemat-Gorgani M, Madison AC, Sandahl MA, Punnamaraju S, Eckhardt AE, Pollack MG, Vigneault F, Church GM, Fair RB, Horowitz MA, Griffin PB. Automated electrotransformation of Escherichia coli on a digital microfluidic platform using bioactivated magnetic beads. BIOMICROFLUIDICS 2017; 11:014110. [PMID: 28191268 PMCID: PMC5291792 DOI: 10.1063/1.4975391] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/20/2017] [Indexed: 05/06/2023]
Abstract
This paper reports on the use of a digital microfluidic platform to perform multiplex automated genetic engineering (MAGE) cycles on droplets containing Escherichia coli cells. Bioactivated magnetic beads were employed for cell binding, washing, and media exchange in the preparation of electrocompetent cells in the electrowetting-on-dieletric (EWoD) platform. On-cartridge electroporation was used to deliver oligonucleotides into the cells. In addition to the optimization of a magnetic bead-based benchtop protocol for generating and transforming electrocompetent E. coli cells, we report on the implementation of this protocol in a fully automated digital microfluidic platform. Bead-based media exchange and electroporation pulse conditions were optimized on benchtop for transformation frequency to provide initial parameters for microfluidic device trials. Benchtop experiments comparing electrotransformation of free and bead-bound cells are presented. Our results suggest that dielectric shielding intrinsic to bead-bound cells significantly reduces electroporation field exposure efficiency. However, high transformation frequency can be maintained in the presence of magnetic beads through the application of more intense electroporation pulses. As a proof of concept, MAGE cycles were successfully performed on a commercial EWoD cartridge using variations of the optimal magnetic bead-based preparation procedure and pulse conditions determined by the benchtop results. Transformation frequencies up to 22% were achieved on benchtop; this frequency was matched within 1% (21%) by MAGE cycles on the microfluidic device. However, typical frequencies on the device remain lower, averaging 9% with a standard deviation of 9%. The presented results demonstrate the potential of digital microfluidics to perform complex and automated genetic engineering protocols.
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Affiliation(s)
- J A Moore
- Stanford Genome Technology Center , 3165 Porter Drive, Palo Alto, California 94304, USA
| | - M Nemat-Gorgani
- Stanford Genome Technology Center , 3165 Porter Drive, Palo Alto, California 94304, USA
| | - A C Madison
- Department of Electrical Engineering, Duke University , Durham, North Carolina 27560, USA
| | - M A Sandahl
- Advanced Liquid Logic , 615 Davis Drive #800, Morrisville, North Carolina 27560, USA
| | - S Punnamaraju
- Advanced Liquid Logic , 615 Davis Drive #800, Morrisville, North Carolina 27560, USA
| | - A E Eckhardt
- Advanced Liquid Logic , 615 Davis Drive #800, Morrisville, North Carolina 27560, USA
| | - M G Pollack
- Advanced Liquid Logic , 615 Davis Drive #800, Morrisville, North Carolina 27560, USA
| | - F Vigneault
- Wyss Institute, Harvard University , Boston, Massachusetts 02115, USA
| | - G M Church
- Department of Genetics, Harvard Medical School , Boston, Massachusetts 02115, USA
| | - R B Fair
- Department of Electrical Engineering, Duke University , Durham, North Carolina 27560, USA
| | - M A Horowitz
- Department of Electrical Engineering, Stanford University , Stanford, California 94305, USA
| | - P B Griffin
- Stanford Genome Technology Center , 3165 Porter Drive, Palo Alto, California 94304, USA
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Perkins G, Lu H, Garlan F, Taly V. Droplet-Based Digital PCR: Application in Cancer Research. Adv Clin Chem 2016; 79:43-91. [PMID: 28212714 DOI: 10.1016/bs.acc.2016.10.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The efficient characterization of genetic and epigenetic alterations in oncology, virology, or prenatal diagnostics requires highly sensitive and specific high-throughput approaches. Nevertheless, with the use of conventional methods, sensitivity and specificity were largely limited. By partitioning individual target molecules within distinct compartments, digital PCR (dPCR) could overcome these limitations and detect very rare sequences with unprecedented precision and sensitivity. In dPCR, the sample is diluted such that each individual partition will contain no more than one target sequence. Following the assay reaction, the dPCR process provides an absolute value and analyzable quantitative data. The recent coupling of dPCR with microfluidic systems in commercial platforms should lead to an essential tool for the management of patients with cancer, especially adapted to the analysis of precious samples. Applications in cancer research range from the analysis of tumor heterogeneity to that of a range of body fluids. Droplet-based dPCR is indeed particularly appropriate for the emerging field of liquid biopsy analysis. In this review, following an overview of the development in dPCR technology and different strategies based on the use of microcompartments, we will focus particularly on the applications and latest development of microfluidic droplet-based dPCR in oncology.
