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Welch LG, Estranero J, Tourlomousis P, Wootton RCR, Radu V, González-Fernández C, Puchtler TJ, Murzeau CM, Dieckmann NMG, Shibahara A, Longbottom BW, Bryant CE, Talbot EL. A programmable and automated optical electrowetting-on-dielectric (oEWOD) driven platform for massively parallel and sequential processing of single cell assay operations. LAB ON A CHIP 2024; 24:3763-3774. [PMID: 39037291 DOI: 10.1039/d4lc00245h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
Recently, there has been an increasing emphasis on single cell profiling for high-throughput screening workflows in drug discovery and life sciences research. However, the biology underpinning these screens is often complex and is insufficiently addressed by singleplex assay screens. Traditional single cell screening technologies have created powerful sets of 'omic data that allow users to bioinformatically infer biological function, but have as of yet not empowered direct functional analysis at the level of each individual cell. Consequently, screening campaigns often require multiple secondary screens leading to laborious, time-consuming and expensive workflows in which attrition points may not be queried until late in the process. We describe a platform that harnesses droplet microfluidics and optical electrowetting-on-dielectric (oEWOD) to perform highly-controlled sequential and multiplexed single cell assays in massively parallelised workflows to enable complex cell profiling during screening. Soluble reagents or objects, such as cells or assay beads, are encapsulated into droplets of media in fluorous oil and are actively filtered based on size and optical features ensuring only desirable droplets (e.g. single cell droplets) are retained for analysis, thereby overcoming the Poisson probability distribution. Droplets are stored in an array on a temperature-controlled chip and the history of individual droplets is logged from the point of filter until completion of the workflow. On chip, droplets are subject to an automated and flexible suite of operations including the merging of sample droplets and the fluorescent acquisition of assay readouts to enable complex sequential assay workflows. To demonstrate the broad utility of the platform, we present examples of single-cell functional workflows for various applications such as antibody discovery, infectious disease, and cell and gene therapy.
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Affiliation(s)
- Lawrence G Welch
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | - Jasper Estranero
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | | | - Robert C R Wootton
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | - Valentin Radu
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | | | - Tim J Puchtler
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | - Claire M Murzeau
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | - Nele M G Dieckmann
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | - Aya Shibahara
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | - Brooke W Longbottom
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
| | - Clare E Bryant
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK
| | - Emma L Talbot
- Lightcast Discovery Ltd, Broers Building, 21 JJ Thomson Avenue, Cambridge, CB3 0FA, UK.
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Karcz A, Van Soom A, Smits K, Van Vlierberghe S, Verplancke R, Pascottini OB, Van den Abbeel E, Vanfleteren J. Development of a Microfluidic Chip Powered by EWOD for In Vitro Manipulation of Bovine Embryos. BIOSENSORS 2023; 13:bios13040419. [PMID: 37185494 PMCID: PMC10136516 DOI: 10.3390/bios13040419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/16/2023] [Accepted: 03/23/2023] [Indexed: 05/17/2023]
Abstract
Digital microfluidics (DMF) holds great potential for the alleviation of laboratory procedures in assisted reproductive technologies (ARTs). The electrowetting on dielectric (EWOD) technology provides dynamic culture conditions in vitro that may better mimic the natural embryo microenvironment. Thus far, EWOD microdevices have been proposed for in vitro gamete and embryo handling in mice and for analyzing the human embryo secretome. This article presents the development of the first microfluidic chip utilizing EWOD technology designed for the manipulation of bovine embryos in vitro. The prototype sustains the cell cycles of embryos manipulated individually on the chips during in vitro culture (IVC). Challenges related to the chip fabrication as well as to its application during bovine embryo IVC in accordance with the adapted on-chip protocol are thoroughly discussed, and future directions for DMF in ARTs are indicated.
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Affiliation(s)
- Adriana Karcz
- Centre for Microsystems Technology (CMST), Imec and Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Belgium
- Reproductive Biology Unit (RBU), Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133 D4, 9820 Merelbeke, Belgium
| | - Ann Van Soom
- Reproductive Biology Unit (RBU), Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133 D4, 9820 Merelbeke, Belgium
| | - Katrien Smits
- Reproductive Biology Unit (RBU), Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133 D4, 9820 Merelbeke, Belgium
| | - Sandra Van Vlierberghe
- Polymer Chemistry and Biomaterials Group, Centre of Macromolecular Chemistry, Ghent University, Campus Sterre, Building S4, Krijgslaan 281, 9000 Ghent, Belgium
| | - Rik Verplancke
- Centre for Microsystems Technology (CMST), Imec and Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Belgium
| | - Osvaldo Bogado Pascottini
- Reproductive Biology Unit (RBU), Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133 D4, 9820 Merelbeke, Belgium
| | - Etienne Van den Abbeel
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - Jan Vanfleteren
- Centre for Microsystems Technology (CMST), Imec and Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Belgium
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Wang Y, Nitta T, Hiratsuka Y, Morishima K. In situ integrated microrobots driven by artificial muscles built from biomolecular motors. Sci Robot 2022; 7:eaba8212. [PMID: 36001686 DOI: 10.1126/scirobotics.aba8212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Microrobots have been developed for applications in the submillimeter domain such as the manipulation of micro-objects and microsurgery. Rapid progress has been achieved in developing miniaturized components for microrobotic systems, resulting in a variety of functional microactuators and soft components for creating untethered microrobots. Nevertheless, the integration of microcomponents, especially the assembly of actuators and mechanical components, is still time-consuming and has inherent restrictions, thus limiting efficient fabrications of microrobots and their potential applications. Here, we propose a method for fabricating microrobots in situ inspired by the construction of microsystems in living organisms. In a microfluidic chip, hydrogel mechanical components and artificial muscle actuators are successively photopatterned from hydrogel prepolymer and biomolecular motors, respectively, and integrated in situ into functional microrobots. The proposed method allows the fast fabrication of microrobots through simple operations and affordable materials while providing versatile functions through the precise spatiotemporal control of in situ integration and reconfiguration of artificial muscles. To validate the method, we fabricated microrobots to elicit different motions and on-chip robots with unique characteristics for microfluidic applications. This study may establish a new paradigm for microrobot integration and lead to the production of unique biohybrid microrobots with various advantages.
