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In this study, the effects of variations in the height ( h ) and bottom radius ( r ) of black silicon microstructures on their absorptance and photoelectric response efficiency were analyzed. By using the relation cot ⁡ θ 2 = h r to combine the parameters, it was found that changes in morphology affected the absorptance of black silicon microstructures, with h being directly proportional to the absorptance, while r was inversely proportional. A positive correlation was observed between cot ⁡ θ 2 and absorptance. However, the correlation between cot ⁡ θ 2 and photoelectric response efficiency was not significant. Through Raman spectroscopy analysis of the samples, it was concluded that as the laser ablation energy density increased, more lattice defects were introduced, weakening the charge carrier transport efficiency. This study further elucidated the mechanism by which microstructural changes impacted the absorptance and energy density of black silicon, providing valuable insights for optimizing its energy density. [ABSTRACT FROM AUTHOR]

Inductors are indispensable parts in power modules of electronic devices. With the rapid development of flexible and wearable electronic devices, developing flexible micro‐inductors with large energy storage has become an urgent task. In this research, a sophisticated femtosecond laser ablation technique is employed to craft circular spiral mini‐inductors via selective etching of soft magnetic amorphous alloy ribbons. Remarkably, while these inductors possess dimensions akin to human fingerprints, they demonstrate an impressively elevated inductance value of ≈1.15 µH at 1 MHz. The inductance density is ≈280–390 nH mm−2, which is ≈10 times larger than conventional circular spiral inductors and is attributed to the high permeability of the amorphous alloys. Furthermore, the inductors showcase commendable flexibility, marked by stellar elasticity and a bending endurance exceeding 2500 cycles, thanks to the amorphous alloys' superior elastic strain limit. When integrated with an LM2576‐3.3BT buck converter, the fabricated inductor achieved a peak power conversion efficiency nearing 70%. These findings underscore the potential of such flexible mini‐inductors in the landscape of flexible electronics. [ABSTRACT FROM AUTHOR]

In this work, a two‐dimensional (2D) waveguide on the 6.0 × 106‐eV C3+‐ion implanted RbTiOPO4 structure was prepared by the femtosecond laser under the manufacturing parameters of 3.0 μJ energy and 50.0 μm/s ablation velocity. The energy loss and damage profile were simulated by the SRIM 2013 for the irradiation with a fluence of 1 × 1014 ions/cm2. The end‐face and the surface of the 2D RbTiOPO4 crystal waveguide were characterized by a Nikon microscope. The refractive index profile and the near‐field intensity profile were studied by the ICM and the end‐face coupling technique, respectively. The RTP crystal 2D waveguide can well confine the light propagation and has the potentiality to serve as integrated photonic devices. [ABSTRACT FROM AUTHOR]

The development of novel antagonistic nanoparticles requires information about the factors that influence the antibacterial and anti-biofilm activity. Even though antibacterial studies relating size and shape of metallic nanoparticles were reported earlier we attempted to comprehend the parameters that control the antibacterial and anti-biofilm efficacy of bimetallic Au/Ag nanoparticles prepared by femtosecond laser ablation. The synthesis of bimetallic nanoparticles was done according to our previous article. Absorption spectra and transmission electron microscopy (TEM) validated the buildup of bimetallic nanoparticles. The samples were investigated for antibacterial activity against Gram negative (Pseudomonas aeruginosa) and Gram positive (Bacillus pumilus, Staphylococcus aureus) microorganisms by agar disc diffusion. Anti-biofilm studies were conducted and the biofilm inhibition percentage was calculated. SEM images clearly support the biofilm inhibition occurring to the microorganisms after the treatment with the nanoparticles. It was observed that the antibacterial and anti-biofilm efficacy of the samples increased with the size, concentration, and composition of the nanoparticles. Considering the morphological aspect, the nanoalloy structure showed better activity compared to the core shell structure. Thus it can be concluded that the size, concentration, composition and morphology are key factors that govern the antibacterial and anti-biofilm effectiveness of the synthesized bimetallic Au/Ag nanoparticles. To our knowledge and belief, this is the first work of its kind discussing all the controlling parameters together. This information could be incorporated while synthesizing nanoparticles for medical applications as coating substances.

Thermal shock cracks are frequently observed in environments where extensive thermal cycling at high amplitudes is common. Typical cases for such are first wall materials in proposed fusion reactors and rotating anodes for computed tomography scanners. The formation of these cracks is driven by significant tensile stresses during the cooldown phase, following prior plastic deformation at elevated temperatures.This work proposes an experimental approach, where artificial thermal shock-like structures are generated via femtosecond laser ablation in WRe as a model material. Following a detailed laser parameter study in a W sheet material, patterns were introduced to WRe samples and investigated by different microscopy techniques. Their morphology as well as their response to thermo-cyclic loads was investigated and compared to conventionally induced thermal shock cracks.The introduction of artificial cracks by femtosecond laser ablation that mimic the morphology and behaviour of naturally induced thermal shock cracks is feasible within certain boundaries. Cuts, comparable to thermal shock cracks in width and depth, can be ablated. The cuts show an effect on the surrounding microstructure in line with the thermal shock cracks. Therefore, comparability could be proven concerning morphological and microstructural aspects. The conducted thermo-cyclic fatigue tests revealed an analogous effect on subsequent damage accumulation between the thermal shock cracks induced by thermal loading and artificial laser ablated cuts, proving the comparability under dynamic loading conditions. The extent of the effect is adjustable by tailoring the geometry of the lasered structures.The presented work suggests the possibility of studying the influence of thermal shock cracks on further fatigue mechanisms in exceptionally demanding applications, such as first wall materials or rotating anodes, by practical experimentation. Based on the resulting in-depth understanding of underlying interactions, the lifetime of these components might be prolonged by a deliberate introduction of crack networks or laser-ablated structures.