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Affiliation(s)
- G Perkins
- Université Sorbonne Paris Cité, INSERM UMR-S1147, CNRS SNC 5014, Centre Universitaire des Saints-Pères, Equipe labélisée LIGUE Contre le Cancer, Paris, France; European Georges Pompidou Hospital, AP-HP - Paris Descartes University, Paris, France
| | - H Lu
- Université Sorbonne Paris Cité, INSERM UMR-S1147, CNRS SNC 5014, Centre Universitaire des Saints-Pères, Equipe labélisée LIGUE Contre le Cancer, Paris, France
| | - F Garlan
- Université Sorbonne Paris Cité, INSERM UMR-S1147, CNRS SNC 5014, Centre Universitaire des Saints-Pères, Equipe labélisée LIGUE Contre le Cancer, Paris, France
| | - V Taly
- Université Sorbonne Paris Cité, INSERM UMR-S1147, CNRS SNC 5014, Centre Universitaire des Saints-Pères, Equipe labélisée LIGUE Contre le Cancer, Paris, France.
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Samiei E, Tabrizian M, Hoorfar M. A review of digital microfluidics as portable platforms for lab-on a-chip applications. LAB ON A CHIP 2016; 16:2376-96. [PMID: 27272540 DOI: 10.1039/c6lc00387g] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Following the development of microfluidic systems, there has been a high tendency towards developing lab-on-a-chip devices for biochemical applications. A great deal of effort has been devoted to improve and advance these devices with the goal of performing complete sets of biochemical assays on the device and possibly developing portable platforms for point of care applications. Among the different microfluidic systems used for such a purpose, digital microfluidics (DMF) shows high flexibility and capability of performing multiplex and parallel biochemical operations, and hence, has been considered as a suitable candidate for lab-on-a-chip applications. In this review, we discuss the most recent advances in the DMF platforms, and evaluate the feasibility of developing multifunctional packages for performing complete sets of processes of biochemical assays, particularly for point-of-care applications. The progress in the development of DMF systems is reviewed from eight different aspects, including device fabrication, basic fluidic operations, automation, manipulation of biological samples, advanced operations, detection, biological applications, and finally, packaging and portability of the DMF devices. Success in developing the lab-on-a-chip DMF devices will be concluded based on the advances achieved in each of these aspects.
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Affiliation(s)
- Ehsan Samiei
- School of Engineering, University of British Columbia, 3333 University Way, Kelowna, BC V1V 1V7, Canada.
