1
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Al-Amshawee SKA, Yunus MYBM. Electrodialysis desalination: The impact of solution flowrate (or Reynolds number) on fluid dynamics throughout membrane spacers. ENVIRONMENTAL RESEARCH 2023; 219:115115. [PMID: 36574794 DOI: 10.1016/j.envres.2022.115115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 11/13/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
The incorporation of a spacer among membranes has a major influence on fluid dynamics and performance metrics. Spacers create feed channels and operate as turbulence promoters to increase mixing and reduce concentration/temperature polarization effects. However, spacer geometry remains unoptimized, and studies continue to investigate a wide range of commercial and custom-made spacer designs. The in-depth discussion of the present systematic review seeks to discover the influence of Reynolds number or solution flowrate on flow hydrodynamics throughout a spacer-filled channel. A fast-flowing solution sweeping one membrane's surface first, then the neighboring membrane's surface produces good mixing action, which does not happen commonly at laminar solution flowrates. A sufficient flowrate can suppress the polarization layer, which may normally require the utilization of a simple feed channel rather than complex spacer configurations. When a recirculation eddy occurs, it disrupts the continuous flow and effectively curves the linear fluid courses. The higher the flowrate, the better the membrane performance, the higher the critical flux (or recovery rate), and the lower the inherent limitations of spacer design, spacer shadow effect, poor channel hydrodynamics, and high concentration polarization. In fact, critical flow achieves an acceptable balance between improving flow dynamics and reducing the related trade-offs, such as pressure losses and the occurrence of concentration polarization throughout the cell. If the necessary technical flowrate is not used, the real concentration potential for transport is relatively limited at low velocities than would be predicted based on bulk concentrations. Electrodialysis stack therefore may suffer from the dissociation of water molecules. Next studies should consider that applying a higher flowrate results in greater process efficiency, increased mass transfer potential at the membrane interface, and reduced stack thermal and electrical resistance, where pressure drop should always be indicated as a consequence of the spacer and circumstances used, rather than a problem.
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Affiliation(s)
| | - Mohd Yusri Bin Mohd Yunus
- Centre for Sustainability of Ecosystem & Earth Resources (Earth Centre), Universiti Malaysia Pahang, 26300, Pahang, Malaysia; Faculty of Chemical and Process Engineering Technology, Universiti Malaysia Pahang, 26300, Pahang, Malaysia
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2
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Liu W, Tao Y, Xue R, Song C, Wu Q, Ren Y. Continuous-Flow Nanoparticle Trapping Driven by Hybrid Electrokinetics in Microfluidics. Electrophoresis 2021; 42:939-949. [PMID: 32705697 DOI: 10.1002/elps.202000110] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/12/2020] [Accepted: 07/17/2020] [Indexed: 11/06/2022]
Abstract
We introduce herein an efficient microfluidic approach for continuous transport and localized collection of nanoparticles via hybrid electrokinetics, which delicately combines linear and nonlinear electrokinetics driven by a composite DC-biased AC voltage signal. The proposed technique utilizes a simple geometrical structure, in which one or a series of metal strips serving as floating electrode (FE) are attached to the substrate surface and arranged in parallel between a pair of coplanar driving electrodes (DE) in a straight microchannel. On application of a DC-biased AC electric field across the channel, nanoparticles can be transported continuously by DC bulk electroosmotic flow, and then trapped selectively onto the metal strips due to AC-field induced-charge electrokinetic (ICEK) phenomenon, which behaves as counter-rotating micro-vortices around the ideally polarizable surfaces of FE. Finite-element simulation is carried out by coupling the dual-frequency electric field, flow field and sample mass transfer in sequence, for guiding a practical design of the microfluidic nanoparticle concentrator. With the optimal device geometry, the actual performance of the technique is investigated with respect to DC bias, AC voltage amplitude, and field frequency by using both latex nanospheres (∼500 nm) and BSA molecules (∼10 nm). Our experimental observation indicates nanoparticles are always enriched into a narrow bright band on the surface of each FE, and a horizontal concentration gradient even emerges in the presence of multiple metal strips, which therefore permits localized analyte enrichment. The proposed trapping method is supposed to guide an elaborate design of flexible electrokinetic frameworks embedding FE for continuous-flow analyte manipulation in modern microfluidic systems.
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Affiliation(s)
- Weiyu Liu
- School of Electronics and Control Engineering, Chang'an University, Middle-Section of Nan'er Huan Road, Xi'an, 710064, P. R. China
| | - Ye Tao
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, 150001, P. R. China
| | - Rui Xue
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, 150001, P. R. China
| | - Chunlei Song
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, 150001, P. R. China
| | - Qisheng Wu
- School of Electronics and Control Engineering, Chang'an University, Middle-Section of Nan'er Huan Road, Xi'an, 710064, P. R. China
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, 150001, P. R. China.,State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-Zhi Street 92, Harbin, Heilongjiang, 150001, P. R. China
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Wu T, Ma Z, He Y, Wu X, Tang B, Yu Z, Wu G, Chen S, Bao N. A Covalent Black Phosphorus/Metal–Organic Framework Hetero‐nanostructure for High‐Performance Flexible Supercapacitors. Angew Chem Int Ed Engl 2021; 60:10366-10374. [DOI: 10.1002/anie.202101648] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Indexed: 12/22/2022]
Affiliation(s)
- Tianyu Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Ziyang Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Yunya He
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Xingjiang Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Bao Tang
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Ziyi Yu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Guan Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Su Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Ningzhong Bao
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
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Wu T, Ma Z, He Y, Wu X, Tang B, Yu Z, Wu G, Chen S, Bao N. A Covalent Black Phosphorus/Metal–Organic Framework Hetero‐nanostructure for High‐Performance Flexible Supercapacitors. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101648] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Tianyu Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Ziyang Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Yunya He
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Xingjiang Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Bao Tang
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Ziyi Yu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Guan Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Su Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
| | - Ningzhong Bao
- State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University (former: Nanjing University of Technology) Nanjing 210009 P. R. China
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Liu W, Sun Y, Yan H, Ren Y, Song C, Wu Q. A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena. MICROMACHINES 2020; 11:mi11060542. [PMID: 32471139 PMCID: PMC7345169 DOI: 10.3390/mi11060542] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 12/25/2022]
Abstract
We propose herein a unique mechanism of generating tunable surface charges in a metal-dielectric Janus nanopore for the development of nanofluidic ion diode, wherein an uncharged metallic nanochannel is in serial connection with a dielectric nanopore of fixed surface charge. In response to an external electric field supplied by two probes located on both sides of the asymmetric Janus nanopore, the metallic portion of the nanochannel is electrochemically polarized, so that a critical junction is formed between regions with an enriched concentration of positive and negative ions in the bulk electrolyte adjacent to the conducting wall. The combined action of the field-induced bipolar induced double layer and the native unipolar double layer full of cations within the negatively-charged dielectric nanopore leads to a voltage-controllable heterogenous volumetric charge distribution. The electrochemical transport of field-induced counterions along the nanopore length direction creates an internal zone of ion enrichment/depletion, and thereby enhancement/suppression of the resulting electric current inside the Janus nanopore for reverse working status of the nanofluidic ion diode. A mathematical model based upon continuum mechanics is established to study the feasibility of the Janus nanochannel in causing sufficient ion current rectification, and we find that only a good matching between pore diameter and Debye length is able to result in a reliable rectifying functionality for practical applications. This rectification effect is reminiscent of the typical bipolar membrane, but much more flexible on account of the nature of a voltage-based control due to induced-charge electrokinetic polarization of the conducting end, which may hold promise for osmotic energy conversion wherein an electric current appears due to a difference in salt concentration. Our theoretical demonstration of a composite metal-dielectric ion-selective medium provides useful guidelines for construction of flexible on-chip platforms utilizing induced-charge electrokinetic phenomena for a high degree of freedom ion current control.
