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Micro- and nanoscale structures produced on surfaces of metals, polymers, ceramics, and glasses have many important applications in different fields such as engineering, medical, biological, etc. Laser ablation using ultrashort pulses has become the prominent technique for generating different surface structures for various functional applications. Ultrashort laser ablation proved to be ideal for producing structures with dimensions down to the nanometre scale. In comparison to other texturing techniques employed to create micro/nano features such as electrochemical machining, micro-milling, ion-beam etching, hot embossing, lithography, and mechanical texturing, ultrashort laser ablation produces high-quality surfaces at low cost in a one-step non-contact process. Advantageous characteristics of polymers such as high strength-to-weight ratio, non-corrosive nature, and high electrical and thermal resistance, have made polymers the preferred choice compared to other materials (e.g., steel, aluminium, titanium) in several fields of application. As a result, laser ablation of polymers has been of great interest for many researchers. This paper reviews the current state-of-the art research and recent progress in laser ablation of polymers starting from laser-material interaction, polymer properties influenced by laser, laser texturing methods, and achievable surface functionalities such as adhesion, friction, self-cleaning, and hydrophilicity on commonly used polymeric materials. It also highlights the capabilities and drawbacks of various micro-texturing techniques while identifying texture geometries that can be generated with these techniques. In general, the objective of this work is to present a thorough review on laser ablation and laser surface modification of a variety of industrially used polymers. Since direct laser interference patterning is an emerging area, considerable attention is given to this technique with the aim of forming a basis for follow-up research that could pave the way for potential technological ideas and optimization towards obtaining complex high-resolution features for future novel applications.

Surface texturing has been frequently used for tribological purposes in the last three decades due to its great potential to reduce friction and wear. Although biological systems advocate the use of hierarchical, multi-scale surface textures, most of the published experimental and numerical works have mainly addressed effects induced by single-scale surface textures. Therefore, it can be assumed that the potential of multi-scale surface texturing to further optimize friction and wear is underexplored. The aim of this review article is to shed some light on the current knowledge in the field of multi-scale surface textures applied to tribological systems from an experimental and numerical point of view. Initially, fabrication techniques with their respective advantages and disadvantages regarding the ability to create multi-scale surface textures are summarized. Afterwards, the existing state-of-the-art regarding experimental work performed to explore the potential, as well as the underlying effects of multi-scale textures under dry and lubricated conditions, is presented. Subsequently, numerical approaches to predict the behavior of multi-scale surface texturing under lubricated conditions are elucidated. Finally, the existing knowledge and hypotheses about the underlying driven mechanisms responsible for the improved tribological performance of multi-scale textures are summarized, and future trends in this research direction are emphasized.

The present work provides an experimental assessment of the impact of liquid surface tension on the single bubble dynamics generated by artificial nucleation cavities during boiling in a quiescent liquid. De-ionized water is used with and without added non-ionic surfactant (Dynol 800) to modify the fluid’s surface tension while keeping the other thermo-physical fluid properties unchanged. Furthermore, two different cavity geometries are investigated: a vertical and a 30°-inclined cone produced via femtosecond laser texturing. This paper shows preliminary results related to the influence of surface tension and cavity geometry on the single bubble dynamics. A methodological baseline is provided to enable future studies aiming to answer still-open questions about vapour bubble nucleation phenomena.

Femtosecond laser etching is applied to fabricate cylindrical, quadrangular and circular hole micro-structures to explore the variation patterns of their reflectivity. The results show that the cylindrical and quadrangular texturing structures have the optimal anti-reflection effect (the reflectivity is always below 6%) in the wavelength range of 350-1000 nm, which is of reference value for the study of fabricating low-reflectivity texturing on monocrystalline silicon surfaces.

Cork and its composites have shown great potential to be employed in protective equipment, damping, and crashworthy systems. Their sustainability is far more positive than that of the solutions currently used. Recent advances in the development of cork composites with shear thickening fluids (STFs) have demonstrated promising results for impact mitigation, mainly focusing on layered structures. This study investigates disruptive configurations of cork-based multilayered structures strategically enhanced with shear-thickening fluid interfaces. In addition, laser texturing of the cork surface to enhance the STF interaction was also investigated. The samples were then subjected to low-energy impact tests with a hemispherical impactor. Additionally, samples were subjected to scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to investigate the interactions with STF and modifications caused by the interaction with the laser beam. Some of the explored configurations substantially reduced the impact force, achieving a maximum reduction of 19.7%, mainly benefiting from the STF incorporation between cork layers and enhanced with laser texturing.

