Structuring of polystyrene surface with ultrashort laser pulses: Comparative studies for ultraviolet, visible and mid-infrared wavelengths
Abstract
Biocompatible polymers, such as polystyrene (PS), are still in the centre of interest for a wide range of applications, such as microsystem technology, micro-optics, fabrication of lab-on- chip devices or investigation of cell growth behaviour [1-4]. For such applications, the surface properties of polymers must be activated or modified that can be achieved by pulsed laser ablation (PLA) with carefully chosen appropriate conditions.
The PLA of polystyrene, similarly to many other polymers, has been extensively investigated mainly for the ultraviolet (UV) spectral range. Polymer ablation in the near-infrared (near-IR) spectral range is still not widely studied, especially in the regimes of ultrashort laser pulses, despite that the non-linear absorption phenomena in IR region offer different features of material response to laser irradiation.
In this work, we present a complex approach to PLA of polystyrene (PS) polymer in a wide range of electromagnetic spectra from UV to mid-IR laser light. The ablation was performed at different pulse durations (ps and fs).
Single- and multi-shot thresholds have been determined and crater/grooves profiles have been analysed. Accurate structuring of this biocompatible polymer is of importance for studies of collective behaviour and growth of cellular systems.