연꽃잎을 모방한 초발수 표면 제작

Lotus leaf displays self cleaning effect. Because the contact angle of water is higher than 140°, water droplets roll easily on the lotus leaf. Rolling water droplets sweep off dusts or contaminants on lotus leaf. Self cleaning effects come from hydrophobicity and rough surface. In order to imitate lotus leaf, PTFE(Polytetraflouroethylene) sputtered in vacuum, CNTs(Carbon Nano Tubes) grown with different densities and replica of AAO(Aluminium Anodic Oxide) template are fabricated. Measured contact angles are 150°, 154° and 135° respectively. These results are analyzed with Wenzel's theory for homogeneous surface and Cassie and Baxters's theory for heterogeneous surface.