The spatial emergence of laser-induced periodic surface structures under lateral displacement irradiation conditions

Abstract

University of Twente Blank Justus EichstädtThe spatial emergence of laser-induced periodic surface structures under lateral displacement irradiation conditions This book is archived in the library of the University of Twente and at the same time a dissertation. Detailed information and a digital version of this book can be found on the following web page: www.utwente.nl and under the specified DOI. A printed and high-resolution digital version can be ordered at the author. University of Twente PrefaceWith this book, I would like to present my contribution to science. The subject concerns the determination of laser irradiation parameters, an issue that puzzled me already for quite some time. Hence, the content of this book is determined by the experience that I have made with the analysis of laser experiments. It was necessary to understand the laser irradiation and the spatial emergence. So, I simply calculated the irradiation, as presented in Chapter 2 and 4, and started to think about the thresholds, as presented in Chapter 3. This work ended up in this scientific contribution.In the following, I will briefly describe the framework in which this work has been carried out. The research results were compiled at the Chair of Applied Laser Technology within the Faculty of Engineering Technology of the University of Twente in Enschede -The Netherlands in the years 2009 to 2014. In the first three years of this period a European research project has been carried out. This project had the acronym NanoClean. The aim of NanoClean was the mass production of permanent self-cleaning plastic parts for the automotive sector under industrial manufacturing conditions. Therefore, a previously lab-scale demonstrated laser based manufacturing technology was implemented and evaluated for an industrial application. NanoClean was performed in a collaboration of seven project partners: Maier S. Coop. A third project was related to the study of the tribological properties of LIPSS for precision positioning applications. This research was carried out by the Chair of Applied Laser Technology. The friction measurements have been performed at the Laboratory for Surface Technology and Tribology by Justus Eichstädt. Furthermore, the results were applied in the national M2i research project: Texturing using ultra short laser pulses, abbreviated TULP, with the industrial partners ASML Holding N.V., Lightmotif B.V., FEI Netherlands B.V., Holst Centre -TNO, Philips Applied V VI Preface Technologies. As part of this, an application project was carried out, in which adhesion measurements have been performed at TNO. The writing of this thesis and a part of the analysis were finished in Rathenow.Rathenow, summer 2015, Justus Eichstädt

Model based optimization of process parameters to produce large homogeneous areas of laser-induced periodic surface structures

“…Earlier studies showed, that with a increasing number of pulses impinging the same spot N OS , the local fluence range decreases, at which LIPSS develop [33,34]. This phenomenom is referred to as the incubation effect [34].…”

“…Earlier studies showed, that with a increasing number of pulses impinging the same spot N OS , the local fluence range decreases, at which LIPSS develop [33,34]. This phenomenom is referred to as the incubation effect [34]. The relation between the fluence threshold, due to one laser pulse F th (1) and the fluence threshold F th (N OS ), due to several laser pulses on the same location (N OS > 1), is usually expressed in the form of a power-law [5,34]:…”

“…This phenomenom is referred to as the incubation effect [34]. The relation between the fluence threshold, due to one laser pulse F th (1) and the fluence threshold F th (N OS ), due to several laser pulses on the same location (N OS > 1), is usually expressed in the form of a power-law [5,34]:…”