Laser induced periodic surface structures on polymer films: From fundamentals to applications

The generation of nanostructured polymer films has been a challenge during the last decades. Surface nanostructuring based on the imprinting of nanoscale patterns on a homogeneous surface or on the deposition of nanostructures on the surface serves advantageously for nanofabrication of functional polymer materials. Advanced nanolithography typically requires multiple-steps procedures involving clean-room facilities, high vacuum or complex mask fabrication. Alternatively, laser-based methods enable high spatial resolution patterning of soft polymeric matter and afford the sought versatility and reliability without the need of stringent ambient conditions. In particular, the technique of laser induced periodic surface structures (LIPSS) has been successfully applied to nanostructuring of polymer films using a polarized laser source at several laser wavelengths and pulse durations. In this paper the formation of LIPSS on polymer films will be described. In particular, the possibilities of tuning the period and shape of the structures will be discussed since the control of the characteristics of the superficial structures can be crucial in order to match the requirements of a particular application. Additionally, an overview about the main and potential applications of LIPSS in polymer films is provided. In particular, the use of rippled polymer films as substrates for cell culture/alignment, surface enhanced Raman scattering sensors, or applications in photovoltaics will be reviewed. (C) 2015 Elsevier Ltd. All rights reserved.