In this study, the effects of variations in the height (h) and bottom radius (r) of black silicon microstructures on their absorptance and photoelectric response efficiency were analyzed. By using the relation cot⁡θ2=hr to combine the parameters, it was found that changes in morphology affected the absorptance of black silicon microstructures, with h being directly proportional to the absorptance, while r was inversely proportional. A positive correlation was observed between cot⁡θ2 and absorptance. However, the correlation between cot⁡θ2 and photoelectric response efficiency was not significant. Through Raman spectroscopy analysis of the samples, it was concluded that as the laser ablation energy density increased, more lattice defects were introduced, weakening the charge carrier transport efficiency. This study further elucidated the mechanism by which microstructural changes impacted the absorptance and energy density of black silicon, providing valuable insights for optimizing its energy density.

Anisotropic conductive film (ACF) is an electrical and electronic material composed of conductive balls embedded in a polymer matrix. ACF plays a crucial role in connecting electrodes and chips in Micro-LEDs. It serves as the target material in the repair process, enhancing production yield. For the application of ACF in the Micro-LED display repair process, flawless selective micro-ablation is essential. However, little research related to ACF micro-ablation has been conducted so far. In this study, we investigated a detailed analysis of the ablation area and defects in ACF by using femtosecond lasers with three different wavelengths: 1026 nm (NIR), 513 nm (Green), and 257 nm (DUV) for selective micro-ablation. By conducting a comparative analysis of these wavelengths, we determined that the optimal ablation results were achieved using a 257 nm wavelength femtosecond laser. These results exhibited no-defect, uniform, reproducible, and symmetrical ablation characteristic, making it suitable for the Micro-LED display repair process. This research is expected to establish the foundation for micro-ablation in all applications where ACF is employed. [ABSTRACT FROM AUTHOR]

In this work, the ridge waveguide was formed by the femtosecond laser ablation with a central wavelength of 0.808 μm and a speed of 50 μm/s on the planar Nd3+‐doped fluorophosphate glass waveguide that was fabricated by the C3+ ion implantation with an energy of 6.0 MeV and a fluence of 1.0×1012 C3+s/mm2. The mechanism of the ion‐implanted waveguide was discussed by the Stopping and Range of Ions in Matter 2013. The cross‐section morphology of the ridge waveguide was captured by an optical microscope. Its mode characteristics were analyzed by the end‐face coupling method. The ridge Nd3+‐doped fluorophosphate glass waveguides have potential as fundamental structures for many optoelectronic devices including waveguide amplifiers and lasers. [ABSTRACT FROM AUTHOR]

Easy, safe, and rapid quantitative methods to determine trace elements in agricultural products are required for efficient food safety management. Microwave-assisted digestion is traditionally used for trace elements in agricultural samples and accurate results and high selectivity are obtained. However, this procedure involves sample preparation, mixing, and extraction, which increases the time and complexity. Here we present femtosecond laser ablation–inductively coupled plasma mass spectrometry (fsLA-ICP-MS) to quantify arsenic, cadmium, and lead in rice. The recoveries by fsLA-ICP-MS for As, Cd, and Pb were 118.1%, 96.9%, and 87.1%, respectively, and 102%, 96.9%, and 107% by ICP-MS. The results by these techniques correlated well (>0.94) with the previously determined concentrations. The results confirm that fsLA-ICP-MS may be used to quantify trace elements in rice and is a promising, inexpensive, and easy-to-use alternative to traditional methods for food analysis. [ABSTRACT FROM AUTHOR]

A new analytical solution has been found for the electronic heat capacity of typical s-band metals. It is valid for high electron temperatures of the order of tens of kK, commonly reached in fs pulsed laser ablation. We have used the density of states (DOS) from the free-electron gas model (FEG) and a special type of function called polylogarithms. From the exact analytical solution, a third order Taylor expansion which works well up to 50kK could be derived. A new term was added to the DOS for d-band metals, which allowed us to find a new semi-analytical solution which predicts accurately the electronic heat capacity of Cu.

[Display omitted] Most droplets on high-efficiency condensing surfaces have radii of less than 100 μm, but conventional droplet transport methods (such as wettability-gradient surfaces and structural-curvature-gradient surfaces) that rely on the unbalanced force of three-phase lines can only transport millimeter-sized droplets efficiently. Regulating high-speed directional transport of condensate droplets is still challenging. Therefore, we present a method for condensate droplet transportation, based on the reaction force of the superhydrophobic saw-tooth surfaces to the liquid bridge, the condensate droplets could be transported at high speed and over long distances. The superhydrophobic saw-tooth surfaces are fabricated by femtosecond laser ablation and chemical etching. Condensation experiments and luminescent particle characterization experiments on different surfaces are conducted. Aided by the theoretical analysis, we illustrate the remarkable performance of condensate droplet transportation on saw-tooth surfaces. Compared with conventional methods, our method improves the transport velocity and relative transport distance by 1–2 orders of magnitude and achieves directional transport of the smallest condensate droplet of about 2 μm. Furthermore, the superhydrophobic saw-tooth surfaces enable multi-hop directional jumping of condensate droplets, leading to cross-scale increases in transport distances from microns to decimeters. [ABSTRACT FROM AUTHOR]

