Durable superhydrophobicity in embossed CYTOP fluoropolymer micro and nanostructures

Abstract

Abstract:Micropillars, nanopillars and dual scale micro-nanopillars were fabricated out of an inherently hydrophobic amorphous CYTOP fluoropolymer by hot embossing. The resulting pillars were superhydrophobic with high apparent contact angles (θ > 160°) and low rolling angles. Abrasion experiments were performed using a novel rotary abrasive slurry setup. Due to their inherent hydrophobicity, CYTOP micro and nanopillars retained their superhydrophobic properties even after 4 hours of abrasion (900 rpm in 10 % slurry of 30 μm alumina particles), unlike control samples prepared out of fluoropolymer coated silicon.

Hierarchical micro and nano structured, hydrophilic, superhydrophobic and superoleophobic surfaces incorporated in microfluidics, microarrays and lab on chip microsystems

“…''Black'' Silicon is one such example of random silicon structures which leads to superamphiphobicity [49], [50] and overhanging nanostructures [51]. Black Silicon structures can also be transferred to polymers to render them superamphiphobic [52,53].…”

Superhydrophobic Blood‐Repellent Surfaces

“…The surface fraction of solid can be well below 10%. Figure c shows a dual micro‐/nanoscale superhydrophobic surface made by hot‐embossing a fluoropolymer material . The point‐like solid–liquid contact is the basis of many proposed mechanisms of blood repellency: a smaller contact area between cells and solid surface leads to reduced adhesion and mismatch between the surface structure size and platelet size prevents adhesion, too.…”

Microbumpers maintain superhydrophobicity of nanostructured surfaces upon touch

“…Hierarchical micro-nano structures, inspired by the lotus leaf, show much promise, with the larger-scale features protecting the nanoscale features. These include nanostructures coating grooves [27,28], micro-pyramids [29] or hillocks [30,31], and micro-pillars [18,[32][33][34][35][36][37][38][39][40]. (We do not include here coatings displaying multiple length scales [41][42][43][44] formed by single-step techniques such as electrodeposition or coating with composites containing multi-sized particles.)…”

“…It has been measured using shear and/or load testing [18,40]; abrasion with sand [24,28,29,44,47,48], slurry [33], or a weighted abrasive surface [29,30,43]; or water jet impact [40,49]. In a few recent studies, rubbing with bare fingers has been tested [50][51][52].…”

“…(We do not include here coatings displaying multiple length scales [41][42][43][44] formed by single-step techniques such as electrodeposition or coating with composites containing multi-sized particles.) Such surfaces have been formed in various ways, including injection [32] or replica [27,33,34,38,40] molding, followed in some cases by nanostructure deposition; micromolding of nanoparticle-containing materials [27,45]; microfabrication (etching) [18,29,35]; microfabrication [37,39,46], sandblasting [30,44] or material deposition [36] followed by surface treatment or other material deposition; and laser microstructuring [28]. A thin hydrophobic film is often applied over these structures.…”