Interactions of mechanical waves and superhydrophobic coatings

Abstract

One of the intriguing effects that exists both in nature and in laboratory fabricated condi- tions is the ability to repel water. Superhydrophobic surfaces have hierarchical roughness and coating that allows water repellency and formation of air interfaces in proximity when submerged. Although there has been continuous research on the samples themselves, there has been little effort to expand it to other fields. In biomedical field, there are applications that utilize nano-scale agents for drug delivery and perfusion. Knowing that superhydro- phobic surfaces have nanoparticles as coating and can form air pockets, it made it a po- tential target to study. So far there has been little to no research regarding superhydropho- bic surface interaction under ultrasound fields, which is the main tool in many biomedical applications. Thus, this thesis tackles different aspects of the superhydrophobic surfaces that cover both uniform (e.g., defined pillar structure) and nonuniform surfaces (using industrial polymer spray product or chemically inducing roughness). Furthermore, various experiments were devised to understand the phenomena occurring at different acoustic pressures, investigate wave propagation on the surfaces, and find out any benefits of applying ultrasound.ㅤ