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The goal of this experiment is to investigate the effect of laser engraving parameters on Al 6063 aluminum alloy specimens using a fiber laser engraving equipment. The experimental design makes use of Taguchi's L16 orthogonal array. Surface roughness and engraving depth are the responses which are to be optimum for machining process parameters such as fill spacing, power, frequency, and scan speed. Using regression analysis, the mathematical models for individual responses were created. Grey relational analysis coupled with the Taguchi technique has been presented for simultaneous response optimization. The optimal setting parameters for multiple performance characteristics is fill spacing at level-3, power at level-4, frequency at level-2 and scan speed at level-4 i.e., FS3-P4-F2-SS4. To determine the significance of the models, the Analysis of Variance (ANOVA) approach is used. Finally, in the confirmation test, it is observed that the grey relational grade is improved from the initial process parameter combination.

The demand inherent to the aeronautical industry in terms of productivity and quality requirements leads to develop new cutting tools. Hence, PCD tools meet the requirements in productivity while machining low machinability aeronautical alloys such as Ti6Al4V. Tool chipbreakers play a considerable role in terms of tool life. However, due to the extreme conditions (temperature and pressure) required to manufacture PCD tools, any complex geometry on tool rake faces is not viable, so chipbreakers are not possible, except for those external to inserts. This work proposes a groove-type laser engraved chipbreaker design and a manufacturing methodology, with experimental validation on turning a Ti6Al4V workpiece. The so-manufactured chipbreakers achieve titanium alloy chip fragmentation, making easy chip removal from the cutting zone. A set of experiments involving various laser parameters to characterize the PCD depth and surface integrity and experimental validation for those chipbreakers designs were carried out in finishing cutting conditions. The optimum parameters for the engraving of PCD were found, obtaining satisfactory breakage of titanium chips. Chip length was always below 17.29 mm. Authors are grateful to Basque government group IT IT1337- 19, the Ministry of Mineco REF DPI2016-74845-R and PID2019- 109340RB-I00, and the UPV/EHU itself for the financial aid for the pre-doctoral grants PIF 19/96.

Laser-engraved graphene (LEG) has been applied increasingly in flexible electronics over the past decade owing to its unique physical and chemical properties, and has shown great promise in energy controls, chemical and physical sensing, and telemedicine. In situ laser engraving has empowered graphene with additional versatilities such as miniaturized patterning, tunable composition, controllable morphology, and environmental friendliness. In this review, the technological advances of LEG from synthesis to applications in flexible and wearable electronic devices are summarized. Specifically, the use of LEG in designing next-generation nanogenerators, batteries, supercapacitors, physical sensors, gas sensors, biosensors, and wearable/telemedicine systems is discussed. An outlook related to LEG-based flexible electronics and key technological bottlenecks is identified.

Laser processing results in modified mechanical properties and microstructural evolution due to high temperatures and fast cooling rates. Different laser surface treatment techniques are under investigation for their potential to alter local microstructure and properties while maintaining properties of the bulk material. Fatigue life of laser-engraved powder metallurgy steel is shown to be significantly reduced compared to as-sintered material, suggesting a degree of microstructural modification with engraving. The misorientation, dislocation density, and phase of samples engraved with a 2D matrix pattern using one laser pass and five laser passes are characterized using optical microscopy and SEM-EBSD, and a CFD simulation of the laser process quantifies the temperature profile of each laser engraving. Deep-engraved samples are seen to result in a possible martensitic transformation at the surface of the engraved region because of increased time at elevated temperature and extreme cooling rates. These findings reinforce the importance of understanding microstructural evolution during precision tailoring via laser surface modification.

Laser engraving is an essential tool of automatic drawings and 3D printers. When the laser engraving tasks become large and complicated, engraving process will be time-consuming. To improve the time and energy efficiency, the trajectory optimization of laser engraving is studied. The trajectory of laser engraving robot is modelled as a large-scale traveling salesman problem (TSP), by converting grayscale images into halftone images. To solve the large-scale TSP, two-layered ant colony system (ACS) is newly proposed to combine k-means, top-layer ACS, and bottom-layer ACS. Finally, we use the presented algorithm to optimize the path of four engraving instances which include tens of thousands of discrete points. Experimental results show that this method can reduce laser engraving time by about 50% compared with traditional engraving methods.

Determining the quality of reproduction obtained by direct laser engraving (DLE — Direct Laser Engraving) engravings of the intaglio printing plates and its dependence on the designed profile parameters is an urgent task that will improve the processing of DLE forms and expand its use in the production of securities. Research by optical metallography of engraved strokes of thirty types, which are different in the designed profile (depth (20‒100 μm), width (30‒100 μm), angle of inclination of the walls of the stroke (600‒900)) and the laser’s engraving power, showed that all the engraved strokes of the sample have significant deviations from the specified geometric profile and are usually asymmetric. Since the condition of the surface of the strokes is another additional factor in ensuring the wear resistance of DLE + PVD forms, to take into account this parameter, the principles of scoring the surface of the strokes were developed based on comparison with the sample on a 5-point scale. Experimental studies have shown that, despite the significant differences between the profile obtained by engraving and designed, in terms of possible tactility of prints (the most important parameter of intaglio printing), the vast majority of manufacturing modes and profiles provide a fairly high match of strokes width between engraved strokes and designed ones (80‒130 %). The depth of the stroke varies significantly — from 60 % of the projected to almost 200 %. Due to the significant deviation of the profile from the projected area of intersection of the strokes is in the range of 40‒90 % of the projected. The best geometric parameters have small rectangular strokes. From the point of view of reproduction of a geometrical form of strokes, the trapezoidal profiles have the best parameters. In terms of surface quality of strokes — rectangular profiles. Reducing the radiation power allows both to ensure better reproduction of the geometric parameters of the stroke, and to ensure a better stroke surface quality. The latter is a particularly important factor in ensuring the proper level of adhesion of the protective coating to the brass base, i.e. in the future — higher run-length resistance. Thus, the condition of the surface of the strokes is another additional factor in ensuring the wear resistance of DLE + PVD forms.