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35
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He JL, Wang DS, Fan SK. Opto-Microfluidic Immunosensors: From Colorimetric to Plasmonic. MICROMACHINES 2016; 7:E29. [PMID: 30407402 PMCID: PMC6189923 DOI: 10.3390/mi7020029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 01/25/2016] [Accepted: 02/04/2016] [Indexed: 02/06/2023]
Abstract
Optical detection has long been the most popular technique in immunosensing. Recent developments in the synthesis of luminescent probes and the fabrication of novel nanostructures enable more sensitive and efficient optical detection, which can be miniaturized and integrated with microfluidics to realize compact lab-on-a-chip immunosensors. These immunosensors are portable, economical and automated, but their sensitivity is not compromised. This review focuses on the incorporation and implementation of optical detection and microfluidics in immunosensors; it introduces the working principles of each optical detection technique and how it can be exploited in immunosensing. The recent progress in various opto-microfluidic immunosensor designs is described. Instead of being comprehensive to include all opto-microfluidic platforms, the report centers on the designs that are promising for point-of-care immunosensing diagnostics, in which ease of use, stability and cost-effective fabrication are emphasized.
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Affiliation(s)
- Jie-Long He
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
| | - Da-Shin Wang
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
| | - Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
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36
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Eribol P, Uguz AK, Ulgen KO. Screening applications in drug discovery based on microfluidic technology. BIOMICROFLUIDICS 2016; 10:011502. [PMID: 26865904 PMCID: PMC4733079 DOI: 10.1063/1.4940886] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/14/2016] [Indexed: 05/03/2023]
Abstract
Microfluidics has been the focus of interest for the last two decades for all the advantages such as low chemical consumption, reduced analysis time, high throughput, better control of mass and heat transfer, downsizing a bench-top laboratory to a chip, i.e., lab-on-a-chip, and many others it has offered. Microfluidic technology quickly found applications in the pharmaceutical industry, which demands working with leading edge scientific and technological breakthroughs, as drug screening and commercialization are very long and expensive processes and require many tests due to unpredictable results. This review paper is on drug candidate screening methods with microfluidic technology and focuses specifically on fabrication techniques and materials for the microchip, types of flow such as continuous or discrete and their advantages, determination of kinetic parameters and their comparison with conventional systems, assessment of toxicities and cytotoxicities, concentration generations for high throughput, and the computational methods that were employed. An important conclusion of this review is that even though microfluidic technology has been in this field for around 20 years there is still room for research and development, as this cutting edge technology requires ingenuity to design and find solutions for each individual case. Recent extensions of these microsystems are microengineered organs-on-chips and organ arrays.
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Affiliation(s)
- P Eribol
- Department of Chemical Engineering, Boğaziçi University , 34342 Bebek, Istanbul, Turkey
| | - A K Uguz
- Department of Chemical Engineering, Boğaziçi University , 34342 Bebek, Istanbul, Turkey
| | - K O Ulgen
- Department of Chemical Engineering, Boğaziçi University , 34342 Bebek, Istanbul, Turkey
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37
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Huang CY, Tsai PY, Lee IC, Hsu HY, Huang HY, Fan SK, Yao DJ, Liu CH, Hsu W. A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay. BIOMICROFLUIDICS 2016; 10:011901. [PMID: 26858807 PMCID: PMC4714987 DOI: 10.1063/1.4939942] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/07/2015] [Indexed: 05/04/2023]
Abstract
Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications.
