Growth morphology and symmetry selection of interfacial instabilities in anisotropic environments

The displacement of a fluid by another less viscous one in quasi-two dimensional geometry typically leads to complex fingering patterns. In an isotropic system, dense-branching growth arises, which is characterized repeated tip-splitting evolving fingers. When anisotropy present the interfacial dynamics, morphology changes dendritic regular structures. We introduce engraving six-fold symmetric lattice channels on Hele-Shaw cell. show that transition miscible fluids depends not only previously reported degree set topography, but also viscosity ratio between two fluids. Remarkably, and govern global features patterns, inducing systematic change from towards twelve-fold dendrites. Varying either control parameter provides new method tune symmetry may have relevance for analogous phenomena gradient-driven such as directional solidification or electrodeposition.