Fabrication of Cotton-like Superhydrophobic Surface on Teflon Using a Pulsed Ultraviolet Laser

Cotton-like micro structures were selectively fabricated on Teflon (Polytetrafluoroethylene) surface by irradiating focused fourth harmonic of Nd:YAG lasers two dimensionally, which were found to have superhydrophobic property. The wavelength, pulse duration, focusing diameter and the energy of the laser were 266 nm, 10 ns, about 2 μm and about 0.1 mJ, respectively. The contact angle of 140 degrees was obtained for the machining pitches of 10 μm, while that for unfabricated surface was about 90 degrees. The method described is purely physical process, therefore the superhydrohobic surface obtained is considered to keep various valuable chemical characteristics of Teflon.