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Affiliation(s)
- Weiyu Liu
- School of Electronics and Control Engineering, Chang’an University, Middle-Section of Nan’er Huan Road, Xi’an 710064, China; (W.L.); (Q.W.)
| | - Yongjun Sun
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, China; (Y.R.); (C.S.)
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-Zhi Street 92, Harbin 150001, China
- Correspondence: (Y.S.); (H.Y.)
| | - Hui Yan
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, China; (Y.R.); (C.S.)
- Correspondence: (Y.S.); (H.Y.)
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, China; (Y.R.); (C.S.)
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-Zhi Street 92, Harbin 150001, China
| | - Chunlei Song
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, China; (Y.R.); (C.S.)
| | - Qisheng Wu
- School of Electronics and Control Engineering, Chang’an University, Middle-Section of Nan’er Huan Road, Xi’an 710064, China; (W.L.); (Q.W.)
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6
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Liu W, Ren Y, Xue R, Song C, Wu Q. On ion transport regulation with field‐effect nonlinear electroosmosis control in microfluidics embedding an ion‐selective medium. Electrophoresis 2020; 41:778-792. [DOI: 10.1002/elps.201900408] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Weiyu Liu
- School of Electronics and Control EngineeringChang'an University Xi'an P. R. China
| | - Yukun Ren
- School of Mechatronics EngineeringHarbin Institute of Technology Harbin P. R. China
| | - Rui Xue
- School of Mechatronics EngineeringHarbin Institute of Technology Harbin P. R. China
| | - Chunlei Song
- School of Mechatronics EngineeringHarbin Institute of Technology Harbin P. R. China
| | - Qisheng Wu
- School of Electronics and Control EngineeringChang'an University Xi'an P. R. China
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7
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Mitra S, Maity S, Sutradhar S, Bandyopadhyay D. Electroosmosis with Augmented Mixing in Rigid to Flexible Microchannels with Surface Patterns. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b04257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shirsendu Mitra
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Surjendu Maity
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Shaon Sutradhar
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Dipankar Bandyopadhyay
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
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8
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Multifrequency Induced-Charge Electroosmosis. MICROMACHINES 2019; 10:mi10070447. [PMID: 31277290 PMCID: PMC6680487 DOI: 10.3390/mi10070447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 01/31/2023]
Abstract
We present herein a unique concept of multifrequency induced-charge electroosmosis (MICEO) actuated directly on driving electrode arrays, for highly-efficient simultaneous transport and convective mixing of fluidic samples in microscale ducts. MICEO delicately combines transversal AC electroosmotic vortex flow, and axial traveling-wave electroosmotic pump motion under external dual-Fourier-mode AC electric fields. The synthetic flow field associated with MICEO is mathematically analyzed under thin layer limit, and the particle tracing experiment with a special powering technique validates the effectiveness of this physical phenomenon. Meanwhile, the simulation results with a full-scale 3D computation model demonstrate its robust dual-functionality in inducing fully-automated analyte transport and chaotic stirring in a straight fluidic channel embedding double-sided quarter-phase discrete electrode arrays. Our physical demonstration with multifrequency signal control on nonlinear electroosmosis provides invaluable references for innovative designs of multifunctional on-chip analytical platforms in modern microfluidic systems.
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9
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Scida K, Eden A, Arroyo-Currás N, MacKenzie S, Satik Y, Meinhart CD, Eijkel JCT, Pennathur S. Fluorescence-Based Observation of Transient Electrochemical and Electrokinetic Effects at Nanoconfined Bipolar Electrodes. ACS APPLIED MATERIALS & INTERFACES 2019; 11:13777-13786. [PMID: 30880379 DOI: 10.1021/acsami.9b01339] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Bipolar electrodes (BPEs) are conductors that, when exposed to an electric field, polarize and promote the accumulation of counterionic charge near their poles. The rich physics of electrokinetic behavior near BPEs has not yet been rigorously studied, with our current understanding of such bipolar effects being restricted to steady-state conditions (under constant applied fields). Here, we reveal the dynamic electrokinetic and electrochemical phenomena that occur near nanoconfined BPEs throughout all stages of a reaction. Specifically, we demonstrate, both experimentally and through numerical modeling, that the removal of an electric field produces solution-phase charge imbalances in the vicinity of the BPE poles. These imbalances induce intense and short-lived nonequilibrium electric fields that drive the rapid transport of ions toward specific BPE locations. To determine the origin of these electrokinetic effects, we monitored the movement and fluorescent behavior (enhancement or quenching) of charged fluorophores within well-defined nanofluidic architectures via real-time optical detection. By systematically varying the nature of the fluorophore, the concentration of the electrolyte, the strength of the applied field, and oxide growth on the BPE surface, we dissect the ion transport events that occur in the aftermath of field-induced polarization. The results contained in this work provide new insights into transient bipolar electrokinetics that improve our understanding of current analytical platforms and can drive the development of new micro- and nanoelectrochemical systems.
