The following step (Figure ) involves compression of the structure to the predefined compression factor. Following the stochastic generation of the microstructure, the transport properties of these GDLs were then digitally characterized through physics-based calculations. This characterization included through-plane (TP) and in-plane (IP) electrical conductivity, thermal conductivity, and diffusivity. Details on these physics-based digital characterizations are presented in supporting information S1-S4.