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Title: Magnetohydrodynamic actuation of droplets for millimetric planar fluidic systems

Abstract

In this work, a magnetohydrodynamic method is proposed for the actuation of droplets in small-scale planar fluidic systems, providing an alternative to commonly used methods such as electrowetting-on-dielectric. Elementary droplet-based operations, including transport, merging, and mixing, are demonstrated. The forces acting on millimetric droplets are carefully investigated, with a primary focus on the magnetic actuation force and on the unbalanced capillary forces that arise due to hysteresis. A super-hydrophobic channel is 3D printed to guide the droplets, with thin wires installed as contact electrodes and permanent magnets providing a static magnetic field. It is shown that droplet motion is enhanced by increasing the droplet size and minimizing the electrode contact surface. The effects of channel geometry on threshold voltage and minimum moveable droplet volume are characterized. Finally, the presence of electrolysis is investigated and mitigating strategies are discussed.

Authors:
; ;  [1]
  1. School of Engineering, University of British Columbia, Kelowna, British Columbia V1V 1V7 (Canada)
Publication Date:
OSTI Identifier:
22489266
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 1; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DIELECTRIC MATERIALS; DROPLETS; ELECTRIC POTENTIAL; ELECTRODES; ELECTROLYSIS; GEOMETRY; MAGNETIC FIELDS; PERMANENT MAGNETS

Citation Formats

Ahmadi, A., E-mail: ali.ahmadi@ubc.ca, McDermid, C. M., and Markley, L. Magnetohydrodynamic actuation of droplets for millimetric planar fluidic systems. United States: N. p., 2016. Web. doi:10.1063/1.4939245.
Ahmadi, A., E-mail: ali.ahmadi@ubc.ca, McDermid, C. M., & Markley, L. Magnetohydrodynamic actuation of droplets for millimetric planar fluidic systems. United States. doi:10.1063/1.4939245.
Ahmadi, A., E-mail: ali.ahmadi@ubc.ca, McDermid, C. M., and Markley, L. Mon . "Magnetohydrodynamic actuation of droplets for millimetric planar fluidic systems". United States. doi:10.1063/1.4939245.
@article{osti_22489266,
title = {Magnetohydrodynamic actuation of droplets for millimetric planar fluidic systems},
author = {Ahmadi, A., E-mail: ali.ahmadi@ubc.ca and McDermid, C. M. and Markley, L.},
abstractNote = {In this work, a magnetohydrodynamic method is proposed for the actuation of droplets in small-scale planar fluidic systems, providing an alternative to commonly used methods such as electrowetting-on-dielectric. Elementary droplet-based operations, including transport, merging, and mixing, are demonstrated. The forces acting on millimetric droplets are carefully investigated, with a primary focus on the magnetic actuation force and on the unbalanced capillary forces that arise due to hysteresis. A super-hydrophobic channel is 3D printed to guide the droplets, with thin wires installed as contact electrodes and permanent magnets providing a static magnetic field. It is shown that droplet motion is enhanced by increasing the droplet size and minimizing the electrode contact surface. The effects of channel geometry on threshold voltage and minimum moveable droplet volume are characterized. Finally, the presence of electrolysis is investigated and mitigating strategies are discussed.},
doi = {10.1063/1.4939245},
journal = {Applied Physics Letters},
number = 1,
volume = 108,
place = {United States},
year = {Mon Jan 04 00:00:00 EST 2016},
month = {Mon Jan 04 00:00:00 EST 2016}
}
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