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Affiliation(s)
- Karen Scida
- Department of Mechanical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Alexander Eden
- Department of Mechanical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences , Johns Hopkins University School of Medicine , Baltimore , Maryland 21205 , United States
| | - Sean MacKenzie
- Department of Mechanical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Yesil Satik
- Department of Mechanical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Carl D Meinhart
- Department of Mechanical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Jan C T Eijkel
- Department of Electrical Engineering, Mathematics and Computer Science , University of Twente , Enschede , Overijssel 7522 , The Netherlands
| | - Sumita Pennathur
- Department of Mechanical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
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Liu W, Ren Y, Chen F, Song J, Tao Y, Du K, Wu Q. A microscopic physical description of electrothermal‐induced flow for control of ion current transport in microfluidics interfacing nanofluidics. Electrophoresis 2019; 40:2683-2698. [DOI: 10.1002/elps.201900105] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Weiyu Liu
- School of Electronics and Control EngineeringSchool of HighwayChang'an University Xi'an Shaanxi P. R. China
| | - Yukun Ren
- State Key Laboratory of Robotics and SystemHarbin Institute of Technology Harbin Heilongjiang P. R. China
- The State Key Laboratory of Nonlinear Mechanics (LNM)Chinese Academy of SciencesInstitute of Mechanics Beijing P. R. China
| | - Feng Chen
- School of Electronics and Control EngineeringSchool of HighwayChang'an University Xi'an Shaanxi P. R. China
| | - Jingni Song
- School of Electronics and Control EngineeringSchool of HighwayChang'an University Xi'an Shaanxi P. R. China
| | - Ye Tao
- State Key Laboratory of Robotics and SystemHarbin Institute of Technology Harbin Heilongjiang P. R. China
| | - Kai Du
- School of Electronics and Control EngineeringSchool of HighwayChang'an University Xi'an Shaanxi P. R. China
| | - Qisheng Wu
- School of Electronics and Control EngineeringSchool of HighwayChang'an University Xi'an Shaanxi P. R. China
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Jiang T, Tao Y, Jiang H, Liu W, Hu Y, Tang D. An Experimental Study of 3D Electrode-Facilitated Particle Traffic Flow-Focusing Driven by Induced-Charge Electroosmosis. MICROMACHINES 2019; 10:E135. [PMID: 30781666 PMCID: PMC6412237 DOI: 10.3390/mi10020135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 02/05/2023]
Abstract
In this paper we present a novel microfluidic approach for continuous, rapid and switchable particle concentration, using induced-charge electroosmosis (ICEO) in 3D electrode layouts. Field-effect control on non-linear electroosmosis in the transverse direction greatly facilitates a selective concentration of biological yeast cells from a straight main microchannel into one of the three downstream branch channels in our microfluidic device. For the geometry configuration of 3D driving electrode plates on sidewalls and a 2D planar gate electrode strip on the channel bottom surface, we briefly describe the underlying physics of an ICEO-based particle flow-focusing method, and provide relevant simulation results to show how gate voltage amplitude can be used to guide the motion trajectory of the concentrated particle stream. With a relatively simple geometrical configuration, the proposed microfluidic device provides new possibilities to controllably concentrate micro/nanoparticles in continuous flow by using ICEO, and is suitable for a high-throughput front-end cell concentrator interfacing with various downstream biosensors.
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Affiliation(s)
- Tianyi Jiang
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China.
| | - Ye Tao
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China.
| | - Hongyuan Jiang
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China.
| | - Weiyu Liu
- School of Electronics and Control Engineering, Chang'an University, Xi'an 710064, China.
| | - Yansu Hu
- School of Electronics and Control Engineering, Chang'an University, Xi'an 710064, China.
| | - Dewei Tang
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China.
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12
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Tao Y, Liu W, Ren Y, Hu Y, Li G, Ma G, Wu Q. On Developing Field-Effect-Tunable Nanofluidic Ion Diodes with Bipolar, Induced-Charge Electrokinetics. MICROMACHINES 2018; 9:E179. [PMID: 30424112 PMCID: PMC6187358 DOI: 10.3390/mi9040179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 04/07/2018] [Accepted: 04/10/2018] [Indexed: 11/17/2022]
Abstract
We introduce herein the induced-charge electrokinetic phenomenon to nanometer fluidic systems; the design of the nanofluidic ion diode for field-effect ionic current control of the nanometer dimension is developed by enhancing internal ion concentration polarization through electrochemical transport of inhomogeneous inducing-counterions resulting from double gate terminals mounted on top of a thin dielectric layer, which covers the nanochannel connected to microfluidic reservoirs on both sides. A mathematical model based on the fully-coupled Poisson-Nernst-Plank-Navier-Stokes equations is developed to study the feasibility of this structural configuration causing effective ionic current rectification. The effect of various physiochemical and geometrical parameters, such as the native surface charge density on the nanochannel sidewalls, the number of gate electrodes (GE), the gate voltage magnitude, and the solution conductivity, permittivity, and thickness of the dielectric coating, as well as the size and position of the GE pair of opposite gate polarity, on the resulted rectification performance of the presented nanoscale ionic device is numerically analyzed by using a commercial software package, COMSOL Multiphysics (version 5.2). Three types of electrohydrodynamic flow, including electroosmosis of 1st kind, induced-charge electroosmosis, and electroosmosis of 2nd kind that were originated by the Coulomb force within three distinct charge layers coexist in the micro/nanofluidic hybrid network and are shown to simultaneously influence the output current flux in a complex manner. The rectification factor of a contrast between the 'on' and 'off' working states can even exceed one thousand-fold in the case of choosing a suitable combination of several key parameters. Our demonstration of field-effect-tunable nanofluidic ion diodes of double external gate electrodes proves invaluable for the construction of a flexible electrokinetic platform for ionic current control and may help transform the field of smart, on-chip, integrated circuits.
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Affiliation(s)
- Ye Tao
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, Heilongjiang, China.
| | - Weiyu Liu
- School of Electronics and Control Engineering, Chang'an University, Middle-Section of Nan'er Huan Road, Xi'an 710064, Shaanxi, China.
| | - Yukun Ren
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, Heilongjiang, China.
| | - Yansu Hu
- School of Electronics and Control Engineering, Chang'an University, Middle-Section of Nan'er Huan Road, Xi'an 710064, Shaanxi, China.
| | - Guang Li
- School of Electronics and Control Engineering, Chang'an University, Middle-Section of Nan'er Huan Road, Xi'an 710064, Shaanxi, China.
| | - Guoyun Ma
- School of Electronics and Control Engineering, Chang'an University, Middle-Section of Nan'er Huan Road, Xi'an 710064, Shaanxi, China.
| | - Qisheng Wu
- School of Electronics and Control Engineering, Chang'an University, Middle-Section of Nan'er Huan Road, Xi'an 710064, Shaanxi, China.