The work aim to the reaction mechanism of laser engraving polycarbonate (PC)-based films. The calculation of infrared-laser acting on the PC films, was carried out by using one-dimensional heat conduction model. The power density of laser device required for laser engraving polycarbonate-based films was determined to be 4.86~7.73×104 W/cm2. Characterized by the FTIR spectra, SEM, DSC and TGA, the reaction mechanism was studied. The results show that the light-sensitive particles in the PC films absorb the laser energy with wavelength of 1064nm. After reaching the temperature of 509°C, the main chain of PC molecule opened due to the breakage of C-O bond in PC molecular terminal group and C-O bond between PC monomers. As the energy continues to be absorbed, the temperature reach to 610°C, the decomposition products decomposed into carbon black, which can form a black carbon spot.

The fracture-control matrix unit (F-CMU) is a special body present in low-permeability fractured reservoirs that can be distinguished by a fracture system and a matrix system. The imbibition phenomenon of the F-CMU provides the possibility for secondary development of low-permeability fractured reservoirs because of the driving force including capillary force and gravity. However, the F-CMU is difficult to obtain during the field core drilling, which has limited the development for laboratory dynamic imbibition tests. Therefore, a new F-CMU reconstruction method is proposed in this study. According to the geometry and parameters, combining laser engraving technology, the fracture system is designed and engraved. Then, the F-CMU is established using a three-dimensional (3D) printed material called polyvinyl alcohol (PVA) as fracture support material which has a faster dissolution rate and causes less damage to the core due to water being the solvent. Finally, the porosity, permeability, and wettability of the matrix system and the T2 spectra from nuclear magnetic resonance (NMR) before and after reconstruction are measured. In addition, numerical simulation calculation of F-CMU permeability is performed. The results show that the characteristic parameters of the matrix system hardly change, indicating low damage to the core. The reconstructed fracture system is found on the T2 spectra, and the fracture permeability is consistent by comparing with the experimental and numerical simulation results. The permeability of the fracture system is about 104 orders of magnitude of the matrix system, which is closer to real core and meets the requirements needed for dynamic permeability experiments.

Hypothesis Selective ozone treatment of Polydimethylsiloxane (PDMS) print-stamps may facilitate local de-wetting of Krytox®1506 oil; the resulting printed pattern can be used as a masking liquid during roll-to-roll vacuum-metallization, exemplified with Ag. This novel method may exploit high-throughput manufacture without chemical etchants or elevated temperatures for thin-film electronics. Experiments The mechanism for selective wetting arose from O3 treatment of PDMS through a shadow-mask to vary surface-energy due to formation of polar silanol (Si-OH) replacing surface methyl groups leading to contact angle reduction from 40°-9° for oil on PDMS. Oiled PDMS was (1) metalized itself and (2) used as a stamp to print onto polyethylene-terephthalate, consisting of oil pick-up/de-wetting/transfer-to-substrate/metallization. Findings Ag (520-568 nm) thick was deposited outside oiled regions, surpassing ∼20 μm resolution of commercial printing. On metalized PDMS, minimum line widths were 2.6 μm (with 10 μm edge-grading from centrifugal oil spreading) or widths of 24 μm (no Ag grading) following spin-coating/roll-coating oil respectively. The progressive effect of thinning oil via five successive stamp-to-substrate impressions, produced line widths of 14 μm (with graded edge of 7.6 μm via spreading from stamp-substrate compression). Developments may reduce reliance on laser engraving/photocuring, and could enhance micro-contact printing through liquid dynamics vs. topographical relief structures.

Glass has many attractive properties including transparency, durability, low electrical conductivity, and corrosion resistance, but its brittleness still limits the range of its applications. Three-dimensional laser engraving has been explored to generate three-dimensional (3D) networks of weak interfaces within the bulk of glass. These interfaces deflect cracks and dissipate energy by friction, with mechanisms that are similar to fracture in mollusk shells or teeth. Confocal microscopy was used to characterize the morphology of laser-induced microcracks in borosilicate glass and ceramic glass, and the effective toughness of laser-engraved interfaces was measured. The effect of microcrack spacing on interface morphology, damage parameter, fracture surface, and fracture toughness was explored. Architectured borosilicate glass panels based on a simple grid pattern were then fabricated. These all-brittle panels do not require mechanical confinement and can absorb significantly more impact energy than monolithic glass provided that the interface toughness is tuned properly.

Laser engraving is the most non - traditional and efficient working method in the machining of materials of different geometry as compared to conventional methods. The main objective of this study is to determine the impact of uArm swift pro robot operated laser engraving process on a wooden pitch board piece. However, the robot was connected with uArm Studio 1.1.22 software to perform laser engraving operation. For this purpose the effect of process parameters like spot diameter and depth of penetration were investigated with different working length of the robot end effector, measured from wooden pitch board base. Experimental observation method was used to investigate the formation of deep and light engraving pattern on the pitch board surface by measuring penetration depth and spot diameter in suitable condition. The result obtained from the experiment and statistical parameters showed a new dimension to find a suitable working length of the robot assisted laser nozzle where the laser penetration effect was clearly perceptible for the wooden material.