In this paper, we report on the ablation of Ti thin films with a thickness of 100 nm, while minimizing defects. Ti thin films are used in the TFT of µ-LEDs, and repair processing is required to increase the production yield of µ-LEDs. The repair process involves selectively ablating specific regions with a femtosecond laser, which must be done with precision to ensure proper TFT operation. Precise ablation means that defects, such as burrs, ripples, and substrate ablation, do not occur. To implement minimizing defects, we conducted COMSOL Multiphysics simulations using both Gaussian and flat-top beams. We irradiated the sample with a laser under various conditions, including pulse fluence, number of pulses, and beam deformation, and assessed the resulting ablation quality. Through careful selection of the laser conditions, which include flat-top beam with 0.28 J/cm2 fluence and 7 pulses, we were able to minimize burrs, ripples, and substrate ablation, resulting in neat and minimizing defect of 100 nm Ti ablation. [ABSTRACT FROM AUTHOR]

Laser-induced periodic surface structures (LIPSS) provide the possibility to functionalize the surface of various materials, which can be used to control the wettability of metal surfaces or influence cell adhesion. LIPSS thus offer great potential for application on implant surfaces if their fabrication process is compatible with standard implant fabrication techniques. Here we demonstrate an easy-to-use two-step fabrication method for stents with different types of LIPSS. The separation between the fabrication of the stent structure and the surface structuring process allows the implementation of any stent structure finishing technique without affecting the LIPSS. The suggested fabrication method may be a step further in implementing laser machining-based surface functionalization in commercial implants.

Ultra-short pulsed laser ablation may be used for high-precision machining with very low thermal influence on the processed materials. Due to this reason, lasers are increasingly used for processing of advanced materials, such as titanium alloys, nickel-based alloys or steel, every year. In this study, four advanced technical materials were analysed and compared under femtosecond laser irradiation with three different wavelengths. The main laser-material interaction parameters were identified, namely the ablation threshold and removal efficiency parameters. Higher removal rates were found for Ti6Al4V alloy with all three harmonic wavelengths. To increase process productivity, a method of increasing the repetition rate and scanning speed was presented. With the maximum repetition rate, the productivity increased five-fold with a similar removed depth and surface quality. Finally, the suitability of the identified parameters with regard to quality and productivity was demonstrated for fabrication of two complex structures – honeycomb and dot – which has the potential to improve friction properties of advanced materials.

The work reports the hydrogen-ion implantation and femtosecond laser ablation in the Er3+-doped germanate glass to make planar and ridge optical waveguides. The energy is 400 keV and the dose is 6 × 1016 ion/cm2 for the ion implantation. The pulse energy is 3 μJ and the scanning speed is 50 μm/s for the femtosecond laser ablation. A microscope is used to observe the cross-section morphologies of the planar and ridge waveguides. A measurement of the near-field intensity distribution at 632.8 nm is performed by the end-face coupling system. The effective refractive indices of the propagation modes are recorded by the m-line technique. It’s the first time that a ridge waveguide is fabricated in the Er3+-doped germanate glass by the proton implantation and femtosecond laser ablation, which is with potential application as new integrated optical devices.

Live imaging of living cells in 3D micro/nano‐environment is important for advanced biological studies. An issue for super‐resolution imaging is refractive index mismatch between the materials used for imaging platform and medium containing cells (water). Fluoropolymer CYTOP is the ideal platform material due to its refractive index close to that of water. Herein, femtosecond laser (220 fs) is exploited to ablate CYTOP at three laser wavelengths of 257, 515, and 1030 nm. Linear power dependences of the ablation rate obtained for all wavelengths indicate that ablation mechanisms of CYTOP are attributed to the production of fragmented CYTOPs (frag‐CYTOPs) inside the film to induce efficient light absorption for subsequent laser pulses. The frag‐CYTOPs can effectively absorb UV–Vis light, whereas those left behind generate green fluorescence. Importantly, the shortest wavelength of 257 nm offers the best ablation quality in terms of surface smoothness and low fluorescence with the highest ablation rate. We elucidate that the refractive‐index matching of CYTOP/water is effective for clear imaging of shapes/fluorescence of cells on 3D structures, e.g., HeLa cells on V‐shaped trenches. The fabrication of a microscopic 3D fluorescence code tag embedded in the CYTOP films is further demonstrated. [ABSTRACT FROM AUTHOR]

Ablation with ultrashort laser pulses as a surface micromachining tool was studied using a hybrid die-excimer laser system that has high energy per laser pulse (tens of mJ's), about 600 fs pulse duration and low repetition rate (2 Hz). The effect of ablation on the material microstructure with this high energy pulsed laser system was studied. Micropillars were fabricated by laser ablation using a spot size of hundreds of micrometers. Two methods were tested for micromachining. Multiple laser pulse ablation on a standing sample resulted in a columnar microscturcure around the micropillars. This unwanted structure was avoided by beam scanning, resulting in a rather homogeneous ditch. By HR-EBSD measurement it was found that the heat affected zone is less than 1 μ m , which was confirmed by numerical temperature simulations, too. The dislocation density measured below the specimen surface was unaltered, meaning that no significant crystal degradation occurred. In summary, large-scale micro objects with a diameter in the order of 100 μ m without significant change in the crystalline microstructure below the surface, like large-scale micropillars for compression tests, can be fabricated. [ABSTRACT FROM AUTHOR]

Strip optical waveguides were realized in Yb3+-doped silicate glass with ultrashort pulse laser ablation assisted He+ ion implantation. Planar waveguides were first prepared near the glass surface by He+ ion implantation (450 keV + 500 keV + 550 keV), followed by annealing at 260℃. After that, under the processing parameters of 3 μJ energy and 50 μm/s ablation velocity, two parallel tracks with separation of 15, 20, and 25 μm were, respectively, inscribed on the sample, which confine the light in lateral direction to form a strip waveguide. The near-field intensity measurement indicates that the strip waveguides maintain the single-mode propagation characteristics with 976 nm laser injection, and present the multi-mode characteristics with 632.8 nm laser injection, showing that the guided modes are well supported in the strip waveguides. The minimum propagation loss of strip waveguide is 1.35 dB/cm. Fluorescence emission spectra indicate that the gain properties of waveguide core were maintained well after waveguide preparation, revealing that the strip waveguide device in Yb3+-doped silicate glass has the potential to become an active device as waveguide laser or waveguide amplifier.