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13
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Zhao C, Yang C. Continuous-flow trapping and localized enrichment of micro- and nano-particles using induced-charge electrokinetics. SOFT MATTER 2018; 14:1056-1066. [PMID: 29335710 DOI: 10.1039/c7sm01744h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In this work, we report an effective microfluidic technique for continuous-flow trapping and localized enrichment of micro- and nano-particles by using induced-charge electrokinetic (ICEK) phenomena. The proposed technique utilizes a simple microfluidic device that consists of a straight microchannel and a conducting strip attached to the bottom wall of the microchannel. Upon application of the electric field along the microchannel, the conducting strip becomes polarized to introduce two types of ICEK phenomena, the ICEK flow vortex and particle dielectrophoresis, and they are identified by a theoretical model formulated in this study to be jointly responsible for the trapping of particles over the edge of the conducting strip. Our experiments showed that successful trapping requires an AC/DC combined electric field: the DC component is mainly to induce electroosmotic flow for transporting particles to the trapping location; the AC component induces ICEK phenomena over the edge of the conducting strip for particle trapping. The performance of the technique is examined with respect to the applied electric voltage, AC frequency and the particle size. We observed that the trapped particles form a narrow band (nearly a straight line) defined by the edge of the conducting strip, thereby allowing localized particle enrichment. For instance, we found that under certain conditions a high particle enrichment ratio of 200 was achieved within 30 seconds. We also demonstrated that the proposed technique was able to trap particles from several microns down to several tens of nanometer. We believe that the proposed ICEK trapping would have great flexibility that the trapping location can be readily varied by controlling the location of the patterned conducting strip and multiple-location trapping can be expected with the use of multiple conducting strips.
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Affiliation(s)
- Cunlu Zhao
- Key Laboratory of Thermo-Fluid Science and Engineering of MOE, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Chun Yang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
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Chen X, Ren Y, Liu W, Feng X, Jia Y, Tao Y, Jiang H. A Simplified Microfluidic Device for Particle Separation with Two Consecutive Steps: Induced Charge Electro-osmotic Prefocusing and Dielectrophoretic Separation. Anal Chem 2017; 89:9583-9592. [PMID: 28783330 DOI: 10.1021/acs.analchem.7b02892] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Continuous dielectrophoretic separation is recognized as a powerful technique for a large number of applications including early stage cancer diagnosis, water quality analysis, and stem-cell-based therapy. Generally, the prefocusing of a particle mixture into a stream is an essential process to ensure all particles are subjected to the same electric field geometry in the separation region. However, accomplishing this focusing process either requires hydrodynamic squeezing, which requires an encumbering peripheral system and a complicated operation to drive and control the fluid motion, or depends on dielectrophoretic forces, which are highly sensitive to the dielectric characterization of particles. An alternative focusing technique, induced charge electro-osmosis (ICEO), has been demonstrated to be effective in focusing an incoming mixture into a particle stream as well as nonselective regarding the particles of interest. Encouraged by these aspects, we propose a hybrid method for microparticle separation based on a delicate combination of ICEO focusing and dielectrophoretic deflection. This method involves two steps: focusing the mixture into a thin particle stream via ICEO vortex flow and separating the particles of differing dielectic properties through dielectrophoresis. To demonstrate the feasibility of the method proposed, we designed and fabricated a microfluidic chip and separated a mixture consisting of yeast cells and silica particles with an efficiency exceeding 96%. This method has good potential for flexible integration into other microfluidic chips in the future.
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Affiliation(s)
- Xiaoming Chen
- School of Mechatronics Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China.,State Key Laboratory of Robotics and System, Harbin Institute of Technology , Harbin 150001, People's Republic of China
| | - Weiyu Liu
- School of Mechatronics Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China
| | - Xiangsong Feng
- School of Mechatronics Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China
| | - Yankai Jia
- School of Mechatronics Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China
| | - Ye Tao
- School of Mechatronics Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China
| | - Hongyuan Jiang
- School of Mechatronics Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China.,State Key Laboratory of Robotics and System, Harbin Institute of Technology , Harbin 150001, People's Republic of China
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Wu Y, Ren Y, Tao Y, Hou L, Hu Q, Jiang H. A novel micromixer based on the alternating current-flow field effect transistor. LAB ON A CHIP 2016; 17:186-197. [PMID: 27934980 DOI: 10.1039/c6lc01346e] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Induced-charge electroosmosis (ICEO) phenomena have been attracting considerable attention as a means for pumping and mixing in microfluidic systems with the advantage of simple structures and low-energy consumption. We propose the first effort to exploit a fixed-potential ICEO flow around a floating electrode for microfluidic mixing. In analogy with the field effect transistor (FET) in microelectronics, the floating electrode act as a "gate" electrode for generating asymmetric ICEO flow and thus the device is called an AC-flow FET (AC-FFET). We take advantage of a tandem electrode configuration containing two biased center metal strips arranged in sequence at the bottom of the channel to generate asymmetric vortexes. The current device is manufactured on low-cost glass substrates via an easy and reliable process. Mixing experiments were conducted in the proposed device and the comparison between simulation and experimental results was also carried out, which indicates that the micromixer permits an efficient mixing effect. The mixing performance can be further enhanced by the application of a suitable phase difference between the driving electrode and the gate electrode or a square wave signal. Finally, we performed a critical analysis of the proposed micromixer in comparison with different mixer designs using a comparative mixing index (CMI). The novel methods put forward here offer a simple solution to mixing issues in microfluidic systems.
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Affiliation(s)
- Yupan Wu
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China. and State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China
| | - Ye Tao
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Likai Hou
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Qingming Hu
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
| | - Hongyuan Jiang
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China. and State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China
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16
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Rubin S, Suss ME, Biesheuvel PM, Bercovici M. Induced-Charge Capacitive Deionization: The Electrokinetic Response of a Porous Particle to an External Electric Field. PHYSICAL REVIEW LETTERS 2016; 117:234502. [PMID: 27982655 DOI: 10.1103/physrevlett.117.234502] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Indexed: 06/06/2023]
Abstract
We demonstrate the phenomenon of induced-charge capacitive deionization that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electric field. The external electric field induces an electric dipole in the porous particle, leading to its capacitive charging by both cations and anions at opposite poles. This regime is characterized by a long charging time, which results in significant changes in salt concentration in the electrically neutral bulk, on the scale of the particle. We qualitatively demonstrate the effect of advection on the spatiotemporal concentration field, which, through diffusiophoresis, may introduce corrections to the electrophoretic mobility of such particles.