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Affiliation(s)
- Cheng-Yeh Huang
- Department of Mechanical Engineering, National Chiao Tung University , Hsinchu, Taiwan
| | - Po-Yen Tsai
- Department of Mechanical Engineering, National Chiao Tung University , Hsinchu, Taiwan
| | - I-Chin Lee
- Department of Applied Chemistry, National Chiao Tung University , Hsinchu, Taiwan
| | - Hsin-Yun Hsu
- Department of Applied Chemistry, National Chiao Tung University , Hsinchu, Taiwan
| | | | - Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University , Taipei, Taiwan
| | | | - Cheng-Hsien Liu
- Department of Power Mechanical Engineering, National Tsing Hua University , Hsinchu, Taiwan
| | - Wensyang Hsu
- Department of Mechanical Engineering, National Chiao Tung University , Hsinchu, Taiwan
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Seo J, Lee SK, Lee J, Seung Lee J, Kwon H, Cho SW, Ahn JH, Lee T. Path-programmable water droplet manipulations on an adhesion controlled superhydrophobic surface. Sci Rep 2015. [PMID: 26202206 PMCID: PMC4511949 DOI: 10.1038/srep12326] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Here, we developed a novel and facile method to control the local water adhesion force of a thin and stretchable superhydrophobic polydimethylsiloxane (PDMS) substrate with micro-pillar arrays that allows the individual manipulation of droplet motions including moving, merging and mixing. When a vacuum pressure was applied below the PDMS substrate, a local dimple structure was formed and the water adhesion force of structure was significantly changed owing to the dynamically varied pillar density. With the help of the lowered water adhesion force and the slope angle of the formed dimple structure, the motion of individual water droplets could be precisely controlled, which facilitated the creation of a droplet-based microfluidic platform capable of a programmable manipulation of droplets. We showed that the platform could be used in newer and emerging microfluidic operations such as surface-enhanced Raman spectroscopy with extremely high sensing capability (10−15 M) and in vitro small interfering RNA transfection with enhanced transfection efficiency of ~80%.
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Affiliation(s)
- Jungmok Seo
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | - Seoung-Ki Lee
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | - Jaehong Lee
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | - Jung Seung Lee
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | - Hyukho Kwon
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | - Seung-Woo Cho
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | - Jong-Hyun Ahn
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
| | - Taeyoon Lee
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749, Republic of Korea
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Hayes CJ, Dalton TM. Microfluidic droplet-based PCR instrumentation for high-throughput gene expression profiling and biomarker discovery. BIOMOLECULAR DETECTION AND QUANTIFICATION 2015; 4:22-32. [PMID: 27077035 PMCID: PMC4822205 DOI: 10.1016/j.bdq.2015.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 01/02/2023]
Abstract
PCR is a common and often indispensable technique used in medical and biological research labs for a variety of applications. Real-time quantitative PCR (RT-qPCR) has become a definitive technique for quantitating differences in gene expression levels between samples. Yet, in spite of this importance, reliable methods to quantitate nucleic acid amounts in a higher throughput remain elusive. In the following paper, a unique design to quantify gene expression levels at the nanoscale in a continuous flow system is presented. Fully automated, high-throughput, low volume amplification of deoxynucleotides (DNA) in a droplet based microfluidic system is described. Unlike some conventional qPCR instrumentation that use integrated fluidic circuits or plate arrays, the instrument performs qPCR in a continuous, micro-droplet flowing process with droplet generation, distinctive reagent mixing, thermal cycling and optical detection platforms all combined on one complete instrument. Detailed experimental profiling of reactions of less than 300 nl total volume is achieved using the platform demonstrating the dynamic range to be 4 order logs and consistent instrument sensitivity. Furthermore, reduced pipetting steps by as much as 90% and a unique degree of hands-free automation makes the analytical possibilities for this instrumentation far reaching. In conclusion, a discussion of the first demonstrations of this approach to perform novel, continuous high-throughput biological screens is presented. The results generated from the instrument, when compared with commercial instrumentation, demonstrate the instrument reliability and robustness to carry out further studies of clinical significance with added throughput and economic benefits.