An intelligent laser machining system is developed for precision processing of superhard materials, such as diamond, silicon carbide, silicon nitride, cubic boron nitride, etc. Multiple processing functions, such as laser cutting, laser engraving, laser cleaning and polishing, can be realized by automatically adjusting laser beam parameters. The laser wavelength is 532 nm that is obtained by the second-harmonic generation of a diode-pumped solid-state laser at 1064 nm. The processing system is highly intelligent and automated, from surface scanning and measurement to self-adjustment of laser beam parameters and motion control variables during processing. In our processing, the workpiece is first scanned using a laser sensor and a 3-D profile of the workpiece is created for customer evaluation. Then, with operator’s input of processing requirements, an optimal processing procedure is designed in terms of comprehensive consideration of machining efficiency, processing duration, machine cost, surface quality, material loss, etc. Next, the material is flatten to a certain flatness by using a suitable engraving process, followed by polishing to a certain roughness, and finally cut to shaped pieces. In both the procedure design and material processing, an artificial neural network method is used in the optimization and adjustment of laser beam and motion control parameters. In the experiment of silicon carbide processing, >10-mm thick bulk materials can be cut with nearly vertical edges and polished with ~0.1 um roughness of surface. The system exhibits broad prospects in the processing applications of superhard materials.

Femtosecond laser engraving offers appealing advantages compared to regular laser engraving such as higher precision and versatility. In particular, the inscription of deep patterns exhibits an increasing interest in industry. In this work, an optimization protocol based on constraining overlap ratio and scan number is demonstrated. The proposed method allows changing overlap ratio while maintaining depth in the same range, which reduces the sampling number. This study WAS applied to stainless steel 316 L and sapphire for engravings deeper than 100 μm. Results exhibit overall depths higher than threshold values and allowed to determine optimized engraving quality, for instance, roughness in steel can be reduced while maintaining depth and taper angle by reducing overlap ratio. The optimized laser parameters such as roughness and taper angle factors for sapphire were also found to be as follows: 200 kHz, 86% overlap and 12 J/cm2. As a demonstration, a logo engraving is illustrated at the end.

Femtosecond laser engraving offers a new avenue for ultimate precision, cleanliness, versatility and supreme quality compared to the already stabilished engraving lasers such as nanosecond or CW CO 2 lasers. Thanks to their non linear light-matter interaction nature it allows not only ablation with negligible thermal effects but also in a wide amount of diferent materials. This later advantage is of special interest for flexible multimaterial engraving which is desired in several industrial sectors. For such purposes, a proper parameter study should be employed for each material in order to achieve highest quality. There are several studies addressing ablation efficiency in several materials [1] , [2] , but this number narrows when other remarkable parameters such as roughness or taper angle are analyzed [3] . This lack of material studies is increased even more for less common materials and when high depth is desired. In this work we have performed a smart parameter optimization of SiC, PEEK and sapphire. The influence of fluence, overlap ratio (OP) and Pulse Repetition Rate (PRR) on roughness, depth and taper angle is discussed. For such purpose, parameter study has been performed employing an Yterbium doped fiber laser from Fibercryst ( λ = 1030 nm , τ = 400 fs ) where a galvo-scanner that passes light trough an f− 0 lens with f=170mm ( ω 0 = 21 µm ) allows 2D inscription faster than a movable stage. Inscriptions were performed at diferent PRRs and OPs. The overlap ratio was changed while maintaining same irradiation time, i.e. compensating lower OPs by increasing scan number.

Laser is considered one of the most influential inventions in the twentieth century and laser technology has been contributing in many areas of life. Today, in any field of manufacturing, laser technology also presents value and brings a range of specific benefits to the field such as machine manufacturing and mechanical tools. Thanks to the cutting edge cleaning ability, delicate welding lines, strong etching strokes, high power operation, accurate distance measurement capability, laser technology has gradually conquered and dominated the mechanical market, especially in the field of material handling, metal parts. Using lasers to cut metal creates highly detailed and continuous details, lines, shapes, patterns ... that open new avenues for the mechanical and machine-building industry. Using laser engraving machines, it will process complex and sophisticated details, saving time and manpower costs. High processing speed, smooth cutting surface and easy programming are the advantages that laser cutting technology offers to this industry. Lasers can be cut on different sheet metal or tubular surfaces at extremely fast speeds on tools, machine parts and even small-sized cutting workpieces. This paper will present an overview of laser technology and its common applications in the mechanical and machine-building industry. The analysis and evaluation in this paper will provide an update on the level of development of laser technology in the current industry age 4.0. In addition, it is a common picture and achievements of the machine manufacturing industry achieved with the support of "Light Amplification by Stimulated Emission of Radiation".

We present a fabrication method for polymer based microfluidic devices using gallium as a sacrificial material during the sealing process based on solvent bonding, allowing for lab-scale prototyping of microfluidic chips. The microfluidic channels are structured by laser engraving of poly(methyl methacrylate) (PMMA) sheets. The devices are temporarily closed by clamping the engraved parts on a flat surface with a thin polymer film in between. Liquid gallium is then injected into the temporarily sealed channels and is subsequently cooled to form a solid sacrificial layer preventing clogging and distortion of the microchannels during the subsequent bonding process. After finally sealing the device, it is warmed up to liquefy the gallium, which is then flushed from the channels. The feasibility of this approach is demonstrated by fabricating a microfluidic flow focusing device and a chemical gradient generator. The proposed method using gallium features distinct advantages compared to previously reported similar approaches that successfully make use of, e.g., wax, hydrogels or water as sacrificial materials.

This work deals with the study of laser engraving process of Al-SiC composite by Q-switched Nd:YAG laser. A series of experiments have been conducted to investigate the effect of process parameters such as assistant gas flow, distance between surface of workpiece and beam focus location (defocus), repetition rate frequency, and pumping current on the quality parameters such as depth, width, and contrast of engraved zone. A central composite design method was used to design experiments based on the response surface methodology (RSM). Empirical models were developed to create relationships between control factors and response variables by considering analysis of variance (ANOVA). To estimate the qualitative characteristics of the process, a feed forward back-propagation neural network (FF-BPNN) was used and accuracy of BPNN method was compared with mathematical models based on RSM model. Finally, the desirability function was used to optimize the multiple responses.

