Large scale roll-to-roll production of polyurethane-acrylate-based hydrophobic film: A next-generation protection layer for solar devices

In the present study, we fabricate a hydrophobic film using a roll-to-roll technique capable of large-area continuous production and examine the film's applicability to solar panels. The hydrophobic film was fabricated using a polyurethane-acrylate (PUA)-based UV-curable material, which has high optical transmittance and high releasability. The roll-to-roll system used in this study was custom manufactured to transfer micro-patterns of 20 μm in size onto the PUA-based film. In addition, a UV irradiation device was attached to the system to enable production of the hydrophobic film at a rate of 150 mm min-1. Through experiments, we confirmed that attaching the fabricated hydrophobic film not only enabled surface self-cleaning on the solar panels, but also ensured stable solar power generation. Thus, the hydrophobic film can be applied to installations that require external periodic cleaning and management, such as the exterior walls of buildings and solar panels.