Nitinol became one of the most prominent materials for biomedical devices. The unique properties such as the shape memory effect and the superelasticity enabled new applications, particularly in the field of stent technologies. Due to their thermosensitivity, manufacturing processes are required that control the heat accumulation in the material. Here we investigate the femtosecond laser ablation of Nitinol supported by a water flow inside the processed tube. We show that laser absorption in the water prevents annealing of the Nitinol, even for high pulse energies. Furthermore, we investigate the groove profiles by scanning electron microscopy and observe minor improvements in the processed structure when using water flow inside the tube. The results show that water-supported femtosecond laser ablation can be used to optimize the fabrication of medical devices such as cardiovascular stents and to reduce processing times.

Herein, significant enhancement of second- and third-harmonic generation efficiencies in a 1 mol% Er3+ and 0.07 mol% Fe2+-doped lithium niobate single-crystal plate were achieved after ablating periodic cylindrical pit arrays on the surface. Enhanced absorption and reduced transmittance of light were measured when the incident light signal passed through the patterned sample. Enhanced photoluminescence and two-photon-pumped upconversion emission spectra were also explored to obtain more details on the efficiency gains. The excitation-energy-dependent second-harmonic generation efficiency was measured, and an enhancement as high as 20-fold was calculated. The conversion efficiency of second-harmonic generation is 1 to 3 orders higher than that from other lithium niobite metasurfaces and nanoantennas. This work provides a convenient and effective method to improve the nonlinear conversion efficiency in a thin lithium niobite plate, which is desirable for applying to integrated optical devices. [ABSTRACT FROM AUTHOR]

Texturing can be used to functionalize the surface of plastic parts and, in particular, to modify the interaction with fluids. Wetting functionalization can be used for microfluidics, medical devices, scaffolds, and more. In this research, hierarchical textures were generated on steel mold inserts using femtosecond laser ablation to transfer on plastic parts surface via injection molding. Different textures were designed to study the effects of various hierarchical geometries on the wetting behavior. The textures are designed to create wetting functionalization while avoiding high aspect ratio features, which are complex to replicate and difficult to manufacture at scale. Nano-scale ripples were generated over the micro-scale texture by creating laser-induced periodic surface structures. The textured molds were then replicated by micro-injection molding using polypropylene and poly(methyl methacrylate). The static wetting behavior was investigated on steel inserts and molded parts and compared to the theoretical values obtained from the Cassie–Baxter and Wenzel models. The experimental results showed correlations between texture design, injection molding replication, and wetting properties. The wetting behavior on the polypropylene parts followed the Cassie–Baxter model, while for PMMA, a composite wetting state of Cassie–Baxter and Wenzel was observed. [ABSTRACT FROM AUTHOR]

Exsolution, as an effective approach to constructing particle-decorated interfaces, is still challenging to yield interfacial films rather than isolated particles. Inspired by in vivo near-infrared laser photothermal therapy, using 3 mol% Y _2 O _3 stabilized tetragonal zirconia polycrystals (3Y-TZP) as host oxide matrix and iron-oxide (Fe _3 O _4 / γ -Fe _2 O _3 / α -Fe _2 O _3 ) materials as photothermal modulator and exsolution resource, femtosecond laser ultrafast exsolution approach is presented enabling to conquer this challenge. The key is to trigger photothermal annealing behavior via femtosecond laser ablation to initialize phase transition from monoclinic zirconia (m-ZrO _2 ) to tetragonal zirconia (t-ZrO _2 ) and induce t-ZrO _2 columnar crystal growth. Fe-ions rapidly segregate along grain boundaries and diffuse towards the outmost surface, and become ‘frozen’, highlighting the potential to use photothermal materials and ultrafast heating/quenching behaviors of femtosecond laser ablation for interfacial exsolution. Triggering interfacial iron-oxide coloring exsolution is composition and concentration dependent. Photothermal materials themselves and corresponding photothermal transition capacity play a crucial role, initializing at 2 wt%, 3 wt%, and 5 wt% for Fe _3 O _4 / γ -Fe _2 O _3 / α -Fe _2 O _3 doped 3Y-TZP samples. Due to different photothermal effects, exsolution states of ablated 5 wt% Fe _3 O _4 / γ -Fe _2 O _3 / α -Fe _2 O _3 -doped 3Y-TZP samples are totally different, with whole coverage, exhaustion (ablated away) and partial exsolution (rich in the grain boundaries in subsurface), respectively. Femtosecond laser ultrafast photothermal exsolution is uniquely featured by up to now the deepest microscale (10 μ m from 5 wt%-Fe _3 O _4 -3Y-TZP sample) Fe-elemental deficient layer for exsolution and the whole coverage of exsolved materials rather than the formation of isolated exsolved particles by other methods. It is believed that this novel exsolution method may pave a good way to modulate interfacial properties for extensive applications in the fields of biology, optics/photonics, energy, catalysis, environment, etc.

Femtosecond (fs) laser ablation has been studied for the potential of fast, high precision machining of difficult-to-machine materials like binderless tungsten carbide. Obstacles that have limited its efficiency include melting from heat accumulation (HA), particle shielding, and plasma shielding. To address HA without shielding effects, high repetition rate (57.4 MHz), ultra-low fluence fs laser irradiation is performed to study the incubation effect and subsequent HA-ablation threshold of fine-grained tungsten carbides. Exposure times on the order of 100 ms were conducted in air with fluences (1.82 to 9.09 mJ/cm2) two orders of magnitude below the single fs pulse ablation thresholds reported in literature (0.4 J/cm2). Heat accumulation at high repetition rate explains the ultra-low fluence melt threshold behavior resulting in melt crowns around ablated holes and grooves. The results of this study aid in predicting heat buildup in high repetition rate laser irradiation for applications that wish to achieve high ablation rates of difficult-to-machine, ultrahard materials and help enable shaping of binderless tungsten carbide for use in applications too extreme for bindered tungsten carbide.