Environmentally friendly paperboard packaging is rapidly increasing its market share. The growth has been driven by consumers’ knowledge of ecological materials and consequent change in their consumption behaviour. Substitution of oil-based materials in the packages with sustainable alternatives, such as paperboard, has major effects on package manufacturing processes. With the advancements in digitalization and automation, the importance of identification and product safety markings has been emphasized and the integration of markings directly into packaging materials is desirable. The object of the study was to investigate manufacturing of small and detailed shapes on surface of the forming tools using these methods and how deviations on the mould surface are transferred (i.e. embossed) to the created pattern. Simultaneously, the impact of manufacturing technology on the process and parameter selection was investigated. A set of small patterned forming tools were manufactured from pre-hardened engineering and tool steel with three different manufacturing methods: precision machining, electro-erosion and laser engraving. Patterns were formed on the surfaces of the uncoated and plastic coated SBS-paperboard samples using a pressing jig designed for the purpose. Trials showed that shape of the pattern edge is essential for the preservation of the surface layer of the material. Similarly, the usable pressing force depends on the pattern edge properties. The results of the study indicate that tested simple geometry marking patterns can be created on the forming tool surfaces with commonly used manufacturing techniques.

Development of 3D hierarchically porous graphene (HPG) with supercapacitor performances at low cost has remained a challenge in electrochemical devices. Recently, laser engraving technology has been proposed as a promising and very useful method to inscribe self-designed electrode array directly onto polymeric substrates by instantaneously converting the starting material into few-layer graphene. Here we show HPG fabrication on commercial bakelite resulting in porous graphene embedded in polymer surface using the high repetition nanosecond fiber laser engraving under nitrogen atmosphere. The results showed that the as-prepared HPG presents a combination of interconnected macro-, meso- and micropores with a multi-modal pore size distribution. The morphologies, microstructures and their properties of HPG films can be governed by the laser processing parameters. Moreover, the HPG-based supercapacitors show outstanding electrochemical performance with specific capacitance superior to other supercapacitors reported previously. The simple, rapid and low-cost approach proposed in this work has great potential in large-scale applications of electronic and energy storage devices.

In this chapter it is presented an experimental investigation of stainless steel SAE304, aluminium 7075, pressure vessel steel P355GH and yellow brass C26000 nanosecond pulsed Q-switched Nd:YAG 1064nm laser engraving process. Laser engraving experiments were performed using a LASERTEC 40 laser machining center made by DMG MORI for various sets of process parameters (average power, repetition rate, scanning speed) and engraving geometry characteristics. The effect of process parameters on removed material layer thickness, material removal rate, average surface roughness and kerf taper angle formation was examined.

Scintillator crystals are widely used as ionizing radiation detectors in nuclear medicine imaging equipment. In many detectors, arrays of small scintillator elements (pixels), optically isolated from each other by a reflective material, are used to provide information on the interaction position of photons in the crystal. The attainable spatial resolution is related to the pixel size. The technique of subsurface laser engraving has been proposed as a low-cost alternative to scintillation crystals arrays to pixelate monolithic crystals. In this work, the first results of the implementation of the laser engraving technique to pixelate cerium doped lutetium yttrium oxyorthosilicate (LYSO:Ce) scintillation crystals in the new Laser Engraving Laboratory at the UNAM Institute of Physics are presented. We characterized the shape and size of the induced microfractures with a Nd:YAG pulsed laser in LYSO crystal, and with this information, we optimized the engraving parameters to produce semi-transparent barriers that optically isolate one pixel from another, thus producing a 6×6 pixelated crystal array with pixel pitch of 1.67 mm.

Laser engraving of photographs on wood surfaces is a challenging task. To optimize the outcome and production quality it is necessary to control every aspect of the laser engraving process. Most of the production machines and technologies overall are mainly focused on laser power control. However, with other systems and deeper knowledge of the wood characteristics it is possible to achieve even better quality. This paper deals with enlarging the number of achievable shades of burned wood and its optimization. A calibration system was developed to control colour shades of engraved wood with a combination of laser power and optic focus. With this approach it is possible to widen achievable palette of engraved shades by continuous control of chemical processes of laser and wood interaction. The production is divided into wood burning and wood carbonization by variation of laser beam focus.

The bandgap tunability in methylammonium (MA) lead halide perovskites has motivated us to design a photoresistor array made of MAPbI3, MAPbBr1.5I1.5, and MAPbBr3. To pattern devices on the same substrate, a novel method of laser engraving the substrate was employed. In this method, first, an indium tin oxide (ITO) coated plastic substrate was laser engraved to make microchannels with a width of 50-100 µm. Capillary motion force was used to fill each channel with a different solution containing the perovskite precursors. The current-voltage characteristics of each sensor were studied under dark and light conditions. Light-emitting diodes with different wavelengths were used to study the response of each sensor to monochromic lights. The results are promising toward the fabrication of larger arrays of photosensors which potentially can be used for compact and integrated photospectrometers in lab-on-a-chip devices.

