Figure focuses on identifying optimal properties that maximize diffusivity while minimizing contact resistance. This balancing act presents a significant challenge. Reducing fiber concentration subsequently increasing porosity and facilitate particle transport through the GDL inherently decreases the probability of fiber in contact with MPL. This disrupts electron transmission between the two layers, consequently increasing contact resistance. As a result, 𝐶 𝑓 1 exhibits a relatively higher contact resistance (0.14 Ω) compared to the other cases (shown in Table ). Figures and display very similar trends, reflecting the comparable nature of their manufacturing parameters. Notably, achieving high electrical and thermal conductivities necessitates a higher fiber concentration alongside a significant compression ratio. This increased compression enhances contact points between carbon fibers, ultimately facilitating mass transport. Finally, figure showcases a slightly deviating trend compared to Figures and. To accommodate the requirement for diffusivity, 𝐶 𝑓 4 implements a slightly lower electrical and thermal conductivities by increasing the thickness of the layer.