Related Experiment Video
Updated: Jun 20, 2026

AC Electrokinetic Phenomena Generated by Microelectrode Structures
Published on: July 28, 2008
Experimental verification of Faradaic charging in ac electrokinetics
Faradaic reactions in AC electrokinetics were confirmed to produce ions, influencing fluid flow. This study provides a method to detect these ions and control flow direction using DC-biased AC electrokinetics.
Area of Science:
- Electrokinetics
- Microfluidics
- Analytical Chemistry
Background:
- Faradaic reactions were hypothesized to cause pumping direction reversal in AC electrokinetics.
- Direct experimental evidence for Faradaic reactions in AC electrokinetics has been lacking.
Purpose of the Study:
- To directly detect ion production from Faradaic hydrolytic reactions in AC electrokinetics.
- To investigate the relationship between applied voltage and ion production.
- To demonstrate flow control using DC-biased AC electrokinetics.
Main Methods:
- Utilized an ion detection strategy with a pH-dependent dye (fluorescein) as an indicator.
- Performed experiments with symmetrical planar electrodes in a microfluidic channel.
- Analyzed fluorescence intensity and distribution under varying AC voltage levels.
Main Results:
- Confirmed ion production from hydrolytic reactions increases with AC voltage.
- Observed a significant enhancement in ion production above 11 V(pp).
- Demonstrated controllable fluid flow direction and magnitude using DC-biased AC electrokinetics.
Conclusions:
- Faradaic reactions are a key factor in AC electrokinetics, leading to ion production.
- The developed ion detection strategy effectively quantifies Faradaic activity.
- DC-biased AC electrokinetics offers a viable method for precise fluid flow control in microfluidic devices.
More Related Videos
09:55Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array
Published on: June 23, 2017
08:41Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation
Published on: October 10, 2018
Related Concept Videos
Voltammetry: Factors Affecting Measurements
Electrochemical Systems
Charging Conductors By Induction
Generally, conductors like metals do not allow any excess charge to be present on them. Any excess charge added to metals easily flows away, for example, when a metal is placed on the Earth. This process is called earthing.
However, conductors can be charged by a process called induction. For example, consider charging a...
The Electrical Double Layer
Processes at Electrodes
Coulometry: Overview