Simple and cost-effective method for fabrication of optically transparent superhydrophobic thin film using reusable pua mold and roll-to-roll machine

In this paper, a cost-effective method for mass production of optically transparent super-hydrophobic PDMS thin film is proposed and characterized. The dual-scaled micro-/nano PDMS patterns are re-replicated using a photoresist mold (reverse image), PDMS mold (dual-scaled positive structures) and UV curable polyurethane acrylate (PUA, negative structures) mold. The PUA mold can be employed as a reusable mold for continuous production of the super-hydrophobic PDMS thin film in a home-made roll-to-roll system. The proposed method is extremely simple and cost-effective in comparing with previous methods. Thanks to the proposed PUV mold and the roll to roll system, continuous production of transparent super-hydrophobic PDMS film is possible, which will be a basis for mass production. The experimental results reveal that the proposed method has great potential to extend the utility of the optically transparent super-hydrophobic thin film.