Quo Vadis LIPSS?—Recent and Future Trends on Laser-Induced Periodic Surface Structures

Nanotechnology and lasers are among the most successful and active fields of research and technology that have boomed during the past two decades. Many improvements are based on the controlled manufacturing of nanostructures that enable tailored material functionalization for a wide range of industrial applications, electronics, medicine, etc., and have already found entry into our daily life. One appealing approach for manufacturing such nanostructures in a flexible, robust, rapid, and contactless one-step process is based on the generation of laser-induced periodic surface structures (LIPSS). This Perspective article analyzes the footprint of the research area of LIPSS on the basis of a detailed literature search, provides a brief overview on its current trends, describes the European funding strategies within the Horizon 2020 programme, and outlines promising future directions.

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One-step fabrication of bi- and quad-directional femtosecond laser-induced periodic surface structures on metal with a depolarizer

Applied Surface Science ◽

10.1016/j.apsusc.2019.07.025 ◽

2019 ◽

Vol 493 ◽

pp. 231-238 ◽

Cited By ~ 1

Author(s):

Taek Yong Hwang ◽

Heedeuk Shin ◽

Jeongjin Kang ◽

Byounghwak Lee ◽

Chunlei Guo

Keyword(s):

Femtosecond Laser ◽

Surface Structures ◽

Periodic Surface ◽

One Step

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SPECIAL ISSUE ON INNOVATION AND APPLICATION OF MECHANICAL ENGINEERING GUEST EDITORIAL

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2015-0026 ◽

2015 ◽

Vol 39 (3) ◽

pp. ix-ix

Author(s):

Wen-Hsiang Hsieh

Keyword(s):

Peer Review ◽

Mechanical Engineering ◽

Technology Innovation ◽

Research Area ◽

Industrial Applications ◽

Canadian Society ◽

Special Issue ◽

Wide Range ◽

Mechanical Products ◽

The Many

Machines make all industrial artifacts and mechanical products in the world. In this 21th century, people enjoy mechanical products that made lives well and convenient. However, creating a useful mechanical product mainly relies on academic development and technology innovation especially in the field of mechanical engineering. This special issue focuses on the innovation and application of mechanical engineering, which covers a wide range of fundamental studies, technical innovation, and industrial applications by applying the knowledge of mechanical-related approaches, processes and techniques. It presents 33 selected papers (Part 1) from the 3rd International Conference on Engineering and Technology Innovation (ICETI 2014) which was held from October 31 to November 4, 2014, in Kenting, Taiwan. These selected papers underwent a complete Transactions of the Canadian Society for Mechanical Engineering peer-review. Acceptance in this special issue was based on completion of the reviewers recommended and mandatory changes and final examination by the Guest Editor. We thank all of the authors who have submitted their work for publication in this special issue. We are also grateful to the many reviewers that provided their time and expertise in providing valuable peer review. Special thanks also go to Professor Paul J. Zsombor-Murray, Editor of Transactions of the Canadian Society for Mechanical Engineering, who had the foresight to support a special issue in this research area. This special issue is expected to be a core issue for academic researches and industrial engineers in the mechanical engineering field.

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Thermochemical Laser-Induced Periodic Surface Structures Formation by Femtosecond Laser on Hf Thin Films in Air and Vacuum

Materials ◽

10.3390/ma14216714 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6714

Author(s):

Dmitrij A. Belousov ◽

Kirill A. Bronnikov ◽

Konstantin A. Okotrub ◽

Sergey L. Mikerin ◽

Victor P. Korolkov ◽

...

Keyword(s):

Laser Radiation ◽

Orientation Angle ◽

Ambient Air ◽

Chemical Oxidation ◽

Surface Structures ◽

Large Area ◽

Temperature Oxidation ◽

Periodic Surface ◽

High Regularity ◽

Wide Range

Thermochemical laser-induced periodic surface structures (TLIPSS) are a relatively new type of periodic structures formed in the focal area of linear polarized laser radiation by the thermally stimulated reaction of oxidation. The high regularity of the structures and the possibility of forming high-ordered structures over a large area open up possibilities for the practical application for changing the optical and physical properties of materials surface. Since the mechanism of formation of these structures is based on a chemical oxidation reaction, an intriguing question involves the influence of air pressure on the quality of structure formation. This paper presents the results on the TLIPSS formation on a thin hafnium film with fs IR laser radiation at various ambient air pressures from 4 Torr to 760 Torr. Despite the decrease in the oxygen content in the ambient environment by two orders of magnitude, the formation of high-ordered TLIPSS (dispersion in the LIPSS orientation angle δθ < 5°) with a period of ≈700 nm occurs within a wide range of parameters variation (laser power, scanning speed). This behavior of TLIPSS formation is in agreement with experimental data obtained earlier on the study of the kinetics of high-temperature oxidation of hafnium at various oxygen pressures.

