Fabrication of micro-textured surfaces using Gravity-assisted EDM process with foil electrode to induce hydrophobicity on Cu surface

Abstract

The fabrication of texture on metallic surfaces to achieve hydrophobicity has piqued the interest of many researchers. The Laser machining process is widely used for this purpose and is also appreciated for nonmetals. However, due to the metal’s high conductivity, the Laser machining process has been limited to some extent. Texturing a metallic surface with Electro-discharge machininghas received little attention. In this work, the texture on the surface of Cu material is fabricatedusing a gravity-assisted EDM process with a foil tool. The fabrication of microchannels in two mutually perpendicular directions resulted in textured surfaces. The width of the microchannels iskept constant, while the spacing between them was varied, resulting in two-dimensional arrays ofsquare-shaped micro-pillars of varying sizes. Three distinct textured surfaces are created, with channel widths of 59.67 μm in all cases but micro-pillar widths of 80.29 μm, 60.72 μm, and 40.57 μm, respectively. The hydrophobic nature of the textured surfaces is also investigated and compared to that of the untextured surface. It has been revealed that texturing the Cu surface improves its hydrophobicity. Hydrophobicity increased with decreasing micro-pillar width for a constant channel width.