Electrowetting droplet

Electrowetting droplet

A proposed mechanism for the enhanced electrowetting response of a nanofluid droplet involves a reduction in surface tension of the droplet as nanoparticles accumulate at the liquid-vapor interface. This amounts to a huge network of nano/picoliter pumps to assemble droplets into architectures for cooling. S. electrowetting-on-dielectric (EWOD) device; (b) the electrowetting principle; (c) driving force derived from integration of the surface tension in contacting line; and ( d ) static effects on the droplet including the contact angle saturation (CAS) effect and pinning effect. The interfacial tensions of the droplets are controlled with the application of voltage. Abstract: We present a liquid droplet mixer to enable mixing of the samples and reagents for chemical and biological analysis in micro total analysis systems (/spl mu/TAS). The present work analyzes the influence of an electrowetting voltage in determining and altering the state of a static droplet resting on a rough surface. Electrowetting on Dielectric (EWOD) is a versatile tool for performing basic operations in Digital Microfluidic Systems. We studied the detailed jumping mechanisms with regard to the jumping height and the energy conversion and demonstrated the transport Here we demonstrate a simple and reliable approach for droplet generation from a continuous electrowetting channel and volume control based on electrode size. Electrowetting actuators require a droplet to overlap the adjacent electrode when the droplet rests on the biased electrode, so that the droplet can response to the voltage applied on the adjacent electrode. NFC007 Net Fish Cambo & Street Food 19,817,489 viewsAuthor: Novel Device Lab at University of CincinnatiViews: 269[PDF]Bouncing of a droplet on a superhydrophobic surface in AC https://arxiv. ; (1) where θ is the contact angle, γ is the surface tension, and S, L, and V represent the surface, liquid, and vapor media, respec- tively. Views: 535[PDF]Fabrication and Actuation of an Electrowetting Droplet mnsa. edu/assets/2015_banerjee. Fig. The normalized droplet height at 51. Electrowetting is a technique used to change the apparent contact angle of a dielectric fluid under the influence of electric potential. Generally, the actuation mechanism of the droplet is based upon surface tension gradients induced in the droplet by the voltage-induced electrowetting effect. The current paper describes a simpler ground-type, single-plate electrowetting configuration for droplet transport in digital microfluidics without performance degradation. Directional motion of fluid droplets is attracting considerable research attention. 1 . Droplet volume was obtained by a simple image processing technique with a precision as high as 99. Electrowetting alters the contact angle of a conductive liquid on a solid surface by Electrowetting-Based Droplet Actuation on a Single-Sided Electrode Array. In electrowetting on a dielectric, the change of contact angle as a. The governing equations for transient microfluidic flow are solved by a finite volume scheme with a two-step projection method on a fixed computational domain. A droplet rests on a hydrophobic surface over an electrode which This oscillation is caused by variations in the electrowetting force with the droplet position. The contact angle is measured within the droplet between the solid surface and the fluid–fluid interface. Conf Proc IEEE Eng Med Biol Soc. Electrowetting-Based Control of Droplet Transition and Morphology on Artificially Microstructured Surfaces Vaibhav Bahadur and Suresh V. Electrowetting-induced microwater droplet detachment from hydrophobic surface has been studied numerically. (B) Droplet moving in response to changing potential over electrode array. e change in contact angle and Laminar Two Phase Flow, Level Set (tpf) for simulation of 2D droplet transport. 7 Figure 4 Electrowetting of a Droplet. The shape of a droplet on a surface can beDrops are attached to the droplet array using etched hydrophilic regions. A numerical study on electrowetting-induced jumping and transport of droplet K. Due to the intense interest in the Hele-Shaw problems, the last ten years has also seen Droplet Actuation on Various Electrode Shapes in Electrowetting-based Microfluidics Negar Rajabi Electrowetting has been widely used in digital microfluidics as a reliable actuation method due to its considerable advantages such as the absence of heat generation, rapid switching response, flexibility, and low power consumption. Wettability is exactly what it sounds like: It’s a measure of how readily liquids can rest on causing the droplet to move until it is aligned onto the center of the new electrode. Optoelectrowetting (OEW) is a method of liquid droplet manipulation used in microfluidics applications. Despite much progress in this field, electrowetting‐based stiction switch that drives unidirectional transport of an underwater oil droplet or air bubble on a wire surface is still a challenge to realize. In electrowetting, application of a voltage across the electrodes of a micro-droplet causes it to change the interfacial energy of solid-liquid interface which in turn changes the contact angle of the liquid on the solid. 5 ms, the droplet height increases to 0. When a droplet straddles two electrodes of differing voltages, the surface tension over one electrode is difference than over the other (due to a different amount of capacitive energy being stored) in each side of the droplet, and the droplet is driven to reside completely over the electrode of higher voltage. For the droplet in a microchannel, the contact angle at one edge of the drop is varied in order to show droplet actuation. In this system, cooling liquids can be transported, in user-defined patterns, under clocked-voltage control over a 2D-array of electrodes without the need for external pumps and valves [9]. 2◦C, relative humidity = 80% and exposed time duration of 60 mins. J. Phil Paik *, Vamsee K. The shape of a droplet on a surface can be In electrowetting on dielectric, the surface tension between the liquid-solid interface is modified by an external electric field, which reduces the meniscus contact angle and induces motion of a droplet. The environmental conditions are. •Dynamics of EW-actuated droplet motion follows the behavior of a second order dynamic system. In their systems, EWOD was used to realize or control processes like on-chip droplet dispensing, moving, merging, or splitting. function of the applied voltage can be related to the dielectric thickness () and dielectric. Abstract: We present a liquid droplet mixer to enable mixing of the samples and reagents for chemical and biological analysis in micro total analysis systems (/spl mu/TAS). •Dynamics of EW-actuated droplet motion follows the behavior of a second order dynamic A Fast Fabricating Electro-wetting Platform to Implement Large Droplet Manipulation Yiyan Li1, Roger Chen2, and R. Electrowetting of a mercury droplet on a parylene film: the squares are measured contact angles and the solid line is a calculation based on Eq. The present work involves a systematic experimental investigation of the The complex electrical and capillary interactions in electrowetting are illustrated by an analysis of an electrowetting configuration that produces an oscillating droplet motion from a steady DC voltage input. 