A microscopic physical description of electrothermal-induced flow for control of ion current transport in microfluidics interfacing nanofluidics | |
Liu WY1; Ren YK(任玉坤)2,3; Chen F1; Song JN1; Tao Y2; Du K1; Wu QS1 | |
Corresponding Author | Ren, Yukun([email protected]) ; Chen, Feng([email protected]) |
Source Publication | ELECTROPHORESIS
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2019-10-01 | |
Volume | 40Issue:20Pages:2683-2698 |
ISSN | 0173-0835 |
Abstract | The phenomenon of electrothermal (ET) convection has recently captured great attention for transporting fluidic samples in microchannels embedding simple electrode structures. In the classical model of ET-induced flow, a conductivity gradient of buffer medium is supposed to arise from temperature-dependent electrophoretic mobility of ionic species under uniform salt concentrations, so it may not work well in the presence of evident concentration perturbation within the background electrolyte. To solve this problem, we develop herein a microscopic physical description of ET streaming by fully coupling a set of Poisson-Nernst-Planck-Navier-Stokes equations and temperature-dependent fluid physicochemical properties. A comparative study on a standard electrokinetic micropump exploiting asymmetric electrode arrays indicates that, our microscopic model always predicts a lower ET pump flow rate than the classical macroscopic model even with trivial temperature elevation in the liquid. Considering a continuity of total current density in liquids of inhomogeneous polarizability, a moderate degree of fluctuation in ion concentrations on top of the electrode array is enough to exert a significant influence on the induction of free ionic charges, rendering the enhanced numerical treatment much closer to realistic experimental measurement. Then, by placing a pair of thin-film resistive heaters on the bottom of an anodic channel interfacing a cation-exchange medium, we further provide a vivid demonstration of the enhanced model's feasibility in accurately resolving the combined Coulomb force due to the coexistence of an extended space charge layer and smeared interfacial polarizations in an externally-imposed temperature gradient, while this is impossible with conventional linear approximation. This leads to a reliable method to achieve a flexible regulation on spatial-temporal evolution of ion-depletion layer by electroconvective mixing. These results provide useful insights into ET-based flexible control of micro/nanoscale solid entities in modern micro-total-analytical systems. |
Keyword | Electrothermal convection Ion transport control Micro nanofluidics Salt concentration perturbation Smeared interfacial polarization |
DOI | 10.1002/elps.201900105 |
Indexed By | SCI |
Language | 英语 |
WOS ID | WOS:000490455400008 |
WOS Keyword | ELECTROKINETICS ; FLUIDS ; ELECTROLYTES ; PARTICLES ; DYNAMICS ; DRIVEN |
WOS Research Area | Biochemistry & Molecular Biology ; Chemistry |
WOS Subject | Biochemical Research Methods ; Chemistry, Analytical |
Classification | 二类 |
Ranking | 1 |
Contributor | Ren, Yukun ; Chen, Feng |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://dspace.imech.ac.cn/handle/311007/80664 |
Collection | 非线性力学国家重点实验室 |
Affiliation | 1.Changan Univ, Sch Elect & Control Engn, Sch Highway, Xian, Shaanxi, Peoples R China; 2.Harbin Inst Technol, State Key Lab Robot & Syst, West Da Zhi St 92, Harbin, Heilongjiang, Peoples R China; 3.Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech LNM, Beijing, Peoples R China |
Recommended Citation GB/T 7714 | Liu WY,Ren YK,Chen F,et al. A microscopic physical description of electrothermal-induced flow for control of ion current transport in microfluidics interfacing nanofluidics[J]. ELECTROPHORESIS,2019,40,20,:2683-2698.Rp_Au:Ren, Yukun, Chen, Feng |
APA | Liu WY.,任玉坤.,Chen F.,Song JN.,Tao Y.,...&Wu QS.(2019).A microscopic physical description of electrothermal-induced flow for control of ion current transport in microfluidics interfacing nanofluidics.ELECTROPHORESIS,40(20),2683-2698. |
MLA | Liu WY,et al."A microscopic physical description of electrothermal-induced flow for control of ion current transport in microfluidics interfacing nanofluidics".ELECTROPHORESIS 40.20(2019):2683-2698. |
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