A robust and user-agnostic step-emulsion platform for scalable microgel fabrication

Area of Science:

• Biomaterials Engineering
• Microfluidics
• Hydrogel Science

Background:

• Microgel-based granular hydrogels are increasingly vital in biomedical technologies.
• Current microfluidic fabrication methods for uniform microgels are complex, costly, and difficult to scale.
• Challenges include specialized equipment, steep learning curves, and extensive calibration.

Purpose of the Study:

• To develop a simplified and robust microfluidic system for scalable, uniform microgel fabrication.
• To investigate the impact of channel geometry and flow conditions on droplet generation.
• To provide an accessible platform for researchers with varying microfluidics experience.

Main Methods:

• Development of a step-emulsion system with variable outlet channel dimensions.
• Experimental characterization of flow rates and channel geometry effects on droplet size and throughput.
• Testing with diverse polymer backbones and viscosity ranges, including high-viscosity alginate solutions.

Main Results:

• Demonstrated robust and repeatable generation of uniform microgel precursor droplets.
• Identified key geometrical parameters of outlet channels influencing droplet size and throughput.
• Achieved consistent results with varying polymer types, user expertise, and viscosities up to 650x water viscosity.
• Validated performance with both syringe pump and manual injection methods.

Conclusions:

• The step-emulsion system offers a user-friendly, scalable, and adaptable solution for microgel fabrication.
• This platform democratizes microgel production, enabling wider adoption in biomedical research.
• It effectively addresses the bottlenecks associated with traditional microfluidic approaches.