While thermal treatment of paper can lead to the formation of aromatic structures via hydrothermal treatment (low temperature) or pyrolysis (high temperature), neither of these approaches allow patterning the substrates. Somewhere in between these two extremes, a handful of research groups have used CO2 lasers to pattern paper and induce carbonization. However, none of the previously reported papers have focused on the possibility to form fluorescent derivatives via laser-thermal engraving. Exploring this possibility, this article describes the possibility of using a CO2 laser engraver to selectively treat paper, resulting in the formation of fluorescent compounds, similar to those present on the surface of carbon dots. To determine the most relevant variables controlling this process, 3 MM chromatography paper was treated using a standard 30 W CO2 laser engraver. Under selected experimental conditions, a blue fluorescent pattern was observed when the substrate was irradiated with UV light (365 nm). The effect of various experimental conditions (engraving speed, engraving power, and number of engraving steps) was investigated to maximize the fluorescence intensity. Through a comprehensive characterization effort, it was determined that 5-(hydroxymethyl)furfural and a handful of related compounds were formed (varying in amount) under all selected experimental conditions. To illustrate the potential advantages of this strategy, that could complement those applications traditionally developed from carbon dots (sensors, currency marking, etc.), a redox-based optical sensor for sodium hypochlorite was developed. Fil: Clark, Kaylee M.. Clemson University; Estados Unidos Fil: Skrajewski, Lauren. Clemson University; Estados Unidos Fil: Benavidez, Tomás Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Clemson University; Estados Unidos Fil: Mendes, Letícia F.. Universidade de Sao Paulo; Brasil Fil: Bastos, Erick L.. Universidade de Sao Paulo; Brasil Fil: Dörr, Felipe A.. Universidade de Sao Paulo; Brasil Fil: Sachdeva, Rakesh. Clemson University; Estados Unidos Fil: Ogale, Amod A.. Clemson University; Estados Unidos Fil: Paixão, Thiago R. L. C.. Universidade de Sao Paulo; Brasil Fil: Garcia, Carlos D.. Clemson University; Estados Unidos

Steering capillary flow in textiles is of great significance in developing affordable and portable microfluidics devices. However, owing to the complex fibrous network, it remains a great challenge to achieve capillary flows with precise filling fronts. Here, an in situ laser engraving route is reported to accurately and rapidly etch textiles for manipulating capillary flow. The heterogeneity of the textile structure is enhanced because of the directional spreading of molten fibers polymer under the control of surface energy minimization. The principle of achieved anisotropic wicking of a water droplet in laser-engraved textiles is proposed. This understanding enables patterning the filling front of a fluid in different shapes, including arrow, straight line, diamond, and annulus. Precise capillary flow in textile-based microfluidics can benefit application in many fields, such as chemical analysis, biological detection, materials synthesis, multiliquid delivery. The laser engraving strategy has the advantages of simplicity, full scalability, and time rapidity, which provides an efficient avenue to steer capillary flow in diverse textiles for manufacturing customized microfluidic devices.

International audience; Laser engraving is more and more commonly used to write permanent identity features on medical devices. In particular, it is performed on ceramic heads for hip prostheses. Since these components are submitted to high mechanical loading during long periods of time (several years), it is critical to assess the influence of laser engraving on their durability. In the present article, laser marking of zirconia-toughened alumina and alumina-toughened zirconia resulted in an important colour change. It did not affect notably the resistance to hydrothermal ageing, despite important microstructural changes (in particular formation of a zirconia-alumina solid solution layer some tenths of micrometres thick). The formation of this original microstructure was explained by the fast cooling rate after lasing.

У статті представлено результати дослідження параметрів профілю гравійованих штрихів, отриманих методом прямого лазерного гравіювання. Дослідження методами оптичної металографії шліфів гравійованих штрихів, що відрізнялися запроектованим профілем показало, що всі гравійовані штрихи зразка мають відхилення від заданого геометричного профілю (нахил стінки штриха 90⁰ зменшується до 60⁰–75⁰), є несиметричними, захисне PVD (Plate Vapour Deposition) покриття має недостатню адгезію до основного матеріалу форми. Дослідження шорсткості поверхні досліджуваних друкарських форм на ділянках пробільних та друкувальних елементів за допомогою механічного профілографування показало, що шорсткість пробільних елементів форм суттєво нижча, ніж шорсткість дна друкувальних елементів, що повністю кореспондується з даними досліджень мікрошліфів. Також це підтверджено мікроскопічними дослідженнями дна друкувальних елементів: нерівності мають регулярний характер, що спричинено особливостями лазерного оброблення поверхні. Аналіз отриманих даних дає підстави стверджувати, що особливості обробки матеріалу форми лазером під час DLE, впливає на шорсткість оброблюваних поверхонь та утворює напливи, що може мати негативний вплив на адгезію захисного PVD покриття, що суттєво знизить тиражостійкість друкарських форм. Зважаючи на цей факт, доцільним є удосконалення технологічних режимів лазерного гравіювання поверхні латуні.

CO2 laser micro-machining is a precise and versatile tool for brittle, low-conductive materials such as agate, a quartz mineral variety of chalcedony. Laser engraving on agate’s polished surface generates a permanent white mark, noticeable to the unaided eye, resulting from several thermal microstructural effects originated by the laser’s focalized heat that rapidly melts, vaporizes, and solidifies specific regions. However, few studies have attempted evaluating and quantifying such micro-scale effects during laser processing. We used a non-destructive, high-resolution method to reconstruct and analyze a 3D model of the laser engraved agate surface based on microtomography (µCT) images. Intrinsic water found in agate’s microstructural defects was identified as the major cause for the development of micro-cracks, fractures, and internal porosity due to the resultant vapor pressure. Molten SiO2 ejection also generated an external porosity composed of large, open cavities, forming the mark on the gemstone’s surface. µCT images allowed the evaluation of the absolute and relative amounts of material ejected and vaporized, and both molecular water (H2O) and hydroxyl bonds on silanole groups (SiOH), within the material’s microstructure, should be considered for a precise and uniform laser engraving. The results show that µCT analysis is an accurate method for evaluating and quantifying the microstructural effects of laser engraving on the surface of silica-based materials.

