Effect of Oxygen Addition on Microstructure Formation on PMMA Plate Surfaces Using Atmospheric Pressure Low-Temperature Plasma

Antifouling properties of the superhydrophilic structure on the surface of a snail shell and the superhydrophobicity of the double roughness structure on the surface of a lotus leaf are well-known examples of biomimetics. For our earlier studies, we replicated a snail shell surface microstructure by irradiating polymer films, fabricated via the solvent casting method, using atmospheric pressure low-temperature plasma (APLTP). For industrial application of biomimetics, establishing techniques for forming microstructures on resin plates is desirable. For this study, we investigated the morphology of microstructures formed on commercially available poly(methyl methacrylate) (PMMA) plates by irradiating them with APLTP under different oxygen addition conditions. Results demonstrated that a coarse spike-like microstructure was formed under low oxygen addition conditions. These findings suggest that control of reactive species in the plasma is crucially important for producing desired microstructural characteristics.