title: Hierarchical nested wrinkles on silica-polymer hybrid films: stimuli-responsive micro periodic surface architectures.
abstract: Stimuli-response on hierarchically-structured surface wrinkles is required for advanced filtration, catalysis and sensing applications. Although conventional processes can form hierarchical surface wrinkles, incorporation of stimuli-responsive features has not been achieved, limiting the potential multi-scale functionality of wrinkles. Here, we demonstrate a novel process that can fabricate stimuli-responsive surface hierarchical structures on silica-polymer hybrid films through precisely controlled UV-polymerization and sol-gel condensation. Starting from uniform hybrid films, UV excitation of the film surface triggers the formation of micrometre-scale wrinkles with dual periodicity. Hierarchical nested wrinkle (NW) structures with controllable periodic lengths at discrete size scales of < 10 µm and > 23 µm show a shape-memory effect with changes in the surrounding humidity. Moreover, the individual responses of wrinkles with different periodicities can be controlled independently. As a proof-of-concept application, we demonstrate that the NW structures are an active size-selective adsorption/release surface for micrometre-sized particles.
authors.affiliation: Department of Materials Science, Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka, Japan. tokudome@photomater.com
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tokudome
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Suzuki
authors.forename: Takuya
authors.initials: T
authors.lastname: Kitanaga
authors.forename: Masahide
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D015374:Biosensing Techniques; D002384:Catalysis; D005374:Filtration; D005782:Gels; D006801:Humans; D006813:Humidity; D057927:Hydrophobic and Hydrophilic Interactions; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D012867:Skin / Q000737:chemistry; D015595:Skin Aging; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D000178:Acrylamides; D005782:Gels; D011108:Polymers; D012821:Silanes; C040733:tetraethoxysilane; D012822:Silicon Dioxide; D011205:Povidone