Fabrication of Superhydrophobic Surfaces Using Inverted Glancing Angle Deposition (I-GLAD)

Abstract

This paper presents a novel approach for fabricating superhydrophobic surfaces using inverted glancing angle deposition (I-GLAD). GLAD is an advanced physical vapor deposition technique that utilizes substrate tilt and rotation to create three-dimensional nanofeature arrays. Unlike conventional top-down nanofabrication methods, GLAD offers unique advantages in generating various nanofeatures such as pillars, springs, chevrons, ribbons, and nanoporous membranes. Superhydrophobicity, inspired by natural examples like lotus leaves and cicada wings, relies on highly porous micro/nanostructures that reduce surface energy and impart water-repellent properties. GLAD’s capability to produce hierarchical and porous nanostructures makes it an ideal candidate for superhydrophobic surface fabrication. Previous researches have proposed GLAD processes for superhydrophobic surfaces; however, these approaches suffer from flaws such as being time-consuming or requiring challenging template assistance. In this paper, we introduce a new I-GLAD approach for creating superhydrophobic surfaces that eliminates the need for a seeding layer and an additional coating, simplifying the fabrication process. The fabrication process of I-GLAD includes natural seeding, growing, capping, and inverting. The resulting superhydrophobic surfaces exhibit a high water contact angle of over 155 deg. We further explore additional GLAD recipes to create surfaces with different water contact angles, enabling a comprehensive analysis of superhydrophobic properties. Potential applications for superhydrophobic surfaces include anti-icing coatings, self-cleaning surfaces, and antimicrobial surfaces.