Fabrication of Superhydrophobic Silicone Rubber with Periodic Micro/Nano-Suction Cup Structure by ArF Excimer Laser-Induced Photodissociation

A 193-nm ArF excimer laser was used to induce the photodissociation of Si-O bonds of silicone rubber in order to fabricate a periodic micro/nano-suction cup silicone structure, approximately 1 mu m in diameter and 2 mu m in height at regular intervals of 2.5 mu m. The laser was focused on Al-coated silicone rubber by each silica glass microsphere 2.5 mu m in diameter, which covered the entire surface of the silicone rubber. The silicone rubber underneath each microsphere photochemically swelled after laser-ablating the coated Al to limit the diameter of the swelling. Simultaneously, the coated Al was able to adjust the focal point to the surface of the silicone rubber to form a hole approximately 500 nm in diameter, centered at the swollen silicone. The dependences of the thickness of the coated-Al and the laser pulse number are discussed, based on the observations of a scanning electron microscope (SEM) and an atomic force microscope (AFM). The superhydrophobic property of the fabricated micro/nano-suction cup structure was successfully found.