Laser-based manufacturing routes for functionalizing surfaces by Jean-Michel Romano May 2019 A thesis submitted to the University of Birmingham for the degree of Doctor of Philosophy Department of Mechanical Engineering School of Engineering College of Engineering and Physical Sciences University of Birmingham University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. Abstract Robust functional surfaces are of a growing industrial interest for a range of optical, easy-to- clean, anti-icing and non-fouling applications. At the same time, nature is a great source of inspiration for micro/nano-scale surface structures with tailored functional properties. There are a number of competing technologies for producing such structures but ultrashort laser processing is emerging as one of the most promising for fabricating bio-inspired surfaces. However, the technology has limitations and its capabilities have to be augmented to achieve the required high- throughput in manufacturing products that incorporate functional surface topographies. Therefore, this research investigates a promising process chain that combines synergistically the capabilities of laser texturing with complementary surface engineering and replication technologies. Several large-area laser texturing techniques are investigated, namely Direct Laser Writing (DLW), Laser-Induced Periodic Surface Structures (LIPSS) and microlenses-induced Photonic Jet (PJ) texturing. The research advances the knowledge in laser-based surface functionalization and also in factors affecting the functional response and durability of laser structured surfaces. - i - Acknowledgments What a journey it has been! During my three years as PhD student, I have met incredible persons who contributed directly or indirectly to my research. Now is the time to acknowledge them appropriately. Primarily, I am grateful to Prof. Stefan Dimov for accepting me in his research group. I valued his guidance and the freedom that he gave me in orientating my research. I would like to acknowledge my colleagues from the School of Engineering and the Laser group. My gratitude goes to my teammate Antonio García Girón for the years spent together in the lab and outside working hours, where he had to listen to my French humor and my musical taste. I am thankful to Prof. Hanshan Dong for the valuable discussions and the fruitful collaborative work with the School of Metallurgy and Materials; I also take the opportunity to thank Behnam Dashtbozorg and Shaojun Qi for your constant support. I would like to thank Rachel Sammons from the School of Dentistry for the valuable discussions and for training me in microbiological characterization. I acknowledge as well Shangfeng Du and Ahmad El-Kharouf for the access to equipment in the School of Chemical Engineering. I thank Olivier Delléa from the CEA-Liten for the deposition of microspheres and my colleague Rajib Ahmed for his skills in simulations and his advices in paper editing. I thank Ralf Helbig from the Leibniz Institute for Polymer Research for his valuable expertise in bio-inspired surfaces and the non-fouling characterizations performed in this work. I am grateful to Prof. Ben Whiteside from the Centre for Polymer Micro and Nano Technology for welcoming me in Bradford where I carried out a research exchange on micro injection - ii - molding, with the precious support of Mert Gülçür. I am also grateful to Virginia Gotor, Andrés Escartín and Francisco Javier Ester for granting Antonio and me with the access to the research facilities at BSH Electrodomésticos in Zaragoza. I would like to thank the researchers in BSH and especially Jorge Fantova Sarasa who contributed to the manufacturing of injection molded parts. I also had the pleasure to meet Prof. José Ignacio Peña and had the opportunity to use his lab at the Universidad de Zaragoza, during my research exchange in Spain. Finally, I thank Elmar Bonaccurso and Vittorio Vercillo for your welcoming in Airbus in Munich and the fruitful collaboration. I would like to acknowledge the European Commission and the Marie Skłodowska-Curie Actions for the financial support to my research. In these tumultuous times, I truly believe that withdrawal is not a solution but that we have to foster intercultural and multidisciplinary interactions. I learned and met great persons within our research consortium on laser texturing and surface functionalization and my research would not have been possible without them. My thoughts are with the other PhD students of the Laser4Fun project: Melissa Sikosana, Antonio García Girón, José Cardoso, Daniel Huerta, Vittorio Vercillo, Gagandeep Singh Joshi, Fotis Fraggelakis, Luigi Capuano, Marek Mezera Sabri Alamri, Alfredo Aguilar Morales, Tobias Stark. There should be no misunderstanding, on top of our hard work and accomplishments, there was indeed a lot of fun, especially during our adventures in Bordeaux, Berlin, Dresden, Zaragoza and Amsterdam. I’ll never forget the trip to Bari, for many reasons including the amazing live concert of Prof. Gert-willem Römer and Prof. Andrés Lasagni. I have to thank several persons that I met during my graduate studies at the Technical University Dresden and the Karlsruhe Institute of Technology and who eventually led me to pursue this PhD experience: Prof. Andrés Lasagni, Stephan Hunze, Mateusz Chlipala and Mathias Heckele. - iii - Moreover, I warmly thank Prof. Philippe Tanguy for inspiring me during our years spent at Total. Last but not least, this journey would not have been possible without the support of my family and friends. To my parents, thank you for encouraging me to follow my dreams. Merci Maman pour ton attention et ta bienveillance. Merci Papa pour me pousser toujours de l’avant et me rappeler de “faire attention”. J’ai des pensées affectueuses pour mes frères et sœurs, Marie, Cynthia et Julien, ainsi que ma petite nièce Séraphine. I am thinking especially at my friends who were there for me for important moments of my life, I know you will recognize yourselves in this few lines. I cannot cite everyone as I don’t want to double the printing costs, but Anne, Pierre-Georges, Guillaume, Léonard and Yann, you are part of them. Thank you, Nashira and Ana Maria for having been such wonderful flatmates, I loved our trips and that we were there for each other. Thanks to Pauline, Sylvain and Jean-Luc for our evenings at the Flapper, the Bacchus, the Prince of Wales and the Shakespeare; and to Aymeric, Vincent and Benoit for being great climbing partners. To my parceros, Ana Maria, Ana, Lorea, Roberto and Antonio: long live the “Consultancy”. You are amazing. - iv - Table of Contents Page Abstract ............................................................................................................................................ i Acknowledgments ........................................................................................................................... ii Table of Contents ............................................................................................................................ v List of Tables .................................................................................................................................. x List of Figures ................................................................................................................................ xi Nomenclature ............................................................................................................................... xxi List of Publications and Presentations ...................................................................................... xxvii Chapter 1: General introduction .................................................................................................... 1 1.1 Motivation ........................................................................................................................... 2 1.2 Research aims and objectives ............................................................................................. 5 1.3 Thesis organization ............................................................................................................. 7 Chapter 2: Literature review ......................................................................................................... 9 2.1 Bio-inspired functional surfaces ....................................................................................... 10 2.1.1 Nature as inspiration: self-organized features ....................................................... 10 2.1.2 Legs and feet ......................................................................................................... 11 2.1.3 Wings and feathers ................................................................................................ 13 2.1.4 Eyes of mosquitos and moths ............................................................................... 15 2.1.5 Body skins and elytra ...........................................................................................