title: Bending induced self-organized switchable gratings on polymeric substrates.
abstract: We present a straightforward procedure of self-surface patterning with potential applications as large area gratings, invisible labeling, optomechanical transducers, or smart windows. The methodology is based in the formation of parallel micrometric crack patterns when polydimethylsiloxane foils coated with tilted nanocolumnar SiO2 thin films are manually bent. The SiO2 thin films are grown by glancing angle deposition at room temperature. The results indicate that crack spacing is controlled by the film nanostructure independently of the film thickness and bending curvature. They also show that the in-plane microstructural anisotropy of the SiO2 films due to column association perpendicular to the growth direction determines the anisotropic formation of parallel cracks along two main axes. These self-organized patterned foils are completely transparent and work as customized reversible diffraction gratings under mechanical activation.
authors.affiliation: Nanotechnology on Surfaces Laboratory, Instituto de Ciencia de Materiales de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Sevilla . c/Américo Vespucio 49, Sevilla 41092, ES, Spain.
authors.forename: Julian
authors.initials: J
authors.lastname: Parra-Barranco
authors.forename: Manuel
authors.initials: M
authors.lastname: Oliva-Ramirez
authors.forename: Lola
authors.initials: L
authors.lastname: Gonzalez-Garcia
authors.forename: Maria
authors.initials: M
authors.lastname: Alcaire
authors.forename: Manuel
authors.initials: M
authors.lastname: Macias-Montero
authors.forename: Ana
authors.initials: A
authors.lastname: Borras
authors.forename: Fabian
authors.initials: F
authors.lastname: Frutos
authors.forename: Agustin R
authors.initials: AR
authors.lastname: Gonzalez-Elipe
authors.forename: Angel
authors.initials: A
authors.lastname: Barranco