Bio-Inspired Flow Field Design for Enhanced Mass Transport in CO₂ Electrolyzers: A Multiphysics Modeling Approach

The electrochemical conversion of CO₂ provides a sustainable route to convert it into value-added fuels and chemicals using a membrane electrode assembly at an industry scale. However, achieving high efficiency and selectivity is often constrained by mass transport limitations and high pressure drop. In this study, various flow patterns inspired from nature such as Victoria amazonica leaf, camel's turbinate, avian lung, and wave flow were systematically investigated through 3D Multiphysics simulations. The developed COMSOL model couples free and porous medium flow using the Brinkman interface and solves for CO₂ transport via the transport of the concentrated species interface under steady-state conditions. Among all the simulated designs, V.amazonica-inspired "A1" and hybrid avian-leaf design "C1" demonstrated high CO₂ concentration on the catalyst surface with the lowest pressure drop, highlighting a balance between mass transport efficiency and pressure drop. On the other hand, wave flow-inspired "D1" exhibited highest CO₂ concentration on the catalyst surface but with a significant pressure drop. A sigmoidal three parameter growth model was used to quantitatively compare the dependence of the CO₂ concentration on the flow rate, indicating that A1 and C1 achieve optimal gas utilization at a lower flow rate than the conventional serpentine flow pattern. The results underscore the potential of bioinspired geometries to improve catalyst utilization, minimize parasitic energy losses, and guide the rational design of scalable, energy-efficient CO₂ electrolyzers.