2005; 2:1941-4 (ISSN: 1557-170X) Li L; Hu H; Lin H; Ye DT. in Abstract—A droplet position sensing scheme for monitoring multiple droplets has been proposed, which gives a Microwater droplet splitting and merging in a parallel-plate electrowetting-on-dielectric (EWOD) device have been studied numerically. and motion can be controlled by many methods including thermocapillary[7], dielectrophoresis[8] and magnetic forces [9], but electrowetting on dielectric (EWOD) [10-. The prerequisite part of the investigation of droplet splitting is to understand the electrowetting-on-dielectric (EWOD) based droplet actuation. Oct 05, 2009 · Figure 5 Image of initiation of droplet purge using electrowetting using ver- tical electrodes, for different elapsed times. Electrowetting on dielectric (EWOD) has emerged as a powerful tool to electrically manipulate tiny individual droplets in a controlled manner. Electrowetting is a process used to manipulate deformation of liquid droplets on a dielectric surface using an external electric field. grant number 5c. 22 If the contact angle of the droplet on the Droplet formation from on-chip reser-voirs, using only electrowetting forces and no external pressure assistance, was possible up to concentrations of 0. project number darp 5e. This induces a capillaj'pressure to move the droplet toward to the optical beam. NFC007 Net Fish Cambo & Street Food 19,817,489 views Two important electric forces, dielectrophoresis (DEP) and electrowetting-on-dielectric (EWOD), are demonstrated by dielectric-coated electrodes on a single chip to manipulate objects on different scales, which results in a dielectrophoretic concentrator in an EWOD-actuated droplet. contract number fa9453-04-1-0043 5b. Pamula *, Michael G. A liquid droplet is squeezed between the plates. , in the hatched region which is both above the stability limit of the attached morphology and below the stability limit of the detached morphology. performing organization name(s) and address(es) 8. A most promising application for EWOD chips is the clinical diagnostics on human physiological fluids. However, the droplet modulation ceases at a certain voltage, which is referred to as the saturation voltage, and the corresponding angle is the saturation angle [9]. Normally, electrowetting is implemented in an oil environment because the droplet in the oil has a much larger contact angle than in an air environment. Electrowetting on dielectric (EWOD) digital microfluidics is a promising method of droplet manipulation that controls each droplet individually by an applying external electric field …Electrowetting-Based Control of Droplet Transition and Morphology on Artificially Microstructured Surfaces Vaibhav Bahadur and Suresh V. Thus a droplet that is partially placed on the electrode can be moved due to asymmetric electrowetting force. The shape of a droplet on a surface can beFluid Flow and Mixing Induced by AC Continuous Electrowetting of Liquid Metal Droplet Qingming Hu 1,2, Yukun Ren 1,3,*, Weiyu Liu 1, Xiaoming Chen 1, Ye Tao 1 and Hongyuan Jiang 1,3,* 1 School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin,. We introduce droplet jumping by electrowetting (DJE), which stretches droplets to store energy for jumping by electrowetting. Impact of ambient phase on drop internal flow patterna) Biomicrofluidics 7, 044104 (2013); 10. Initiated by a task in tunable microoptics, but not limited to this application, a microfluidic droplet array in an upright standing module with 3 × 3 subcells and droplet actuation via electrowetting is presented. Taking the contact angle for the left half of the droplet to be θ L andNormally, electrowetting is implemented in an oil environment because the droplet in the oil has a much larger contact angle than in an air environment. Maximum droplet actuation before contact angle saturation is achieved at only 10 V for a concentration of 0. An analysis based on the theories of thermodynamics and thermal activation processes is presented for the electrowetting of a conducting droplet on a dielectric layer. They provide the effective energy conversion from the surface. This model of EWOD fluid dynamics includes surface tension and electrowetting interface forces, viscous low Reynolds 2-phase fluid flow, and the essential loss mechanisms due to contact angle saturation, triple point line pinning, and the related mechanism of contact angle hysteresis. A droplet of silicone oil confined in an aqueous solution works as a lens. 4 Two-particle separation into two satellite drops (same format as in Fig. The transient governing equations for the microfluidic flow are solved by a finite volume scheme with a two-step projection method on a fixed computational domain. Electrowetting-induced microwater droplet detachment from hydrophobic surface has been studied numerically. Formation, mixing, and splitting of microdroplets was also demonstrated using the same microactuator structures. Over the last decade, growing interest in EWOD has led to a wide range of scientific and technological investigations motivated by its applicability in microfluidics, especially for droplet-based optical and lab-on-a-chip systems. Electrowetting of a mercury droplet on a parylene film: the squares are measured contact angles and the solid line is a calculation based on Eq. 1 A parallel plate device to manipulate droplets by EWOD on an array of dielectric-covered driving electrodes. : Condens. There are several studies directed at using an air environment to actuate the liquids by using smaller electrodes and more hydrophobic surfaces. The result was in good agreement with electrowetting theory. The proposed microfluidic device demanded a copper droplet cap seat to locate the Galinstan droplet, hence a hole with height of 500 um must be fabricated electrowetting, consider a liquid droplet of volume V sandwiched between two plates with a channel depth of h shown in Figure 3a. A droplet (magenta) on a hydrophobic layer (H) on top of a dielectric layer (D) is relaxed by an external electric field (center). It enables control over fluid shape and flow by electrical signals alone, which is viable by effective utilization of the excess charge accumulation at the interface between the droplet and the dielectric surface, also by polarization of line tension at the three-phase line. The related work of Lee, Lowen-grub & Goodman (2002a) considered a difiuse interface in the absence of electrowettingSince then, significant work has been done using electrowetting for paper-like displays. Droplet Actuation on Various Electrode Shapes in Electrowetting-based Microfluidics Negar Rajabi Electrowetting has been widely used in digital microfluidics as a reliable actuation method due to its considerable advantages such as the absence of heat generation, rapid switching response, flexibility, and low power consumption. This lab-on-a-chip electrowetting simulation demonstrates an electric field being applied in order to split a small droplet. A series of experiments is run and verifies the criterion. In this study, we analytically investigate effects of the opening ratio on electrowetting operations. Electrowetting is a technique used to manipulate the wetting properties of a substrate under an external electric field [23]. If no voltage is applied, the droplet is in a bistable position (left or right). author(s) chang-jim kim and ming c. 01mg/mL. ∗Email:ssohail@iitkgp. Electrowetting (EW) is a powerful tool to control fluid motion at the microscale and has promising applications in the field of microfluidics. Electrowetting droplet trap - Two electrodes separated by a small gap provide an electrically tunable pinning center for droplets sliding down an inclined plane. Among various approaches to control the droplet motion, electrowetting (EW) is particularly convenient and versatile for its ability to tune the surface wetting property with an external electric field. C. However, mixing of liquids is very difficult in continuous flow microfluidics due to laminar flow conditions. The electrowetting response is determined by interactions between the electrical and surface energies of the systems that can combine to produce a large variety of behaviors. 