Journal ArticleDOI
Condensation Droplet Distribution Regulated by Electrowetting
Run Yan,Chung-Lung Chen +1 more
TLDR
In this paper, a visualization of condensation droplet distribution affected by the electrowetting-on-dielectric (EWOD) approach is presented, where a single-side double-layer electrode design (grid wire, thin wire, and thick wire) and coplanar-electrode zigzag design (zigzag) are discussed.Abstract:
\n This paper presents a visualization of condensation droplet distribution affected by the electrowetting-on-dielectric (EWOD) approach. A single-side double-layer-electrode design (grid wire, thin wire, and thick wire) and coplanar-electrode design (zigzag) are discussed. Side-by-side experiments with applied 40 V DC electric potential are carried out to compare droplet distribution between identically designed charged and uncharged devices. The uncharged devices show a random droplet distribution, whereas charged devices have a regulated distribution based on the designed patterns. As droplets on the electrode boundaries become larger, they are likely to slide away and stay in electrode-free regions. The droplets “sit” inside the grid wires and distribute vertically along thin and thick wires. On the coplanar-electrode zigzag device, droplets are distributed vertically. The charged surfaces lead to a faster droplet growth rate and more dispersed droplet distribution. This phenomenon accelerates the shedding frequency of the droplets and frees up more areas for small droplets to nucleate and grow. The first shedding moment of the charged surfaces occurs earlier than the uncharged ones for all types of EWOD devices. The detected droplet shedding diameter ranges from 1.2 mm to 2.5 mm in this study. The number of large droplets is found greater on the charged devices compared with the uncharged devices and theoretical model. The work presented in this paper introduces a novel approach to actively influence droplet distribution on microfabricated condensing surfaces and indicates great potential for improving the condensation heat transfer rate via EWOD.read more
Citations
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Journal ArticleDOI
Increased droplet coalescence using electrowetting on dielectric (EWOD)
TL;DR: In this paper, small-scale electrodes and gaps subjected to repeated short bursts of AC voltage were used to improve droplet coalescence and growth for water harvesting by actively bashing smaller droplets together to form larger ones.
Journal ArticleDOI
Statistical modeling of electrowetting-induced droplet coalescence for condensation applications
TL;DR: In this article, the influence of the applied voltage, frequency of the AC waveform and the geometry of the electrowetting (EW) device on two parameters related to droplet coalescence was quantified.
Journal ArticleDOI
AC electrowetting promoted droplet shedding on hydrophobic surfaces
TL;DR: In this paper, the influence of AC electrowetting fields on short-duration droplet shedding on hydrophobic surfaces was studied, with three parameters being varied (voltage, AC frequency, and device geometry).
Journal ArticleDOI
Electrowetting-Controlled Dropwise Condensation with Patterned Electrodes : Physical Principles, Modeling, and Application Perspectives
TL;DR: In this paper, a detailed analysis of the experimental distribution of millions of drops reveals that despite the presence of contact angle hysteresis and the occurrence of random drop coalescence events, preferential drop positions closely follow the numerically calculated local minima of the electrostatic energy for variable drop size.
Posted Content
Electrowetting-Controlled Dropwise Condensation with Patterned Electrodes: Physical Principles, Modeling, and Application Perspectives for Fog Harvesting and Enhanced Heat Transfer
TL;DR: In this paper, a detailed analysis of the experimental distribution of millions of drops reveals that despite the presence of contact angle hysteresis and the occurrence of random drop coalescence events, the preferential drop position closely follows the evolution of the local minima of the numerically calculated drop size-dependent electrostatic energy landscape in two dimensions.
References
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Journal ArticleDOI
Electrowetting: from basics to applications
TL;DR: In this paper, the authors compare the various approaches used to derive the basic electrowetting equation, which has been shown to be very reliable as long as the applied voltage is not too high.
Journal ArticleDOI
Creating, transporting, cutting, and merging liquid droplets by electrowetting-based actuation for digital microfluidic circuits
TL;DR: In this paper, the authors report the completion of four fundamental fluidic operations considered essential to build digital microfluidic circuits, which can be used for lab-on-a-chip or micro total analysis system (/spl mu/TAS): 1) creating, 2) transporting, 3) cutting, and 4) merging liquid droplets, all by electrowetting.
Journal ArticleDOI
Electrowetting-based actuation of liquid droplets for microfluidic applications
TL;DR: In this article, a microactuator for rapid manipulation of discrete microdroplets is presented, which is accomplished by direct electrical control of the surface tension through two sets of opposing planar electrodes fabricated on glass.
Book
Micro- and Nanoscale Fluid Mechanics: Transport in Microfluidic Devices
TL;DR: In this article, the Laplace and Stokes equations were used to model the fluid and current flow in molecular-scale and thick-double-layer systems and the dynamics of diffuse charge.
Journal ArticleDOI
Jumping-Droplet-Enhanced Condensation on Scalable Superhydrophobic Nanostructured Surfaces
Nenad Miljkovic,Ryan Enright,Ryan Enright,Youngsuk Nam,Youngsuk Nam,Ken Lopez,Nicholas G. Dou,Jean Sack,Evelyn N. Wang +8 more
TL;DR: This work shows that silanized copper oxide surfaces created via a simple fabrication method can achieve highly efficient jumping-droplet condensation heat transfer and promises a low cost and scalable approach to increase efficiency for applications such as atmospheric water harvesting and dehumidification.