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Affiliation(s)
- S Rubin
- Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - M E Suss
- Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - P M Biesheuvel
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - M Bercovici
- Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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17
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Ren Y, Liu J, Liu W, Lang Q, Tao Y, Hu Q, Hou L, Jiang H. Scaled particle focusing in a microfluidic device with asymmetric electrodes utilizing induced-charge electroosmosis. LAB ON A CHIP 2016; 16:2803-12. [PMID: 27354159 DOI: 10.1039/c6lc00485g] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We propose a novel continuous-flow microfluidic particle concentrator with a specified focusing-particle number ratio (FR) at different channel outlets using induced-charge electroosmosis (ICEO). The particle-focusing region contains two floating electrodes of asymmetric widths L2 and L1 in the gap between a driving electrode pair, all of which are fabricated in parallel in the main channel. Applying an AC voltage over the driving electrodes, an ICEO flow with two vortexes can be induced over each of the two floating electrodes, and the actuation range of the ICEO vortex is proportional to the respective electrode size. We establish a preliminary physical model for the value of FR: at a moderate voltage and frequency range, FR approaches L2/L1 due to the scaled ICEO actuation range; by further modifying the voltage or frequency, FR is freely adjustable because of the variation in ICEO velocity. Furthermore, by connecting multiple focusing regions in series, i.e., high FR = (L2/L1)(n) can be conveniently generated in an n-stage flow focusing device. Our results provide a promising method for yielding transverse concentration gradients of particles useful in pre-processing before analysis.
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Affiliation(s)
- Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, West Da-zhi Street 92, Harbin, Heilongjiang, 150001 PR China.
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18
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Persat A, Santiago JG. An Ohmic model for electrokinetic flows of binary asymmetric electrolytes. Curr Opin Colloid Interface Sci 2016. [DOI: 10.1016/j.cocis.2016.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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Sarkar S, Lai SCS, Lemay SG. Unconventional Electrochemistry in Micro-/Nanofluidic Systems. MICROMACHINES 2016; 7:E81. [PMID: 30404256 PMCID: PMC6189913 DOI: 10.3390/mi7050081] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 12/18/2022]
Abstract
Electrochemistry is ideally suited to serve as a detection mechanism in miniaturized analysis systems. A significant hurdle can, however, be the implementation of reliable micrometer-scale reference electrodes. In this tutorial review, we introduce the principal challenges and discuss the approaches that have been employed to build suitable references. We then discuss several alternative strategies aimed at eliminating the reference electrode altogether, in particular two-electrode electrochemical cells, bipolar electrodes and chronopotentiometry.
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Affiliation(s)
- Sahana Sarkar
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Stanley C S Lai
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Serge G Lemay
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
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20
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Liu W, Shao J, Ren Y, Liu J, Tao Y, Jiang H, Ding Y. On utilizing alternating current-flow field effect transistor for flexibly manipulating particles in microfluidics and nanofluidics. BIOMICROFLUIDICS 2016; 10:034105. [PMID: 27190570 PMCID: PMC4866955 DOI: 10.1063/1.4949771] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 05/03/2016] [Indexed: 05/28/2023]
Abstract
By imposing a biased gate voltage to a center metal strip, arbitrary symmetry breaking in induced-charge electroosmotic flow occurs on the surface of this planar gate electrode, a phenomenon termed as AC-flow field effect transistor (AC-FFET). In this work, the potential of AC-FFET with a shiftable flow stagnation line to flexibly manipulate micro-nano particle samples in both a static and continuous flow condition is demonstrated via theoretical analysis and experimental validation. The effect of finite Debye length of induced double-layer and applied field frequency on the manipulating flexibility factor for static condition is investigated, which indicates AC-FFET turns out to be more effective for achieving a position-controllable concentrating of target nanoparticle samples in nanofluidics compared to the previous trial in microfluidics. Besides, a continuous microfluidics-based particle concentrator/director is developed to deal with incoming analytes in dynamic condition, which exploits a design of tandem electrode configuration to consecutively flow focus and divert incoming particle samples to a desired downstream branch channel, as prerequisite for a following biochemical analysis. Our physical demonstrations with AC-FFET prove valuable for innovative designs of flexible electrokinetic frameworks, which can be conveniently integrated with other microfluidic or nanofluidic components into a complete lab-on-chip diagnostic platform due to a simple electrode structure.
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Affiliation(s)
- Weiyu Liu
- Micro and Nano-Technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, People's Republic of China
| | - Jinyou Shao
- Micro and Nano-Technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, People's Republic of China
| | | | - Jiangwei Liu
- School of Mechatronics Engineering, Harbin Institute of Technology , West Da-zhi Street 92, Harbin, Heilongjiang 150001, People's Republic of China
| | - Ye Tao
- School of Mechatronics Engineering, Harbin Institute of Technology , West Da-zhi Street 92, Harbin, Heilongjiang 150001, People's Republic of China
| | | | - Yucheng Ding
- Micro and Nano-Technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, People's Republic of China
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21
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Liu W, Shao J, Jia Y, Tao Y, Ding Y, Jiang H, Ren Y. Trapping and chaining self-assembly of colloidal polystyrene particles over a floating electrode by using combined induced-charge electroosmosis and attractive dipole-dipole interactions. SOFT MATTER 2015; 11:8105-12. [PMID: 26332897 DOI: 10.1039/c5sm01063b] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We propose a novel low-frequency strategy to trap 10 μm colloidal polystyrene (PS) particles of small buoyancy velocity on the surface of a floating electrode, on the basis of combined induced-charge electroosmotic (ICEO) flow and dipole-dipole chaining phenomenon. For field frequencies of 5-50 Hz, much lower than the reciprocal RC time scale, double-layer polarization makes electric field lines pass around the 'insulating' surface of the ideally polarizable floating electrode. Once the long-range ICEO convective micro-vortexes transport particles quickly from the bulk fluid to the electrode surface, neighbouring particles aligned along the local horizontal electric field attract one another by attractive dipolar interactions, and form arrays of particle chains that are almost parallel with the applied electric field. Most importantly, this low-frequency trapping method takes advantage of the dielectrophoretic (DEP) particle-particle interaction to enhance the downward buoyancy force of this dipolar chaining assembly structure, in order to overcome the upward ICEO fluidic drag and realize stable particle trapping around the flow stagnation region. For the sake of comparison, the field frequency is further raised far above the DC limit. At the intermediate frequencies of 200 Hz-2 kHz, this trapping method fails to work, since the normal electric field component emanates from the conducting electrode surface. Besides, at high field frequencies (>3 kHz), particles can be once again effectively trapped at the electrode center, though with a compact (3 kHz) or disordered (10 kHz) 2D packing state on the electrode surface and mainly governed by the short-range negative DEP force field, resulting in requiring a much longer trapping time. To gain a better interpretation of the various particle behaviours observed in experiments, we develop a theoretical framework that takes into account both Maxwell-Wagner interfacial charge relaxation at the particle/electrolyte interface and the field-induced double-layer polarization at the electrode/electrolyte interface, and apply it to quantify the particle-particle electrokinetic interactions. With this simple geometrical configuration of a floating electrode, our results provide a new way to realize trapping of colloidal particles with a small buoyancy velocity under the combined action of ICEO flow and an attractive dipole-dipole interaction.
