Geometric screening of core/shell hydrogel microcapsules using a tapered microchannel with interdigitated electrodes

Area of Science:

• Biomaterials Science
• Microfluidics
• Analytical Chemistry

Background:

• Core/shell hydrogel microcapsules are promising for tissue engineering, food, and drug delivery.
• Existing methods for microcapsule generation often result in geometric variations, necessitating removal of defective capsules.
• High-throughput geometric characterization is crucial for quality control and application development.

Purpose of the Study:

• To develop a continuous-flow device for high-throughput geometric characterization of core/shell hydrogel microcapsules.
• To enable accurate measurement of shell thickness and diameter without complex optical systems.
• To demonstrate the utility of geometric screening for optimizing microcapsule-based applications like drug delivery.

Main Methods:

• A continuous-flow device utilizing a tapered microchannel with interdigitated microelectrodes was designed.
• Microcapsules were flowed through the device, and geometric parameters were derived from microcapsule displacement profiles.
• The system achieved a throughput of up to 584 microcapsules per minute.

Main Results:

• The developed device accurately distinguishes unencapsulated microparticles and measures geometric properties like shell thickness and diameter.
• The method demonstrated high accuracy in geometric characterization.
• Optimization of electrospray processes based on geometric screening led to controlled and extended drug release profiles.

Conclusions:

• A simplified, miniaturized, and high-throughput device for core/shell hydrogel microcapsule geometric characterization has been successfully developed.
• This method eliminates the need for high-speed optical systems, reducing complexity and cost.
• The technology provides a powerful tool for screening microcapsules, facilitating their broader application in various fields.