Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation Study

We numerically study herein the AC electrokinetic motion of Janus mobile microelectrode (ME) arrays in electrolyte solution in a wide field frequency, which holds great potential for biomedical applications. A fully coupled physical model, which incorporates the fluid-structure interaction under the...

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Main Authors: Weiyu Liu, Yukun Ren, Ye Tao, Hui Yan, Congda Xiao, Qisheng Wu
Format: Article
Language:English
Published: MDPI AG 2020-03-01
Series:Micromachines
Subjects:
Online Access:https://www.mdpi.com/2072-666X/11/3/289
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spelling doaj-45254855bb654d4db968be9dcd3cc6fc2020-11-25T02:57:38ZengMDPI AGMicromachines2072-666X2020-03-0111328910.3390/mi11030289mi11030289Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation StudyWeiyu Liu0Yukun Ren1Ye Tao2Hui Yan3Congda Xiao4Qisheng Wu5School of Electronics and Control Engineering, Chang’an University, Middle-Section of Nan’er Huan Road, Xi’an 710064, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, ChinaSchool of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, ChinaSchool of Electronics and Control Engineering, Chang’an University, Middle-Section of Nan’er Huan Road, Xi’an 710064, ChinaSchool of Electronics and Control Engineering, Chang’an University, Middle-Section of Nan’er Huan Road, Xi’an 710064, ChinaWe numerically study herein the AC electrokinetic motion of Janus mobile microelectrode (ME) arrays in electrolyte solution in a wide field frequency, which holds great potential for biomedical applications. A fully coupled physical model, which incorporates the fluid-structure interaction under the synergy of induced-charge electroosmotic (ICEO) slipping and interfacial Maxwell stress, is developed for this purpose. A freely suspended Janus cylinder free from buoyancy, whose main body is made of polystyrene, while half of the particle surface is coated with a thin conducting film of negligible thickness, will react actively on application of an AC signal. In the low-frequency limit, induced-charge electrophoretic (ICEP) translation occurs due to symmetric breaking in ICEO slipping, which renders the insulating end to move ahead. At higher field frequencies, a brand-new electrokinetic transport phenomenon called “ego-dielectrophoresis (e-DEP)” arises due to the action of the localized uneven field on the inhomogeneous particle dipole moment. In stark contrast with the low-frequency ICEP translation, the high-frequency e-DEP force tends to drive the asymmetric dipole moment to move in the direction of the conducting end. The bidirectional transport feature of Janus microspheres in a wide AC frequency range can be vividly interpreted as an array of ME for continuous loading of secondary bioparticles from the surrounding liquid medium along its direction-controllable path by long-range electroconvection. These results pave the way for achieving flexible and high-throughput on-chip extraction of nanoscale biological contents for subsequent on-site bioassay based upon AC electrokinetics of Janus ME arrays.https://www.mdpi.com/2072-666X/11/3/289induced-charge electrokinetic phenomenonego-dielectrophoresismobile electrodejanus microspherecontinuous biomolecule collectionelectroconvection
collection DOAJ
language English
format Article
sources DOAJ
author Weiyu Liu
Yukun Ren
Ye Tao
Hui Yan
Congda Xiao
Qisheng Wu
spellingShingle Weiyu Liu
Yukun Ren
Ye Tao
Hui Yan
Congda Xiao
Qisheng Wu
Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation Study
Micromachines
induced-charge electrokinetic phenomenon
ego-dielectrophoresis
mobile electrode
janus microsphere
continuous biomolecule collection
electroconvection
author_facet Weiyu Liu
Yukun Ren
Ye Tao
Hui Yan
Congda Xiao
Qisheng Wu
author_sort Weiyu Liu
title Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation Study
title_short Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation Study
title_full Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation Study
title_fullStr Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation Study
title_full_unstemmed Buoyancy-Free Janus Microcylinders as Mobile Microelectrode Arrays for Continuous Microfluidic Biomolecule Collection within a Wide Frequency Range: A Numerical Simulation Study
title_sort buoyancy-free janus microcylinders as mobile microelectrode arrays for continuous microfluidic biomolecule collection within a wide frequency range: a numerical simulation study
publisher MDPI AG
series Micromachines
issn 2072-666X
publishDate 2020-03-01
description We numerically study herein the AC electrokinetic motion of Janus mobile microelectrode (ME) arrays in electrolyte solution in a wide field frequency, which holds great potential for biomedical applications. A fully coupled physical model, which incorporates the fluid-structure interaction under the synergy of induced-charge electroosmotic (ICEO) slipping and interfacial Maxwell stress, is developed for this purpose. A freely suspended Janus cylinder free from buoyancy, whose main body is made of polystyrene, while half of the particle surface is coated with a thin conducting film of negligible thickness, will react actively on application of an AC signal. In the low-frequency limit, induced-charge electrophoretic (ICEP) translation occurs due to symmetric breaking in ICEO slipping, which renders the insulating end to move ahead. At higher field frequencies, a brand-new electrokinetic transport phenomenon called “ego-dielectrophoresis (e-DEP)” arises due to the action of the localized uneven field on the inhomogeneous particle dipole moment. In stark contrast with the low-frequency ICEP translation, the high-frequency e-DEP force tends to drive the asymmetric dipole moment to move in the direction of the conducting end. The bidirectional transport feature of Janus microspheres in a wide AC frequency range can be vividly interpreted as an array of ME for continuous loading of secondary bioparticles from the surrounding liquid medium along its direction-controllable path by long-range electroconvection. These results pave the way for achieving flexible and high-throughput on-chip extraction of nanoscale biological contents for subsequent on-site bioassay based upon AC electrokinetics of Janus ME arrays.
topic induced-charge electrokinetic phenomenon
ego-dielectrophoresis
mobile electrode
janus microsphere
continuous biomolecule collection
electroconvection
url https://www.mdpi.com/2072-666X/11/3/289
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AT congdaxiao buoyancyfreejanusmicrocylindersasmobilemicroelectrodearraysforcontinuousmicrofluidicbiomoleculecollectionwithinawidefrequencyrangeanumericalsimulationstudy
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