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Affiliation(s)
- Weiyu Liu
- Micro and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
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22
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Davidson SM, Andersen MB, Mani A. Chaotic induced-charge electro-osmosis. PHYSICAL REVIEW LETTERS 2014; 112:128302. [PMID: 24724683 DOI: 10.1103/physrevlett.112.128302] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Indexed: 05/11/2023]
Abstract
We present direct numerical simulations of the coupled Poisson-Nernst-Planck and Navier-Stokes equations for an electrolyte around a polarizable cylinder subject to an external electric field. For high fields, a novel chaotic flow phenomenon is discovered. Our calculations indicate significant improvement in the prediction of the mean flow relative to standard asymptotic models. These results open possibilities for chaos-enhanced mixing in microdevices and provide insight into barriers to efficient electrokinetic micropumps with broad applications in electrochemical and lab-on-a-chip systems.
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Affiliation(s)
- Scott M Davidson
- Center for Turbulence Research, Stanford University, Stanford, California 94305, USA and Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA
| | - Mathias B Andersen
- Center for Turbulence Research, Stanford University, Stanford, California 94305, USA and Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA
| | - Ali Mani
- Center for Turbulence Research, Stanford University, Stanford, California 94305, USA and Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA
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23
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Xu Z, Oleschuk RD. A fluorous porous polymer monolith photo-patterned chromatographic column for the separation of a flourous/fluorescently labeled peptide within a microchip. Electrophoresis 2013; 35:441-9. [DOI: 10.1002/elps.201300365] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/15/2013] [Accepted: 10/15/2013] [Indexed: 11/12/2022]
Affiliation(s)
- Zhenpo Xu
- Department of Chemistry; Queen's University; Kingston Ontario Canada
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24
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Ko SH, Song YA, Kim SJ, Kim M, Han J, Kang KH. Nanofluidic preconcentration device in a straight microchannel using ion concentration polarization. LAB ON A CHIP 2012; 12:4472-82. [PMID: 22907316 DOI: 10.1039/c2lc21238b] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this paper, we introduce a simple, straight microchannel design for a nanofluidic protein concentration device. Compared with concentration devices previously developed, the anode channel and cathode channel in this new concentration scheme are both integrated into a straight microchannel, with one inlet and one outlet. Most of the functions of a conventional two-channel concentration device can be achieved by this concentration device, and the efficiency of sample accumulation can be controlled by the dimension of the Nafion membrane. Also, the operating mechanism of this device was tested on various material combinations such as PDMS (polydimethyl-siloxane) channel-glass substrate and silicon channel-PDMS substrate. Using a combined PDMS-silicon device which was sealed reversibly without plasma bonding, surface based immunoassay for concentrator-enhanced detection of clinically relevant samples such as C-reactive protein (CRP) was demonstrated. As a result, it was possible to enhance the detection sensitivity of the immunoassay by more than 500 folds compared to the immunoassay without preconcentration process.
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Affiliation(s)
- Sung Hee Ko
- Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyojadong, Pohang, Gyeongbuk 790-784, Korea
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25
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Mani A, Bazant MZ. Deionization shocks in microstructures. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:061504. [PMID: 22304094 DOI: 10.1103/physreve.84.061504] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Indexed: 05/31/2023]
Abstract
Salt transport in bulk electrolytes is limited by diffusion and advection, but in microstructures with charged surfaces (e.g., microfluidic devices, porous media, soils, or biological tissues) surface conduction and electro-osmotic flow also contribute to ionic fluxes. For small applied voltages, these effects lead to well known linear electrokinetic phenomena. In this paper, we predict some surprising nonlinear dynamics that can result from the competition between bulk and interfacial transport at higher voltages. When counterions are selectively removed by a membrane or electrode, a "deionization shock" can propagate through the microstructure, leaving in its wake an ultrapure solution, nearly devoid of coions and colloidal impurities. We elucidate the basic physics of deionization shocks and develop a mathematical theory of their existence, structure, and stability, allowing for slow variations in surface charge or channel geometry. Via asymptotic approximations and similarity solutions, we show that deionization shocks accelerate and sharpen in narrowing channels, while they decelerate and weaken, and sometimes disappear, in widening channels. These phenomena may find applications in separations (deionization, decontamination, biological assays) and energy storage (batteries, supercapacitors) involving electrolytes in microstructures.
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Affiliation(s)
- Ali Mani
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA.
