Pulsation of electrified jet in capillary microfluidics

Area of Science:

• Physics
• Fluid Dynamics
• Microfluidics

Background:

• Electrically charged jets in microfluidics are crucial for generating emulsions.
• Understanding jet pulsation is key to controlling droplet size and distribution.

Purpose of the Study:

• To investigate the pulsation dynamics of an electrically charged jet in a dielectric liquid.
• To characterize different pulsation modes and their impact on droplet generation.
• To demonstrate control over submicron emulsion droplet size.

Main Methods:

• Utilized flow-focusing capillary microfluidics for jet generation.
• Applied electrical charges to the jet.
• Characterized low-frequency and high-frequency pulsation modes.
• Analyzed droplet size distribution and average size.

Main Results:

• Identified two distinct pulsation types: low-frequency large-amplitude and high-frequency small-amplitude.
• Low-frequency pulsation leads to broad droplet size distribution.
• High-frequency pulsation yields narrow droplet size distribution.
• Droplet size is tunable by adjusting pulsation frequency via jet diameter.

Conclusions:

• Pulsation dynamics offer a method for controlling submicron emulsion droplet generation.
• Microfluidic-electrospray platforms can achieve precise control over droplet characteristics.
• Findings advance the development of tailored emulsion production in microfluidics.