1 A parallel plate device to manipulate droplets by EWOD on …In contrast, increasing the opening ratio hampers successful electrowetting operations of droplets and thus sampling of microparticles. . Electrowetting on Dielectric (EWOD) is a versatile tool for performing basic operations in Digital Microfluidic Systems. Basic Principle Demonstration. Nikapitiya1 1Department of Mechanical and Aerospace Engineering, University of Texas - Arlington, Arlington, TX, USA Abstract Electrowetting on Dielectric (EWOD) is a versatile tool for performing basic operations inDroplet shape. Droplet transport is rapid and efficient with average velocities exceeding 10 cm s(-1 The surface energy bal- ance between droplet, substrate, and surrounding medium de- termines the contact angle of the droplet, by Young’s equation cos θY γSV − γSL. applied electric field. M. It was developed from elecrtrocap-J. Phys. Ravi Annapragada United Technologies Research Center East Hartford, Connecticut 06118, USA annaprs@utrc. Using this methodology, the influence of the switching frequency and actuation voltage is studied. Fair[PDF]Fabrication and Actuation of an Electrowetting Droplet mnsa. A conical gripper was used to pick up a droplet and release it onto a substrate by controlling the wetting property between the droplet and the substrate using electrowetting. jumping, and superhydrophobic surface minimizes adhesion and hysteresis. 5a, a net force arises between the ends of the droplet due to the out- of-balance surface tension forces acting along the contact line. Electrowetting has drawn significant interests due to the potential applications in electronic displays, lab-on-a-chip devices and electro-optical switches, etc. Electrowetting Actuation. 5 μM. nevada. The most basic form of a modern electrowetting structure consists of a sessile droplet,planarßuoropolymerdielectric,aplanarsubstrate,andaDCvoltagesource (Fig. Abstract: The Comsol Multiphysics platform has been used to achieve effective transport of droplets on DMF platform using the Electrowetting on dielectric (EWOD) principle. (b) A liquid droplet sitting on top of a single-plate chip. plified EWOD circuit model. org/pdf/0910. The black arrows inside the droplet denote the fluid velocity field inside the droplet. Electrowetting-based droplet mixers for microfluidic systems†. THX = 0. The oil filler fluid is doped with a surfactant that enhances droplet operations using the protein sample. Electrowetting is a microfluidic pumping technique which operates by applying a voltage across a liquid droplet to change the surface energy balance of the liquid/solid interface. PCB (printed circuit board) substrate electrowetting devices are low cost and quickly fabricated, and they can be placed easily with digital controlling systems. Murthy and Suresh V. The droplets in the mixer are actuated based on electrowetting phenomenon. Garimella Cooling Technologies Research Center School of Mechanical Engineering and Birck Nanotechnology Centerelectrowetting-based driving of liquid-metal droplet for reliable rf switching 5a. electrowetting curve U. With the capacitive droplet position detection system, the PCB-based electrowetting on dielectric device (EWOD) reported in this work has promise in automating immunohistochemistry experiments. BACKGROUND ART Effectively, this results in an electrical force at the droplet interface, which causes the liquid to cover the activated electrode (B). The greaterHowever, the droplet modulation ceases at a certain voltage, which is referred to as the saturation voltage, and the corresponding angle is the saturation angle [9]. A polarizable and Besides, it appears that the higher the DNA concentration is, the higher the DNA droplet velocity will be; as the ionic strength and the total effective charge increase with DNA concentration. The present work involves a systematic experimental investigation of the @article{osti_15011159, title = {Electrowetting-Induced Droplet Movement in an Immiscible Medium}, author = {Kuo, Jason S. Saturation angle is often between 60° and 70° [10]. edu/Publications/J93/J93. ReVised Manuscript ReceiVed April 23, 2008A Difiuse Interface Model for Electrowetting Droplets In a Hele-Shaw Cell By H. Garimella Cooling Technologies Research Center School of Mechanical Engineering and Birck Nanotechnology Center Electrowetting Droplet Operations on a Digital Microfluidic Cartridge. High-throughput automated droplet microfluidic system for screening of reaction conditions Krzysztof Churski et al 2010 Lab on a Chip 10 816 Crossref Dynamics of a Leidenfrost Droplet Modulated by Electrowetting Yi Lu, Jiming Bao and Dong Liu University of Houston, Houston, TX 77204 Leidenfrost phenomenon is closely related to film boiling and the critical heat flux (CHF) limit of boiling heat transfer. task number sc 5f. 1. focal point of a fixed lens telescope [21]. 8 Figure 5 Top View of the Sample and Stacked View of the Sample Used for Contact Angle Measurement and Electrochemical Impedance Electrowetting on Dielectric (EWOD) is a versatile tool for performing basic operations in Digital Microfluidic Systems. A laser beam is focused on one edge of the droplet, which reduces the contact angles on both the top and the hottom surfaces. Protein sample droplets and reagent droplets are dispensed, transported, and merged to yield an array of crystallization conditions by electrowetting droplet operations in a gap comprising oil filler fluid. Typically, saturation angle is independent of the droplet voltage polarity. When applying a voltage between the top and bottom plates, the surface above the energized. 1–4 The results pre- sented in this article will address the problem of localizing the droplet and make the operating process electrically vis- ible to a PC. 2, (4) where CEQ(x)is the equivalent capacitance, which varies spatially according to the location x …Electrowetting refers to an electrostatically induced reduction in the contact angle of an electrically conductive liquid droplet on a surface. 11] is a particularly promising method for low-cost, flexible and swift droplet actuation. Pamula, Michael G. In this paper, the splitting of microdroplet in a closed electrowetting-based digital microfluidic system has been studied via a numerical model. A droplet rests on …Feb 03, 2016 · Contact for use permissions. However, at 53. 66786, deviating from the equilibrium state for optical focusing and therefore leading to an unfocused image. and Spicar-Mihalic, Paolo and Rodriguez, Indalesio and Chiu, Daniel T. In particular we use Laminar Two-Phase Flow, Moving Mesh (tpfmm) for simulation of Lippmann-Young equation i. A larger interest in the technique has been in the automation of biology—popularly known as digital microfluidics. : Condens. electrowetting prism, we can also control the tip-tilt or beam steering angle [6], [8]. Over the next few years, a number of groups [6], [12]–[16] reported on utilizing impedance spectroscopy in EWOD-based microfluidic systems. Therefore, the interleaves electrodes were designed to facilitate the droplet actuation. For the sessile drop, the response of the drop to a step voltage is studied. Li , 1 and Zuankai Wang a, 1, 3 A hybrid microfluidic chip with electrowetting functionality using ultraviolet (UV)-curable polymer Hao Gu et al 2010 Lab on a Chip 10 1550 Crossref. energy to the kinetic energy and improve the …Characterization of electrowetting actuation on addressable single-side coplanar electrodes View the table of contents for this issue, or go to the journal homepage for more droplet-moving devices demonstrate the successful moving, cutting and merging of droplets An alternative mixing strategy is presented based on the discretization of liquids into droplets and further manipulation of those droplets by electrowetting. Jump to navigation Jump to search. al to force) of a 12. Pollack, Richard B. ACKNOWLEDGMENTS Over the length of this project, many people provided their support to make this dissertation possible. In this work, we demonstrate a new and simple method to enhance the mixing efficiency through a continuous electrowetting base Galinstan liquid metal droplet mixer. Electrowetting is proposed as a new principle for micromanipulation of a liquid