Laser micro drilled glass semipermeable membranes for microfluidic blood oxygenators

Abstract Extracorporeal membrane oxygenation (ECMO) is a life-saving therapy for patients with severe respiratory failure, but current technology remains limited by hemocompatibility challenges. We previously developed microfluidic oxygenator prototypes utilizing rigid, flat-plate silicon membranes with etched micropores to improve blood flow dynamics and hemocompatibility. However, fabrication of the micropores with deep reactive ion etching (DRIE) is costly and limits scalability. In this study, we report the development of a low-cost alternative semipermeable membrane composed of laser micro drilled borosilicate glass bonded to a thin, gas-permeable polydimethylsiloxane (PDMS) layer. Uniform arrays of through-pores (10 μm diameter, 20 μm pitch) were successfully fabricated through the full 400 μm thickness of the glass substrate, achieving near-vertical sidewalls and robust mechanical integrity. Scanning electron microscopy confirmed precise pore geometry and uniform distribution. Oxygen transfer performance was evaluated using a benchtop flow circuit under varying sweep gas pressures and water flow rates. Compared to prior PDMS-on-silicon membranes, the glass-based membranes demonstrated improved oxygen transfer (volume percent: 0.59 ± 0.13% [laser micro drilling] versus 0.28 ± 0.09% [DRIE]) due to elimination of non-porous support regions. Importantly, laser micro drilling reduced projected membrane fabrication costs by more than an order of magnitude (estimated membrane costs for a 4000 cm 2 neonatal oxygenator: $100,000 [DRIE] versus $8500 [laser micro drilling]), supporting the feasibility of scaling toward clinically relevant ECMO devices.