(45c) Cellular Fluidics: Tuning Multiphase Interfaces in 3D Using Architected Porous Media

Many processes in both nature and industry occur at the microscale and involve complex multiphase interfaces. Most microporous media, both natural and man-made, tend to be stochastic and therefore difficult to predict or control reliably. On the other hand, conventional microfluidic devices are often limited to enclosed channels and planar geometries, which hinders their usefulness in multiphase reaction or transport processes involving gas phases. We present a novel platform based on capillary fluid flow in ordered three-dimensional open-cell lattices. Using deterministic cell and lattice design, combined with additive manufacturing methods that provide access to length scales < 100 μm, we can fabricate complex 3D structures with tuned porosity and advanced functionalities. This approach enables selective placement and direction of liquid flow into predetermined continuous paths through the structure, as well as optimizing for the occurrence of gas-liquid, liquid-liquid, or gas-liquid-solid interfaces. We demonstrate the application of cellular fluidics for processes such as transpiration cooling, CO₂ capture, and selective patterning of catalytic materials for electrochemical CO₂ reduction. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 within the LDRD program 19-SI-005. LLNL-ABS-778327.