droplet. Nelson Mechanical and Aerospace Engineering Department , University of California, Los Angeles (UCLA) , Los Angeles , CA , 90095 , USA & Chang-Jin ‘CJ’ Kim Mechanical and Aerospace Engineering Department , University of California, Los Angeles (UCLA) , Los Angeles Multiphysics for a sessile droplet and for a droplet in a microchannel. Garimella* School of Mechanical Engineering and Birck Nanotechnology Center, Purdue UniVersity, West Lafayette, Indiana 47907-2088 ReceiVed February 20, 2008. Research on the employed electrowetting technique to manipulate droplet on inclined, twisted and upside-down geometries. Saturation angle is often between 60° and 70° [10]. Therefore, both electrowetting and electrophoretic forces contribute to the movement of the negatively charged droplets of DNA solutions. More importantly, a dimensionless parameter κ ̃ has been proposed, which can be used for (a) determining the splitting mode and (b) estimating satellite droplet volume for electrowetting-induced droplet splitting process. Zhe1* 1Department of Mechanical Engineering, The University of Akron, Akron, Ohio, USA ABSTRACT We present a new microgripper utilizing a liquid droplet to pick up and release micro objects. 0 ms is 0. In a compound droplet based microfluidic platform, merging of two droplets (cores) co-encapsulated in a single oil-shell is slowed down due to the difficulty in draining the thin layer of oil between the two cores. We introduce droplet jumping by electrowetting (DJE), which stretches droplets to store energy for jumping by electrowetting. Cited by: 367Publish Year: 2003Author: Phil Paik, Vamsee K. The dependence of the velocity on voltage is roughly independent of the droplet size within certain limits, thus the smallest droplets studied (∼3 nl) could be transported over 1000 times their length per second. Here droplet oscillation and continuous pumping are demonstrated by asymmetric electrowetting on an open surface with embedded electrodes powered by a square wave electrical signal without control circuits. of transmitted light, which can be achieved by placing the electrowetting lens at the. 1063/1. The capillarity-driven droplet jumping is effective to overcome the energy barrier, where the threshold for jumping is less than 100 V. wu 5d. pdfA droplet of silicone oil, an insulator, is placed atop the underlying electrowetting electrodes and then surrounded by water which is conductive and serves as a floating electrode. droplets that undergo topological changes by electrowetting. electrowetting-on-dielectric and dielectrophoresis ef-fects make it possible to manipulate both conductive and dielectric droplets simultaneously on a substrate. [22] [23] The fringing field at the corners of the electrolyte droplet tends to pull the droplet down onto the electrode, lowering the macroscopic contact angle and increasing the droplet contact area. The actuator comprises of two parallel glass plates between which the droplet is actuated on a planar array of electrodes. Due to the intense interest in the Hele-Shaw problems, the last ten years has also seen a development of numerical methods for Hele-Shaw problem. Bindiganavane1, J. hancement of droplet movement. Droplet microfluidics; Electrowetting on dielectric (EWOD); Electrowetting on insulator-coated electrodes (EICE) Definition Electrowetting is the electrostatically induced decrease of the liquid contact angle at a contact line formed at the intersection of a liquid, solid, and a third fluid that can be a gas or immiscible liquid. Ex-perimental data for the critical angle for onset of droplet motion are presented along with a theoretical description using a one-dimensional force balance at the TCL based on macroscopic droplet topological observables. Tiny droplet will grow faster towards a droplet that has enough mass for gravity to get a grip on. This net force may induce bulk flow of the droplet. 1a). We Index Terms—Droplet configuration, electrowetting on dielectric, impedance spectroscopy. Fair Department of Electrical Engineering, Duke University, Durham, North Carolina 27708, USA. 5a, a net force arises between the ends of the droplet due to the out- of-balance surface tension forces acting along the contact line. The location of the droplet is indicated using arrows. Bead speed is maximized at 200 kHz due to DEP. Electrowetting refers to an electrostatically induced reduction in the contact angle of an electrically conductive liquid droplet on a surface. 4817006 Electrowetting on dielectric driven droplet resonance and mixing enhancement in parallel-plate configuration model is applied to electrowetting induced droplet motion between parallel plates in the case of a single actuation electrode and for an array of electrodes. In EWOD, surface tension between a liquid droplet and solid the electrowetting droplet may provide a direct means to investigate the correct boundary condition for the multiphase °uid dynamics in a Hele-Shaw cell. For most experiments of this sort, the droplets can be moved at speeds in the range of 10s of cm/s which is extremely fast for those size scales. Electrowetting on dielectric (EWOD) digital microfluidics is a promising method of droplet manipulation that controls each droplet individually by an applying external electric field …Electrowetting is a technique used to change the apparent contact angle of a dielectric fluid under the influence of electric potential. droplets by electrowetting, a phenomenon based on the in-teraction of the electrostatic, gravity, and surface forces. Aque-ous and nonaqueous liquid droplets precisely dispensed from two reservoirs on a microfluidic chip are trans-portedandcombinedtoformoil-in-water-in-airorwater-in-oil-in-air DE Electrowetting is an effect that, upon applying some electricity, alters a material’s wettability. In the basic model, the contact angles (θ) will depend on the voltage (V) between the pad and the droplet and the liquid wetting angle (θ. Electrowetting on liquid-infused film (EWOLF): Complete reversibility and controlled droplet oscillation suppression for fast optical imaging Chonglei Hao , 1 Yahua Liu , 1 Xuemei Chen , 1 Yuncheng He , 2 Qiusheng Li , 2 K. There has been considerable interest in droplet-based micro-fluidic systems13 in recent years as an alternative paradigm to continuous-flow channel-based systems. pdfMicromachines 2015, 6 174 electrowetting-on-dielectrics (EWOD) platform by introducing the fluid from inside of the needle tip [25]. The present invention is generally related to the field of droplet-based liquid handling and processing, such as droplet-based sample preparation, mixing, and dilution on a microfluidic scale. The droplet. ticles. That in turn, will lead to accelerated condensation . Electrowetting Droplet Operations on a Digital Microfluidic Cartridge. 