Microscale Computed Tomography (μCT) Imaging of Leak Pathways for Optimized Leak-Free 3D Printed Fluidics

Area of Science:

• Materials Science
• Engineering
• Fluid Dynamics

Background:

• Fused filament fabrication (FFF) is an accessible 3D printing method for microfluidic devices.
• Default FFF settings often lead to leakages in microfluidic devices.
• Understanding structural causes of leakage is crucial for optimizing FFF.

Purpose of the Study:

• Investigate the structural reasons for leakage in FFF-printed microfluidic devices.
• Determine the effect of optimizing print parameters on device performance and leakage.
• Identify key parameters for reliable and cost-effective microfluidic device fabrication.

Main Methods:

• Combined microscale computed tomography (μCT) X-ray imaging with bulk leak testing.
• Analyzed the relationship between print parameters (infill, layer height, flow rate) and channel wall quality.
• Quantified time and material cost savings through parameter optimization.

Main Results:

• Leakage in FFF-printed devices is determined solely by channel wall quality, not infill percentage.
• Reduced infill significantly decreases print time and material costs (over 50% savings).
• Smaller layer heights (<0.1 mm) and increased flow rates (>100%) improve channel wall integrity and prevent leaks.

Conclusions:

• Optimizing channel wall quality is paramount for leak-free microfluidic devices fabricated with FFF.
• FFF parameter adjustments allow for substantial cost and time reductions without compromising device performance.
• This study provides a data-driven approach to reliable and economical microfluidic device manufacturing.