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26
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Vennela N, Bhattacharjee S, De S. Sherwood number in porous microtube due to combined pressure and electroosmotically driven flow. Chem Eng Sci 2011. [DOI: 10.1016/j.ces.2011.09.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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27
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Kwak R, Kim SJ, Han J. Continuous-Flow Biomolecule and Cell Concentrator by Ion Concentration Polarization. Anal Chem 2011; 83:7348-55. [DOI: 10.1021/ac2012619] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rhokyun Kwak
- Department of Mechanical Engineering, ‡Department of Electrical Engineering and Computer Science, and §Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Sung Jae Kim
- Department of Mechanical Engineering, ‡Department of Electrical Engineering and Computer Science, and §Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jongyoon Han
- Department of Mechanical Engineering, ‡Department of Electrical Engineering and Computer Science, and §Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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28
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Dydek EV, Zaltzman B, Rubinstein I, Deng DS, Mani A, Bazant MZ. Overlimiting current in a microchannel. PHYSICAL REVIEW LETTERS 2011; 107:118301. [PMID: 22026706 DOI: 10.1103/physrevlett.107.118301] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Indexed: 05/11/2023]
Abstract
We revisit the classical problem of diffusion-limited ion transport to a membrane (or electrode) by considering the effects of charged sidewalls. Using simple mathematical models and numerical simulations, we identify three basic mechanisms for overlimiting current in a microchannel: (i) surface conduction carried by excess counterions, which dominates for very thin channels, (ii) convection by electro-osmotic flow on the sidewalls, which dominates for thicker channels, and (iii) transitions to electro-osmotic instability on the membrane end in very thick channels. These intriguing electrokinetic phenomena may find applications in biological separations, water desalination, and electrochemical energy storage.
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Affiliation(s)
- E Victoria Dydek
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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29
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Zhao C, Yang C. ac Electrokinetic phenomena over semiconductive surfaces: effective electric boundary conditions and their applications. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:066304. [PMID: 21797474 DOI: 10.1103/physreve.83.066304] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 10/30/2010] [Indexed: 05/31/2023]
Abstract
Electrokinetic boundary conditions are derived for ac electrokinetic phenomena over leaky dielectric (i.e., semiconducting) surfaces. Such boundary conditions correlate the electric potentials across a semiconductor-electrolyte interface (consisting of an electric double layer inside the electrolyte solution and a space charge layer inside the semiconductor) in an ac electric field with arbitrary wave forms. The presented electrokinetic boundary conditions allow for evaluation of the induced ζ potential contributed by both bond charges (due to electric polarization) and free charges (due to electric conduction) from the leaky dielectric materials. Two well-known limiting cases, (i) the conventional insulating boundary condition and (ii) the perfectly polarizable boundary condition, can be recovered from the generalized electrokinetic boundary conditions derived in the present paper. Subsequently, we demonstrate the implementation of the derived boundary conditions for analyzing the ac induced-charge electrokinetic flow around a semiconducting cylinder. The results show that the flow circulations exist around the semiconducting cylinder and become stronger in the ac field with a lower frequency and around the semiconducting cylinder with a higher conductivity.
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Affiliation(s)
- Cunlu Zhao
- School of Mechanical and Aerospace Engineering, Nanyang Technological University 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
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30
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Zhao C, Yang C. AC field induced-charge electroosmosis over leaky dielectric blocks embedded in a microchannel. Electrophoresis 2011; 32:629-37. [DOI: 10.1002/elps.201000493] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 11/21/2010] [Accepted: 12/09/2010] [Indexed: 11/09/2022]
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31
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Napoli M, Eijkel JCT, Pennathur S. Nanofluidic technology for biomolecule applications: a critical review. LAB ON A CHIP 2010; 10:957-85. [PMID: 20358103 DOI: 10.1039/b917759k] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In this review, we present nanofluidic phenomena, particularly as they relate to applications involving analysis of biomolecules within nanofabricated devices. The relevant length scales and physical phenomena that govern biomolecule transport and manipulation within nanofabricated nanofluidic devices are reviewed, the advantages of nanofabricated devices are presented, and relevant applications are cited. Characteristic length scales include the Debye length, the Van der Waals radius, the action distance of hydrogen bonding, the slip length, and macromolecular dimensions. On the basis of the characteristic lengths and related nanofluidic phenomena, a nanofluidic toolbox will be assembled. Nanofluidic phenomena that affect biomolecule behavior within such devices can include ion depletion and enrichment, modified velocity and mobility, permselectivity, steric hindrance, entropy, adsorption, and hydrodynamic interaction. The complex interactions and coupled physics of such phenomena allow for many applications, including biomolecule separation, concentration, reaction/hybridization, sequencing (in the case of DNA) and detection. Examples of devices for such applications will be presented, followed by a discussion of near-term challenges and future thoughts for the field.
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Affiliation(s)
- M Napoli
- Engineering II Building, Room 2330, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
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Towards an understanding of induced-charge electrokinetics at large applied voltages in concentrated solutions. Adv Colloid Interface Sci 2009; 152:48-88. [PMID: 19879552 DOI: 10.1016/j.cis.2009.10.001] [Citation(s) in RCA: 427] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 09/29/2009] [Accepted: 10/01/2009] [Indexed: 11/22/2022]
Abstract
The venerable theory of electrokinetic phenomena rests on the hypothesis of a dilute solution of point-like ions in quasi-equilibrium with a weakly charged surface, whose potential relative to the bulk is of order the thermal voltage (kT/e approximately 25 mV at room temperature). In nonlinear electrokinetic phenomena, such as AC or induced-charge electro-osmosis (ACEO, ICEO) and induced-charge electrophoresis (ICEP), several V approximately 100 kT/e are applied to polarizable surfaces in microscopic geometries, and the resulting electric fields and induced surface charges are large enough to violate the assumptions of the classical theory. In this article, we review the experimental and theoretical literatures, highlight discrepancies between theory and experiment, introduce possible modifications of the theory, and analyze their consequences. We argue that, in response to a large applied voltage, the "compact layer" and "shear plane" effectively advance into the liquid, due to the crowding of counterions. Using simple continuum models, we predict two general trends at large voltages: (i) ionic crowding against a blocking surface expands the diffuse double layer and thus decreases its differential capacitance, and (ii) a charge-induced viscosity increase near the surface reduces the electro-osmotic mobility; each trend is enhanced by dielectric saturation. The first effect is able to predict high-frequency flow reversal in ACEO pumps, while the second may explain the decay of ICEO flow with increasing salt concentration. Through several colloidal examples, such as ICEP of an uncharged metal sphere in an asymmetric electrolyte, we show that nonlinear electrokinetic phenomena are generally ion-specific. Similar theoretical issues arise in nanofluidics (due to confinement) and ionic liquids (due to the lack of solvent), so the paper concludes with a general framework of modified electrokinetic equations for finite-sized ions.