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Affiliation(s)
- Yingzhe Wang
- Department of Mechanical Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Takahiro Nitta
- Applied Physics Course, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu City 501-1193, Japan
| | - Yuichi Hiratsuka
- School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Keisuke Morishima
- Department of Mechanical Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.,Center for Medical Engineering and Informatics, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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Karcz A, Van Soom A, Smits K, Verplancke R, Van Vlierberghe S, Vanfleteren J. Electrically-driven handling of gametes and embryos: taking a step towards the future of ARTs. LAB ON A CHIP 2022; 22:1852-1875. [PMID: 35510672 DOI: 10.1039/d1lc01160j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Electrical stimulation of gametes and embryos and on-chip manipulation of microdroplets of culture medium serve as promising tools for assisted reproductive technologies (ARTs). Thus far, dielectrophoresis (DEP), electrorotation (ER) and electrowetting on dielectric (EWOD) proved compatible with most laboratory procedures offered by ARTs. Positioning, entrapment and selection of reproductive cells can be achieved with DEP and ER, while EWOD provides the dynamic microenvironment of a developing embryo to better mimic the functions of the oviduct. Furthermore, these techniques are applicable for the assessment of the developmental competence of a mammalian embryo in vitro. Such research paves the way towards the amelioration and full automation of the assisted reproduction methods. This article aims to provide a summary on the recent developments regarding electrically stimulated lab-on-chip devices and their application for the manipulation of gametes and embryos in vitro.
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Affiliation(s)
- Adriana Karcz
- Centre for Microsystems Technology (CMST), Imec and Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Ghent, Belgium.
- Reproductive Biology Unit (RBU), Faculty of Veterinary Medicine, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133 D4 entrance 4, 9820 Merelbeke, Belgium
| | - Ann Van Soom
- Reproductive Biology Unit (RBU), Faculty of Veterinary Medicine, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133 D4 entrance 4, 9820 Merelbeke, Belgium
| | - Katrien Smits
- Reproductive Biology Unit (RBU), Faculty of Veterinary Medicine, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133 D4 entrance 4, 9820 Merelbeke, Belgium
| | - Rik Verplancke
- Centre for Microsystems Technology (CMST), Imec and Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Ghent, Belgium.
| | - Sandra Van Vlierberghe
- Polymer Chemistry and Biomaterials Group, Centre of Macromolecular Chemistry, Ghent University, Campus Sterre, building S4, Krijgslaan 281, 9000 Ghent, Belgium
| | - Jan Vanfleteren
- Centre for Microsystems Technology (CMST), Imec and Ghent University, Technologiepark Zwijnaarde 126, 9052 Zwijnaarde, Ghent, Belgium.
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5
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Ye WQ, Wei YY, Wang DN, Yang CG, Xu ZR. A digital microfluidic platform based on a near-infrared light-responsive shape-memory micropillar array. LAB ON A CHIP 2021; 21:1131-1138. [PMID: 33533387 DOI: 10.1039/d0lc01324b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this work, we developed a digital microfluidic platform based on a shape memory micropillar array responsive to near-infrared light, and the droplets were programmatically manipulated through light-induced micropillar deformation. The micropillar array was constructed on the surface of a poly(ethylene-vinyl acetate) copolymer, a shape memory polymer sensitive to near-infrared light. Before droplet manipulation, the micropillar array was kept temporarily tilted by heating and pressing. Under the irradiation of a near-infrared laser, the micropillar array achieved the transition from the temporary shape to the original shape. Temperature gradient and micropillar deformation caused by near-infrared light irradiation produce the driving force for droplet movement. The movement of the laser mounted on an electronically controlled displacement platform was controlled by a computer to achieve the programmed control of the droplets. Moreover, we demonstrated light-manipulated droplet movement and fusion, and achieved ascorbic acid detection using this digital microfluidic platform. In particular, the micropillar array chip is able to manipulate droplets in a wide range of 0.1 μL to 10 μL. The proposed digital microfluidic platform will broaden the application of digital microfluidic technology in analytical chemistry and biomedicine.
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Affiliation(s)
- Wen-Qi Ye
- Research Center for Analytical Sciences, Northeastern University, Shenyang, 110819, China.
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Wei Q, Yao W, Gu L, Fan B, Gao Y, Yang L, Zhao Y, Che C. Modeling, simulation, and optimization of electrowetting-on-dielectric (EWOD) devices. BIOMICROFLUIDICS 2021; 15:014107. [PMID: 33569090 PMCID: PMC7853767 DOI: 10.1063/5.0029790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
With widespread research studies on electrowetting-on-dielectric (EWOD) for droplet manipulation in the field of lab-on-a-chip, how to improve the driving capability of droplets has increasingly attracted enormous interest. Aiming to decrease driving voltages and improve driving effectiveness, this paper studies the modeling, simulation, and optimization of EWOD devices. The theoretical model is refined mainly in consideration of the saturation effect of the contact angle and then verified by both simulation and experiments. As a design guide to decrease the driving voltage, a theoretical criterion of droplet splitting, the most difficult one among four basic droplet manipulations, is developed and then verified by experimental results. Moreover, a novel sigmoid electrode shape is found by the optimization method based on finite element analysis and achieves better driving effectiveness and consistent bidirectional driving capability, compared with the existing electrode shapes. Taken together, this paper provides an EWOD analysis and optimization method featuring a lower voltage and a better effectiveness and opens up opportunities for optimization designs in various EWOD-based applications.
