ELECTROWETTING-INDUCED DROPLET JUMPING SIMULATION USING MANY-BODY DISSIPATIVE PARTICLE DYNAMICS

Many-body dissipative particle dynamics (MDPD) is a particle-based mesh-free method that can capture complex physics to study the dynamics of fluid-structure interaction. In this work, droplet detachment from solid surface at mesoscale is simulated using MDPD approach. The geometrical evolution of the jumping droplet and the mechanism behind it have been investigated. By changing the wettability of solid surface from hydrophilic to superhydrophobic, all successful jumping cases and non-jumping cases are incorporated in a jumping map. It is found that the threshold contact angle for jumping is around 150 degree in the investigated cases. Droplet can jump more easily with larger wettability change. In this study, sample velocity fields within the droplet during the jumping process are reported for the first time. There is obvious vortex flow inside the droplet at the beginning of the droplet deformation. The results can greatly advance the fundamental understanding of hydrodynamics behavior of electrowetting-induced droplet jumping.