This paper studies the effect of the modified soda-lime glass surface that reduces water adhesion and raises the water contact angle by modifying the laser processing parameter. The study looked at how these variables affected the water contact angle and surface morphology. The characterization was performed using an inverted metallurgical microscope for surface morphology, and a sessile drop test setup for water contact angle measurement and bricklayer pattern with two different hatch spacings of 0.3 and 0.5 mm was used. The results revealed that the highest water contact angle achieved after surface modification for 0.3 mm was 98.97° at 1000 mm/min and 1.0 W while for 0.5 mm at 93.01°, at 600 mm/min and 1.2 W, improved its hydrophobicity from untextured glass 32.35°. Both sample patterns with 0.3 and 0.5 mm show no defect and all samples seem to have a mark from laser texturing with an increase in power, the laser mark on the surface becomes wider and the large gap between the line becomes more distinct. These findings are significant for designing hydrophobic glass surfaces using laser texturing.

Zirconia ceramic is an ideal dental restoration material owing to its good biocompatibility, superior physical behaviors, and excellent aesthetic properties. However, peri-implant inflammation and excessive occlusal surface wear are critical issues that hinder the clinical application of zirconia ceramic dentures. The surface texturing technique is an unique means to improve the surface properties of products, such as biocompatibility. This paper provides a detailed overview of the definition and development of surface texturing techniques. A comprehensive review is conducted on the machining mechanisms and features of common texture preparation techniques, such as laser texturing and ultrasonic vibration texturing. The mechanisms of surface textures on the tribological behaviors, wettability, and antibacterial behaviors of specimens such as restorations are deeply discussed. The limitations of current studies on surface texturing techniques of dental zirconia ceramics and the future prospects are outlined. The review can help scientists improve the currently available cost-effective texture preparation process and develop high-performance denture restorations.

This paper analyzes the tribological behavior of the Ti6Al4V ELI alloy subjected to laser texturization for medical purposes. Laser texturing enables one to observe specific patterns of the material surface at established depths. Microtexturing of the samples was performed using a 355 nm picosecond laser. The influence of the microtexturing process (depending on the process parameters) on the geometric parameters of the proposed laser texturing pattern was evaluated. Selected samples were subjected to tribological testing using the ball-on-plate technique in dry and lubricant-sliding methods (in Ringer solution). The wear properties were evaluated by comparing the coefficient friction, wear volumes, and wear ratio. A scanning electron microscope characterized the morphologies of the wear scar and the wear mechanism. The experimental results show that the surface texturing and the changes in microgrooves can reduce wear. The results indicate, that samples after laser texturing were characterized by 15% higher microhardness, compared to those in the initial state. It was found, a 26% reduction in friction coefficient and 29% in the wear volume compared to the smooth, untextured surface samples under lubricated conditions. The decrease in value of the coefficient friction and wear volume for the samples after the laser texturing process is an effect of synergistic of entrapped wear debris in micro-grooves and increased hardness for samples after laser textured.

An experimental study is presented to evaluate the influence of anisotropically shaped textures on the behaviour of sliding friction and sensitivity to sliding direction. The plate samples were textured with triangular sloped dimples using an ultrafast laser surface texturing technique. Reciprocating cylinder-on-plate tests were conducted with steel sliding pairs using mineral base oil as a lubricant to compare the tribological performance of reference non-textured specimen and dimpled samples. The dimples were designed with varying converging angles in the transverse y – z plane and top-view x – y plane. In this study, no dimple was fully covered in the contact area since the dimples size is much larger than the Hertzian line contact width. Stribeck style dynamic friction curves across boundary, mixed and hydrodynamic lubrication regimes were used to determine the benefit or antagonism of texturing. Observation of the directional friction effect of the anisotropic textures indicated that the converging shapes are beneficial for friction reduction, and the dimpled specimens have a lower friction coefficient particular under prevailing boundary lubrication conditions. It was also found that the real contact length variation rate is a major factor controlling the local friction response. The sloped bottoms of the textures produce effective converging wedge action to generate hydrodynamic pressure and contribute to the overall directional friction effects.

Surface textures with micro-scale feature dimensions still hold great potential to enhance the frictional performance of tribological systems. Apart from the ability of surface texturing to reduce friction, surface textures can also be used to intentionally increase friction in various applications that rely on friction for their adequate functioning. Therefore, this review aims at presenting the state-of-the-art regarding textured surfaces for high-friction purposes. After a brief general introduction, the recent trends and future paths in laser surface texturing are summarized. Then, the potential of surface textures to increase friction in different applications including adhesion, movement transmission and control, biomimetic applications, and road-tire contacts is critically discussed. Special emphasis in this section is laid on the involved mechanisms responsible for friction increase. Finally, current short-comings and future research directions are pointed out thus emphasizing the great potential of (laser-based) surface texturing methods for innovations in modern surface engineering.