Dancing Electrohydrodynamic Tip Streaming Modulated by Faraday Instability

Area of Science:

• Fluid dynamics
• Microfluidics
• Electrohydrodynamics

Background:

• Tip streaming generates micro/nanoscale droplets for 3D printing, nanomaterials, and drug delivery.
• High-frequency jetting is crucial for efficiency but challenging to control.
• Electrohydrodynamic (EHD) tip streaming involves fluid behavior under electric fields.

Purpose of the Study:

• To report and elucidate the mechanism of dancing EHD tip streaming with subharmonic ejection modes.
• To demonstrate precise control over high-frequency EHD tip streaming.
• To explore the potential of this phenomenon for drop-on-demand technologies.

Main Methods:

• Inducing high-frequency electric fields to observe tip streaming phenomena.
• Analyzing meniscus oscillations and Faraday instability.
• Investigating interfacial instability at Faraday wave crests.

Main Results:

• Observed dancing EHD tip streaming with subharmonic ejection modes.
• Elucidated the mechanism involving global meniscus oscillations and local interfacial instability.
• Identified optimal frequencies governed by Faraday instability and ejection voltage thresholds determined by electric Bond number.

Conclusions:

• Dancing EHD tip streaming provides a controllable method for high-frequency micro/nanoscale droplet generation.
• The phenomenon enhances throughput and enables multi-path delivery.
• This offers new prospects for precision 3D printing, nanomaterial fabrication, and drug delivery systems.