Femtosecond (fs) laser ablation has been studied for the potential of fast, high precision machining of difficult-to-machine materials like binderless tungsten carbide. Obstacles that have limited its efficiency include melting from heat accumulation (HA), particle shielding, and plasma shielding. To address HA without shielding effects, high repetition rate (57.4 MHz), ultra-low fluence fs laser irradiation is performed to study the incubation effect and subsequent HA-ablation threshold of fine-grained tungsten carbides. Exposure times on the order of 100 ms were conducted in air with fluences (1.82 to 9.09 mJ/cm2) two orders of magnitude below the single fs pulse ablation thresholds reported in literature (0.4 J/cm2). Heat accumulation at high repetition rate explains the ultra-low fluence melt threshold behavior resulting in melt crowns around ablated holes and grooves. The results of this study aid in predicting heat buildup in high repetition rate laser irradiation for applications that wish to achieve high ablation rates of difficult-to-machine, ultrahard materials and help enable shaping of binderless tungsten carbide for use in applications too extreme for bindered tungsten carbide.

A two-dimensional waveguide is the building block in integrated photonic circuits. In this work, the 5.0 MeV oxygen ion implantation at a dose of 5. 0 × 1 0 1 4 ions/cm2 was carried out on the fused silica glass for the formation of the planar waveguide. Then, a femtosecond laser was employed to ablate the ion-implanted surface at a speed of 200 μ m/s for the construction of the ridge waveguide. The energy depositions of the oxygen ion implantation into the fused silica glass were simulated by the SRIM 2013. The microscopic morphology of the ridge waveguide was photographed by a Nikon microscope. The near-field intensity distributions of the ridge waveguide at 532 nm and 976 nm were measured by using the end-face coupling system. The ion-implanted and femtosecond-ablated ridge waveguide on the fused silica glass has the potential as a photonic device for integrated optical systems at the visible and near-infrared bands. [ABSTRACT FROM AUTHOR]

We study the properties of laser-induced periodic surface structures (LIPSS) formed on titanium-doped diamond-like nanocomposite (DLN) a-C:H:Si:O films during ablation processing with linearly-polarized beams of a visible femtosecond laser (wavelength 515 nm, pulse duration 320 fs, pulse repetition rates 100 kHz-2 MHz, scanning beam velocity 0.05–1 m/s). The studies are focused on (i) laser ablation characteristics of Ti-DLN films at different pulse frequencies and constant fluence close to the ablation threshold, (ii) effects of the polarization angle rotation on the properties of low spatial frequency LIPSS (LSFL), and (iii) nanofriction properties of the 'rotating' LIPSS using atomic force microscopy (AFM) in a lateral force mode. It is found that (i) all LSFL are oriented perpendicular to the beam polarization direction, so being rotated with the beam polarization, and (ii) LSFL periods are gradually changed from 360 ± 5 nm for ripples parallel to the beam scanning direction to 420 ± 10 nm for ripples formed perpendicular to the beam scanning. The obtained results are discussed in the frame of the surface plasmon polaritons model of the LIPSS formation. Also, the findings of the nanoscale friction behavior, dependent on the LIPSS orientation relative to the AFM tip scanning direction, are presented and discussed. [ABSTRACT FROM AUTHOR]

Modern life and global communication would not be possible without technologically tailored thin films; they are omnipresent in daily life applications. In most cases, the films are deposited entirely at the carrying substrates in a specific processing step of the device or sample. In some cases, however, removal or modification must be performed locally, i.e., site-controlled and material selective through an additional laser processing step. For that ultrashort laser pulses with durations in the femtosecond and picosecond range can provide unique advantages and capabilities in industrially scalable schemes. This article reviews the current state of the research and corresponding industrial transfer related to the structuring of thin films by ultrashort pulsed lasers. It focuses on the pertinent historic developments, reveals the relevant physical and chemical effects, explores the ultimate limits, and discusses selected industrial and scientific applications. [ABSTRACT FROM AUTHOR]

• A theoretical model of Bessel beam processing α-quartz is proposed. • Rapid evolutions in electron density and temperature affect the optical properties. • The optical penetration depth decreases rapidly at the edge of focused region. • The localized laser intensity leads to the high electron density from ionization. • A new perspective for the propagation of Bessel beam in dielectrics is presented. Femtosecond laser processing of dielectric has been widely studied. Nevertheless, a direct theoretical model for Bessel beam on α-quartz is still essential. The purpose of this study is to explore the interaction mechanism between Bessel beam and α-quartz. Bessel beam is generated by a combination of femtosecond laser Gaussian beam and beam shaping techniques. In the simulation, the optical and thermophysical properties are studied. The simulation results show that rapid evolutions in electron density and electron temperature affect the optical properties during laser energy deposition in α-quartz. In a few tens of femtoseconds, the optical properties change from transparent to opaque. The optical penetration depth rapidly drops to hundreds of nanometers at the edge of focused region during this period. Therefore, the laser intensity decreases exponentially along the propagation path. The electron density is high at the edge and low at the center of focused region. After sufficient laser energy deposition, microholes are finally formed. The ablation region is predicted by the critical electron density criterion and the critical volumetric energy density criterion. The experimental results verify the results calculated by the theoretical model. In addition, this study provides a new perspective for the theoretical modeling of Bessel beam and provides an important reference for the broad applications in the field of micro-/nano-processing. [ABSTRACT FROM AUTHOR]

