Direct 3D-printing of cell-laden constructs in microfluidic architectures

Area of Science:

• Biomedical Engineering
• Microfluidics
• 3D Printing

Background:

• Microfluidic platforms offer significant advantages in biological and medical research but face high costs and limitations in device fabrication.
• Three-dimensional (3D) printing enhances device iteration but cannot fabricate components within microfluidic devices, increasing production costs for diverse research needs.

Purpose of the Study:

• To develop a cost-effective and versatile microfluidic device using projection 3D printing and soft lithography.
• To demonstrate enhanced fluid mixing capabilities at reduced flow rates.
• To showcase the ability to fabricate complex, cell-laden 3D tissue models directly within the microfluidic device.

Main Methods:

• Fabrication of a variable height micromixer (VHM) using projection 3D printing and soft lithography.
• Theoretical analysis and flow experiments to evaluate mixing efficiency at different z-heights and flow rates.
• Direct 3D printing of complex, user-defined cell-laden scaffolds within the VHM.

Main Results:

• The VHM demonstrated significantly improved mixing at lower flow rates compared to simple geometries.
• Efficient mixing was achieved at 320 μL min⁻¹ in the VHM, contrasting with 2.4 mL min⁻¹ required for full mixing in planar zigzag regions.
• Complex, cell-laden scaffolds were successfully printed directly inside the VHM, demonstrating the platform's versatility.

Conclusions:

• The developed VHM, fabricated via projection 3D printing and soft lithography, offers enhanced mixing efficiency at reduced flow rates.
• This integrated approach enables the direct fabrication of 3D tissue models within microfluidic devices.
• The technology presents a promising platform for advanced medical diagnostics and disease modeling.