Microfluidic on-chip production of microgels using combined geometries

Area of Science:

• Biotechnology
• Microfluidics
• Materials Science

Background:

• Microfluidic on-chip production of microgels is vital for encapsulating sensitive materials.
• Challenges include precursor solution viscosity increases leading to device clogging.

Purpose of the Study:

• To develop a novel microfluidic device design to prevent clogging during microgel production.
• To ensure stable and monodisperse droplet generation for microgel synthesis.

Main Methods:

• A microfluidic device with a step-induced sudden expansion before a flow-focusing nozzle was designed.
• A shielding oil phase was employed to prevent simultaneous emulsification and gelation.
• Alginate microgels were produced using on-chip calcium chloride emulsion.

Main Results:

• The device generated highly monodisperse spherical droplets (CV < 2%) with diameters ranging from 90-190 μm.
• The step geometry facilitated effective shielding of the dispersed phase.
• Validated microgel production with an average diameter of ~100 μm.

Conclusions:

• The novel microfluidic design effectively prevents clogging and ensures stable droplet generation.
• The device is suitable for on-chip microgel production via external gelation.
• This approach enhances microfluidic applications involving sensitive cargo encapsulation.