The copper isotopic compositions of 12 copper-rich minerals (including native copper, sulfides, carbonates, oxides, and copper chloride) have been determined using a 206 nm ultraviolet femtosecond laser ablation multi-collector inductively coupled plasma mass spectrometry (UV-fs-LA-MC-ICP-MS). A pure copper wire NWU-Cu-B and a natural chalcopyrite TC1725 were used as bracketing standards for calibration. Reliable and precise (2SD<0.07‰) δ65Cu values can be obtained using matrix-matched standards under dry plasma condition and calibrated by the standard-sample bracketing method (SSB). However, the δ65Cu values calibrated by non-matrix-matched standards were seriously affected by matrix effect, with a deviation of up to 1.42‰. Therefore, matrix-matched standards are necessary for reliable in situ Cu isotope ratio measurement. Although the analytical precision (2SD) is slightly improved, the use of Ga as an internal standard combined with the SSB correction does not reduce the deviation caused by the matrix effect. However, the matrix effect can be significantly suppressed by adding 8.6 µL min−1 water into the carrier gas. The matrix-induced δ65Cu deviation of the TC1725 calibrated against the pure copper NWU-Cu-B was reduced from 0.99‰ in dry plasma mode to 0.03‰ in wet plasma mode and achieved a long-term reproducibility of 0.10‰ (2SD). For the Cu isotopic compositions of 12 natural copper-rich minerals determined under wet plasma mode, the deviation of δ65Cu was less than 0.13‰ if the mineral is homogeneous. These results indicate that the non-matrix-matched standardization can be achieved by fs-LA-MC-ICP-MS under wet plasma condition, whether using chalcopyrite or pure copper as the external bracketing standards. [ABSTRACT FROM AUTHOR]

Femtosecond laser processing of fused silica has been widely investigated. Nevertheless, a theoretical model to provide effective and direct guidance to the actual processing is still essential. By investigating the ablation threshold, depth, and crater shape of fused silica for femtosecond laser processing experimentally and numerically, a theoretical model is proposed and validated at the wavelength of 800 nm. It is carried out based on tracing the spatiotemporal distribution of the free electron density, electron temperature, and laser intensity. The electron temperature and electron density, as well as the transient optical and thermo-physical properties of femtosecond laser-irradiated fused silica are quantitatively determined. The experimentally measured saturation of the ablation depth at high laser fluence is predicted by the proposed model. The electron relaxation time at different laser fluences and pulse durations throughout the photoionization and impact ionization processes are probed. The results show that electron relaxation time plays a crucially important role in determining the evolutions of material optical properties and femtosecond laser energy absorption. The laser fluence is proved to affect the shape of the ablation crater strongly. With the increment of laser fluence for a given laser pulse duration, the ablation volume is more sensitive for the case with shorter pulse durations. Suitable laser parameters should be taken according to actual processing needs. [ABSTRACT FROM AUTHOR]

The development of antireflection coatings is crucially important to improve the performance of various photonic devices, for example, to increase the efficiency of harmonic generators based on high-refractive index crystals with significant Fresnel losses. A promising technique for the reducing of radiation reflection is to change the refractive index by fabrication of antireflection microstructures (ARM) on the surface. This paper presents the results of ARM direct writing on the surfaces of a nonlinear GaSe crystal (of ε modification, according to Raman and photoluminescence spectroscopy data) using fs laser radiation and a multiples approach. An increase in transmission from 65% to 80% for an ARM fabricated on one side of the crystal and up to 94% for ARMs fabricated on both sides is demonstrated. The increase in transmission with the increasing pulse energy, as well as with an increase in the number of pulses used for the formation of a single crater, is shown. The experimental results of ARM transmission of GaSe are in qualitative agreement with the simulation results based on the measured profiles and morphology of the ARM structures. [ABSTRACT FROM AUTHOR]

Nanoscale white light sources are being pursued for many practical applications such as spectroscopy and imaging. Here, we proposed a simple method for fabricating Si/Au hybrid nanoparticles and demonstrated highly efficient white light emission from such nanoparticles. We fabricated Si nanoparticles by using femtosecond laser ablation and constructed Si/Au nanocavities by placing Si nanoparticles on a thin Au film. We excited Si/Au nanocavities with femtosecond laser pulses and observed the burst of hot electron luminescence from such nanocavities. It was found that Si/Au hybrid nanoparticles can be obtained by intentionally irradiating Si/Au nanocavities with a large excitation irradiance (or laser fluence). Burst of hot electron luminescence was also observed in Si/Au hybrid nanoparticles. Efficient and stable white light emission with a quantum efficiency of ∼1.0% could be achieved above the threshold. The luminescence lifetime of Si/Au hybrid nanoparticles was found to be ∼1.00 ns, which is much longer than that observed for Si/Au nanocavities. Our findings are helpful for understanding the nonlinear optical emission from semiconductor–metal hybrid nanostructures and useful for designing nanoscale white light sources for practical applications. [ABSTRACT FROM AUTHOR]

In this paper, we propose a surface integrity technique referred to as pulse laser grinding (PLG). This method is a combination of laser ablation and the averaging processes, such as grinding, and has two characteristic features. The first feature is that the irradiation area consists of a long-focus lens and a pulse laser with a Gaussian profile, and this method has a laser irradiation area equivalent to that of the grinding wheel. However, owing to the difference in the removal process of PLG and that of conventional grinding, the surface roughness after processing is expected to be different. The second feature is that the workpiece is placed at an approximately parallel angle between the laser axis and the work surface to undergo laser ablation on the surface. The characteristic piece placement restrains laser-specific problems such as debris and redeposition. This study targets sintered tungsten carbide (WC–Co), for which it is particularly difficult to form low-roughness surfaces. Binder removal followed by WC grain detachment caused by conventional grinding contributes to the increase in roughness and deterioration of corner sharpness. The experimental results of PLG with a sufficiently averaged surface of a WC–Co tool confirmed that the parallel roughness reached an arithmetical mean roughness (Ra) of 0.025 μm, and the perpendicular roughness reached Ra below 0.006 μm, in agreement with the aforementioned considerations. [ABSTRACT FROM AUTHOR]

