Article
Chemistry, Multidisciplinary
Yongxin Lei, Bin Liu, Lei Zhuang, Yuanyuan Guo, Hailing Sun, Dong Yuan, Biao Tang, Feilong Liu, Guofu Zhou
Summary: The lattice Boltzmann method is more computationally efficient than traditional methods for numerically solving fluid mechanics equations. Electrowetting, a component of interfacial sciences, can be modeled using the lattice Boltzmann method through surface and bulk methods. However, accurately modeling electrowetting using the lattice Boltzmann method is challenging due to inaccuracies caused by the discontinuous electric fields at the interface. Additional modeling work, especially regarding the treatment of interfacial electric fields, is needed to improve the accuracy of the method.
Article
Engineering, Electrical & Electronic
Chun-Hong Chen, Shen-Yu Chen, Chun Yu Pierce Chu, Yuan-Hsuan Tai
Summary: This study derives an equation related to the threshold actuation voltage and all important parameters and successfully explains the effects of conductivity and frequency on liquid actuation. The theoretical and experimental data can be used to predict the applied voltage of EWOD and LDEP for a broad range of buffers and organic solvents.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Chemistry, Multidisciplinary
Qinggong Wang, Long Li, Junping Gu, Ce Zhang, Junfu Lyu, Wei Yao
Summary: In this study, electrowetting was used to manipulate non-conductive oil droplets in a conductive water environment. Experimental results show that at specific AC frequencies, droplets exhibit oscillation resonance on the substrate, promoting detachment.
Article
Chemistry, Analytical
Iftekhar Khan, Stefania Castelletto, Gary Rosengarten
Summary: The ability to manipulate a liquid meniscus using electrowetting has many applications. In this study, it was discovered that a bare ground electrode leads to an increase in the contact angle of a sessile drop with increasing DC voltage, while a dielectric-coated electrode follows the Lippmann-Young equation and decreases the contact angle. The research also suggests using a dielectric-coated ground electrode for applications requiring precise control of the contact angle.
Article
Physics, Applied
Quoc Vo, Tuan Tran
Summary: Under the electrowetting effect, fast contact-line motion generates strong capillary waves on a droplet's surface, potentially leading to the ejection of satellite droplets. The size and ejection time of the satellite droplets are not only dependent on the contact-line velocity, but also influenced by the ejection dynamics.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Mainak Basu, Vedant P. Joshi, Soumen Das, Sunando DasGupta
Summary: The study extensively investigated the dynamic performance of droplet movement in a newly designed triangular coplanar electrode system, and developed a model to explore the process. The efficiency of the fabricated digital microfluidic platform was quantified and compared in terms of driving force and velocities.
JOURNAL OF ELECTROSTATICS
(2021)
Article
Biochemical Research Methods
Kai Jin, Chenxuan Hu, Siyi Hu, Chengyou Hu, Jinhua Li, Hanbin Ma
Summary: A one-to-three droplet splitting technique was proposed in this study to generate micro-droplets in digital microfluidics for parallel detection, allowing for the retention of magnetic beads by reduced magnetic force. The technique was demonstrated in an on-chip magnetic bead chemiluminescence immunoassay, showing promising results for in vitro diagnostic applications.
Review
Chemistry, Analytical
Xianming Liu, Dachuan Ma, Haiyue Ye, Yue Hou, Xue Bai, Yaru Xing, Xing Cheng, Bingcheng Lin, Yao Lu
Summary: Digital microfluidics (DMF) has achieved significant scientific and technical advancements in the past two decades due to its distinctive droplet actuation via electrowetting on individually addressable electrodes. Offering reduced sample consumption, programmability, reconfigurability, and ease of intelligent recognition and closed-loop control, DMF provides preciseness and flexibility in biological and chemical sample handling. This paper comprehensively reviews recent developments in DMF chip fabrication, control and automation, system integration, instrumentation, and applications, highlighting the trend towards high-level integration and miniaturization.
