Design Applicable 3D Microfluidic Functional Units Using 2D Topology Optimization with Length Scale Constraints.

Area of Science:

• Computational fluid dynamics
• Microfluidics
• Topology optimization

Background:

• 2D models are often used for fluidic flow topology optimization due to computational limits.
• 3D fabricated devices can have different fluidic performance than their 2D counterparts due to finite depth and no-slip conditions.
• This discrepancy limits the practical application of 2D topology optimization for microfluidic devices.

Purpose of the Study:

• To develop an improved 2D topology optimization model for fluidic flow.
• To reduce the performance gap between 2D optimized designs and their 3D fabricated versions.
• To ensure the manufacturability of the optimized microfluidic designs.

Main Methods:

• Inspired by electric circuit analogy, microchannel widths were limited in the 2D optimization process.
• Morphology-mimicking filters were used to impose maximum or minimum length scales on solid and fluidic phases.
• The proposed model was validated using two lab-on-chip functional units: a Tesla valve and a fluidic channel splitter.

Main Results:

• The proposed 2D optimization model successfully reduced the discrepancy in fluidic performance between 2D and 3D models.
• Length scale control ensured the manufacturability of the optimized microfluidic layouts.
• Validated designs for Tesla valves and fluidic splitters demonstrated the effectiveness of the approach.

Conclusions:

• The developed 2D topology optimization method with width constraints and length scale control is effective for microfluidic device design.
• This approach enhances the practical utility of 2D topology optimization by bridging the gap to 3D fabrication.
• The method ensures both functional performance and manufacturability for microfluidic applications.