2, (4) where CEQ(x)is the equivalent capacitance, which varies spatially according to the location x of the moving droplet. INTRODUCTION E LECTROWETTING on dielectric (EWOD) is a phenom-enon where the wetting properties of a dielectric covered electrode are altered via the application of an electric field between the electrode and a conducting liquid [1]. In EWOD, surface tension between a liquid droplet and solid substrate is modulated by applying voltage to an electrode and a hydrophobic …Knowledge of the electrowetting droplet may provide a direct means to investigate the correct boundary condition for the multiphase °uid dynamics in a Hele-Shaw cell. electrowetting-on-dielectric (EWOD) device; (b) the electrowetting principle; (c) driving force derived from integration of the surface tension in contacting line; and ( d ) static effects on the droplet including the contact angle saturation (CAS) effect and pinning effect. Vasudev1 and J. @article{osti_15011159, title = {Electrowetting-Induced Droplet Movement in an Immiscible Medium}, author = {Kuo, Jason S. 5 μM. Droplet Actuation by Electrowetting Droplets are actuated electrostatically in which the interfacial tension of a liquid droplet and a solid surface are modulated, a phenomenon known as electrowetting [11]. Multiphysics for a sessile droplet and for a droplet in a microchannel. Figure 3 Electrowetting of a Droplet. The phenomenon of electrowetting can be understood in terms of the forces that result from the applied electric field. The present work involves a systematic experimental investigation of the influence of electrowetting in determining and altering the state of a static droplet resting on an artificially microstructured surface. Microfluidic manipulation of liquids by electrowetting was demonstrated first with mercury droplets in water and later with water in air and water in oil. 2. Electrowetting then controls the shape of the confined silicone oil, and the focal length may be @inproceedings{Hao2014ElectrowettingOL, title={Electrowetting on liquid-infused film (EWOLF): Complete reversibility and controlled droplet oscillation suppression for fast optical imaging}, author={Chonglei Hao and Yahua Liu and Xuemei Chen and Yuncheng He and Qiusheng Li and Kwok Yan Li and Droplet Actuation by Electrowetting-on-Dielectric (EWOD): A Review Wyatt C. Therefore, when the electrodes are cycled in sequence, the drops and droplet …Feb 03, 2016 · Contact for use permissions. Keywords: Level-Set Method, Electrowetting, Multiphase Flow, Contact Angle. In particular, we are looking at the reversibility of electrowetting operation. Electrowetting (EW) or electrowetting-on-dielectric (EWOD) is an indispensable and versatile means for droplet manipulation. (a) A liquid droplet sandwiched between two plates. Electrowetting Abstract Electrowetting (EW) enables facile manipulation of a liquid droplet on a hydrophobic surface. Nahar1, H. The free surface of the liquid is tracked by a coupled level-set and volume-of-fluid method, with We introduce droplet jumping by electrowetting (DJE), which stretches droplets to store energy for jumping by electrowetting. Electrowetting-on-dielectric (EWOD) is a new method for handling droplets on the microfluidic chips. Lee et al. Electrowetting is a technique used to manipulate the wetting properties of a substrate under an external electric field [23]. ReVised Manuscript ReceiVed April 23, 2008This thesis focuses on the symmetric and asymmetric splitting of droplets, which is a prominent fluidic operation in a digital microfluidic system (DMFS). 0 ms is 0. 22 If the contact angle of the droplet on the electrode is large enough in air, then the oil environment can be …The condition for successful cutting is theoretically analyzed by examining the channel gap, the droplet size and the degree of contact angle change by electrowetting on dielectric (EWOD). Knowledge of the electrowetting droplet may provide a direct means to investigate the correct boundary condition for the multiphase °uid dynamics in a Hele-Shaw cell. ReVised Manuscript ReceiVed April 23, 2008@article{osti_15011159, title = {Electrowetting-Induced Droplet Movement in an Immiscible Medium}, author = {Kuo, Jason S. DMF uses quick manipulation of separate droplets by electrical control of surface tension (electrowetting) to perform bioassay protocols. electrowetting. com Jayathi Y. Electrowetting can be performed without a physical dielectric but a non-insulated liquid/electrode system is not highly reversible and will not be reviewedNumerical simulation for a droplet fission process of electrowetting on dielectric device Dongdong Hea, Huaxiong Huangb,∗, Yongji Tana aDepartment of Mathematical Sciences, Fudan University, Shanghai, China bDepartment of Mathematics and Statistics, York University, Toronto, Canada Abstract Electrowetting has been proposed as a technique for manipulating droplets surrounded byElectrowetting Actuation. Droplet Shapes on Superhydrophobic Surfaces under Electrowetting Actuation . Moon1, G. Index Terms—Droplet configuration, electrowetting on dielectric, impedance spectroscopy. 22 If the contact angle of the droplet on the electrode is large enough in air, then the oil environment can be avoided. Due to the intense interest in the Hele-Shaw problems, the last ten years has also seen a development of numerical methods for …Asymmetric electrowetting - Moving droplets by a square wave. In the basic model, the contact angles (θ) will depend on the Contact for use permissions. Oct 02, 2018 · Simple droplet operations of dispensing from a reagent reservoir, droplet transport across electrodes, merging two droplets into a larger combined droplet, mixing the combined droplet, and Author: Baebies, Inc. liquid metal droplet. This thesis focuses on the symmetric and asymmetric splitting of droplets, which is a prominent fluidic operation in a digital microfluidic system (DMFS). Microwater droplet splitting and merging in a parallel-plate electrowetting-on-dielectric (EWOD) device have been studied numerically. Electrowetting Electrowetting-based actuation of droplets for integrated microfluidics. program element number 63739e 6. 5 nL droplet (blue, 40 Vppk) and speed of a 10 μm polystyrene bead (red, 10 Vppk). Nelson Mechanical and Aerospace Engineering Department , University of California, Los Angeles (UCLA) , Los Angeles , CA , 90095 , USA & Chang-Jin ‘CJ’ Kim Mechanical and Aerospace Engineering Department , University of California, Los Angeles (UCLA) , Los Angeles Electrowetting has been proposed as a technique for manipulating droplets surrounded by air or oil. The inset shows the stills of the droplet at 0V and 180V. Current understanding of electrowetting-induced droplet dynamics is hindered by the inadequacy of available numerical and theoretical models in properly handling the dynamic contact Electrowetting refers to an electrostatically induced reduction in the contact angle of an electrically conductive liquid droplet on a surface. The greater Normally, electrowetting is implemented in an oil environment because the droplet in the oil has a much larger contact angle than in an air environment. (b) Simplified circuit diagram of a droplet and a dielectric layer in series between top and bottom electrodes. Dynamic Contact Angles and Hysteresis under knowledge of howresistance forces are related to electrowetting voltage and droplet sliding speed. }, abstractNote = {As the characteristic dimension of fluid flow is reduced to the micrometer range, surface energy becomes an increasingly important factor in determining the flow behavior. droplet on a 2D-network of such pumps will move towards hot spots by thermal propulsion and will be returned to the sink via electrowetting. Electrowetting is commonly characterized by the change in contact angle on a substrate as a function of applied voltage. Due to this electrowetting effect, the liquids – trapped in a hydrophobic system – can be manipulated on the microscale in various ways. A system in which oscillatory droplet motion is produced from a steady DC input along …The volume of the droplet is about 800nl. Results of this work show that an electrowetting-induced motion of an aqueous droplet in immiscible oils can be achieved reversibly across the boundary of the horizontal and vertical surfaces of the 3-D electrode surface. work unit number ak 7. [22] introduced droplet jumping by electrowetting and demonstrated the transport of ses- The droplet is sandwiched between the top and the bottom surfaces. Droplet velocities of several centimetres per second have been observed in droplet electrowetting in microchannels. Droplet oscillations occur only when both morphologies are unstable, i. e. The condition for successful cutting is theoretically analyzed by examining the channel gap, the droplet size and the degree of contact angle change by electrowetting on dielectric (EWOD). Traditional electrowetting runs into problems because it requires a two-dimensional array of electrodes for droplet actuation, the large number of electrodes leads to complexity for both control and packaging of these chips, especially for droplet sizes of smaller scales. Best Mouse Trap Ever, How To Make Bucket Mouse Trap - Duration: 10:59. Electrowetting is the modification of the wetting properties of a surface (which is typically hydrophobic) with an applied electric field. Electrowetting is a commonly used technique to actuate liquids on microfluidic platforms. If several electrodes are placed in succession, a discrete droplet can be pulled along a surface. A sinusoidal AC voltage signal was applied to induce inhomogeneity in surface tension of the metal droplet, which Droplet on the liquid-infused film exhibits nearly perfect electrowetting reversibility with apparent CA switching between ~103° and ~53° when the droplet is excited by voltage-on and voltage Electrowetting (EW) has recently been demonstrated as a powerful tool for controlling droplet morphology on smooth and artificially structured surfaces. EWOD enables automated handling of droplets in an optically transparent platform that allows for in situ droplet observation. 