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Affiliation(s)
| | | | | | | | | | | | - Yingying Zhao
- Authors to whom correspondence should be addressed: and
| | - Chuncheng Che
- Authors to whom correspondence should be addressed: and
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Rui X, Song S, Wang W, Zhou J. Applications of electrowetting-on-dielectric (EWOD) technology for droplet digital PCR. BIOMICROFLUIDICS 2020; 14:061503. [PMID: 33312327 PMCID: PMC7719047 DOI: 10.1063/5.0021177] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/24/2020] [Indexed: 05/25/2023]
Abstract
Digital microfluidics is an elegant technique based on single droplets for the design, composition, and manipulation of microfluidic systems. In digital microfluidics, especially in the electrowetting on dielectric (EWOD) system, each droplet acts as an independent reactor, which enables a wide range of multiple parallel biological and chemical reactions at the microscale. EWOD digital microfluidics reduces reagent and energy consumption, accelerates analysis, enables point-of-care diagnostic, simplifies integration with sensors, etc. Such a digital microfluidic system is especially relevant for droplet digital PCR (ddPCR), thanks to its nanoliter droplets and well-controlled volume distribution. At low DNA concentration, these small volumes allow less than one DNA strand per droplet on average (limited dilution) so that after a fixed number of PCR cycles (endpoint PCR), only the DNA in droplets containing the sequence of interest has been amplified and can be detected by fluorescence to yield an accurate count of the sequences of interest using statistical models. Focusing on ddPCR, this article summarizes the latest development and research on EWOD technology for droplet PCR over the last decade.
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Affiliation(s)
| | | | | | - Jia Zhou
- Author to whom correspondence should be addressed:
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8
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Li H, Shen R, Dong C, Chen T, Jia Y, Mak PI, Martins RP. Turning on/off satellite droplet ejection for flexible sample delivery on digital microfluidics. LAB ON A CHIP 2020; 20:3709-3719. [PMID: 32974634 DOI: 10.1039/d0lc00701c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Digital microfluidics has the potential to minimize and automate reactions in biochemical labs. However, the complexity of drop manipulation and sample preparation on-chip has limited its incorporation into daily workflow. In this paper, we report a novel method for flexible sample delivery on digital microfluidics in a wide volume range spanning four orders of magnitude from picoliters to nanoliters. The method is based on the phenomenon of satellite droplet ejection, triggered by a sudden change in the strength of the electric field across a drop on a hydrophobic dielectric surface. By precisely modulating the actuation signal with convenient external electric controls, satellite droplet ejection can be turned on to dispense samples or turned off to transport picking-up drops. A pico-dosing design is presented and validated in this work to demonstrate the direct and flexible on-chip sample delivery. This approach could pave the way for the acceptance of microfluidics as a common platform for daily reactions to realize lab-on-a-chip.
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Affiliation(s)
- Haoran Li
- The State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau SAR, China.
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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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Sattari A, Hanafizadeh P, Hoorfar M. Multiphase flow in microfluidics: From droplets and bubbles to the encapsulated structures. Adv Colloid Interface Sci 2020; 282:102208. [PMID: 32721624 DOI: 10.1016/j.cis.2020.102208] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/19/2020] [Accepted: 07/04/2020] [Indexed: 12/14/2022]
Abstract
Microfluidic technologies have a unique ability to control more precisely and effectively on two-phase flow systems in comparison with macro systems. Controlling the size of the droplets and bubbles has led to an ever-increasing expansion of this technology in two-phase systems. Liquid-liquid and gas-liquid two-phase flows because of their numerous applications in different branches such as reactions, synthesis, emulsions, cosmetic, food, drug delivery, etc. have been the most critical two-phase flows in microfluidic systems. This review highlights recent progress in two-phase flows in microfluidic devices. The fundamentals of two-phase flows, including some essential dimensionless numbers, governing equations, and some most well-known numerical methods are firstly introduced, followed by a review of standard methods for producing segmented flows such as emulsions in microfluidic systems. Then various encapsulated structures, a common two-phase flow structure in microfluidic devices, and different methods of their production are reviewed. Finally, applications of two-phase microfluidic flows in drug-delivery, biotechnology, mixing, and microreactors are briefly discussed.
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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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Nakao T, Kazoe Y, Morikawa K, Lin L, Mawatari K, Kitamori T. Femtoliter Volumetric Pipette and Flask Utilizing Nanofluidics. Analyst 2020; 145:2669-2675. [PMID: 32049074 DOI: 10.1039/c9an02258a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microfluidics has achieved integration of analytical processes in microspaces and realized miniaturized analyses in fields such as chemistry and biology. We have proposed a general concept of integration and extended this concept to the 10-1000 nm scale exploring ultimate analytical performances (e.g. immunoassay of a single-protein molecule). However, a sampling method is still challenging for nanofluidics despite its importance in analytical chemistry. In this study, we developed a femtoliter (fL) sampling method for volume measurement and sample transport. Traditionally, sampling has been performed using a volumetric pipette and flask. In this research, a nanofluidic device consisting of a femtoliter volumetric pipette and flask was fabricated on glass substrates. Since gravity, which is exploited in bulk fluidic operations, becomes less dominant than surface effects on the nanometer scale, fluidic operation of the femtoliter sampling was designed utilizing surface tension and air pressure control. The working principle of an 11 fL volumetric pipette and a 50 fL flask, which were connected by a nanochannel, was verified. It was found that evaporation of the sample solution by air flow was a significant source of error because of the ultra-small volumes being processed. Thus, the evaporation issue was solved by suppressing the air flow. As a result, the volumetric measurement error was decreased to ±0.06 fL (CV 0.6%), which is sufficiently low for use in nanofluidic analytical applications. This study will present a fundamental technology for the development of novel analytical methods for femtoliter volume samples such as single molecule analyses.
