Related Experiment Video
Updated: Feb 2, 2026
11:13
Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles
Published on: March 13, 2016
11.2K
On Developing Field-Effect-Tunable Nanofluidic Ion Diodes with Bipolar, Induced-Charge Electrokinetics
Ye Tao1, Weiyu Liu2, Yukun Ren3
1State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-zhi Street 92, Harbin 150001, Heilongjiang, China. tarahit@gmail.com.
Micromachines
|November 15, 2018
Summary
We developed a nanofluidic ion diode using induced-charge electrokinetics for precise ionic current control. This device, tunable via external gates, achieves over a thousand-fold rectification, paving the way for advanced on-chip circuits.
Area of Science:
- Nanotechnology
- Electrokinetics
- Fluid Dynamics
Background:
- Induced-charge electrokinetic phenomenon is crucial for micro/nanofluidic systems.
- Controlling ionic current at the nanoscale is essential for integrated circuits.
- Existing methods lack precise, tunable control over ionic flow.
Purpose of the Study:
- To design and analyze a nanofluidic ion diode for field-effect ionic current control.
- To enhance internal ion concentration polarization using electrochemical transport.
- To investigate the feasibility of a double gate electrode configuration for ionic current rectification.
Main Methods:
- Developed a mathematical model based on coupled Poisson-Nernst-Plank-Navier-Stokes equations.
- Numerically analyzed the device performance using COMSOL Multiphysics.
- Investigated the effects of various physiochemical and geometrical parameters on rectification.
Main Results:
- Achieved effective ionic current rectification exceeding one thousand-fold.
- Demonstrated field-effect tunability of ionic current using double gate electrodes.
- Identified complex interplay of three electrohydrodynamic flow types influencing current flux.
Conclusions:
- The designed nanofluidic ion diode offers significant ionic current control.
- The device is valuable for constructing flexible electrokinetic platforms.
- This technology may transform smart, on-chip integrated circuits.
Related Concept Videos
03:27Ions and Ionic Charges
79.1K
In ordinary chemical reactions, the nucleus — which contains the protons and neutrons of each atom and thus identifies the element — remains unchanged. Electrons, however, can be added to atoms by transfer from other atoms, lost by transfer to other atoms, or shared with other atoms. The transfer and sharing of electrons among atoms govern the chemistry of the elements. During the formation of some compounds, atoms gain or lose electrons to form electrically charged particles called...
79.1K
02:54Trends in Lattice Energy: Ion Size and Charge
26.7K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
26.7K
01:19Electric Field of a Continuous Line Charge
2.5K
In physics, symmetry in a system means that something in the considered system remains unchanged due to a specific operation to which it is subjected. For example, consider a horizontal square. The square looks the same if its right and left sides are interchanged. Hence, it is symmetric under a right-left interchange.
In calculations of electric fields, symmetry is of great use. For example, while calculating electric fields of continuous charge distributions.
Consider a line element with a...
In calculations of electric fields, symmetry is of great use. For example, while calculating electric fields of continuous charge distributions.
Consider a line element with a...
2.5K
01:30Electric Field of Two Equal and Opposite Charges
7.1K
Atoms generally contain the same number of positively and negatively charged particles, protons, and electrons. Hence, they are electrically neutral. However, the centers of the positive and negative charges do not always coincide. In such a scenario, the electric field of an atom may not be zero.
A separation of the positive and negative charges can lead to a weak, remnant effect of the positive and negative charges. The expectation is that the more the distance between the positive and...
A separation of the positive and negative charges can lead to a weak, remnant effect of the positive and negative charges. The expectation is that the more the distance between the positive and...
7.1K
01:23Electric Field of a Charged Disk
3.2K
The simplest case of a surface charge distribution is the uniformly charged disk. Calculating its electric field also helps us calculate the electric field of a large plane of charge.
The system's symmetry is in the cylindrical directions across the plane of the charge. As a result, the electric fields created by various surface charge elements nullify each other in the direction parallel to the surface. Thereby, the resulting electric field is perpendicular to the plane. Since the disk is...
The system's symmetry is in the cylindrical directions across the plane of the charge. As a result, the electric fields created by various surface charge elements nullify each other in the direction parallel to the surface. Thereby, the resulting electric field is perpendicular to the plane. Since the disk is...
3.2K
01:23Magnetic Field due to Moving Charges
11.6K
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
11.6K