Related Experiment Video
Updated: Apr 16, 2026
08:32
Electrochemical Roughening of Thin-Film Platinum Macro and Microelectrodes
Published on: June 30, 2019
8.4K
Contact charge electrophoresis: experiment and theory
Aaron M Drews1, Charles A Cartier1, Kyle J M Bishop1
1Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|March 19, 2015
Summary
Contact charge electrophoresis (CCEP) precisely moves conductive particles in microfluidics. Experiments and theory show charge transfer occurs via electric discharge, not mechanical contact, at separations over 0.1 μm.
Area of Science:
- Physics
- Microfluidics
- Physical Chemistry
Background:
- Contact charge electrophoresis (CCEP) utilizes electric fields for particle and droplet motion in microfluidic systems.
- DC voltage can rectify rapid oscillations for directed microfluidic object movement.
Purpose of the Study:
- To compare high-precision experimental measurements of CCEP with theoretical predictions.
- To investigate the charge transfer mechanism during particle-electrode interactions in microfluidics.
Main Methods:
- Utilized a capillary microfluidic platform with synchronized high-speed imaging and electrical measurements.
- Employed a Stokesian dynamics theoretical model to analyze electrostatic and hydrodynamic forces.
- Compared experimental particle location and electric current data with theoretical predictions.
Main Results:
- Demonstrated remarkable agreement between experimental CCEP measurements and theoretical predictions.
- Confirmed that particle motion is accurately described by electrostatics and low-Reynolds number hydrodynamics.
- Revealed that charge transfer occurs at separations >0.1 μm via electric discharge through a lubricating film, not mechanical contact.
Conclusions:
- Particle motion in CCEP is accurately predictable using classical physics principles.
- Charge transfer in CCEP involves non-contact electric discharge, impacting particle charging and dynamics.
- Findings offer insights into optimizing CCEP for microfluidic applications.
Related Concept Videos
01:20Electrophoresis: Overview
5.2K
Electrophoresis is a powerful analytical separation technique that relies on the differential migration of charged species when subjected to an electric field. The core strength of electrophoresis lies in its ability to separate high-molecular-weight species in complex mixtures. It has found widespread use in biochemistry, molecular biology, and analytical chemistry, allowing the separation of compounds like amino acids, nucleotides, carbohydrates, and proteins with excellent resolution.
There...
There...
5.2K
01:24Electrochemical Systems
146
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,...
146
01:30The Electrical Double Layer
197
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...
197
01:20Capillary Electrophoresis: Instrumentation
1.8K
Capillary electrophoresis instrumentation typically consists of several key components. A high-voltage power supply generates the electric field necessary for the separation by connecting to an anode (the positively charged electrode) and a cathode (the negatively charged electrode) located in buffer reservoirs at each end of the capillary tube. The system includes a sample vial, a fused silica capillary tube coated with polyimide for mechanical strength through which the sample components...
1.8K
01:00Coulometry: Overview
2.7K
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...
2.7K
01:26Charge on a Conductor
5.9K
An interesting property of a conductor in static equilibrium is that extra charges on the conductor end up on its outer surface, regardless of where they originate. Consider a hollow metallic conductor with a uniform surface charge density. Since the conductor itself is in electrostatic equilibrium, there should not be any electric field inside the conductor. Now, assume a Gaussian surface enclosing the hollow portion. Applying Gauss's law, the inner surface of the hollow conductor will not...
5.9K