In order to avoid bacterial infection and mechanical damage to minor skin wounds, a bandage is usually put on the surface of the wound. The existing textile bandage can quickly absorb biofluids on the wound surface, but these absorbed biofluids remain in the interface between the wound and the bandage, which may not avoid the infection caused by these biofluids. Herein, a hydrophobic/hydrophilic Janus hydrogel composite membrane (JHCM) with a commercial band‐aid to achieve efficient cleaning of the biofluids on the wound surface is combined. By using the UV curing and femtosecond laser perforation method to fabricate the JHCM, the unidirectional biofluid transport performance of this JHCM is investigated. The JHCM can pump this biofluid to the hydrophilic layer through the hydrophilic inner wall of conical micropores and hydrogel layer driven. Also, this JHCM can weaken undesired wet adhesion and heat loss due to the removal of liquid while maintaining excellent antibacterial properties. Compared to the commercial band‐aid, there is significantly better in vivo wound healing effects for the JHCM@ band‐aid. This study is valuable for designing and fabricating next‐generation bandages with high performance for clinical applications. [ABSTRACT FROM AUTHOR]

A simple femtosecond laser alloying process is applied under two different process gases nitrogen and air to create novel molybdenum-nickel alloyed and surface enhanced catalysts. A three-day electrochemical test protocol is applied in an alkaline half-cell at 298 K and 353 K to examine the catalytic activity and initial degradation mechanisms in the hydrogen evolution reaction. It is found, that the surface enhancement and the stability of the electrode significantly depends on the process gas. Molybdenum is degraded at the beginning of the test protocol, but it is shown that higher concentrations are not necessarily required for an increase performance. The highest catalytic activity on an electrode alloyed with molybdenum under nitrogen emerges in a steady state operation at 353 K. An overpotential of 135 mV at −100 mA cm−2 is measured. [Display omitted] • A new fs-laser based manufacturing process is presented to create surface enlarged and alloyed electrodes. • The utilized process gas affects the catalytic activity, the surface enlargement, morphology and stability of an electrode. • The overpotential of an electrode structured under nitrogen but not alloyed increases with increasing temperature. • Alloying of molybdenum under nitrogen reduces the overpotential at 353 K and −100 mA cm−2 up to 57%. [ABSTRACT FROM AUTHOR]

• Fast and sensitive multi-elemental mapping of thin tissue sections of a liver metastasis, from colorectal cancer patient, after oxaliplatin-based chemotherapy, using UV-fs-LA-ICP-TOFMS. • Useful analytical tool for examining highly heterogeneous cancer tissues, allowing for more effective elemental mapping over multiple locations, including cancer cells and tumor microenvironment cells. • Importance of UV-fs laser operating parameters to achieve proper ablation conditions of thin tissue sections. • Spatial distributions of elements at cellular level, superimposing UV-fs-LA-ICP-TOFMS elemental mappings on original histological images of the tumoral tissue, taken before the laser ablation process. The characterization of the multi-elemental distributions within a thin tissue section of a liver metastasis from colorectal cancer patient after oxaliplatin-based chemotherapy, is critically evaluated using Ultraviolet Femtosecond Laser Ablation Inductively Coupled Plasma-Time of Flight Mass Spectrometry (UV-fs-LA-ICP-TOFMS). Different femtosecond laser ablation conditions, in terms of spot size and energy per pulse, were investigated to achieve proper ablation of the formalin-fixed paraffin-embedded tumor sections, while also trying to minimize the ablation of the glass substrate. Moreover, histological images of the tissues before and after the ablation processes were combined with UV-fs-LA-ICP-TOFMS elemental mapping to achieve multi-elemental spatial distributions at cellular level. For instance, spatial distributions of endogenous 31P, 56Fe, 63Cu and 64Zn analytes were determined within the thin tissue section. Furthermore, spatial distribution of elements such as 24Mg, 28Si, and 40Ca were employed to study glass substrate ablation during tissue analysis. Additional analytes, which might be partially associated to compounds employed on hematoxylin and eosin tissue staining processes, such as 23Na, 27Al, 32S, 39K, 79Br and 127I, were also detected. Finally, the accumulation of the oxaliplatin-based chemotherapy products in the stroma was confirmed from the spatial distribution of 196Pt ion signals within the tissue. [ABSTRACT FROM AUTHOR]

In recent years, superhydrophobic coatings on aircraft surfaces have garnered significant attention due to their ability to protect the surface from corrosive source like raindrops, sand, and gasoline, etc. However, to date, research on enhancing the hydrophobicity of commercial aviation coatings on aircraft Al surface is still insufficient. In the present study, the femtosecond laser ablation technique is used to texture acrylic polyurethane coatings (denoted as APU) which has been used in the aviation field to achieve a superhydrophobic surface. The relationship between micro-/nanostructures fabricated on the coatings under different laser processing parameters and the corresponding hydrophobicity was studied. The microcone-structured superhydrophobic APU surface prepared under the optimal parameters exhibited a contact angle of 151.2° and a sliding angle of 4.2°. Durability test results show that the APU surface remains at a contact angle of more than 150° after a 140° high-temperature test and 6 h acid-base solution immersion, indicating good chemical and thermal stability. The adopted femtosecond laser fabrication technology and the resultant superhydrophobic coating in the present study may have potential applications to protect aircraft parts from corrosion damage. • One-step femtosecond laser preparation of superhydrophobic surfaces is achieved by creating micro-/nanostructures on APU. • The relationship between different micro-/nanostructures and the corresponding hydrophobicity was studied. • The microcone-structured APU achieved superhydrophobicity with a contact angle of 151.2° and a sliding angle of 4.2°. • The APU superhydrophobic surface exhibits excellent self-cleaning ability and chemical and thermal stability. [ABSTRACT FROM AUTHOR]