TRAC-TRENDS IN ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Israr Ahmad, Manabendra Pathak, Mohd Kaleem Khan
Summary: This work presents numerical and experimental techniques for studying electrowetting-induced oscillating water droplets on surfaces with different hydrophobicity. The results show that the hydrophobicity of the surface affects the deformation, internal flow structures, amplitude, and frequency of the oscillating droplets. Additionally, a simplified analytical model is developed to establish the correlation between the maximum amplitude of the oscillating droplets and the static contact angle.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Biochemical Research Methods
Mohammad Javad Kiani, Amin Dehghan, Mohammad Saadatbakhsh, Shahin Jamali Asl, Norouz Mohammad Nouri, Esmail Pishbin
Summary: Developing automated platforms for point-of-need testing is crucial worldwide. Robotic digital microfluidics provides precise and inexpensive manipulation of micro/nanoliter droplets, offering a promising solution for integrated testing devices.
Article
Engineering, Electrical & Electronic
Johannes Strassner, Christoph Doering, Emerson Oliveira, Henning Fouckhardt
Summary: This article discusses the phenomena and techniques of electrowetting on dielectric (EWOD) and optoelectrowetting (OEW), and explores the operating points of OEW through discussion and modification.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Mechanics
Xiaozhi Huo, Long Li, Yang Yang, Xuefeng Liu, Qiang Yu, Qinggong Wang
Summary: Directional fluid transport by electrowetting is studied in this research. A numerical model based on the phase field method is established to investigate the process of a sensible droplet transported directionally in an electrowetting channel. The results show that the droplet motion can be divided into three stages, and at a certain voltage, the droplet can be transported at a velocity of 17 mm/s. Various influencing factors are considered, including voltage, droplet size, friction factor, pinning force, channel height, gravity level, and tilted angle of the channel. The contact line friction and pinning force retard the droplet motion, and an increase in gravity level reduces the transport velocity of large droplets, while small droplets display good anti-gravity capability even under a 90° tilted channel.
Article
Thermodynamics
Robin Pham, Run Yan, Sheng Wang, Chung-Lung Chen
Summary: In contrast to traditional point of view, electrowetting allows for dynamic wetting regime, where hydrophilicity can penetrate or recede based on liquid location rather than substrate structure. Droplets form clusters through size regulation as condensation accumulates and are transferred by coalescence cascades and mass imbalances. This passive electrostatic liquid conveyor enables the removal of condensation from self-stagnating cycles. Each working zone functions independently for nucleation and diffusion, accumulation and collection. 40 to 50 percent of the liquid recovery increase is attributed to spatial-size regulation, while higher nucleations are influenced by electrostatic voltage. The migration of condensates is determined by the competition between dropwise and filmwise tendencies. The autonomy of nucleations allows for unhindered electrostatic voltage, limited only by material strength and endurance. © 2023 Elsevier Ltd. All rights reserved.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Review
Chemistry, Physical
Athanasios A. Papaderakis, Robert A. W. Dryfe
Summary: The control of wetting on conducting surfaces is crucial for the operation of various technologies. Electrowetting is a change in contact angle of a liquid upon the application of a potential bias. While electrowetting has been known for almost a century, recent research focuses on its applications. This review discusses the purely electrochemical aspects of electrowetting on conductors and highlights the remaining open questions.
CURRENT OPINION IN ELECTROCHEMISTRY
(2023)
Article
Physics, Applied
K. Yamamoto, S. Takagi, Y. Ichikawa, M. Motosuke
Summary: In this study, droplet-migration characteristics on oil-infused electrowetting-on-dielectric substrates were investigated. It was found that the droplet velocity is scaled as U approximate to E-2, which differs from a relationship of U approximate to E-3 predicted from the dominant drag force. The achieved high velocity is explained by a lubrication-flow effect.
JOURNAL OF APPLIED PHYSICS
(2022)