To effectively manipulate droplets via surface charge, a stable and uniform potential distribution across the substrate should be achieved. A corona charging configuration was designed to apply negative potentials at the needle to ionize the adjacent gas. The generated electrons and negative ions are accelerated toward a grounded metal plate at the base. As they pass through an intermediate metal wire mesh (grid), they become uniformly trapped on the underlying FEP film. By adjusting the potential difference across the grid, the electrostatic energy was transferred to the film. To evaluate the reliability and durability of the injected surface charges, a non-contact probe setup was implemented. By tracking the surface potential over time 2 cm above the sample, the system demonstrated exceptional charge retention capabilities. The initial applied voltages of -1000 V, -2000 V, and -3000 V were maintained without leakage for exceeding 100 days. Measurements taken immediately after condensation revealed a slight decrease in the recorded voltage. This reduction is driven by the dipole polarization within the condensed water droplets, which partially screens the electric field of the polymer film. Nevertheless, despite this screening effect, the majority of the initial potential remained intact. An acrylic chamber—integrating a heater, a humidity controller, and a cold plate—was constructed to visually capture the droplet nucleation and evolution. The condensation process onto the Peltier-cooled substrate was recorded utilizing a 50x optical microscope lens. Computer-vision-based image processing algorithms were introduced to analyze condensation behavior. Masking was applied to image datasets, achieving segmentation between the liquid droplets and the solid background. Through pixel-level droplet tracking, the individual growth trajectories of droplets were color-coded and visualized. As a result, a clear relationship was derived: as the negative surface voltage applied to the film increases, the droplet number density rises.