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Large-Area Fabrication of Laser-Induced Periodic Surface Structures on Fused Silica Using Thin Gold Layers

Nanomaterials ◽

10.3390/nano10061187 ◽

2020 ◽

Vol 10 (6) ◽

pp. 1187 ◽

Cited By ~ 2

Author(s):

Clemens Kunz ◽

Sebastian Engel ◽

Frank Müller ◽

Stephan Gräf

Keyword(s):

Fused Silica ◽

Surface Structures ◽

Spatial Period ◽

Direct Writing ◽

Large Area ◽

Periodic Surface ◽

Single Spot ◽

Research Activities ◽

Wide Range ◽

Fs Laser

Despite intensive research activities in the field of laser-induced periodic surface structures (LIPSS), the large-area nanostructuring of glasses is still a challenging problem, which is mainly caused by the strongly non-linear absorption of the laser radiation by the dielectric material. Therefore, most investigations are limited to single-spot experiments on different types of glasses. Here, we report the homogeneous generation of LIPSS on large-area surfaces of fused silica using thin gold layers and a fs-laser with a wavelength λ = 1025 nm, a pulse duration τ = 300 fs, and a repetition frequency frep = 100 kHz as radiation source. For this purpose, single-spot experiments are performed to study the LIPSS formation process as a function of laser parameters and gold layer thickness. Based on these results, the generation of large-area homogenous LIPSS pattern was investigated by unidirectional scanning of the fs-laser beam across the sample surface using different line spacing. The nanostructures are characterized by a spatial period of about 360 nm and a modulation depth of around 160 nm. Chemical surface analysis by Raman spectroscopy confirms a complete ablation of the gold film by the fs-laser irradiation. The characterization of the functional properties shows an increased transmission of the nanostructured samples accompanied by a noticeable change in the wetting properties, which can be additionally modified within a wide range by silanization. The presented approach enables the reproducible LIPSS-based laser direct-writing of sub-wavelength nanostructures on glasses and thus provides a versatile and flexible tool for novel applications in the fields of optics, microfluidics, and biomaterials.

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Ten Open Questions about Laser-Induced Periodic Surface Structures

Nanomaterials ◽

10.3390/nano11123326 ◽

2021 ◽

Vol 11 (12) ◽

pp. 3326

Author(s):

Jörn Bonse ◽

Stephan Gräf

Keyword(s):

Industrial Applications ◽

Surface Structures ◽

Theoretical Modelling ◽

Periodic Surface ◽

Long Term Stability ◽

Energy Technologies ◽

Current State ◽

Open Questions ◽

Technological Limitations

Laser-induced periodic surface structures (LIPSS) are a simple and robust route for the nanostructuring of solids that can create various surface functionalities featuring applications in optics, medicine, tribology, energy technologies, etc. While the current laser technologies already allow surface processing rates at the level of m2/min, industrial applications of LIPSS are sometimes hampered by the complex interplay between the nanoscale surface topography and the specific surface chemistry, as well as by limitations in controlling the processing of LIPSS and in the long-term stability of the created surface functions. This Perspective article aims to identify some open questions about LIPSS, discusses the pending technological limitations, and sketches the current state of theoretical modelling. Hereby, we intend to stimulate further research and developments in the field of LIPSS for overcoming these limitations and for supporting the transfer of the LIPSS technology into industry.

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Generalized Plasmonic Modelling of the Effect of Refractive Index on Laser-Induced Periodic Nanostructures

Journal of Materials and Applications ◽

10.32732/jma.2019.8.2.73 ◽

2019 ◽

Vol 8 (2) ◽

pp. 73-79

Author(s):

A. Abdelmalek ◽

Z. Bedrane ◽

V. Bharadwaj ◽

E.-H. Amara ◽

R. Ramponi ◽

...

Keyword(s):

Laser Irradiation ◽

High Spatial Frequency ◽

Refraction Index ◽

Dielectric Materials ◽

Laser Wavelength ◽

Surface Structures ◽

Femtosecond Laser Irradiation ◽

Periodic Nanostructures ◽

Periodic Surface ◽

Wide Range

Laser-induced periodic surface structures (LIPSS) have been studied theoretically employing generalized plasmonic modelling on several dielectric materials such as SiO2, Al2O3, ZnO, AlAs and diamond exposed to 800 nm wavelength multi-pulse femtosecond laser irradiation. The study of the optical properties of the materials during laser irradiation reveals a formation of a metallic like pseudo-material on the irradiated layer during excitation. A study of the grating periodicity of the nanostructures shows that the materials having a high refraction index allow LIPSS formation with a wide range of grating periodicities. Results also show High Spatial Frequency LIPSS formation with periodicities 3 to 8 times lower than the laser wavelength.

