A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena
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 extern...
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| Format: | Article |
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MDPI AG
2020-05-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/11/6/542 |
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| author | Weiyu Liu Yongjun Sun Hui Yan Yukun Ren Chunlei Song Qisheng Wu |
| author_facet | Weiyu Liu Yongjun Sun Hui Yan Yukun Ren Chunlei Song Qisheng Wu |
| author_sort | Weiyu Liu |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-10T19:34:17Z |
| format | Article |
| id | doaj.art-fff95f05f83b4816952ef0abe073e563 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-10T19:34:17Z |
| publishDate | 2020-05-01 |
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| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-fff95f05f83b4816952ef0abe073e5632023-11-20T01:54:13ZengMDPI AGMicromachines2072-666X2020-05-0111654210.3390/mi11060542A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic PhenomenaWeiyu Liu0Yongjun Sun1Hui Yan2Yukun Ren3Chunlei Song4Qisheng Wu5School of Electronics and Control Engineering, Chang’an University, Middle-Section of Nan’er Huan Road, Xi’an 710064, ChinaSchool of Mechatronics Engineering, 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 Mechatronics Engineering, 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, ChinaWe 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.https://www.mdpi.com/2072-666X/11/6/542induced-charge electrokinetic phenomenaion diodeconcentration polarizationmetal-dielectric Janus ion-exchange mediumnanofluidics |
| spellingShingle | Weiyu Liu Yongjun Sun Hui Yan Yukun Ren Chunlei Song Qisheng Wu A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena Micromachines induced-charge electrokinetic phenomena ion diode concentration polarization metal-dielectric Janus ion-exchange medium nanofluidics |
| title | A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena |
| title_full | A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena |
| title_fullStr | A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena |
| title_full_unstemmed | A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena |
| title_short | A Simulation Analysis of Nanofluidic Ion Current Rectification Using a Metal-Dielectric Janus Nanopore Driven by Induced-Charge Electrokinetic Phenomena |
| title_sort | simulation analysis of nanofluidic ion current rectification using a metal dielectric janus nanopore driven by induced charge electrokinetic phenomena |
| topic | induced-charge electrokinetic phenomena ion diode concentration polarization metal-dielectric Janus ion-exchange medium nanofluidics |
| url | https://www.mdpi.com/2072-666X/11/6/542 |
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