Droplet breakup in an asymmetric microfluidic T junction

Area of Science:

• Fluid dynamics
• Microfluidics
• Droplet microfluidics

Background:

• Controlling droplet size and breakup is crucial in microfluidic applications.
• Asymmetric geometries in T junctions offer unique possibilities for droplet manipulation.
• Previous methods for non-uniform droplet generation have limitations in efficiency.

Purpose of the Study:

• To numerically investigate the breakup of non-uniform droplets in an asymmetric T junction.
• To develop analytical relations using lubrication approximation for system verification.
• To identify key parameters influencing droplet breakup and system performance.

Main Methods:

• Numerical simulations were employed to model droplet breakup dynamics.
• An analytical approach based on lubrication approximation was used for validation.
• System performance was analyzed by varying parameters like capillary number and geometry.

Main Results:

• Increasing the capillary number leads to the production of smaller droplets.
• Symmetric geometries result in a decreased pressure drop across the junction.
• The asymmetric T junction method shows reduced breakup time and pressure drop compared to uniform junctions.

Conclusions:

• Asymmetric T junctions provide an efficient method for generating non-uniform droplets.
• Controlling capillary number and junction geometry are key to optimizing droplet size and system performance.
• This approach offers advantages over existing methods for droplet breakup and generation.