5 ms, the droplet height increases to 0. •Dynamics of droplet motion induced by electrowetting was investigated. the surface tension between a liquid droplet and solid substrate is modulated by applying voltage to an electrode and thus surface can be transformed from hydrophobic to hydrophilic. Jacob Baker Abstract A low-cost and high-resolution capacitive-to-digital converter integrated circuit is used for droplet position detection in a digital microfluidic system. The present invention relates to a method for controlling a hydrophilic droplet using the principle of electrowetting, and more particularly, to a method for controlling the contact angle of the droplet in electrowetting and an apparatus for controlling the droplet formed by the method. Mun Mun Nahar* 1, Govindraj Shreyas Bindiganavane, Jagath Nikapitiya and Hyejin Moon . Electrowetting (EW) has recently been demonstrated as a powerful tool for controlling droplet morphology on smooth and artificially structured surfaces. Electrowetting has been used to demonstrate droplet actuation [5–11] and other microfluidic operations such as the formation, mixing and splitting of droplets [12]. Among several approaches that have been reported in the literature for manipu-lating droplets, microfluidic devices based on electrowetting,14–16If only one side of the droplet is sitting on an electrode, the droplet will move towards the electrode, since surface energy is lower there. Thereafter, contact electrowetting using the homemade MKWD was studied. 1A. This paper reviews publications that have fortified our understanding of the electrowetting-on-dielectric (EWOD) actuation mechanism. edu Abstract Droplet actuation, merging, and splitting using A Low-Cost and High-Resolution Droplet Position Detector for an Intelligent Electrowetting on Dielectric Device Yiyan Li 1, Hongzhong Li , and R. Simple droplet operations of dispensing from a reagent reservoir, droplet transport across electrodes, merging two droplets into a larger combined droplet, mixing the combined droplet, and splitting the droplet are accomplished by strategically applying voltagesThe chip uses electrowetting for droplet transport and cell deformability, on an open configuration. Y. Ashoke Raman⇑, Rajeev K. A hybrid microfluidic chip with electrowetting functionality using ultraviolet (UV)-curable polymer Hao Gu et al 2010 Lab on a Chip 10 1550 Crossref. strength (R) as proposed by the Young- Lippmann equation [23]. Alternatively In electrowetting, application of a voltage across the electrodes of a micro-droplet causes it to change the interfacial energy of solid-liquid interface which in turn changes the contact angle of the liquid on the solid. The aspects of the invention thus far have been described in connection with the use of a droplet actuating apparatus that has a two-sided electrode configuration such as microactuator mechanism 10 illustrated in FIG. Aque-ous and nonaqueous liquid droplets precisely dispensed from two reservoirs on a microfluidic chip are trans-portedandcombinedtoformoil-in-water-in-airorwater-in-oil-in-air DE In electrowetting on dielectric, the surface tension between the liquid-solid interface is modified by an external electric field, which reduces the meniscus contact angle and induces motion of a droplet. More recently, Chiou et al. com Jayathi Y. When a droplet is in contact with a surface having a gradient of surface energy as shown in Figure 1. Using level set methods, Walker & Shapiro (2004) considered a similar problem with the addition of inertia. LU1, K. Electrowetting has been used to actuate and control the motion of droplets on solid surfaces. A LOW VOLTAGE CAPILLARY MICROGRIPPER USING ELECTROWETTING A. γLV. Here an electric field is being applied in order to merge two small droplets. It was developed from elecrtrocap- A novel approach for droplet position sensing in electrowetting devices Shiraz Sohail∗ and Karabi Biswas Department of Electrical Engineering, Indian Institute of Technology Kharagpur, India-721302. The dependence of the velocity on voltage is roughly independent of the droplet size within certain limits, thus the smallest droplets studied (approximately 3 nl) could be transported over 1000 times their length per second. High-throughput automated droplet microfluidic system for screening of reaction conditions Krzysztof Churski et al 2010 Lab on a Chip 10 816 Crossref Microwater droplet splitting and merging in a parallel-plate electrowetting-on-dielectric (EWOD) device have been studied numerically. In EWOD, surface tension between a liquid droplet and solid@article{osti_15011159, title = {Electrowetting-Induced Droplet Movement in an Immiscible Medium}, author = {Kuo, Jason S. In this paper, we discuss the modeling and simulation of the droplet fission process between two parallel plates inside an electrowetting on dielectric (EWOD) device. effects. Methods of using protein crystallization droplet actuators are provided. of engineering applications, such as droplet-based microfluidics [1], optofluidic optical attenuators [2,3] and reflective displays [4], etc. Among many applications Droplet Shapes on Superhydrophobic Surfaces under Electrowetting Actuation . utc. electrowetting dropletIn this case, the space charge region at the droplet-semiconductor interface plays the role of the insulator in the EWOD. In this case, the space charge region at the droplet-semiconductor interface plays the role of the insulator in the EWOD. wisc. Electrowetting (EW) has recently been demonstrated as a powerful tool for controlling droplet morphology on smooth and artificially structured surfaces. both integrated light activation technology in EWOD to generate droplets from a channel [26,27]. Note that electrodes can be insulated to prevent electrolysis of liquids: the technique is called electrowetting on a dielectric (EWOD). Taking the contact angle for the left half of the droplet to be θ L and The condition for successful cutting is theoretically analyzed by examining the channel gap, the droplet size and the degree of contact angle change by electrowetting on dielectric (EWOD). 