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.

Polycrystalline diamonds, polycrystalline cubic boron nitrides and tungsten carbides are considered difficult to process due to their superior mechanical (hardness, toughness) and wear properties. This paper aims to review the recent progress in the use of lasers to texture hard and ultra-hard materials to a high and reproducible quality. The effect of wavelength, beam type, pulse duration, fluence, and scanning speed is extensively reviewed, and the resulting laser mechanisms, induced damage, surface integrity, and existing challenges discussed. The cutting performance of different textures in real applications is examined, and the key influence of texture size, texture geometry, area ratio, area density, orientation, and solid lubricants is highlighted. Pulsed laser ablation (PLA) is an established method for surface texturing. Defects include melt debris, unwanted allotropic phase transitions, recast layer, porosity, and cracking, leading to non-uniform mechanical properties and surface roughness in fabricated textures. An evaluation of the main laser parameters indicates that shorter pulse durations (ns—fs), fluences greater than the ablation threshold, and optimised multi-pass scanning speeds can deliver sufficient energy to create textures to the required depth and profile with minimal defects. Surface texturing improves the tribological performance of cutting tools in dry conditions, reducing coefficient of friction (COF), cutting forces, wear, machining temperature, and adhesion. It is evident that cutting conditions (feed speed, workpiece material) have a primary role in the performance of textured tools. The identified gaps in laser surface texturing and texture performance are detailed to provide future trends and research directions in the field.

Late in-stent thrombus and restenosis still represent two major challenges in stents’ design. Surface treatment of stent is attracting attention due to the increasing importance of stenting intervention for coronary artery diseases. Several surface engineering techniques have been utilised to improve the biological response in vivo on a wide range of biomedical devices. As a tailorable, precise, and ultra-fast process, laser surface engineering offers the potential to treat stent materials and fabricate various 3D textures, including grooves, pillars, nanowires, porous and freeform structures, while also modifying surface chemistry through nitridation, oxidation and coatings. Laser-based processes can reduce the biodegradable materials' degradation rate, offering many advantages to improve stents’ performance, such as increased endothelialisation rate, prohibition of SMC proliferation, reduced platelet adhesion and controlled corrosion and degradation. Nowadays, adequate research has been conducted on laser surface texturing and surface chemistry modification. Laser texturing on commercial stents has been also investigated and a promotion of performance of laser-textured stents has been proved.

Laser surface texturing has attracted growing interest, particularly in functional surface modification. Lasers with nanosecond pulse widths and infrared wavelengths are commonly used for metallic surface texturing because of their low cost and potential for fabricating a large range of textures. In this research, a laser with a nanosecond pulse width and infrared wavelength was used for the surface texturing of 316 stainless steels. Standard grooved and near-isotropic surface textures, as well as novel porous texture and feather-like dendrite texture, were fabricated through single-time laser texturing. Water contact angle tests were performed on the post-process surfaces, and they showed wettability changes from superhydrophilic to superhydrophobic according to different types of textures. Discussion on the relationship between water contact angle and surface roughness, groove width/depth ratio, surface carbon and oxygen contents indicated that it is the surface morphology that impacts changes in wettability. The comprehensive formation mechanism of different textures and the wettability control mechanism through different textures have been systematically discussed. For the first time, the three-level (point-line-area) laser surface ablation mechanism has been established. The proposed findings can be used for future laser texturing process designs on metals using lasers with a nanosecond pulse width and an infrared wavelength for various applications including wettability modification.