Periodic Cylindrical Structure of Micro-Swelling Silicone Rubber Fabricated by ArF Excimer Laser

Abstract

Cylindrical structure of micro-swelling silicone rubber of approximately 1 µm diameter and 1.5 to 2 µm height was fabricated by the 193-nm ArF excimer laser-induced photodissociation of Si-O bonds of silicone rubber. To be periodically, single layer of silica glass microspheres was aligned on aluminum-coated silicone rubber during laser irradiation. The silicone rubber underneath each microsphere photochemically swelled, after laser-ablating aluminum to limit a diameter of the swelling. The aluminum also adjusted a focal point to the surface of silicone rubber to form a hole approximately 0.5 μm diameter centered at each the swelled silicone rubber. A purging O₂ molecules in the laser beam path by N₂ gas and lowering the laser pulse repetition rate were effective for fabricating the regular cylindrical structure. The regular cylindrical structure of micro-swelling silicone rubber showed superhydrophobicity.