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Affiliation(s)
- Tatsuro Nakao
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
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Ducrée J. Efficient Development of Integrated Lab-On-A-Chip Systems Featuring Operational Robustness and Manufacturability. MICROMACHINES 2019; 10:mi10120886. [PMID: 31861126 PMCID: PMC6953106 DOI: 10.3390/mi10120886] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/09/2019] [Accepted: 12/11/2019] [Indexed: 12/28/2022]
Abstract
The majority of commercially oriented microfluidic technologies provide novel point-of-use solutions for laboratory automation with important areas in the context of the life sciences such as health care, biopharma, veterinary medicine and agrifood as well as for monitoring of the environment, infrastructures and industrial processes. Such systems are often composed of a modular setup exhibiting an instrument accommodating rather conventional actuation, detection and control units which interfaces with a fluidically integrated "Lab-on-a-Chip" device handling (bio-)sample(s) and reagents. As the complex network of tiny channels, chambers and surface-functionalised zones can typically not be properly cleaned and regenerated, these microfluidic chips are mostly devised as single-use disposables. The availability of cost-efficient materials and associated structuring, functionalisation and assembly schemes thus represents a key ingredient along the commercialisation pipeline and will be a first focus of this work. Furthermore, and owing to their innate variability, investigations on biosamples mostly require the acquisition of statistically relevant datasets. Consequently, intermediate numbers of consistently performing chips are already needed during application development; to mitigate the potential pitfalls of technology migration and to facilitate regulatory compliance of the end products, manufacture of such pilot series should widely follow larger-scale production schemes. To expedite and de-risk the development of commercially relevant microfluidic systems towards high Technology Readiness Levels (TRLs), we illustrate a streamlined, manufacturing-centric platform approach employing the paradigms of tolerance-forgiving Design-for-Manufacture (DfM) and Readiness for Scale-up (RfS) from prototyping to intermediate pilot series and eventual mass fabrication. Learning from mature industries, we further propose pursuing a platform approach incorporating aspects of standardisation in terms of specification, design rules and testing methods for materials, components, interfaces, and operational procedures; this coherent strategy will foster the emergence of dedicated commercial supply chains and also improve the economic viability of Lab-on-a-Chip systems often targeting smaller niche markets by synergistically bundling technology development.
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Affiliation(s)
- Jens Ducrée
- FPC@DCU-Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, School of Physical Sciences, Glasnevin, Dublin 9, Ireland
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Zhou M, Wu Z, Zhao Y, Yang Q, Ling W, Li Y, Xu H, Wang C, Huang X. Droplets as Carriers for Flexible Electronic Devices. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1901862. [PMID: 31871863 PMCID: PMC6918117 DOI: 10.1002/advs.201901862] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/16/2019] [Indexed: 05/30/2023]
Abstract
Coupling soft bodies and dynamic motions with multifunctional flexible electronics is challenging, but is essential in satisfying the urgent and soaring demands of fully soft and comprehensive robotic systems that can perform tasks in spite of rigorous spatial constraints. Here, the mobility and adaptability of liquid droplets with the functionality of flexible electronics, and techniques to use droplets as carriers for flexible devices are combined. The resulting active droplets (ADs) with volumes ranging from 150 to 600 µL can conduct programmable functions, such as sensing, actuation, and energy harvesting defined by the carried flexible devices and move under the excitation of gravitational force or magnetic force. They work in both dry and wet environments, and adapt to the surrounding environment through reversible shape shifting. These ADs can achieve controllable motions at a maximum velocity of 226 cm min-1 on a dry surface and 32 cm min-1 in a liquid environment. The conceptual system may eventually lead to individually addressable ADs that offer sophisticated functions for high-throughput molecule analysis, drug assessment, chemical synthesis, and information collection.
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Affiliation(s)
- Mingxing Zhou
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
| | - Ziyue Wu
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
| | - Yicong Zhao
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
| | - Qing Yang
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
| | - Wei Ling
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
| | - Ya Li
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
| | - Hang Xu
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
| | - Cheng Wang
- Department of Mechanical EngineeringMissouri University of Science and Technology400 West 13th StreetRollaMO65401USA
| | - Xian Huang
- Department of Biomedical EngineeringTianjin University92 Weijin RoadTianjin300072P. R. China
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16
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De Jong E, Wang Y, Den Toonder JMJ, Onck PR. Climbing droplets driven by mechanowetting on transverse waves. SCIENCE ADVANCES 2019; 5:eaaw0914. [PMID: 31214650 PMCID: PMC6570512 DOI: 10.1126/sciadv.aaw0914] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 05/07/2019] [Indexed: 05/03/2023]
Abstract
Many applications in modern technology, such as self-cleaning surfaces and digital microfluidics, require control over individual fluid droplets on flat surfaces. Existing techniques may suffer from side effects resulting from high electric fields and high temperatures. Here, we introduce a markedly different method, termed "mechanowetting," that is based on the surface tension-controlled droplet motion on deforming surfaces. The method is demonstrated by transporting droplets using transverse surface waves on horizontal and (vertically) inclined surfaces at transport velocities equal to the wave speed. We fully capture the fundamental mechanism of the mechanowetting force numerically and theoretically and establish its dependence on the fluid properties, surface energy, and wave parameters. Mechanowetting has the potential to lead to a range of new applications that feature droplet control through dynamic surface deformations.
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Affiliation(s)
- Edwin De Jong
- Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, Netherlands
| | - Ye Wang
- Department of Mechanical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, Netherlands
| | - Jaap M. J. Den Toonder
- Department of Mechanical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, Netherlands
| | - Patrick R. Onck
- Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, Netherlands
- Corresponding author.
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17
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Self-propulsion of aluminum particle-coated Janus droplet in alkaline solution. J Colloid Interface Sci 2018; 532:657-665. [DOI: 10.1016/j.jcis.2018.08.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/08/2018] [Accepted: 08/10/2018] [Indexed: 11/20/2022]
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18
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Kim J, Shin D, Lee J, Koo G, Kim C, Sim JH, Jung G, Won YH. Electro-wetting lenticular lens with improved diopter for 2D and 3D conversion using lens-shaped ETPTA chamber. OPTICS EXPRESS 2018; 26:19614-19626. [PMID: 30114132 DOI: 10.1364/oe.26.019614] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/13/2018] [Indexed: 06/08/2023]
Abstract
In this paper, we introduce a method for improving the lens diopter of 2D/3D convertible devices using electro-wetting. For stable operation, an electro-wetting device requires high dioptric performance and this was achieved using bi-convex liquid-liquid-solid phases. 1-Chloronaphthalene with a refractive index of 1.633 was used as an oil phase to achieve high diopters. ETPTA (trimethylolpropane ethoxylate triacrylate), a UV-sensitive material with low chemical reactivity to the 1-Chloronaphthalene, was used as a chamber material. This resulted in a diopter of 3030D for high quality multi-view images without unstable oil movement or trembling. The ETPTA was molded on a 0.3mm thick glass substrate that was coated with UV adhesive (NOA 81). The maximum diopter capable of stable operation was 3425D. 2D and 3D conversion and parallax motion were demonstrated.