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Affiliation(s)
- Christopher J Hayes
- Stokes Institute, Department of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick, Limerick, Ireland; Department of Life Sciences, University of Limerick, Limerick, Ireland
| | - Tara M Dalton
- Stokes Institute, Department of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick, Limerick, Ireland
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40
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Kleinert J, Srinivasan V, Rival A, Delattre C, Velev OD, Pamula VK. The dynamics and stability of lubricating oil films during droplet transport by electrowetting in microfluidic devices. BIOMICROFLUIDICS 2015; 9:034104. [PMID: 26045729 PMCID: PMC4441711 DOI: 10.1063/1.4921489] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 05/11/2015] [Indexed: 05/21/2023]
Abstract
The operation of digital microfluidic devices with water droplets manipulated by electrowetting is critically dependent on the static and dynamic stability and lubrication properties of the oil films that separate the droplets from the solid surfaces. The factors determining the stability of the films and preventing surface fouling in such systems are not yet thoroughly understood and were experimentally investigated in this study. The experiments were performed using a standard digital microfluidic cartridge in which water droplets enclosed in a thin, oil-filled gap were transported over an array of electrodes. Stable, continuous oil films separated the droplets from the surfaces when the droplets were stationary. During droplet transport, capillary waves formed in the films on the electrode surfaces as the oil menisci receded. The waves evolved into dome-shaped oil lenses. Droplet deformation and oil displacement caused the films at the surface opposite the electrode array to transform into dimples of oil trapped over the centers of the droplets. Lower actuation voltages were associated with slower film thinning and formation of fewer, but larger, oil lenses. Lower ac frequencies induced oscillations in the droplets that caused the films to rupture. Films were also destabilized by addition of surfactants to the oil or droplet phases. Such a comprehensive understanding of the oil film behavior will enable more robust electrowetting-actuated lab-on-a-chip devices through prevention of loss of species from droplets and contamination of surfaces at points where films may break.
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Affiliation(s)
| | - Vijay Srinivasan
- Advanced Liquid Logic, Inc., PO Box 14025, Research Triangle Park , North Carolina 27709, USA
| | - Arnaud Rival
- Advanced Liquid Logic France , MINATEC - BHT - Bat 52, 7 parvis Louis Néel, 38000 Grenoble, France
| | - Cyril Delattre
- Advanced Liquid Logic France , MINATEC - BHT - Bat 52, 7 parvis Louis Néel, 38000 Grenoble, France
| | - Orlin D Velev
- Department of Chemical and Biomolecular Engineering, North Carolina State University , Raleigh, North Carolina 27695-7905, USA
| | - Vamsee K Pamula
- Advanced Liquid Logic, Inc., PO Box 14025, Research Triangle Park , North Carolina 27709, USA
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41
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Collignon S, Friend J, Yeo L. Planar microfluidic drop splitting and merging. LAB ON A CHIP 2015; 15:1942-1951. [PMID: 25738425 DOI: 10.1039/c4lc01453g] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Open droplet microfluidic platforms offer attractive alternatives to closed microchannel devices, including lower fabrication cost and complexity, significantly smaller sample and reagent volumes, reduced surface contact and adsorption, as well as drop scalability, reconfigurability, and individual addressability. For these platforms to be effective, however, they require efficient schemes for planar drop transport and manipulation. While there are many methods that have been reported for drop transport, it is far more difficult to carry out other drop operations such as dispensing, merging and splitting. In this work, we introduce a novel alternative to merge and, more crucially, split drops using laterally-offset modulated surface acoustic waves (SAWs). The energy delivery into the drop is divided into two components: a small modulation amplitude excitation to initiate weak rotational flow within the drop followed by a short burst in energy to induce it to stretch. Upon removal of the SAW energy, capillary forces at the center of the elongated drop cause the liquid in this capillary bridge region to drain towards both ends of the drop, resulting in its collapse and therefore the splitting of the drop. This however occurs only below a critical Ohnesorge number, which is a balance between the viscous forces that retard the drainage and the sufficiently large capillary forces that cause the liquid bridge to pinch. We show the possibility of reliably splitting drops into two equal sized droplets with an average deviation in their volumes of only around 4% and no greater than 10%, which is comparable to the 7% and below splitting deviation obtained with electrowetting drop splitting techniques. In addition, we also show that it is possible to split the drop asymmetrically to controllably and reliably produce droplets of different volumes. Such potential as well as the flexibility in tuning the device to operate on drops of different sizes without requiring electrode reconfiguration, i.e., the use of different devices, as is required in electrowetting-therefore makes the present method an attractive alternative to electrowetting schemes.
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Affiliation(s)
- Sean Collignon
- Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3000, Australia.