The development of industrial technology can help the manufacturing industry for producing quality products. One tool that can help produce such quality products is CNC machines. As we know that the price of CNC machines is not cheap. Therefore, in this article, the researchers suggest how to design a prototype CNC laser engraving machine for the acrylic workpiece. The machine is designed as cheaply as possible but provide great benefits. The machine frame is designed using aluminum extrusion, the laser uses a laser diode type, the actuators of axis uses the stepper motor, and the control software uses a USB CNC controller. The dimension of workpiece that can be machined is 600 mm x 300 mm x 2 mm. The optimization of the stepper motor movement system is chosen 1/8 micro stepping after testing full-step method, half-step, 1/8 micro stepping, and 1/16 micro stepping. Using a 2.5 watt diode laser module, the radiant heat received by the acrylic workpiece during the engraving process is 558.8 x 10-5 cal/sec.

Since polydimethylsiloxane (PDMS) is notorious for its severe sorption to biological compounds and even nanoparticles, thermoplastics become a promising substrate for microdevices. Although CO2 laser engraving is an efficient method for thermoplastic device fabrication, it accompanies with poor bonding issues due to severe bulging and large feature size determined by the diameter of laser beam. In this study, a low-cost microfabrication method is proposed by reversibly sealing a 1 mm thick polymethylmethacrylate (PMMA) over an engraving substrate to reduce channel feature size and minimize bulges of laser engraved channels. PMMA, polycarbonate (PC), polystyrene (PS), perfluoroalkoxy alkane (PFA), cyclic-olefin polymers (COP) and polylactic acid (PLA) were found compatible with this sacrificial layer assisted laser engraving technique. Microchannel width as small as ∼40 μm was attainable by a laser beam that was 5 times larger in diameter. Bulging height was significantly reduced to less 5 μm for most substrates, which facilitated leak proof device bonding without channel deformation. Microdevices with high aspect ratio channels were prepared to demonstrate the applicability of this microfabrication method. We believe this fast and low-cost fabrication approach for thermoplastics will be of interest to researchers who have encountered problem with polydimethylsiloxane based microdevices in their applications.

Laser engraving, which is a high-precision and non-contact processing technology, has been widely used to process the difficult-to-cut mould steel. However, the efficiency is still low and the influence of laser engraving on the microstructure and properties of engraved surface also needs further study. By varying the assist gas (Argon, Compressed air, and Oxygen) of nanosecond laser engraving of Cr12MoV mould steel, the material removal rate and surface quality were compared, and the mechanisms of elemental diffusion and microstructural evolution in surface remelting layer were investigated to understand the variation in micro-hardness values. The results showed that the exothermal chemical reactions significantly increased the efficiency of laser engraving, but the surface quality was deteriorated and the detachment of elements C and Cr in remelting layer was promoted. Thus, lower hardness was observed for the remelted layer in the presence of oxygen or compressed air compared to Argon, although the micro-hardness of remelted layers was all increased attributed to grain refinements. Results suggested that the use of oxygen gas during rough engraving increased the material removal rate and reduced the cost, and the use of Argon gas at final engraving steps improved the quality and mechanical properties of the engraved surface.

Laser texturing is a process that allows the selective removal of material by applying a high energy density over a small area during a very short time interval. Although it is generally common to use ultra-short pulse (ps or fs) lasers for tool engraving, in certain applications it is possible to use short pulse (ns) lasers. In this work, the material removal rate of an ns laser has been evaluated in chip-breaker milling on Al2O3 cutting inserts reinforced with SiC whiskers. The results obtained show that by milling chip-breaker geometries it is possible to reduce the cutting forces, however, the process parameters used are key to obtain an adequate surface finish without embrittlement of the tool. By means of an adequate design, a reduction in cutting forces of 20% was achieved; additionally, it has been proved that there is a high dependence between tool life and the milling strategy used.

The pick and place mechatronic structures have a wide use in the industrial world. From semi finished positioning systems, to planting parts, to welding systems, engraving systems, cutting machining, or 3D printers. In this paper the authors have proposed to create a complete pick and place system, with a low price, able to reconfigure the entire mechatronic system by using an HMI interface, developed by the authors, through a minimal intervention on the adaptation of the z axis to the specific application. Thus, the system can be set up via the HMI interface to support a drawing, cutting, laser engraving or 3D printer. Such a structure is extremely useful in training, with every engine being tracked via the HMI interface for the developed torque, speed, current and voltage absorbed in real time but also to service-providing Small and Medium Enterprises through its versatility and low cost.

Based on the Fresnel half-wave band interference and laser engraving, a high-frequency self-focusing piezoelectric composite ultrasound transducer (FPCUT) is presented in this article. The theoretical analysis was performed based on the concept of constructive interference of acoustic waves and the electromechanical response of piezoelectric composites. The calculated and simulation results showed that the FPCUT combined the advantages of the composite transducer and the plate self-focusing transducer and can achieve high electromechanical coupling coefficient (>0.66), low acoustic impedance (~15 MRayl), high intensity, and short focal length. Furthermore, a 30-MHz self-focusing piezoelectric composite transducer prototype was fabricated and tested. It is composed of 11 lead zirconate titanates (PZTs) and ten epoxy annuluses. A UV engraving laser with a linewidth of 10 $\mu \text{m}$ was used in each of the PZTs to form the annuluses, and the kerf among the annuluses was filled with epoxy. The measured center frequency, bandwidth, and focal length were 27 MHz, 50.37%, and 3.7 mm, respectively. A vertical wire phantom was imaged using a fabricated transducer and a contrast flat transducer; the images showed significant improvement in the lateral resolution over a range of 9 mm. Because this self-focusing piezoelectric composite transducer was based on the precise laser engraving systems, the fabrication process was accurate and controllable, which enabled it to have good potential for medical imaging and industrial nondestructive testing applications.

