Mechanically switchable wetting petal effect in self‐patterned nanocolumnar films on poly(Dimethylsiloxane)
|Parra Barranco, Julián
López Santos, Carmen
Sánchez Valencia, Juan Ramón
Borrás Martos, Ana Isabel
Rodríguez González-Elipe, Agustín
Barranco Quero, Ángel
|Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear
Universidad de Sevilla. Departamento de Física Aplicada I
|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 ...
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.
|Parra Barranco, J., López Santos, C., Sánchez Valencia, J.R., Borrás Martos, A.I., Rodríguez González-Elipe, A. y Barranco Quero, Á. (2021). Mechanically switchable wetting petal effect in self‐patterned nanocolumnar films on poly(Dimethylsiloxane). Nanomaterials, 11 (10), 2566.