FIG. 1.

Schematic representation of the computational domain, modeled after the LOAC design of Huh et al.²⁴ The upper channel (in blue) is separated from the bottom channel (in pink) by an elastic membrane (in magenta). The top mimics the alveolus through which air flows and the bottom mimics the blood vessel. The two side chambers are for the purpose of imposing vacuum to stretch the elastic membrane. The air flows along the $-z$ direction, and $\theta$ denotes the angle between the air flow and gravity $\mathit{g}$. Most of the computations have $\theta ={90}^{°}$, but $\theta$ can be varied to allow different inclinations of the device relative to gravity.