4896actuation enables a droplet to accumulate sufficient surface energy for. lab. Through the process of electrowetting, these drops are pulled by electrodes into the electrode array. Pollack and Richard B. Abstract. First and foremost, I would like to thank Professor Crane, my …Author: Qi NiPublish Year: 2016[PDF]Programmable Electrowetting with Channels and Dropletshttps://papautsky. Programmable droplet manipulations and assemblies on the electromicrofluidic platform are facilitated by electrowetting and die-lectrophoresis between plates holding appropriate electrodes and dielectric and hydrophobic layers, as shown in Fig. Electrowetting-based droplet mixers for microfluidic systems† Phil Paik *, Vamsee K. This thesis demonstrates that not only the EWOD actuation is a self-feedback A droplet resting on a flat electrode changes its contact angle if a voltage difference between the droplet and the electrode is applied. -W. electrowetting system [1], [12]. Droplet shape. Droplet Actuation on Various Electrode Shapes in Electrowetting-based Microfluidics Negar Rajabi Electrowetting has been widely used in digital microfluidics as a reliable actuation method due to its considerable advantages such as the absence of heat generation, rapid switching response, flexibility, and low power consumption. Maximum droplet actuation before contact angle saturation is achieved at only 10 V for a concentration of 0. The voltages on the grid are time varying in such a way as to keep the particle moving along the desired path with less than 20 mm deviation. In contrast, increasing the opening ratio hampers successful electrowetting operations of droplets and thus sampling of microparticles. GLASNER3, Electrowetting has recently been explored as a mechanism for moving small amounts the electrowetting droplet may provide a direct means to investigate the correct boundaryWe introduce droplet jumping by electrowetting (DJE), which stretches droplets to store energy for jumping by electrowetting. In this study, manipulation of an electrolyte droplet having a small floating object on it was investigated on a solid hydrophobic substrate under the EW process. C , (1) where U is the potential energy of the system, q is the charge, and C is the capacitance. The chip configuration is of engineering applications, such as droplet-based microfluidics [1], optofluidic optical attenuators [2,3] and reflective displays [4], etc. investigation of droplet splitting is to understand the electrowetting-on-dielectric (EWOD) based droplet actuation. }, abstractNote = {As the characteristic dimension of fluid flow is reduced to the micrometer range, surface energy becomes an increasingly important factor in determining the flow behavior. NFC007 Net Fish Cambo & Street Food 19,817,489 viewselectrowetting, consider a liquid droplet of volume V sandwiched between two plates with a channel depth of h shown in Figure 3a. The electrowetting equation predicts that the droplet contact angle θ should decrease with the increase in the applied voltage. Since the However, the droplet modulation ceases at a certain voltage, which is referred to as the saturation voltage, and the corresponding angle is the saturation angle [9]. Bistable electrowetting-display principle. Electrowetting on dielectric (EWOD) digital microfluidics is a promising method of droplet manipulation that controls each droplet individually by an applying external electric field to the designated electrodes [1–3]. Jaiman⇑, Thong-See Lee, Hong-Tong Low Department of Mechanical Engineering, National University Singapore, 10 Kent Ridge Crescent, Singapore 117576, SingaporeOct 05, 2009 · Figure 5 Image of initiation of droplet purge using electrowetting using ver- tical electrodes, for different elapsed times. Electrowetting (EW) has recently been demonstrated as a powerful tool for controlling droplet morphology on smooth and artificially structured surfaces. 66786, deviating from the equilibrium state for optical focusing and therefore leading to an unfocused image. Coplanar electrowetting-induced stirring as a tool to manipulate biological samples in lubricated digital microfluidics. An interface between a well-plate format and the electrowetting chip, and a scheme to passively stamp droplets onto a target substrate was then designed and tested by stamping BSA solutions. In contact electrowetting, the droplet is in contact with a working electrode that applies the voltage. Among several approaches that have been reported in the literature for manipu-lating droplets, microfluidic devices based on electrowetting,14–16The droplet is placed between top and bottom plates, with the height determined by the thickness of the spacers. Droplet mixer based on electrowetting Droplet mixer based on electrowetting The manipulation of droplets on the microscale is a growing area of research for Lab-on-a-chip applications. TOWARDS DIGITAL MICROFLUIDIC CIRCUITS: CREATING, TRANSPORTING, CUTTING AND MERGING LIQUID DROPLETS BY ELECTROWETTING-BASED ACTUATION Sung Kwon Cho, Shih-Kang Fan, Hyejin Moon, and Chang-Jin “CJ” KimDroplet spreading on substrates by electrowetting exhibits either of the two transient behaviours: one characterised by contact line oscillation, and the other one by slow spreading dynamics. As a result the droplet tends to spread and position itself in such a way as to maximize its overlap with the dielectric-film-coated electrode. ece. This induces a capillaj'pressure to move the droplet toward to the optical beam. We also show ed that electrowetted fluid segments can be portioned into precisely metered volumes using voltage ramping [31] and can be manipulated on arrayed electrodes [32]. More specifically, the present invention relates to the manipulation of droplets by electrowetting-based techniques. ac. Current understanding of electrowetting-induced droplet dynamics is hindered by the inadequacy of available numerical and theoretical models in properly handling the dynamic contact angle at the moving contact line. Films were observed during transport of droplets forward and backward along rows of electrodes at 275 V and 100 Hz on 3 different cartridges. The chip uses electrowetting for droplet transport and cell deformability, on an open configuration. 1 Department of Mechanical and Aerospace Engineering, University of Texas at Arlington. More recently, detachment of droplets from solid surfaces has been established through electrowetting [22–24]. Relevant dimensions and angles of electrowetting designs. Electrowetting (EW) or electrowetting-on-dielectric (EWOD) is an indispensable and versatile means for droplet manipulation. The third aspect of wavefront engineering requires control over the piston, or phase. Electrowetting droplet trap - Two electrodes separated by a small gap provide an electrically tunable pinning center for droplets sliding down an inclined plane. utc. Droplet Actuation by Electrowetting-on-Dielectric (EWOD): A Review Wyatt C. Furthermore, Electrowetting is a commonly used technique to actuate liquids on microfluidic platforms. First and foremost, I would like to thank Professor Crane, my advisor and mentor whom electrowetting channels can retain their geometry under pressure- driven flows [30]. Most designs ground the droplet by either sandwichingdroplet on a 2D-network of such pumps will move towards hot spots by thermal propulsion and will be returned to the sink via electrowetting. Despite tremendous progress over the past two decades, current EWOD operating in ambient conditions has limited functionalities posing challenges for its applications, including electronic display, energy generation, and microfluidic systems. uic. The dotted area corresponds to the region ofdroplet manipulations, such as droplet generation, splitting, merging and mixing. electrowetting. Adaptive liquid lens for fast optical focusing. In this so-called electrowetting phenomenon, it is Electrowetting on dielectric (EWOD) digital microfluidics is a promising method of droplet manipulation that controls each droplet individually by an applying external electric field to the designated electrodes [1 – 3]. Due to the intense interest in the Hele-Shaw problems, the last ten years has also seen a development of numerical methods for …Electrowetting on Dielectric (EWOD) is a versatile tool for performing basic operations in Digital Microfluidic Systems. A droplet was transported by switching off the electrode under the droplet,In contrast, increasing the opening ratio hampers successful electrowetting operations of droplets and thus sampling of microparticles. Research on the We introduce droplet jumping by electrowetting (DJE), which stretches droplets to store energy for jumping by electrowetting. When a droplet is in contact with a surface having a gradient of surface energy as shown in Figure 1. A Coplanar Electrodes Configuration. Observation and characterization of oil films during electrowetting-driven droplet transport. We describe a method to determine ATPS binodals and tie‐lines that overcomes these disadvantages: microscale droplet manipulation by electrowetting‐on‐dielectric (EWOD). 