Lasers are nowadays widely applied in additive manufacturing and several laser based techniques related to inkjet printing are emerging. In this paper, surface treatment of nanoparticle coatings using a commercial laser engraving machine are presented. Experiments were performed on (i) thin thermally cured silver nanoparticle coatings on glass and (ii) iron oxide (Fe 2 O 3 ) nanoparticle dispersion coatings on glass. The laser treatment on Ag films illustrates local melting or dewetting behavior dependent on laser power and on the density of engraving patterns. For Fe 2 O 3 coatings, direct laser writing on dried layers and laser treatment on fluid nanoparticle ink layers are investigated. We demonstrate and discuss in particular the generation of large area laser induced microstructures in vertically confined nanoparticle ink films. Controlled ink accumulation is generated by the laser pulses. Furthermore, 2D porous network structures, as well as laser induced large area filament structures are generated by heat driven capillary flow. Tailored adjustments of nanoparticle inks, film thickness and laser treatment patterns open perspectives for the generation of laser induced self-assemblies, e.g. for novel fabrication processes for 2D metamaterials, for sensor developments or advanced anti-counterfeit applications.

Brass Alloy 260 is widely used in mechanical engineering (odometer contacts, radiator cores), electrical engineering (electrical connectors, screw shells), plumbing (bathroom fixtures), consumers (watch parts, buttons, lamps) etc. The paper presents an analysis of the laser marking and engraving process. The ability Rofin powerline f20 laser system to engrave on Brass Alloy 260 is described. Recommendations are given on choosing the right parameters for laser marking and engraving of Brass Alloy 260 products.

Studying the impact of speed on a number of laser processes such as marking, engraving, cutting, welding and others is crucial for the optimization of these technological processes. The processing speed, along with the frequency of laser pulses and their duration, also determines the time of action in the processing area and hence the absorbed quantity of electromagnetic energy. Based on numerical experiments with specialized software TEMPERATURFELD3D, the report analyzes the temperature variation in the processing area as a function of speed. The researches were analyzed for processing with two types of lasers emitting in the visible and infrared areas of the electromagnetic spectrum and two types of steels (tool and structural). From the course of the obtained temperature fields the dependence of temperature on the speed at two power densities was obtained. The obtained results help to make a preliminary assessment the speed work intervals for the processes as laser marking, laser engraving, laser cutting, laser welding and others. In this way, it is assisted in building an optimal concept for the passing of a particular technological process in function of the laser source, the material and the type of the technological operation.

The automotive industry is facing a multitude of laser-engraving's technical solutions for decorative application. However, the reproducibility of laser-engraving's surface results is not guaranteed at that time. A study of transferability of the process was carried out on four different types of laser-engraving machines in order to understand the phenomena involved and to be able to get rid of it. The samples studied consist in industrial reference polymers already used for application of decorative automotive part: Polypropylene (PP), Polymethyl methacrylate (PMMA) and a blend of Acrylonitrile butadiene styrene and polycarbonate (ABS-PC).

Polyimide-laser-engraved porous graphene (LEPG) are hopeful electrode modification materials for flexible electrochemical sensing based on its high-efficiency preparation and low cost. Herein, a flexible, multi-patterned, and miniaturized electrode was fabricated via a simple and novel direct laser engraving. 3D LEPG with porous network structure can selective decorated with Pt nanoparticles (Pt NPs) by in situ electrochemical depositions (Pt-LEPG) as sensitively H2O2 sensors with a wide range of linear (0.01-29 nM) and high sensitivity (575.75 μA mM-1 cm-2). Subsequently, a glucose biosensor was successfully constructed through immobilized glucose oxidases (GOD) onto Pt-LEPG electrode. New-designed GOD/Pt-LEPG glucose sensor exhibited a noteworthy lower limit of detection (0.3 μM, S/N = 3) and high sensitivity (241.82 μA mM-1 cm-2), as much a wide-range of linear (0.01-31.5 mM) at near-neutral pH conditions, enabling detect glucose in real human serum specimens with satisfactory results. Predictably, these outstanding performance sensors have great potential in terms of flexible and wearable electronics.

On the ceramic tile production there are plenty of different possible origins inside the process that can lead to hue variation. Many tile producers use to increase the speed of production and the machinery industry follow this tendency to please their costumers; and so this scenario creates a need of a study on the influence of the speed production on hue variation. In this work this influence was verified using the silicon laser engraving method, one of the most methods worldwide used.

Combining high strength, hardness and high toughness remains a tremendous challenge in materials engineering. Interestingly nature overcomes this limitation, with materials such as bone which display unusual combinations of these properties in spite of their weak constituents. In these materials, highly mineralized “building-blocks” provide stiffness and strength, while weak interfaces between the blocks channel non-linear deformation and trigger powerful toughening mechanisms. This strategy is also exploited in multilayered ceramics, fiber-reinforced composites, and more recently in topologically-interlocked materials. In this work we apply these concepts to the toughening of glass panels by incorporating internal architectures carved within the material using three-dimensional laser engraving. Glass is relatively stiff and hard but it has no microstructure, no inelastic deformation mechanism, low toughness and poor resistance to impacts. We demonstrate how introducing controlled architectures in glass completely changes how this material deforms and fails. In particular, our new architectured glass panels can resist about two to four times more impact energy than plain glass. Our architectured glass also displays non-linear deformation, progressive damage and failure contained within a few building blocks. This work demonstrates how micro-architecture, bio-inspiration and top-down fabrication strategies provide new pathways to transform the mechanics and performance of materials and structures.

