To meet the high throughput required at the clinical level, the challenge for microfluidic oxygenators is to enhance their gas exchange performance at higher blood flow rates (up to 4-7 L/min). To do so, the combination of two approaches is necessary: 1) fabricating devices with larger gas exchange surface area (i.e., not only one or two-sided gas exchange) to improve the oxygenation capacity of a single device and 2) parallelization of several devices to increase the overall throughput. Although the work of Santos et al. 215 demonstrated a single device capable of achieving a reasonable oxygen transfer at a blood flow rate of 30 ml/min, further improvements must still be made toward the goal of treating adult blood flow rates with physiological shear rates and pressure drops.