A Scalable, Modular Degasser for Passive In-Line Removal of Bubbles from Biomicrofluidic Devices.

Area of Science:

• Biomicrofluidics
• Cell Culture Technology
• Microfabrication

Background:

• Gas bubbles frequently cause malfunctions in microfluidic devices, particularly in cell culture applications.
• Existing microscale degassing solutions can be expensive or difficult to fabricate, limiting their accessibility.
• There is a need for cost-effective, modular bubble traps for continuous perfusion in microfluidic systems.

Purpose of the Study:

• To develop an affordable and accessible bubble trap for in-line use in microfluidic perfusion systems.
• To adapt a previously manual PDMS degasser design for scalable manufacturing via commercial machining and 3D printing.
• To evaluate the performance, stability, and biocompatibility of the fabricated degassers.

Main Methods:

• A manual PDMS degasser design was modified for reproducible manufacturing using commercial machining and fused deposition modeling (FDM) 3D printing.
• Optimized degassers were tested for stability, leak-proof operation, and bubble trapping capacity under constant perfusion.
• Biocompatibility was assessed for cell culture applications, and material leaching and reagent absorption were evaluated.

Main Results:

• Machined and 3D printed degassers demonstrated stability for over two weeks without leaks under constant perfusion.
• The degassers exhibited a significant bubble trapping capacity, estimated to last 5-20 weeks depending on bubble formation rates.
• Both degasser types were biocompatible, prevented bubble propagation to downstream devices, and maintained fluidic integrity across a wide flow rate range (1 µL/min to >1 mL/min).

Conclusions:

• Scalable fabrication of bubble traps using machining and 3D printing provides an affordable and accessible solution for microfluidic degassing.
• These degassers are robust, biocompatible, and effective for long-term bubble removal in microfluidic perfusion setups, including organs-on-chip.
• The developed bubble traps facilitate continuous perfusion and enhance the reliability of microfluidic cell culture experiments.