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19
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Zulkepli SNIS, Hamid NH, Shukla V. Droplet Velocity Measurement Based on Dielectric Layer Thickness Variation Using Digital Microfluidic Devices. BIOSENSORS 2018; 8:E45. [PMID: 29738428 PMCID: PMC6022883 DOI: 10.3390/bios8020045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/22/2018] [Accepted: 03/22/2018] [Indexed: 11/16/2022]
Abstract
In recent years, the number of interdisciplinary research works related to the development of miniaturized systems with integrated chemical and biological analyses is increasing. Digital microfluidic biochips (DMFBs) are one kind of miniaturized systems designed for conducting inexpensive, fast, convenient and reliable biochemical assay procedures focusing on basic scientific research and medical diagnostics. The role of a dielectric layer in the digital microfluidic biochips is prominent as it helps in actuating microliter droplets based on the electrowetting-on-dielectric (EWOD) technique. The advantages of using three different material layers of dielectric such as parafilm, polytetrafluoroethylene (PTFE) and ethylene tetrafluoroethylene (ETFE) were reported in the current work. A simple fabrication process of a digital microfluidic device was performed and good results were obtained. The threshold of the actuation voltage was determined for all dielectric materials of varying thicknesses. Additionally, the OpenDrop device was tested by utilizing a single-plate system to transport microliter droplets for a bioassay operation. With the newly proposed fabrication methods, these dielectric materials showed changes in contact angle and droplet velocity when the actuation voltage was applied. The threshold actuation voltage for the dielectric layers of 10⁻13 μm was 190 V for the open plate DMFBs.
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Affiliation(s)
| | - Nor Hisham Hamid
- Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskander 32610, Malaysia.
| | - Vineeta Shukla
- Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskander 32610, Malaysia.
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20
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Maglione MS, Casalini S, Georgakopoulos S, Barbalinardo M, Parkula V, Crivillers N, Rovira C, Greco P, Mas-Torrent M. Fluid Mixing for Low-Power 'Digital Microfluidics' Using Electroactive Molecular Monolayers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:1703344. [PMID: 29280286 DOI: 10.1002/smll.201703344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/03/2017] [Indexed: 06/07/2023]
Abstract
A switchable electrode, which relies on an indium-tin oxide conductive substrate coated with a self-assembled monolayer terminated with an anthraquinone group (AQ), is reported as an electrowetting system. AQ electrochemical features confer the capability of yielding a significant modulation of surface wettability as high as 26° when its redox state is switched. Hence, an array of planar electrodes for droplets actuation is fabricated and integrated in a microfluidic device to perform mixing and dispensing on sub-nanoliter scale. Vehiculation of cells across microfluidic compartments is made possible by taking full advantage of surface electrowetting in culture medium.
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Affiliation(s)
- Maria Serena Maglione
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus UAB, 08193, Bellaterra, Spain
| | - Stefano Casalini
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus UAB, 08193, Bellaterra, Spain
| | - Stamatis Georgakopoulos
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus UAB, 08193, Bellaterra, Spain
| | - Marianna Barbalinardo
- Istituto per lo Studio dei Materiali Nanostrutturati, CNR. Via P. Gobetti 101, 40129, Bologna, Italy
- Scriba Nanotecnologie srl, via di Corticell 183/8, 40128, Bologna, Italy
| | - Vitaliy Parkula
- Scriba Nanotecnologie srl, via di Corticell 183/8, 40128, Bologna, Italy
| | - Núria Crivillers
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus UAB, 08193, Bellaterra, Spain
| | - Concepció Rovira
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus UAB, 08193, Bellaterra, Spain
| | - Pierpaolo Greco
- Scriba Nanotecnologie srl, via di Corticell 183/8, 40128, Bologna, Italy
| | - Marta Mas-Torrent
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus UAB, 08193, Bellaterra, Spain
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21
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Madison AC, Royal MW, Vigneault F, Chen L, Griffin PB, Horowitz M, Church GM, Fair RB. Scalable Device for Automated Microbial Electroporation in a Digital Microfluidic Platform. ACS Synth Biol 2017; 6:1701-1709. [PMID: 28569062 DOI: 10.1021/acssynbio.7b00007] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electrowetting-on-dielectric (EWD) digital microfluidic laboratory-on-a-chip platforms demonstrate excellent performance in automating labor-intensive protocols. When coupled with an on-chip electroporation capability, these systems hold promise for streamlining cumbersome processes such as multiplex automated genome engineering (MAGE). We integrated a single Ti:Au electroporation electrode into an otherwise standard parallel-plate EWD geometry to enable high-efficiency transformation of Escherichia coli with reporter plasmid DNA in a 200 nL droplet. Test devices exhibited robust operation with more than 10 transformation experiments performed per device without cross-contamination or failure. Despite intrinsic electric-field nonuniformity present in the EP/EWD device, the peak on-chip transformation efficiency was measured to be 8.6 ± 1.0 × 108 cfu·μg-1 for an average applied electric field strength of 2.25 ± 0.50 kV·mm-1. Cell survival and transformation fractions at this electroporation pulse strength were found to be 1.5 ± 0.3 and 2.3 ± 0.1%, respectively. Our work expands the EWD toolkit to include on-chip microbial electroporation and opens the possibility of scaling advanced genome engineering methods, like MAGE, into the submicroliter regime.
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Affiliation(s)
- Andrew C. Madison
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Matthew W. Royal
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Frederic Vigneault
- Wyss Institute for Biologically Inspired Engineering, Boston, Massachusetts 02115, United States
| | - Liji Chen
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Peter B. Griffin
- Stanford
Genome Technology Center, Stanford University, Palo Alto, California 94304, United States
| | | | - George M. Church
- Wyss Institute for Biologically Inspired Engineering, Boston, Massachusetts 02115, United States
- Department
of Genetics, Harvard Medical School, Harvard University, Boston, Massachusetts 02115, United States
| | - Richard B. Fair
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
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22
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Wondimu SF, von der Ecken S, Ahrens R, Freude W, Guber AE, Koos C. Integration of digital microfluidics with whispering-gallery mode sensors for label-free detection of biomolecules. LAB ON A CHIP 2017; 17:1740-1748. [PMID: 28406508 DOI: 10.1039/c6lc01556e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present a multi-sensor chip comprising an array of whispering-gallery mode (WGM) micro-goblet lasers integrated into a digital microfluidic (DMF) system. In contrast to earlier demonstrations, the lasers are fabricated from dye-doped poly-methyl methacrylate (PMMA) at low cost using spin-coating, mask-based optical lithography, wet chemical etching, and thermal reflow techniques. Pumping and read-out of the devices is accomplished via simple free-space optics, thereby allowing large-scale sensor arrays to be addressed. We demonstrate the viability of the system by bulk refractive index-sensing and by measuring the specific binding of streptavidin to a biotinylated sensor surface. This is the first time that optical cavities are used for label-free detection of biomolecules in a DMF system. This approach can be extended to a versatile detector platform that targets a wide range of clinically relevant biomolecules.