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History of the Study of Apocrypha in Early Medieval England

Bulletin for the Study of Religion ◽

10.1558/bsor.37171 ◽

2020 ◽

Vol 48 (3-4) ◽

pp. 13-26

Author(s):

Brandon W. Hawk

Keyword(s):

Old Testament ◽

Medieval England ◽

Medieval Period ◽

Early Medieval ◽

Future Directions ◽

Early Judaism ◽

Wide Range ◽

History Of ◽

The Subject ◽

Early English

Literature written in England between about 500 and 1100 CE attests to a wide range of traditions, although it is clear that Christian sources were the most influential. Biblical apocrypha feature prominently across this corpus of literature, as early English authors clearly relied on a range of extra-biblical texts and traditions related to works under the umbrella of what have been called “Old Testament Pseudepigrapha” and “New Testament/Christian Apocrypha." While scholars of pseudepigrapha and apocrypha have long trained their eyes upon literature from the first few centuries of early Judaism and early Christianity, the medieval period has much to offer. This article presents a survey of significant developments and key threads in the history of scholarship on apocrypha in early medieval England. My purpose is not to offer a comprehensive bibliography, but to highlight major studies that have focused on the transmission of specific apocrypha, contributed to knowledge about medieval uses of apocrypha, and shaped the field from the nineteenth century up to the present. Bringing together major publications on the subject presents a striking picture of the state of the field as well as future directions.

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Substituent Effects on the Thermal Decomposition of Phosphate Esters on Ferrous Surfaces

10.26434/chemrxiv.11418978.v1 ◽

2019 ◽

Author(s):

James Ewen ◽

Carlos Ayestaran Latorre ◽

Arash Khajeh ◽

Joshua Moore ◽

Joseph Remias ◽

...

Keyword(s):

Thermal Decomposition ◽

Film Formation ◽

Substituent Effects ◽

Vapour Phase ◽

Industrial Applications ◽

Phosphate Esters ◽

Antiwear Additives ◽

Formation Mechanisms ◽

Phosphate Ester ◽

Wide Range

Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe3O4(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe3O4, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe3O4(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe3O4. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe3O4(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe3O4(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.

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A review on aversive Pavlovian-to-Instrumental transfer in humans

10.31234/osf.io/dyz29 ◽

2020 ◽

Author(s):

Anna Gerlicher ◽

Merel Kindt

Keyword(s):

Avoidance Behavior ◽

Neural Circuits ◽

Transfer Effects ◽

Future Directions ◽

Transfer Paradigm ◽

Wide Range ◽

Threat Cues ◽

Imminent Threat ◽

Fear And Anxiety ◽

Pathological Anxiety

A cue that indicates imminent threat elicits a wide range of physiological, hormonal, autonomic, cognitive, and emotional fear responses in humans and facilitates threat-specific avoidance behavior. The occurrence of a threat cue can, however, also have general motivational effects and affect behavior. That is, the encounter with a threat cue can increase our tendency to engage in general avoidance behavior that does neither terminate nor prevent the threat-cue or the threat itself. Furthermore, the encounter with a threat-cue can substantially reduce our likelihood to engage in behavior that leads to rewarding outcomes. Such general motivational effects of threat-cues on behavior can be informative about the transition from normal to pathological anxiety and could also explain the development of comorbid disorders, such as depression and substance abuse. Despite the unmistakable relevance of the motivational effects of threat for our understanding of anxiety disorders, their investigation is still in its infancy. Pavlovian-to-Instrumental transfer is one paradigm that allows us to investigate such motivational effects of threat cues. Here, we review studies investigating aversive transfer in humans and discuss recent results on the neural circuits mediating Pavlovian-to-Instrumental transfer effects. Finally, we discuss potential limitations of the transfer paradigm and future directions for employing Pavlovian-to-Instrumental transfer for the investigation of motivational effects of fear and anxiety.

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PLATINUM

Alloy Digest ◽

10.31399/asm.ad.pt0001 ◽

1970 ◽

Vol 19 (11) ◽

Keyword(s):

Corrosion Resistance ◽

High Temperature ◽

Heat Treating ◽

Industrial Applications ◽

High Melting ◽

High Melting Point ◽

White Metal ◽

Temperature Performance ◽

Wide Range ◽

Corrosion And Oxidation

Abstract PLATINUM is a soft, ductile, white metal which can be readily worked either hot or cold. It has a wide range of industrial applications because of its excellent corrosion and oxidation resistance and its high melting point. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Pt-1. Producer or source: Matthey Bishop Inc..

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