Experimental verification of Faradaic charging in ac electrokinetics

Biomicrofluidics
|August 21, 2009
PubMed
Summary

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.

Related Concept Videos

Voltammetry: Factors Affecting Measurements01:21

Voltammetry: Factors Affecting Measurements

A current produced due to the redox reactions of the analyte at the working and auxiliary electrodes is called a faradaic current. The reaction can be divided into two types. The current generated due to the reduction of the analyte is called cathodic current, and it carries a positive charge. In contrast, the current produced by analyte oxidation is known as an anodic current, and it has a negative charge. The applied potential at the working electrode determines the faradaic current flow, and...
Electrochemical Systems01:24

Electrochemical Systems

Electrochemical systems provide a fascinating insight into the dynamic interplay of charged species within various phases. One notable example is the interaction between a membrane permeable to K⁺ ions but not to Cl⁻ ions, separating an aqueous KCl solution from pure water. As K⁺ ions diffuse through the membrane, they generate net charges on each phase, leading to a potential difference between them.Similarly, when a piece of Zn is immersed in an aqueous ZnSO₄ solution, the Zn metal, composed...
Charging Conductors By Induction01:15

Charging Conductors By Induction

The Earth is a good conductor of electricity, and it is so big that it can be considered an infinite source or sink of charges. It can easily exchange charges with any matter.
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 Layer01:30

The Electrical Double Layer

In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
Processes at Electrodes01:30

Processes at Electrodes

The electrode interacts with ions in the electrolyte solution at its interface. The rate of oxidation and reduction depends on the speed at which electrons can transfer through this interface. As ions attach to or leave the electrode surface, the electrode acquires a charge, and an electrical potential forms across the interface, making the process more difficult to reach equilibrium. The charge on the electrode affects the local ion concentrations in the solution, though thermal motion...
Coulometry: Overview01:00

Coulometry: Overview

Coulometry is one of the rapid, most accurate, and precise analytical techniques that determine the quantity of an analyte by measuring the electrical charge needed for its complete electrolysis without using any analytical standards. The total charge passed during electrolysis correlates with the analyte amount by Faraday's laws of electrolysis. For accurate coulometric measurements, a charge equal to Faraday's constant multiplied by the number of electrons involved in the relevant...