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Affiliation(s)
- Sentayehu F Wondimu
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
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23
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Heinemann J, Deng K, Shih SCC, Gao J, Adams PD, Singh AK, Northen TR. On-chip integration of droplet microfluidics and nanostructure-initiator mass spectrometry for enzyme screening. LAB ON A CHIP 2017; 17:323-331. [PMID: 27957569 DOI: 10.1039/c6lc01182a] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Biological assays often require expensive reagents and tedious manipulations. These shortcomings can be overcome using digitally operated microfluidic devices that require reduced sample volumes to automate assays. One particular challenge is integrating bioassays with mass spectrometry based analysis. Towards this goal we have developed μNIMS, a highly sensitive and high throughput technique that integrates droplet microfluidics with nanostructure-initiator mass spectrometry (NIMS). Enzyme reactions are carried out in droplets that can be arrayed on discrete NIMS elements at defined time intervals for subsequent mass spectrometry analysis, enabling time resolved enzyme activity assay. We apply the μNIMS platform for kinetic characterization of a glycoside hydrolase enzyme (CelE-CMB3A), a chimeric enzyme capable of deconstructing plant hemicellulose into monosaccharides for subsequent conversion to biofuel. This study reveals NIMS nanostructures can be fabricated into arrays for microfluidic droplet deposition, NIMS is compatible with droplet and digital microfluidics, and can be used on-chip to assay glycoside hydrolase enzyme in vitro.
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Affiliation(s)
- Joshua Heinemann
- Joint Bioenergy Institute, Emeryville, California 94608, USA and Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
| | - Kai Deng
- Joint Bioenergy Institute, Emeryville, California 94608, USA and Sandia National Laboratories, Livermore, California 94551, USA
| | - Steve C C Shih
- Department of Electrical and Computer Engineering, Concordia University, Montreal, Quebec, Canada
| | - Jian Gao
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
| | - Paul D Adams
- Joint Bioenergy Institute, Emeryville, California 94608, USA and Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. and Department of Bioengineering, University of California, Berkeley, California, 94720, USA
| | - Anup K Singh
- Joint Bioenergy Institute, Emeryville, California 94608, USA and Sandia National Laboratories, Livermore, California 94551, USA
| | - Trent R Northen
- Joint Bioenergy Institute, Emeryville, California 94608, USA and Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. and Joint Genome Institute, Walnut creek, California, 94598, USA
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24
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Clement CE, Jiang D, Thio SK, Park SY. A Study of Dip-Coatable, High-Capacitance Ion Gel Dielectrics for 3D EWOD Device Fabrication. MATERIALS 2017; 10:ma10010041. [PMID: 28772400 PMCID: PMC5344548 DOI: 10.3390/ma10010041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/06/2016] [Accepted: 12/26/2016] [Indexed: 11/16/2022]
Abstract
We present a dip-coatable, high-capacitance ion gel dielectric for scalable fabrication of three-dimensional (3D) electrowetting-on-dielectric (EWOD) devices such as an n × n liquid prism array. Due to the formation of a nanometer-thick electric double layer (EDL) capacitor, an ion gel dielectric offers two to three orders higher specific capacitance (c ≈ 10 μF/cm2) than that of conventional dielectrics such as SiO2. However, the previous spin-coating method used for gel layer deposition poses several issues for 3D EWOD device fabrication, particularly when assembling multiple modules. Not only does the spin-coating process require multiple repetitions per module, but the ion gel layer also comes in risks of damage or contamination due to handling errors caused during assembly. In addition, it was observed that the chemical formulation previously used for the spin-coating method causes the surface defects on the dip-coated gel layers and thus leads to poor EWOD performance. In this paper, we alternatively propose a dip-coating method with modified gel solutions to obtain defect-free, functional ion gel layers without the issues arising from the spin-coating method for 3D device fabrication. A dip-coating approach offers a single-step coating solution with the benefits of simplicity, scalability, and high throughput for deposition of high-capacitance gel layers on non-planar EWOD devices. An ion gel solution was prepared by combining the [EMIM][TFSI] ionic liquid and the [P(VDF-HFP)] copolymer at various wt % ratios in acetone solvent. Experimental studies were conducted to fully understand the effects of chemical composition ratios in the gel solution and how varying thicknesses of ion gel and Teflon layers affects EWOD performance. The effectiveness and potentiality of dip-coatable gel layers for 3D EWOD devices have been demonstrated through fabricating 5 × 1 arrayed liquid prisms using a single-step dip-coating method. Each prism module has been individually controlled to achieve spatial beam steering without the need for bulky mechanical moving parts.
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Affiliation(s)
- Carlos E Clement
- Department of Mechanical Engineering, National University of Singapore, Block EA, #07-08, 9 Engineering Drive 1, Singapore 117576, Singapore.
| | - Dongyue Jiang
- Department of Mechanical Engineering, National University of Singapore, Block EA, #07-08, 9 Engineering Drive 1, Singapore 117576, Singapore.
| | - Si Kuan Thio
- Department of Mechanical Engineering, National University of Singapore, Block EA, #07-08, 9 Engineering Drive 1, Singapore 117576, Singapore.
| | - Sung-Yong Park
- Department of Mechanical Engineering, National University of Singapore, Block EA, #07-08, 9 Engineering Drive 1, Singapore 117576, Singapore.