Laser engraving technology is a type of laser processing technology, widely used for product coding, marking, and so on. A large amount of research has reported the results of metal surface engraving; however, few research results, to the best of our knowledge, have provided theoretical support for the application of paper packaging laser engraving. In this paper, the quality of paper laser engraving is investigated by experimental methods. First, various phenomena appearing in paper carving were studied, including plant fiber burning, charcoal, and edge marks; second, the main factors affecting the quality of laser engraving are researched, and the influence of laser intensity and the preset width of carving marks on the engraving quality are discussed. The results show that the engraving precision is the best when the laser power is 11 W and the preset width is small (0.26 mm). Finally, the laser engraving precision of UV coated paper is studied, and the effect of UV material melting and secondary crystallization on engraving the quality of paper laser engraving quality is discussed. When the laser power is small, the maximum and minimum values of UV film melting and secondary crystallization engraving trace are relatively small as well; further, when the laser power increases, the maximum width of engraving is basically consistent with the preset width, and the precision of laser engraving is optimal.

This work describes the production of electronic-skin (e-skin) piezoresistive sensors, which micro-structuration is performed using laser engraved molds. With this fabrication approach, low-cost sensors are easily produced with a tailored performance. Sensors with micro-cones and a high sensitivity of −1 kPa−1 under 600 Pa are more adequate for the blood pressure wave detection, while sensors micro-structured with semi-spheres and a maximum sensitivity of −6 × 10−3 kPa−1 in a large pressure range (1.6 kPa to 100 kPa) are more suitable for robotics and functional prosthesis.

The influence of aqua blasting and laser engraving on the atmospheric chloride-induced stress corrosion cracking (AISCC) resistance of type 316 L stainless steel has been elucidated by using MgCl2-laden droplet deposits as the test medium. Aqua blasted surfaces showed no evidence of AISCC. Laser engraving resulted in tensile residual stresses, and led to AISCC within two weeks of exposure, with crack growth rates similar to U-bend samples. Introducing compressive residual stresses via peening inhibited crack nucleation, whereas oxide layer removal of engraved surfaces had no effect on AISCC. Strategies to reduce the likelihood of AISCC of laser engraved components are discussed.

With high sensitivity at single molecule level, surface-enhanced Raman scattering (SERS) is considered as an ultrasensitive optical detection technology with broad application prospects in lots of fields. However, the complicated fabrication and unaffordable price of SERS substrate are still a roadblock on the way to be widely used in industry. In this work, the SERS spectra on a commercial laser engraved Teflon (PTFE) film with engraved microarray are investigated. The wettability of film surface modulated by laser engraving make the microarray have the ability to decrease the contact area on film surface while water evaporation. The SEM image of the engraved area points out the micro/nanostructures generated engraving process is crucial to its superhydrophobic property. The probing molecules (i.e., methylene blue and rhodamine6G) were utilized to investigate with the limit of detection (1 × 10−14 M). Furthermore, the biomolecule (bovine serum albumin) was used to demonstrate its benefits in biological applications. The measured intensities of Raman spectra on this PTFE with laser engraved microarray demonstrate its potential value for a SERS substrate. Our work on this simple, cheap SERS substrate with high sensitivity has a great commercial value and plenty of application in lots of fields. Electronic supplementary material The online version of this article (10.1186/s11671-018-2658-3) contains supplementary material, which is available to authorized users.

In this paper we present fabrication of hollow and solid chitosan microneedles using a recently proposed low-cost and cleanroom-free fabrication method called Cross-Over Lines (COL) laser engraving. COL engraving is achieved using a commercial CO 2 laser-cutter to create microneedle molds on acrylic sheet. PDMS is then casted on the acrylic sheet microneedle mold to create base PDMS microneedles which are then used to generate other polymeric needles. In this paper, we cast and cure chitosan solution on the base PDMS microneedles which easily detaches from PDMS needles on drying. The resulted microneedles are hollow chitosan microneedles. We also made solid microneedles by silanizing and casting PDMSon-PDMS microneedles. We report promising preliminary results on drug delivery using these hollow and solid chitosan microneedles.

Downward trend in laser technology price and increase of the accuracy achieved has allowed it to acquire a new dimension in recent times. This paper proposes, with a practical approach, focusing on the RF field, the use of an innovative low-cost laser technology as part of the practical syllabus of an Advanced Electronics Prototyping Techniques course or similar. It provides with conceptual understanding on industrial manufacturing limitations while studying different materials engraving, professional software suites and PCB Exposure, in contrast with the expensive CNC milling methods typically used, an alternative cheaper laser engraving technique for RF is exposed.”.

In this paper, we propose an artificial neural network (ANN) model for prediction of color properties, including color yield (in terms of K/S value) and CIE L, a and b values of 1005 cotton knitted fabrics under the effect of laser engraving process with different process parameters. Fabric factors to be examined in the ANN model included fiber composition, fabric density, mass of fabric, fabric thickness, linear density of yarn, yarn twist, direction of yarn twist and crimp. After obtaining the ANN model, its performance was compared with linear regression model. It is noted that the ANN model produced superior results in prediction of color properties of laser engraved 100 % cotton knitted fabrics. The relative importance of the examined factors influencing color properties was also investigated.

The rapid development of portable and wearable electronic devices has increased demand for flexible and efficient energy harvesting and storage units. Conventionally, these are built and used separately as discrete components. Herein, we propose a simple and cost-effective laser engraving technique for fabricating a flexible self-charging micro-supercapacitor power unit (SCMPU), by integrating a triboelectric nanogenerator (TENG) and a micro-supercapacitor (MSC) array into a single device. The SCMPU can be charged directly by ambient mechanical motion. We demonstrate the ability of the SCMPU to continuously power light-emitting diodes and a commercial hygrothermograph. This investigation may promote the development of sustainable self-powered systems and provide a promising new research application for supercapacitors.