Fabrication of Superhydrophobic Surfaces Using Glancing Angle Deposition

Abstract

Abstract This paper introduces the fabrication of superhydrophobic surfaces using glancing angle deposition (GLAD). GLAD is an advanced physical vapor deposition technique, during which the tilt and rotation of the substrate are maneuvered with some algorithm. GLAD has the unique advantage of creating three-dimensional nanofeature arrays, comparing to conventional top-down nanofabrication techniques. Various nanofeatures created by GLAD have been reported, including pillars, springs, chevrons, ribbons, and those structures as templates for creating nanoporous membranes. Superhydrophobicity is nature inspired, such as from lotus leaf and cicada wings, which are with highly porous micro/nanostructures that reduce the surface energy of the surfaces to achieve the water repellent property. The ability to create hierarchical and porous nanostructures makes GLAD the perfect candidate for creating superhydrophobic surfaces. GLAD processes for superhydrophobic surfaces is proposed by other research groups. However, the processes are flawed: either time consuming, or need to be assisted by templates that are challenging to be made. This paper will introduce a new approach with GLAD for creating superhydrophobic surfaces. This approach does not need the seeding layer that are proposed by for creating the hierarchical nanoporous surfaces. Superhydrophobic surfaces are achieved with the water contact angle of 155 degrees. More GLAD surfaces with higher/lower water contact angles by different GLAD recipes are created and analyzed. The superhydrophobic surfaces are potentially used for applications such as anti-icing surfaces, self-cleaning surfaces, and antimicrobial surfaces.