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25
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Chiang MY, Hsu YW, Hsieh HY, Chen SY, Fan SK. Constructing 3D heterogeneous hydrogels from electrically manipulated prepolymer droplets and crosslinked microgels. SCIENCE ADVANCES 2016; 2:e1600964. [PMID: 27819046 PMCID: PMC5091359 DOI: 10.1126/sciadv.1600964] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/26/2016] [Indexed: 05/13/2023]
Abstract
Formation of multifunctional, heterogeneous, and encoded hydrogel building blocks, or microgels, by crosslinking and assembly of microgels are two essential steps in establishing hierarchical, complicated, and three-dimensional (3D) hydrogel architectures that recapitulate natural and biological structures or originate new materials by design. However, for the variety of the hydrogel materials crosslinked differently and for the varied scales of microgels and architectures, the formation and assembly processes are usually performed separately, which increases the manufacturing complexity of designed hydrogel materials. We show the construction of hydrogel architectures through programmable formation and assembly on an electromicrofluidic platform, adopting two reciprocal electric manipulations (electrowetting and dielectrophoresis) to manipulate varied objects (i) in multiple phases, including prepolymer liquid droplets and crosslinked microgels, (ii) on a wide range of scales from micrometer functional particles or cells to millimeter-assembled hydrogel architectures, and (iii) with diverse properties, such as conductive and dielectric droplets that are photocrosslinkable, chemically crosslinkable, or thermally crosslinkable. Prepolymer droplets, particles, and dissolved molecules are electrically addressable to adjust the properties of the microgel building blocks in liquid phase that subsequently undergo crosslinking and assembly in a flexible sequence to accomplish heterogeneous and seamless hydrogel architectures. We expect the electromicrofluidic platform to become a general technique to obtain 3D complex architectures.
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Affiliation(s)
- Min-Yu Chiang
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Yao-Wen Hsu
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Hsin-Yi Hsieh
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
| | - San-Yuan Chen
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
- Center of Biotechnology, National Taiwan University, Taipei, Taiwan
- Corresponding author.
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26
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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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27
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Jiang D, Park SY. Light-driven 3D droplet manipulation on flexible optoelectrowetting devices fabricated by a simple spin-coating method. LAB ON A CHIP 2016; 16:1831-1839. [PMID: 27094708 DOI: 10.1039/c6lc00293e] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Technical advances in electrowetting-on-dielectric (EWOD) over the past few years have extended our attraction to three-dimensional (3D) devices capable of providing more flexibility and functionality with larger volumetric capacity than conventional 2D planar ones. However, typical 3D EWOD devices require complex and expensive fabrication processes for patterning and wiring of pixelated electrodes that also restrict the minimum droplet size to be manipulated. Here, we present a flexible single-sided continuous optoelectrowetting (SCOEW) device which is not only fabricated by a spin-coating method without the need for patterning and wiring processes, but also enables light-driven 3D droplet manipulations. To provide photoconductive properties, previous optoelectrowetting (OEW) devices have used amorphous silicon (a-Si) typically fabricated through high-temperature processes over 300 °C such as CVD or PECVD. However, most of the commercially-available flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) experience serious thermal deformation under such high-temperature processes. Because of this compatibility issue of conventional OEW devices with flexible substrates, light-driven 3D droplet manipulations have not yet been demonstrated on flexible substrates. Our study overcomes this compatibility issue by using a polymer-based photoconductive material, titanium oxide phthalocyanine (TiOPc) and thus SCOEW devices can be simply fabricated on flexible substrates through a low-cost, spin-coating method. In this paper, analytical studies were conducted to understand the effects of light patterns on static contact angles and EWOD forces. For experimental validations of our study, flexible SCOEW devices were successfully fabricated through the TiOPc-based spin-coating method and light-driven droplet manipulations (e.g. transportation, merging, and splitting) have been demonstrated on various 3D terrains such as inclined, vertical, upside-down, and curved surfaces. Our flexible SCOEW technology offers the benefits of device simplicity, flexibility, and functionality over conventional EWOD and OEW devices by enabling optical droplet manipulations on a 3D featureless surface.
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Affiliation(s)
- Dongyue Jiang
- Department of Mechanical Engineering, National University of Singapore, 117576, Singapore.
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28
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Huang HY, Shen HH, Chung LY, Chung YH, Chen CC, Hsu CH, Fan SK, Yao DJ. Fertilization of Mouse Gametes in Vitro Using a Digital Microfluidic System. IEEE Trans Nanobioscience 2015; 14:857-63. [PMID: 26529769 DOI: 10.1109/tnb.2015.2485303] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We demonstrated in vitro fertilization (IVF) using a digital microfluidic (DMF) system, so-called electrowetting on dielectric (EWOD). The DMF device was proved to be biocompatible and the DMF manipulation of a droplet was harmless to the embryos. This DMF platform was then used for the fertilization of mouse gametes in vitro and for embryo dynamic culture based on a dispersed droplet form. Development of the embryos was instantaneously recorded by a time-lapse microscope in an incubator. Our results indicated that increasing the number of sperms for IVF would raise the rate of fertilization. However, the excess of sperms in the 10 μL culture medium would more easily make the embryo dead during cell culture. Dynamic culture powered with EWOD can manipulate a single droplet containing mouse embryos and culture to the eight-cell stage. The fertilization rate of IVF demonstrated by DMF system was 34.8%, and about 25% inseminated embryos dynamically cultured on a DMF chip developed into an eight-cell stage. The results indicate that the DMF system has the potential for application in assisted reproductive technology.
