Straightforward Patterning of Functional Polymers by Sequential Nanosecond Pulsed Laser Irradiation.

Edgar Gutiérrez-Fernández,Esther Rebollar,Aurora Nogales,Tiberio A Ezquerra

doi:10.3390/nano11051123

Abstract

Laser-based methods have demonstrated to be effective in the fabrication of surface micro- and nanostructures, which have a wide range of applications, such as cell culture, sensors or controlled wettability. One laser-based technique used for micro- and nanostructuring of surfaces is the formation of laser-induced periodic surface structures (LIPSS). LIPSS are formed upon repetitive irradiation at fluences well below the ablation threshold and in particular, linear structures are formed in the case of irradiation with linearly polarized laser beams. In this work, we report on the simple fabrication of a library of ordered nanostructures in a polymer surface by repeated irradiation using a nanosecond pulsed laser operating in the UV and visible region in order to obtain nanoscale-controlled functionality. By using a combination of pulses at different wavelengths and sequential irradiation with different polarization orientations, it is possible to obtain different geometries of nanostructures, in particular linear gratings, grids and arrays of nanodots. We use this experimental approach to nanostructure the semiconductor polymer poly(3-hexylthiophene) (P3HT) and the ferroelectric copolymer poly[(vinylidenefluoride-co-trifluoroethylene] (P(VDF-TrFE)) since nanogratings in semiconductor polymers, such as P3HT and nanodots, in ferroelectric systems are viewed as systems with potential applications in organic photovoltaics or non-volatile memories.

Highlights

More and more effort is being made to fabricate functional surfaces with an increased number of applications
Fabrication of superhydrophobic surfaces by laser irradiation has been reported for different materials [6,7] by the chemical modification of the surface or micro-structuring
laser-induced periodic surface structures (LIPSS) are formed upon repetitive irradiation at fluences well below the ablation threshold and, in particular, linear structures are formed in the case of irradiation with linearly polarized laser beams, while irradiation with circularly polarized lasers gives rise to the formation of circular nanostructures [30]

Summary

Introduction

More and more effort is being made to fabricate functional surfaces with an increased number of applications. The fabrication of structures in the micro- and nanoscale allows the design of materials with advanced surface properties. Examples of complex structures possessing specific functions and properties can be found in nature [1]. The control of wettability by the presence of hierarchical surface structures, ranging from micro- to the nanometer scale, may provide self-cleaning properties similar to the lotus leaf in nature [2,3]. Changing and controlling the wetting properties of a material by nanostructuring may allow new applications in the fields of microfluidics, nanofluidics, optofluidics, biomedicine, environmental science and self-cleaning, among others [4,5]. Fabrication of superhydrophobic surfaces by laser irradiation has been reported for different materials [6,7] by the chemical modification of the surface or micro-structuring

Methods

Results

Conclusion