Design Analysis and Optimization of a Single-Layer PDMS Microfluidic Artificial Lung

Objective: Microfluidic artificial lungs (μALs) are being researched for future clinical use due to the potential for increased gas exchange efficiency, small blood contacting surface area, small priming volume, and biomimetic blood flow paths. However, a current roadblock to clinical use is the need to stack hundreds to thousands of these small-scale μALs in parallel to reach clinically relevant blood flows. The need for so many layers not only increases the complexity and projected cost to manufacture a μAL, but also could result in devices which are cumbersome, and, therefore, not suitable for portable artificial lung systems. Methods: Here, we describe the design analysis and optimization of a single-layer μAL that simultaneously calculates rated blood flow, blood contacting surface area, blood volume, pressure drop, and shear stress as a function of blood channel height using previously developed closed-form mathematical equations. A μAL designed using this procedure is then implemented and tested. Results: The resulting device exhibits a rated flow of 17 mL/min and reduces the number of layers required for clinically relevant μAL devices by a factor of up to 32X compared to previous work. Conclusion: This procedure could significantly reduce manufacturing complexity as well as eliminate a barrier to the clinical application of these promising devices. Significance: The described method results in the highest rated flow for any single-layer μAL to date.