Engineering of Removing Sacrificial Materials in 3D-Printed Microfluidics

Area of Science:

• Microfluidics
• Additive Manufacturing
• Materials Science

Background:

• Three-dimensional (3D) printing enables complex microfluidic chip fabrication.
• Sacrificial materials are essential for creating internal channels and external support during printing.
• Effective removal of these sacrificial materials is critical for functional microfluidic devices.

Purpose of the Study:

• To investigate and optimize techniques for removing both outer and inner sacrificial materials from 3D-printed microfluidic chips.
• To develop and propose quantification methods for assessing the efficiency of sacrificial material removal.
• To identify cost-effective and industrially viable methods for sacrificial material removal.

Main Methods:

• Investigated hot bath vegetable oil immersion for outer sacrificial material removal.
• Studied the injection of 70°C vegetable oil over time for inner sacrificial material removal.
• Quantified removal efficiency using transmittance measurements and visual inspection for deformation.

Main Results:

• A hot bath in vegetable oil removed 89.9% ± 0.1% of outer sacrificial materials, outperforming other methods.
• Injecting 70°C vegetable oil for 720 minutes yielded high transmittance (93.8% ± 6.8%) without deformation for inner channels.
• A cost-effective removal time of approximately 10 minutes was identified for industrial applications.

Conclusions:

• Optimized vegetable oil-based methods provide efficient and effective removal of sacrificial materials from 3D-printed microfluidic chips.
• The proposed quantification methods allow for reliable assessment of removal efficiency.
• These advancements facilitate the broader adoption of 3D printing in microfluidics manufacturing.