Mechanistic studies of droplet electrophoresis: A review

Electrophoresis (EP) of droplets is an intriguing phenomenon that has applications in biological systems, separation strategies, and reactor engineering. Droplet EP is significantly different from the classic particle EP because of droplet characteristics such as a mobile surface charge and the nonrigidity of the interface. Also, the liquid-liquid system, where there is an interplay between the hydrodynamic and electrokinetic forces in both phases, adds to the complexity of electrophoretic motion. Due to the vast amount of potential applications of droplet EP, a mechanistic understanding of the droplet motion in the presence of an external electric field is crucial. This review provides a background on the mechanism of droplet EP and summarizes the intrinsic interplay between the different relevant forces in these systems. The review also describes the key differences between droplet EP and particle EP, and the impact of these differences on droplet mobility. Additionally, we schematically summarize the effects of key parameters on droplet EP mobility, such as electric double layer polarization, the development of internal flow inside a droplet and boundary effects.

Automated summary

Electrophoresis of droplets, with characteristics such as mobile surface charge and nonrigidity of the interface, differs significantly from classic particle electrophoresis. In liquid-liquid systems, the complexity of electrophoretic motion is increased due to the interplay between hydrodynamic and electrokinetic forces. Understanding the mechanism of droplet motion in the presence of an external electric field is crucial for the vast potential applications of droplet electrophoresis. Factors such as electric double layer polarization, development of internal flow, and boundary effects have significant impacts on droplet electrophoresis mobility.