3). 0) without the applied voltage. I. In EWOD, surface tension between a liquid droplet and solid substrate is modulated by applying voltage to an electrode and a hydrophobic surface is transformed into a hydrophilic one. We have been developing a digital microfluidic lab-on-a-chip based on the principles of …Oct 05, 2009 · Figure 5 Image of initiation of droplet purge using electrowetting using ver- tical electrodes, for different elapsed times. 61905, which is consistent with the steady-state value. ACKNOWLEDGMENTS Over the length of this project, many people provided their support to make this dissertation possible. We studied the detailed jumping mechanisms with regard to the jumping height and the energy conversion and demonstrated the transport Numerical Modeling of 3D Electrowetting Droplet Actuation and Cooling of a Hotspot M. More importantly, a dimensionless parameter κ ̃ has been proposed, which can be used for (a) determining the splitting mode and (b) estimating satellite droplet volume for electrowetting-induced droplet splitting process. History . A droplet position sensing scheme for monitoring multiple droplets has been proposed, which gives a direct voltage output linearly proportional to droplet position in electrowetting-on-dielectric (EWOD) based devices. continuous electrowetting effect to induce chaotic advection over surface of a liquid metal droplet when activated by a sinusoidal signal [37]. •Transient responses of the droplet to EW excitation were measured by high-speed photography. Droplet transport is rapid and efficient with average velocities exceeding 10 cm s(-1) having been observed. The result was in good agreement with electrowetting theory. Adaptive liquid lens for fast optical focusing. A droplet of silicone oil, an insulator, is placed atop the underlying electrowetting electrodes and then surrounded by water which is conductive and serves as a floating electrode. electrowetting-based driving of liquid-metal droplet for reliable rf switching 5a. The reported data Mixing of analytes and reagents is a critical step in realizing a lab-on-a-chip. A liquid droplet is squeezed between the plates. The droplet will quickly reach a steady state terminal velocity upon application of the electrowetting force. In this example, the fluid is originally hydrophobic and beads on the surface. Most recently, we demonstrated droplet splitting Electrowetting is the electrostatically-induced decrease of the liquid contact angle at a contact line formed at the intersection of a liquid, solid, and a third fluid that can be a gas or immiscible liquid. The electrowetting behavior of mercury and other liquids on variably charged surfaces was probably first explained by Gabriel Lippmann in 1875 [1] and was certainly observed much earlier. Jacob Baker1 1 Department of Electrical and Computer Engineering, University of Nevada, Las Vegas and 2 Genia Corporation liy10@unlv. In this paper, a generic simplified macroscopic model is described to predict the dynamics of droplet motion as a reaction to the application of a voltage at a single electrode or subsequently at anNumerical Modeling of 3D Electrowetting Droplet Actuation and Cooling of a Hotspot . Dynamics of a Leidenfrost Droplet Modulated by Electrowetting Yi Lu, Jiming Bao and Dong Liu University of Houston, Houston, TX 77204 Leidenfrost phenomenon is closely related to film boiling and the critical heat flux (CHF) limit of boiling heat transfer. movement is maximized at 10 kHz due to electrowetting, though a secondary hump is present at 200 kHz due to DEP en-. A low-cost and high-resolution capacitive-to-digital converter integrated circuit is used for droplet position detection in a digital microfluidic system. •Numerical models were developed to incorporate a MKT-based dynamic contact angle model. We consider a °ow dominated by viscosity inside the droplet. Despite much progress in this field, electrowetting‐based stiction switch that drives unidirectional transport of an underwater oil droplet or air bubble on a wire surface is still a challenge to realize. Electrowetting of the blood droplet on the hydrophobic film of the EWOD chips. The mechanisms of the invention allow the droplets to be transported while also acting as virtual chambers for mixing to be performed anywhere on a chip. Garimella Cooling Technologies Research Center School of Mechanical Engineering and Birck Nanotechnology CenterElectrowetting on Dielectric (EWOD) is a versatile tool for performing basic operations in Digital Microfluidic Systems. Most designs ground the droplet by either sandwiching the droplet with a grounding plate on top or by inserting a wire into the droplet. electrowetting droplet Electrowetting has drawn significant interests due to the potential applications in electronic displays, lab-on-a-chip devices and electro-optical switches, etc. and Park et al. Knowledge of the electrowetting droplet may provide a direct means to investigate the correct boundary condition for the multiphase °uid dynamics in a Hele-Shaw cell. 61905, which is consistent with the steady-state value. 4 Electrowetting Electrowetting-on-dielectric is the process of changing the wetting properties of a surface by applying an external electric field. Lifting force is evolved from a liquid bridge formed between the gripper Electrowetting actuators require a droplet to overlap the adjacent electrode when the droplet rests on the biased electrode, so that the droplet can response to the voltage applied on the adjacent electrode. Simple droplet operations of dispensing from a reagent reservoir, droplet transport across electrodes, merging two droplets into a larger combined droplet, mixing the combined droplet, and splitting the droplet are accomplished by strategically applying voltages Electrowetting (EW) has recently been demonstrated as a powerful tool for controlling droplet morphology on smooth and artificially structured surfaces. 11 If a droplet of conductive liquid is exposed to an external electric field, the distribution of ions within the droplet changes, and as a result the shape of thedroplet speed Ud is obtained by equating the above two equations: (cos cos ) 6 R L LV d a h U θ θ πµ γ = − 3(a) 3(b) Figure 3. The governing equations for the fluid flow are solved by a finite volume formulation with a two-step projection method on a fixed computational domain. An alternative mixing strategy is presented based on the discretization of liquids into droplets and further manipulation of those droplets by electrowetting. This technique builds on the principle of electrowetting, which has proven useful in liquid actuation due to fast switching response times and low power consumption. - At low voltages the droplets can pass the trap, above a certain critical voltage U C (that increases with theThe cooling approach is based on a novel electrowetting-based droplet transport technology. * Corresponding author: Department of Mechanical and Aerospace Engineering, University ofElectrowetting is the electrostatically-induced decrease of the liquid contact angle at a contact line formed at the intersection of a liquid, solid, and a third fluid that can be a gas or immiscible liquid. The droplet is sandwiched between the top and the bottom surfaces. 95%. Bistable electrowetting-display principle. Research on theElectrowetting on Dielectric (EWOD) is a versatile tool for performing basic operations in Digital Microfluidic Systems. J. The droplet is placed between top and bottom plates, with the height determined by the thickness of the spacers