Efficient Mixing of Microfluidic Chip with a Three-Dimensional Spiral Structure

Area of Science:

• Microfluidics
• Chemical Engineering
• Materials Science

Background:

• Passive micromixers are crucial for efficient fluid manipulation in microfluidic devices.
• Traditional 2D micromixers often exhibit limited mixing efficiency, necessitating improved designs.
• 3D printing and polymer dissolution offer advanced fabrication capabilities for microfluidic devices.

Purpose of the Study:

• To design and fabricate a novel three-dimensional (3D) helical passive micromixer.
• To evaluate the mixing efficiency of the 3D helical micromixer compared to traditional 2D designs.
• To optimize the helical structure parameters and flow rates for maximum mixing performance.

Main Methods:

• Fabrication of a 3D spiral channel mold using high-impact polystyrene (HIPS) via 3D printing.
• Dissolution of the HIPS mold in limonene solvent to create the microchannel.
• Experimental testing of mixing efficiency using varying helical structures and flow rates.

Main Results:

• The single helix structure improved mixing efficiency to 0.85, surpassing the 0.78 efficiency of a traditional 2D T-shaped channel.
• Optimal performance was achieved with a 5 mm helical structure at a flow rate of 2.0 mL/min.
• The optimized 3D helical micromixer demonstrated a maximum mixing efficiency of 0.948.

Conclusions:

• The 3D helical passive micromixer design significantly enhances fluid mixing efficiency.
• 3D printing and polymer dissolution are effective techniques for fabricating complex microfluidic devices.
• The developed helical micromixer shows great potential for applications requiring efficient microscale mixing.