The Dynamic Behavior of Charged Particles During the Relaxation Process of Electrophoretic Displays

Electrophoretic displays (EPDs) are commonly employed in applications like e-books and electronic price tags due to their benefits of minimal power consumption, excellent contrast, and broad viewing angles. This article establishes a dynamic model for nanoparticles after the removal of the applied electric field. The model combines the Poisson equation, the Navier-Stokes equation, and the Nernst-Planck equation. The Arbitrary Lagrangian-Eulerian method is applied to simulate nanoparticle diffusion motion under varying conditions, such as solution viscosity, particle radius, and reverse micelle radius, after the electric field is removed. The results indicate that after the electric field is removed, high-viscosity solutions exert a stronger hindrance on the particles, resulting in a shorter displacement over the same time period. With equal charge, smaller particle radius exhibits higher surface charge density, allowing them to travel further within the same time frame. Additionally, a smaller reverse micelle radius facilitates the rapid neutralization of surface charge on the particles, thereby limiting their diffusion distance. These findings provide theoretical support for a deeper understanding of the operating mechanism of EPDs.