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42
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Brown CV, McHale G, Trabi CL. Dielectrophoresis-driven spreading of immersed liquid droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:1011-1016. [PMID: 25519875 DOI: 10.1021/la503931p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In recent years electrowetting-on-dielectric (EWOD) has become an effective tool to control partial wetting. EWOD uses the liquid-solid interface as part of a capacitive structure that allows capacitive and interfacial energies to adjust by changes in wetting when the liquid-solid interface is charged due to an applied voltage. An important aspect of EWOD has been its applications in microfluidics in chemistry and biology and in optical devices and displays in physics and engineering. Many of these rely on the use of a liquid droplet immersed in a second liquid due to the need either for neutral buoyancy to overcome gravity and shield against impact shocks or to encapsulate the droplet for other reasons, such as in microfluidic-based DNA analyses. Recently, it has been shown that nonwetting oleophobic surfaces can be forcibly wetted by nonconducting oils using nonuniform electric fields and an interface-localized form of liquid dielectrophoresis (dielectrowetting). Here we show that this effect can be used to create films of oil immersed in a second immiscible fluid of lower permittivity. We predict that the square of the thickness of the film should obey a simple law dependent on the square of the applied voltage and with strength dependent on the ratio of difference in permittivity to the liquid-fluid interfacial tension, Δε/γ(LF). This relationship is experimentally confirmed for 11 liquid-air and liquid-liquid combinations with Δε/γ(LF) having a span of more than two orders of magnitude. We therefore provide fundamental understanding of dielectrowetting for liquid-in-liquid systems and also open up a new method to determine liquid-liquid interfacial tensions.
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Affiliation(s)
- Carl V Brown
- Nottingham Trent University , School of Science & Technology, Clifton Lane, Nottingham NG11 8NS, United Kingdom
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43
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Xu X, Sun L, Chen L, Zhou Z, Xiao J, Zhang Y. Electrowetting on dielectric device with crescent electrodes for reliable and low-voltage droplet manipulation. BIOMICROFLUIDICS 2014; 8:064107. [PMID: 25553184 PMCID: PMC4247374 DOI: 10.1063/1.4902554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 11/13/2014] [Indexed: 05/31/2023]
Abstract
Digital microfluidics based on electrowetting on dielectric is an emerging popular technology that manipulates single droplets at the microliter or even the nanoliter level. It has the unique advantages of rapid response, low reagent consumption, and high integration and is mainly applied in the field of biochemical analysis. However, currently, this technology still has a few problems, such as high control voltage, low droplet velocity, and continuity in flow, limiting its application. In this paper, through theoretical analysis and numerical simulation, it is deduced that a drive electrode with a crescent configuration can reduce the driving voltage. The experimental results not only validate this deduction but also indicate that crescent electrode can improve the droplet motion continuity and the success in split rate.
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Affiliation(s)
- Xiaowei Xu
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
| | - Lining Sun
- Robotics and Microsystem Center and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215001, China
| | - Liguo Chen
- Robotics and Microsystem Center and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215001, China
| | - Zhaozhong Zhou
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
| | - Junjian Xiao
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
| | - Yuliang Zhang
- College of Mechanical Engineering, Quzhou University , Quzhou 324000, China
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44
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Zec H, Shin DJ, Wang TH. Novel droplet platforms for the detection of disease biomarkers. Expert Rev Mol Diagn 2014; 14:787-801. [PMID: 25109704 DOI: 10.1586/14737159.2014.945437] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Personalized medicine - healthcare based on individual genetic variation - has the potential to transform the way healthcare is delivered to patients. The promise of personalized medicine has been predicated on the predictive and diagnostic power of genomic and proteomic biomarkers. Biomarker screening may help improve health outcomes, for example, by identifying individuals' susceptibility to diseases and predicting how patients will respond to drugs. Microfluidic droplet technology offers an exciting opportunity to revolutionize the accessibility of personalized medicine. A framework for the role of droplet microfluidics in biomarker detection can be based on two main themes. Emulsion-based microdroplet platforms can provide new ways to measure and detect biomolecules. In addition, microdroplet platforms facilitate high-throughput screening of biomarkers. Meanwhile, surface-based droplet platforms provide an opportunity to develop miniaturized diagnostic systems. These platforms may function as portable benchtop environments that dramatically shorten the transition of a benchtop assay into a point-of-care format.
