Demonstration of Four Fundamental Operations of Liquid Droplets for Digital Microfluidic Systems Based on an Electrowetting-on-Dielectric Actuator

How to take advantage of superhydrophobic microgrids to address the problem of coupling continuous to digital microfluidic systems? A reconfigurable capillary connection for digital microfluidic devices is presented.

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Electrowetting-on-dielectric (EWOD) digital microfluidic device for in-line workup in organic reactions: A critical step in the drug discovery work cycle

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2020.129252 ◽

2021 ◽

Vol 330 ◽

pp. 129252

Author(s):

Matin Torabinia ◽

Udaya Sree Dakarapu ◽

Parham Asgari ◽

Junha Jeon ◽

Hyejin Moon

Keyword(s):

Drug Discovery ◽

Microfluidic Device ◽

Organic Reactions ◽

Electrowetting On Dielectric ◽

Critical Step ◽

Work Cycle ◽

Digital Microfluidic

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Numerical Multiphysics Modeling of Microdroplet Motion Dynamics in Digital Microfluidic Systems

ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels: Parts A and B ◽

10.1115/fedsm-icnmm2010-30754 ◽

2010 ◽

Cited By ~ 1

Author(s):

Ali Ahmadi ◽

Jonathan F. Holzman ◽

Homayoun Najjaran ◽

Mina Hoorfar

Keyword(s):

Numerical Algorithm ◽

Moving Boundary ◽

Microfluidic Systems ◽

Multiphysics Modeling ◽

Transient Motion ◽

Proposed Model ◽

Digital Microfluidic ◽

Motion Dynamics

In this paper a novel numerical algorithm is proposed for modeling the transient motion of microdroplets in digital microfluidic systems. The new methodology combines the effects of the electrostatic and hydrodynamic pressures to calculate the actuating and opposing forces and the moving boundary of the microdroplet. The proposed model successfully predicts transient motion of the microdroplet in digital microfluidic systems, which is crucial in the design, control and fabrication of such devices. The results of such an analysis are in agreement with the expected trend.

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Numerical Investigation of the Combined Effects of Biomolecular Adsorption and Microdroplet Evaporation on the Performance of the Electrocapillary-Based Digital Microfluidic Systems

ASME 2011 9th International Conference on Nanochannels, Microchannels, and Minichannels, Volume 1 ◽

10.1115/icnmm2011-58166 ◽

2011 ◽

Author(s):

Ali Ahmadi ◽

Mina Hoorfar

Keyword(s):

Mass Loss ◽

Protein Concentration ◽

Adsorption Rate ◽

Force Balance ◽

Combined Effects ◽

Microfluidic Systems ◽

Gibbs Equation ◽

Rate Effects ◽

Digital Microfluidic ◽

Force Balance Equation

In this article, microdroplet motion in the electrocapillary-based digital microfluidic systems is modeled accurately, and the combined effects of the biomolecular adsorption and micro-droplet evaporation on the performance of the device are investigated. An electrohydrodynamic approach is used to model the driving and resisting forces, and Fick’s law and Gibbs equation are used to calculate the microdroplet evaporation and adsorption rate. Effects of the adsorption and evaporation rates are then implemented into the microdroplet dynamics by adding new terms into the force balance equation. It is shown that mass loss due to the evaporation tends to increase the protein concentration, and on the other hand, the increased concentration due to the mass loss increases the biomolecular adsorption rate which has a reverse effect on the concentration. The modeling results indicate that evaporation and adsorption play crucial roles in the microdroplet dynamics.

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Self-Cleaning: From Bio-Inspired Surface Modification to MEMS/Microfluidics System Integration

Micromachines ◽

10.3390/mi10020101 ◽

2019 ◽

Vol 10 (2) ◽

pp. 101 ◽

Cited By ~ 13

Author(s):

Di Sun ◽

Karl Böhringer

Keyword(s):

Surface Modification ◽

System Integration ◽

State Of The Art ◽

Mechanical Systems ◽

Surface Cleaning ◽

Practical Application ◽

Microfluidic Systems ◽

Micro Electro Mechanical Systems ◽

Self Cleaning ◽

Digital Microfluidic

This review focuses on self-cleaning surfaces, from passive bio-inspired surface modification including superhydrophobic, superomniphobic, and superhydrophilic surfaces, to active micro-electro-mechanical systems (MEMS) and digital microfluidic systems. We describe models and designs for nature-inspired self-cleaning schemes as well as novel engineering approaches, and we discuss examples of how MEMS/microfluidic systems integrate with functional surfaces to dislodge dust or undesired liquid residues. Meanwhile, we also examine “waterless” surface cleaning systems including electrodynamic screens and gecko seta-inspired tapes. The paper summarizes the state of the art in self-cleaning surfaces, introduces available cleaning mechanisms, describes established fabrication processes and provides practical application examples.

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Phase separation of multiphase droplets in a digital microfluidic device

Micro and Nano Systems Letters ◽

10.1186/s40486-019-0099-0 ◽

2019 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

Mun Mun Nahar ◽

Hyejin Moon

Keyword(s):

Phase Separation ◽

Capillary Number ◽

Digital Microfluidics ◽

Separation Performance ◽

Comprehensive Investigation ◽

Electrowetting On Dielectric ◽

Splitting Technique ◽

Droplet Splitting ◽

Two Phases ◽

Digital Microfluidic

Abstract This study reports the first comprehensive investigation of separation of the immiscible phases of multiphase droplets in digital microfluidics (DMF) platform. Electrowetting-on-dielectric (EWOD) actuation has been used to mechanically separate the phases. Phase separation performance in terms of percentage residue of one phase into another phase has been quantified. It was conceived that the residue formation can be controlled by controlling the deformation of the phases. The larger capillary number of the neck forming phase is associated with the larger amount of deformation as well as more residue. In this study, we propose two different ways to control the deformation of the phases. In the first method, we applied different EWOD operation voltages on two phases to maintain equal capillary numbers during phase separation. In the second method, while keeping the applied voltages same on both sides, we tested the phase separation performance by varying the actuation schemes. Less than 2% of residue was achieved by both methods, which is almost 90% improvement compared to the phase separation by the conventional droplet splitting technique in EWOD DMF platform, where the residue percentage can go up to 20%.

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