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29
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Huang HY, Shen HH, Tien CH, Li CJ, Fan SK, Liu CH, Hsu WS, Yao DJ. Digital Microfluidic Dynamic Culture of Mammalian Embryos on an Electrowetting on Dielectric (EWOD) Chip. PLoS One 2015; 10:e0124196. [PMID: 25933003 PMCID: PMC4416819 DOI: 10.1371/journal.pone.0124196] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/26/2015] [Indexed: 01/04/2023] Open
Abstract
Current human fertilization in vitro (IVF) bypasses the female oviduct and manually inseminates, fertilizes and cultivates embryos in a static microdrop containing appropriate chemical compounds. A microfluidic microchannel system for IVF is considered to provide an improved in-vivo-mimicking environment to enhance the development in a culture system for an embryo before implantation. We demonstrate a novel digitalized microfluidic device powered with electrowetting on a dielectric (EWOD) to culture an embryo in vitro in a single droplet in a microfluidic environment to mimic the environment in vivo for development of the embryo and to culture the embryos with good development and live births. Our results show that the dynamic culture powered with EWOD can manipulate a single droplet containing one mouse embryo and culture to the blastocyst stage. The rate of embryo cleavage to a hatching blastocyst with a dynamic culture is significantly greater than that with a traditional static culture (p<0.05). The EWOD chip enhances the culture of mouse embryos in a dynamic environment. To test the reproductive outcome of the embryos collected from an EWOD chip as a culture system, we transferred embryos to pseudo-pregnant female mice and produced live births. These results demonstrate that an EWOD-based microfluidic device is capable of culturing mammalian embryos in a microfluidic biological manner, presaging future clinical application.
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Affiliation(s)
- Hong-Yuan Huang
- Department of Obstetrics and Gynecology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Department of Obstetrics and Gynecology, Chang Gung University and College of Medicine, Taoyuan, Taiwan
| | - Hsien-Hua Shen
- Institute of Nanoengineering and Microsystem, National Tsing Hua University, Hsinchu, Taiwan
| | - Chang-Hung Tien
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
| | - Chin-Jung Li
- Department of Obstetrics and Gynecology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan, 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
| | - Wen-Syang Hsu
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Da-Jeng Yao
- Institute of Nanoengineering and Microsystem, National Tsing Hua University, Hsinchu, Taiwan
- Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan
- * E-mail:
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30
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Shen HH, Chung LY, Yao DJ. Improving the dielectric properties of an electrowetting-on-dielectric microfluidic device with a low-pressure chemical vapor deposited Si3N4 dielectric layer. BIOMICROFLUIDICS 2015; 9:022403. [PMID: 25825614 PMCID: PMC4376753 DOI: 10.1063/1.4915613] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 02/18/2015] [Indexed: 05/29/2023]
Abstract
Dielectric breakdown is a common problem in a digital microfluidic system, which limits its application in chemical or biomedical applications. We propose a new fabrication of an electrowetting-on-dielectric (EWOD) device using Si3N4 deposited by low-pressure chemical vapor deposition (LPCVD) as a dielectric layer. This material exhibits a greater relative permittivity, purity, uniformity, and biocompatibility than polymeric films. These properties also increase the breakdown voltage of a dielectric layer and increase the stability of an EWOD system when applied in biomedical research. Medium droplets with mouse embryos were manipulated in this manner. The electrical properties of the Si3N4 dielectric layer-breakdown voltage, refractive index, relative permittivity, and variation of contact angle with input voltage-were investigated and compared with a traditional Si3N4 dielectric layer deposited as a plasma-enhanced chemical vapor deposition to confirm the potential of LPCVD Si3N4 applied as the dielectric layer of an EWOD digital microfluidic system.
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Affiliation(s)
- Hsien-Hua Shen
- Institute of NanoEngineering and MicroSystems, National Tsing Hua University , Hsinchu 30013, Taiwan
| | - Lung-Yuan Chung
- Institute of NanoEngineering and MicroSystems, National Tsing Hua University , Hsinchu 30013, Taiwan
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31
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Gao J, Chen T, Dong C, Jia Y, Mak PI, Vai MI, Martins RP. Adhesion promoter for a multi-dielectric-layer on a digital microfluidic chip. RSC Adv 2015. [DOI: 10.1039/c5ra08202a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A silane-based adhesion promoter suitable for a multi-dielectric-layer coating on a digital microfluidic chip is reported.
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Affiliation(s)
- Jie Gao
- State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE
- University of Macau
- Avenida da Universidade
- Taipa
- China
| | - Tianlan Chen
- State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE
- University of Macau
- Avenida da Universidade
- Taipa
- China
| | - Cheng Dong
- State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE
- University of Macau
- Avenida da Universidade
- Taipa
- China
| | - Yanwei Jia
- State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE
- University of Macau
- Avenida da Universidade
- Taipa
- China
| | - Pui-In Mak
- State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE
- University of Macau
- Avenida da Universidade
- Taipa
- China
| | - Mang-I. Vai
- State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE
- University of Macau
- Avenida da Universidade
- Taipa
- China
| | - Rui P. Martins
- State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE
- University of Macau
- Avenida da Universidade
- Taipa
- China
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32
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Aijian AP, Garrell RL. Digital microfluidics for automated hanging drop cell spheroid culture. ACTA ACUST UNITED AC 2014; 20:283-95. [PMID: 25510471 DOI: 10.1177/2211068214562002] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Indexed: 11/15/2022]
Abstract
Cell spheroids are multicellular aggregates, grown in vitro, that mimic the three-dimensional morphology of physiological tissues. Although there are numerous benefits to using spheroids in cell-based assays, the adoption of spheroids in routine biomedical research has been limited, in part, by the tedious workflow associated with spheroid formation and analysis. Here we describe a digital microfluidic platform that has been developed to automate liquid-handling protocols for the formation, maintenance, and analysis of multicellular spheroids in hanging drop culture. We show that droplets of liquid can be added to and extracted from through-holes, or "wells," and fabricated in the bottom plate of a digital microfluidic device, enabling the formation and assaying of hanging drops. Using this digital microfluidic platform, spheroids of mouse mesenchymal stem cells were formed and maintained in situ for 72 h, exhibiting good viability (>90%) and size uniformity (% coefficient of variation <10% intraexperiment, <20% interexperiment). A proof-of-principle drug screen was performed on human colorectal adenocarcinoma spheroids to demonstrate the ability to recapitulate physiologically relevant phenomena such as insulin-induced drug resistance. With automatable and flexible liquid handling, and a wide range of in situ sample preparation and analysis capabilities, the digital microfluidic platform provides a viable tool for automating cell spheroid culture and analysis.
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Affiliation(s)
- Andrew P Aijian
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Robin L Garrell
- Department of Bioengineering, University of California, Los Angeles, CA, USA Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA California NanoSystems Institute, University of California, Los Angeles, CA, USA
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33
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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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