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Affiliation(s)
- Helena Zec
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore MD 21218, USA
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45
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Shin DJ, Wang TH. Magnetic droplet manipulation platforms for nucleic acid detection at the point of care. Ann Biomed Eng 2014; 42:2289-302. [PMID: 25008142 DOI: 10.1007/s10439-014-1060-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/19/2014] [Indexed: 12/13/2022]
Abstract
This review summarizes recent developments in the use of magnetically actuated droplets in point-of-care molecular diagnostic platforms. We discuss the fundamentals of magnetic droplet manipulation and the various modes of actuation. The balance of forces acting on a droplet during transport and particle extraction, as well as the devices and instrumentation developed to perform these operations will be presented and discussed. Furthermore, we review some of the recent advances on the diagnostic applications of platforms utilizing magnetic manipulation for genetic assessment of biological samples.
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Affiliation(s)
- Dong Jin Shin
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
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46
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Shamsi MH, Choi K, Ng AHC, Wheeler AR. A digital microfluidic electrochemical immunoassay. LAB ON A CHIP 2014; 14:547-54. [PMID: 24292705 DOI: 10.1039/c3lc51063h] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Digital microfluidics (DMF) has emerged as a popular format for implementing quantitative immunoassays for diagnostic biomarkers. All previous reports of such assays have relied on optical detection; here, we introduce the first digital microfluidic immunoassay relying on electrochemical detection. In this system, an indium tin oxide (ITO) based DMF top plate was modified to include gold sensing electrodes and silver counter/pseudoreference electrodes suitable for in-line amperometric measurements. A thyroid stimulating hormone (TSH) immunoassay procedure was developed relying on magnetic microparticles conjugated with primary antibody (Ab1). Antigen molecules are captured followed by capture of a secondary antibody (Ab2) conjugated with horseradish peroxidase enzyme (HRP). HRP catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) which can be detected amperometrically. The limit of detection of the technique (2.4 μIU mL(-1)) is compatible with clinical applications; moreover, the simplicity and the small size of the detector suggest utility in the future for portable analysis.
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Affiliation(s)
- Mohtashim H Shamsi
- Department of Chemistry, University of Toronto, 80 St George St., Toronto, ON M5S 3H6, Canada.
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47
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Haque AUL, Kumar A. Hybrid optoelectric techniques for molecular diagnostics. Expert Rev Mol Diagn 2014; 12:9-11. [DOI: 10.1586/erm.11.87] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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48
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Zhang Y, Shin DJ, Wang TH. Serial dilution via surface energy trap-assisted magnetic droplet manipulation. LAB ON A CHIP 2013; 13:4827-31. [PMID: 24162777 PMCID: PMC3963271 DOI: 10.1039/c3lc50915j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
This paper demonstrates a facile method of generating precise serial dilutions in the form of droplets on an open surface platform. The method relies on the use of surface energy traps (SETs), etched areas of high surface energy on a Teflon coated glass substrate, to assist in the magnetic manipulation of droplets to meter and dispense liquid of defined volumes for the preparation of serial dilutions. The volume of the dispensed liquid can be precisely controlled by the size of the SETs, facilitating generation of concentration profiles of high linearity. We have applied this approach to the generation of serial dilutions of antibiotics for anti-microbial susceptibility testing (AST).
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Affiliation(s)
- Yi Zhang
- Department of Biomedical Engineering, Johns Hopkins University, 3400 North Charles Street, Clark 122, Baltimore, Maryland, USA.
