Related Experiment Video
Updated: Aug 7, 2026

Methods for Measuring the Orientation and Rotation Rate of 3D-printed Particles in Turbulence
Published on: June 24, 2016
Direct measurement of colloidal particle rotation and field dependence in alternating current electrohydrodynamic
Jesús Santana-Solano1, David T Wu, David W M Marr
1Chemistry and Chemical Engineering Departments, Colorado School of Mines, Golden, Colorado 80401, USA.
Abstract:
We have measured the influence of both applied alternating current (AC) field strength and frequency on the electrohydrodynamic (EH) flows present in colloidal systems near an electrode surface. The effect of the flows is visualized by the rotation of the colloids, fluorescently labeled by a novel technique involving EH-driven aggregation of much smaller tracer colloids to the surface of the larger colloids. Our results show an E2 dependence of these flows, consistent with an induced charge mechanism for effective colloidal interactions. We have also observed a crossover in frequency that suggests a change in the origin of the induced charge, consistent with predictions from available theory. The EH flows appear to be hydrodynamically screened inside clusters, as evidenced by the lack of rotation of interior colloids and the cluster-size independent rotation rate of colloids on the boundary.
More Related Videos
Related Concept Videos
Electrochemical Systems
The Hall Effect
Faraday Disk Dynamo
Voltammetric Techniques: Linear-Scan (E vs Time)
Coulometry: Overview
Torque On A Current Loop In A Magnetic Field
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...

