Simulation of electrodynamics for nanofluid composite droplet electrowetting

This study employed COMSOL 5.6 software to establish a two-dimensional axisymmetric model for the simulation of the electrowetting in composite droplets, with vegetable oil LB2000 and graphite water-based nanofluid as the external and internal fluids. The simulation results indicate that the internal fluid, possessing a higher electrostatic capability, is more susceptible to charge accumulation and experiences a greater axial electric field force. Acting as the "driving fluid" within the charged composite droplet, the flow of the internal fluid propels the spreading of the entire droplet, leading to a decrease in the contact angle. Additionally, the simulation also observed the velocity field and pressure field within the composite droplet, further revealing the process whereby the internal fluid, under the influence of the electric field force, flows outward and facilitates the spreading of the external fluid.