On-demand electrostatic droplet charging and sorting
Related Experiment Video
Updated: May 30, 2026

Taking Advantage of Reduced Droplet-surface Interaction to Optimize Transport of Bioanalytes in Digital Microfluidics
Published on: November 10, 2014
Byungwook Ahn1, Kangsun Lee, Rajagopal Panchapakesan
1SMALL (Sensors and MicroActuators Learning Lab), Department of Electrical Engineering, University at Buffalo, The State University of New York (SUNY-Buffalo), Buffalo, New York 14260, USA.
Abstract:
This study reports a droplet-based microfluidic device for on-demand electrostatic droplet charging and sorting. This device combines two independent modules: one is a hydrodynamic flow focusing structure to generate water-in-oil droplets, and the other is the two paired-electrodes for charging and sorting of the droplets. Depending on the polarity on charging electrodes, water-in-oil droplets can be electrostatically charged positively or negatively, followed by automatic real-time electric sorting. This approach will be useful when preformed droplets, with a positive, a negative, or with no charge, need to be manipulated for further on-chip droplet manipulation.
Related Concept Videos
The Electrical Double Layer
Van de Graaff Generator
Van de Graaff uses both smooth and pointed surfaces, conductors, and insulators to generate large static charges and, hence, large voltages. A substantial excess charge can be deposited on the sphere because it moves...
Capillary Electrophoresis: Applications
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...
Capillary Electrophoresis: Instrumentation
Electrospray Ionization (ESI) Mass Spectrometry
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
Colloidal precipitates

