Directional transport of a droplet on biomimetic ratchet structure

Directional liquid transport is of importance in some engineering fields, and the problem is also very complicated since it involves interface moving, deforming, and pinning/depinning of the contact line. In this work, a consistent and conservative phase-field based lattice Boltzmann (LB) method is applied to study the phenomenon of directional liquid transport. We first test the LB method by conducting simulations and find that the numerical results agree well with the analytical solutions. We then design the biomimetic surface with the ratchet structure and consider the directional transport of a droplet on such a surface. Furthermore, a force analysis is conducted to analyze the transport mechanism of a droplet on the ratchet structure. It is worth pointing out that the results in the present work may play an instructive role on the design of microchannel for intelligently guiding fluid transportation.