Electrowetting on dielectric device with crescent electrodes for reliable and low-voltage droplet manipulation

Xu, Xiaowei; Sun, Lining; Chen, Liguo; Zhou, Zhongmin; Xiao, Jian; Zhang, Yuliang

doi:10.1063/1.4902554

Cited by 19 publications

(9 citation statements)

References 27 publications

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“…A T-shaped chip (see Figure 1 ) was designed with four major regions: (1) a reservoir for LAMP reagents; (2) a reservoir for DNA sample; (3) a reaction reservoir, where LAMP reagents will be mixed with the DNA sample, and where LAMP reactions will occur; (4) a retrieving reservoir, from which reaction products may be withdrawn from the device. Several electrode designs have been reported in DMF [ 20 , 21 ]; however, in this work, zig-zag crenelated electrodes with a gap between neighboring electrodes of 30 µm were used. This electrode configuration places indentations of one electrode inside the area of another, forcing the droplet to occupy some of the area belonging to the next electrode, thus improving droplet motion by reducing the effect of the hydrophobic gap.…”

Section: Methodsmentioning

confidence: 99%

A Digital Microfluidics Platform for Loop-Mediated Isothermal Amplification Detection

Coelho

Veigas

Águas

et al. 2017

Sensors

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Digital microfluidics (DMF) arises as the next step in the fast-evolving field of operation platforms for molecular diagnostics. Moreover, isothermal schemes, such as loop-mediated isothermal amplification (LAMP), allow for further simplification of amplification protocols. Integrating DMF with LAMP will be at the core of a new generation of detection devices for effective molecular diagnostics at point-of-care (POC), providing simple, fast, and automated nucleic acid amplification with exceptional integration capabilities. Here, we demonstrate for the first time the role of coupling DMF and LAMP, in a dedicated device that allows straightforward mixing of LAMP reagents and target DNA, as well as optimum temperature control (reaction droplets undergo a temperature variation of just 0.3 °C, for 65 °C at the bottom plate). This device is produced using low-temperature and low-cost production processes, adaptable to disposable and flexible substrates. DMF-LAMP is performed with enhanced sensitivity without compromising reaction efficacy or losing reliability and efficiency, by LAMP-amplifying 0.5 ng/µL of target DNA in just 45 min. Moreover, on-chip LAMP was performed in 1.5 µL, a considerably lower volume than standard bench-top reactions.

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Section: Methodsmentioning

confidence: 99%

A Digital Microfluidics Platform for Loop-Mediated Isothermal Amplification Detection

Coelho

Veigas

Águas

et al. 2017

Sensors

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“…Parafilm or double-sided tape. However, this requires more handling experience [39,[69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84].…”

Section: Plos Onementioning

confidence: 99%

PortaDrop: A portable digital microfluidic platform providing versatile opportunities for Lab-On-A-Chip applications

et al. 2020

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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, standalone 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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“…Among all of the techniques that have been employed as the droplet actuation mechanism, electrowetting-on-dielectric (EWOD) is an innovative approach that has been broadly used for manipulating discrete microdrops in various DMF platforms. − In closed (also referred to as double-plate or parallel-plate) EWOD-based DMF systems, a microliter droplet sandwiched in the microchannel can be separated, merged, produced, and relocated with the assistance of the surface tension induced electrowetting force. − In all of these operations, the droplet generation process has been extensively investigated in recent years owing to the increasing requirement of excellent microdrop volume accuracy in many DMF applications such as compound separation, chemical synthesis, drug discovery, and hotspot cooling. − ,, Conventionally, electrowetting-based microdrop generation involves three continuous steps: liquid filling, neck cutting, and droplet relocating, which requires a close coordination of generating, cutting, and reservoir electrodes. ,, To date, highly controllable microdrop generating process with extremely precise droplet volume still remains as a major challenge due to its complex procedures and insufficient understanding of its control methods.…”

Section: Introductionmentioning

confidence: 99%

Stripped Electrode Based Electrowetting-on-Dielectric Digital Microfluidics for Precise and Controllable Parallel Microdrop Generation

Guan

et al. 2020

Langmuir

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Microdrop generation with excellent controllability and volume precision is of paramount significance for a large variety of microfluidic applications. In this work, we propose a new configuration comprising only stripped electrodes of rectangular shape for the closed electrowetting-on-dielectric digital microfluidic (EWOD DMF) system and investigate its parallel microdrop generation outcomes via a numerical approach. The microfluidic droplet motion is solved by a finite-volume scheme on a fixed computational domain. The numerical model is verified by an experimental study of microdrop production from an EWOD DMF device with three different electrode designs. After model verification, we examine the influences of the equilibrium contact angle and the spacing of the microchannel on stripped electrode based microdrop generation outcomes and discover five different regimes including the phenomena of satellite droplet formation and separation cessation. Despite the various generation outcomes, the daughter droplet size is found to vary linearly with a dimensionless EWOD parameter κ*. More importantly, for all successful generations, the deviation of the daughter droplet size from that of the stripped electrode is smaller than 3.5%, which even reaches zero in proper conditions. This new configuration can be utilized as a convenient alternative for electrowetting-induced parallel microdrop production with excellent precision and controllability.

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Electrowetting on dielectric device with crescent electrodes for reliable and low-voltage droplet manipulation

Cited by 19 publications

References 27 publications

A Digital Microfluidics Platform for Loop-Mediated Isothermal Amplification Detection

A Digital Microfluidics Platform for Loop-Mediated Isothermal Amplification Detection

PortaDrop: A portable digital microfluidic platform providing versatile opportunities for Lab-On-A-Chip applications

Stripped Electrode Based Electrowetting-on-Dielectric Digital Microfluidics for Precise and Controllable Parallel Microdrop Generation

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