Microswellings of 1 µm height, 1.5 µm diameter, and regular intervals of 2.5 µm on a silicone rubber surface were fabricated using a 193 nm ArF excimer laser. The laser was focused on silicone by each microsphere made of silica glass of 2.5 µm diameter; these microspheres covered the entire surface of the silicone. The surface underneath each microsphere selectively swelled owing to the photodissociation of the Si–O bonds of silicone. The contact angle of water was measured to be approximately 155°, indicating a clear superhydrophobicity. The samples successfully repelled water in water to form an air gap layer between silicone and water.

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Silicone ([SiO(CH3)2] n ) films were photochemically modified into SiO2 by irradiation with a 157 nm F2 laser. The dissociation of Si–CH3 bonds of silicone simply depended on the photon number of the F2 laser. The quantum yield of the modification was estimated to be approximately 1×10-2. Mechanisms of oxidation and O–H production in the modified films were clarified. The depth of the modification was not limited by the absorption coefficient of silicone because SiO2 of the modified films is transparent for the F2 laser. A fine pattern of the 1.5-µm-thick silicone films could be fabricated by immersing the modified samples in 0.2 wt% hydrogen fluoride solution.

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Photochemical modification of the polytetrafluoroethylene (PTFE) with incorporation of the CH3 radical released from the B(CH3)3 molecule excited by an ArF excimer laser has been demonstrated. The incorporation of CH3 radicals and the depletion of fluorine atoms of the polymer surface were studied by XPS analysis and infrared ATR spectrum measurement. In these photochemical reactions, the photoirradiated surface changed into oleophilic. The properties were studied by contact angle measurement. The stability of the oleophilic surface was examined at the elevated temperature of 200 °C for 6 h in O2 or N2 ambient and also by immersing in alkaline or acid water solutions.