On the improvement of alveolar-like microfluidic devices for efficient blood oxygenation

Abstract

In this work, we study alveolar-like microfluidic devices with a horizontal membrane arrangement that demonstrate a great potential as small-scale blood oxygenator. The design criteria for the fabricated devices were to maximize the oxygen saturation level and minimize liquid chamber volume while ensuring the physiological blood flow in order to avoid thrombus formation and channel blockage during operation. The liquid chamber architecture was iteratively modified upon analysis of the fluid dynamics by computer modelling. Accordingly, two alveolar type architectures were fabricated, Alveolar Design 1 (AD1) and Alveolar Design 2 (AD2), and evaluated for oxygenation of sheep blood. The attained O2 transfer rate at 1 mL/min of blood flow rate for both devices was rather similar: 123 mL·min-1 ·m-2 and 127 mL·min-1 ·m-2 for AD1 and AD2 microfluidic devices, respectively. Among the studied, AD2 type geometry would lead to the lowest pressure drop and shear stress value upon implementation in a scaled microfluidic artificial lung (µAL) to satisfy oxygenation requirements of a 2.0 kg neonate.