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Zhao C, Yang C. Analysis of induced-charge electro-osmotic flow in a microchannel embedded with polarizable dielectric blocks. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 80:046312. [PMID: 19905441 DOI: 10.1103/physreve.80.046312] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Indexed: 05/28/2023]
Abstract
Within the frame work of classic electromagnetic theory, a general electrical boundary condition describing the induced-charge electrokinetic phenomena at the liquid-dielectric interface is proposed in the present study. Two well-known limiting cases, i.e., perfectly insulating and perfectly polarizable wall boundary conditions, can be recovered from the present electrical boundary condition. By utilizing the proposed boundary condition, the induced-charge electro-osmosis (ICEO) flow in an infinitely long microchannel patterned with two symmetric polarizable dielectric blocks is investigated analytically. Fourier transform method is invoked to solve a biharmonic equation, which governs the (ICEO) flow field described by the stream function. Dimensionless parameters are introduced, and their effects on flow characteristics are analyzed. It is found that an increase in polarizability of the dielectric block enhances the slip velocity on its surface and thus induces a pair of counter-rotating vortices. Also, increasing the natural zeta potential on the upstream and downstream of the insulating microchannel walls leads to extinction of the vortex near the upstream insulating microchannel and suppression of the vortex near the downstream insulating microchannel.
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Affiliation(s)
- Cunlu Zhao
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Republic of Singapore
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García-Sánchez P, Ramos A, González A, Green NG, Morgan H. Flow reversal in traveling-wave electrokinetics: an analysis of forces due to ionic concentration gradients. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4988-97. [PMID: 19320476 DOI: 10.1021/la803651e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Pumping of electrolytes using ac electric fields from arrays of microelectrodes is a subject of current research. The behavior of fluids at low signal amplitudes (<2-3 V(pp)) is in qualitative agreement with the prediction of the ac electroosmosis theory. At higher voltages, this theory cannot account for the experimental observations. In some cases, net pumping is generated in the direction opposite to that predicted by the theory (flow reversal). In this work, we use fluorescent dyes to study the effect of ionic concentration gradients generated by Faradaic currents. We also evaluate the influence of factors such as the channel height and microelectrode array shape in the pumping of electrolytes with traveling-wave potentials. Induced charge beyond the Debye length is postulated to be responsible for the forces generating the observed flows at higher voltages. Numerical calculations are performed in order to illustrate the mechanisms that might be responsible for generating the flow.
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Affiliation(s)
- P García-Sánchez
- Departamento de Electronica y Electromagnetismo, Facultad de Fisica, Universidad de Sevilla, 41012, Seville, Spain.
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Abstract
Biochemical sample mixtures are commonly separated in batch processes, such as filtration, centrifugation, chromatography or electrophoresis. In recent years, however, many research groups have demonstrated continuous flow separation methods in microfluidic devices. Such separation methods are characterised by continuous injection, real-time monitoring, as well as continuous collection, which makes them ideal for combination with upstream and downstream applications. Importantly, in continuous flow separation the sample components are deflected from the main direction of flow, either by means of a force field (electric, magnetic, acoustic, optical etc.), or by intelligent positioning of obstacles in combination with laminar flow profiles. Sample components susceptible to deflection can be spatially separated. A large variety of methods has been reported, some of these are miniaturised versions of larger scale methods, others are only possible in microfluidic regimes. Researchers now have a diverse toolbox to choose from and it is likely that continuous flow methods will play an important role in future point-of-care or in-the-field analysis devices.
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Affiliation(s)
- Nicole Pamme
- The University of Hull, Department of Chemistry, Cottingham Road, Hull, UK HU6 7RX.
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Wang M, Chen S. Electroosmosis in homogeneously charged micro- and nanoscale random porous media. J Colloid Interface Sci 2007; 314:264-73. [PMID: 17585928 DOI: 10.1016/j.jcis.2007.05.043] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 05/01/2007] [Accepted: 05/16/2007] [Indexed: 10/23/2022]
Abstract
Electroosmosis in homogeneously charged micro- and nanoscale random porous media has been numerically investigated using mesoscopic simulation methods which involve a random generation-growth method for reproducing three-dimensional random microstructures of porous media and a high-efficiency lattice Poisson-Boltzmann algorithm for solving the strongly nonlinear governing equations of electroosmosis in three-dimensional porous media. The numerical modeling and predictions of EOF in micro- and nanoscale random porous media indicate that the electroosmotic permeability increases monotonically with the porosity of porous media and the increasing rate rises with the porosity as well; the electroosmotic permeability increases with the average solid particle size for a given porosity and with the bulk ionic concentration also; the proportionally linear relationship between the electroosmotic permeability and the zeta potential on solid surfaces breaks down for high zeta potentials. The present predictions agree well with the available experimental data while some results deviate from the predictions based on the macroscopic theories.
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Affiliation(s)
- Moran Wang
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA.
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Wang M, Wang J, Chen S, Pan N. Electrokinetic pumping effects of charged porous media in microchannels using the lattice Poisson-Boltzmann method. J Colloid Interface Sci 2006; 304:246-53. [PMID: 16989843 DOI: 10.1016/j.jcis.2006.08.050] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 08/24/2006] [Accepted: 08/24/2006] [Indexed: 11/16/2022]
Abstract
The electrokinetic pumping characteristics of nanoscale charged porous media packed in microchannels are investigated using a mesoscopic evolution method. When the pore size of porous media is comparable to the thickness of electric double layer, the effects of particle surface potentials on the bulk electric potential distribution will not be negligible. The lattice Poisson-Boltzmann method provides an accurate numerical solution for such problems, which combines two sets of lattice evolution methods solving the nonlinear Poisson-Boltzmann equation for electric potential distribution and the Navier-Stokes equations for fluid flow, respectively. The effects of the finite particle size, the bulk ionic concentration, the external electric field strength and the surface potentials on the electroosmotic micropump performances are therefore studied. The results show that for a certain porosity the maximum pumping pressure is inversely proportional to the particle diameter and the flow rate under zero pressure drop increases with the particle size. The pumping flow rate decreases with the backpressure yet increases with the external electric field strength, linearly respectively. The averaged flow rate increases with the bulk ionic concentration and the particle surface potential, but is slightly influenced by the surface potentials of channel walls. The numerical results agree with the published experimental data while some results deviate from the predictions based on the macroscopic linear assumptions.
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Affiliation(s)
- Moran Wang
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA.
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Dittrich PS, Tachikawa K, Manz A. Micro Total Analysis Systems. Latest Advancements and Trends. Anal Chem 2006; 78:3887-908. [PMID: 16771530 DOI: 10.1021/ac0605602] [Citation(s) in RCA: 781] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Petra S Dittrich
- Institute for Analytical Sciences, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany
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