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49
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Choi K, Ng AHC, Fobel R, Chang-Yen DA, Yarnell LE, Pearson EL, Oleksak CM, Fischer AT, Luoma RP, Robinson JM, Audet J, Wheeler AR. Automated Digital Microfluidic Platform for Magnetic-Particle-Based Immunoassays with Optimization by Design of Experiments. Anal Chem 2013; 85:9638-46. [DOI: 10.1021/ac401847x] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Kihwan Choi
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto,
Ontario M5S 3H6, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - Alphonsus H. C. Ng
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - Ryan Fobel
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - David A. Chang-Yen
- AbbVie, 200 Abbott Park Road, Abbott Park,
Illinois 60064, United States
| | - Lyle E. Yarnell
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - Elroy L. Pearson
- AbbVie, 200 Abbott Park Road, Abbott Park,
Illinois 60064, United States
| | - Carl M. Oleksak
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - Andrew T. Fischer
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - Robert P. Luoma
- Abbott Diagnostics, 1921 Hurd Drive, Irving,
Texas 75038, United States
| | - John M. Robinson
- Abbott Diagnostics, 100 Abbott Park Road, Abbott Park,
Illinois 60064, United States
| | - Julie Audet
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
| | - Aaron R. Wheeler
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto,
Ontario M5S 3H6, Canada
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
- Donnelly Centre for Cellular and Biomolecular Research, 160 College Street,
Toronto, Ontario M5S 3E1, Canada
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50
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Davoust L, Fouillet Y, Malk R, Theisen J. Coplanar electrowetting-induced stirring as a tool to manipulate biological samples in lubricated digital microfluidics. Impact of ambient phase on drop internal flow pattern. BIOMICROFLUIDICS 2013; 7:44104. [PMID: 24404038 PMCID: PMC3739825 DOI: 10.1063/1.4817006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 07/17/2013] [Indexed: 05/26/2023]
Abstract
Oscillating electrowetting on dielectrics (EWOD) with coplanar electrodes is investigated in this paper as a way to provide efficient stirring within a drop with biological content. A supporting model inspired from Ko et al. [Appl. Phys. Lett. 94, 194102 (2009)] is proposed allowing to interpret oscillating EWOD-induced drop internal flow as the result of a current streaming along the drop surface deformed by capillary waves. Current streaming behaves essentially as a surface flow generator and the momentum it sustains within the (viscous) drop is even more significant as the surface to volume ratio is small. With the circular electrode pair considered in this paper, oscillating EWOD sustains toroidal vortical flows when the experiments are conducted with aqueous drops in air as ambient phase. But when oil is used as ambient phase, it is demonstrated that the presence of an electrode gap is responsible for a change in drop shape: a pinch-off at the electrode gap yields a peanut-shaped drop and a symmetry break-up of the EWOD-induced flow pattern. Viscosity of oil is also responsible for promoting an efficient damping of the capillary waves which populate the surface of the actuated drop. As a result, the capillary network switches from one standing wave to two superimposed traveling waves of different mechanical energy, provided that actuation frequency is large enough, for instance, as large as the one commonly used in electrowetting applications (f ∼ 500 Hz and beyond). Special emphasis is put on stirring of biological samples. As a typical application, it is demonstrated how beads or cell clusters can be focused under flow either at mid-height of the drop or near the wetting plane, depending on how the nature of the capillary waves is (standing or traveling), and therefore, depending on the actuation frequency (150 Hz-1 KHz).
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Affiliation(s)
- Laurent Davoust
- Grenoble Institute of Technology (Grenoble-INP), Materials and Processes Science and Engineering Laboratory (SIMAP), BP 75, 38402 Saint Martin d'Hères, France
| | | | - Rachid Malk
- CEA-LETI-MINATEC, 38041 Grenoble cedex 9, France
| | - Johannes Theisen
- University of Grenoble (UJF), Laboratory of Geophysical and Industrial Fluid Flows (LEGI), BP 53, 38041 Grenoble, France
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