Mechanically switchable wetting petal effect in self‐patterned nanocolumnar films on poly(Dimethylsiloxane)

Switchable mechanically induced changes in the wetting behavior of surfaces are of para-mount importance for advanced microfluidic, self‐cleaning and biomedical applications. In this work we show that the well‐known polydimethylsiloxane (PDMS) elastomer develops self‐patterning when it is coated wit...

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Detalles Bibliográficos
Autores: Parra Barranco, Julián, López Santos, Carmen, Sánchez Valencia, Juan Ramón, Borrás Martos, Ana Isabel, Rodríguez González-Elipe, Agustín, Barranco Quero, Ángel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/128830
Acceso en línea:https://hdl.handle.net/11441/128830
https://doi.org/10.3390/nano11102566
Access Level:acceso abierto
Palabra clave:Anisotropic wetting
Droplet sliding
GLAD coatings
PDMS
Self‐surface patterning
Descripción
Sumario:Switchable mechanically induced changes in the wetting behavior of surfaces are of para-mount importance for advanced microfluidic, self‐cleaning and biomedical applications. In this work we show that the well‐known polydimethylsiloxane (PDMS) elastomer develops self‐patterning when it is coated with nanostructured TiO2 films prepared by physical vapor deposition at glancing angles and subsequently subjected to a mechanical deformation. Thus, unlike the disordered wrinkled surfaces typically created by deformation of the bare elastomer, well‐ordered and aligned micro‐scaled grooves form on TiO2/PDMS after the first post‐deposition bending or stretching event. These regularly patterned surfaces can be reversibly modified by mechanical deformation, thereby inducing a switchable and reversible wetting petal effect and the sliding of liquid droplets. When performed in a dynamic way, this mechanical actuation produces a unique capacity of liquid droplets (water and diiodomethane) transport and tweezing, this latter through their selective capture and release depending on their volume and chemical characteristics. Scanning electron and atomic force microscopy studies of the strained samples showed that a dual‐scale rough-ness, a parallel alignment of patterned grooves and their reversible widening upon deformation, are critical factors controlling this singular sliding behavior and the possibility to tailor their response by the appropriate manufacturing of surface structures.