• Ablation threshold of graphite for different number of pulses. • Surface morphology of created laser spots on graphite electrode. • Low spatial frequency laser induced periodic surface structures. • High spatial frequency laser induced periodic surface structures. • Formation of Nanoparticles and Filaments by laser ablation. This study investigates the effects of femtosecond laser irradiation on graphite, a highly sought-after material known for its exceptional chemical stability and ability to withstand extreme temperatures. The ablation threshold and surface morphology of graphite were determined using a tightly focused laser beam with varying pulse numbers and laser fluences. The results showed that the laser beam produced diverse morphological structures within different regions of a single laser spot, and the ablation threshold and surface morphology were significantly influenced by the number of pulses and the energy density of the incident laser. The study found that the ablation threshold of graphite was 107, 90, 76, and 56 ± 0.5 mJ/cm2 for 5, 50, 200, and 500 laser pulses, respectively. The resulting surface structures ranged from quasi-periodic to periodic, with varying periodicities, and the ablation debris exhibited morphologies from fine particles to long filaments. The crystal structure of the specimen was analyzed via X-ray diffraction and micro-Raman spectroscopy, with compositional analysis performed using energy-dispersive X-ray spectroscopy (EDX). Notably, a significant broadening of the Raman spectrum peaks with increasing pulse energy suggested the formation of a more disordered structure. These findings demonstrate that femtosecond laser ablation can precisely manipulate the surface morphology and nanoparticle production, presenting potential applications in fields such as nanoparticle generation and engineering surface properties like adhesion, biocompatibility, spectral reflectivity, wear resistance, and wettability. [ABSTRACT FROM AUTHOR]

Herein, significant enhancement of second- and third-harmonic generation efficiencies in a 1 mol% Er3+ and 0.07 mol% Fe2+-doped lithium niobate single-crystal plate were achieved after ablating periodic cylindrical pit arrays on the surface. Enhanced absorption and reduced transmittance of light were measured when the incident light signal passed through the patterned sample. Enhanced photoluminescence and two-photon-pumped upconversion emission spectra were also explored to obtain more details on the efficiency gains. The excitation-energy-dependent second-harmonic generation efficiency was measured, and an enhancement as high as 20-fold was calculated. The conversion efficiency of second-harmonic generation is 1 to 3 orders higher than that from other lithium niobite metasurfaces and nanoantennas. This work provides a convenient and effective method to improve the nonlinear conversion efficiency in a thin lithium niobite plate, which is desirable for applying to integrated optical devices.

In the present work, we have fabricated a novel plasmonic multi-metal nanoalloy colloid engaging a less-explored and versatile femtosecond (fs) Bessel beam ablation technique. A thorough morphological, elemental characterization has been performed with transmission electron microscope (TEM), high-resolution TEM, and energy-dispersive X-ray spectroscopy (EDX) measurements. The nanoalloys were engaged in SERS-based sensing studies, efficiently detecting traces of RDX (5 μM) and PA (500 nM), two explosive molecules. The computed enhancement factor (EF) values for RDX and PA were determined to be 1.7 × 104 and 2.4 × 105, respectively. The nanoalloy particles (NAPs) were also probed with fs pulses, revealing a domineering three-photon absorption (3 PA) phenomenon in the open aperture Z-scan measurements. The 3 PA coefficient (γ) value has been extracted to be 1.8 × 10−22 cm3/W2, and the nonlinear refraction (NLR) coefficient n 2 value was 1.1 × 10−15 cm2/W. Further, the 3 PA cross-section (σ 3) was estimated to be 1.9 × 10−75 cm6/s2. Additionally, we have demonstrated the optical limiting capability of these nanoalloys. We also performed fs transient absorption spectroscopy (fs TAS), revealing the time-resolved response of the photoexcited electrons in this nanoalloy system. The photoexcited processes of electron-electron/thermalization (τ e-e = 0.7 ± 0.1 ps), electron-phonon (τ e-ph = 1.2 ± 0.1 ps), and phonon-phonon scattering (τ ph-ph = 47.5 ± 8 ps) were retrieved from the TAS data and fit. Several additional aspects of the nanoalloy system, such as interband-excitation-induced plasmon (EIP), delayed ESA band lifetime, and bleach splitting, were systematically understood through the TAS measurements. The results from this study advocate the advantages of the fs BB-induced ablation technique in fabricating novel, multi-metal plasmonic nanoalloys and establish its potential applications in a wide range of fields, including sensors, photonics, and optical limiting. [Display omitted] • Multi-metal nanoalloy particles' colloid fabricated using femtosecond Bessel beam. • We detected traces of RDX (5 μM) and PA (500 nM), real-time explosive molecules. • The computed EFs' values for RDX and PA were 1.7 × 104 and 2.4 × 105, respectively. • 3 PA coefficient value was extraced to be 1.8 × 10−22 cm3/W2. • Electron-electron (1.5 ps) and electron-phonon scattering (52.5 ps) times were obtained. [ABSTRACT FROM AUTHOR]

Texturing can be used to functionalize the surface of plastic parts and, in particular, to modify the interaction with fluids. Wetting functionalization can be used for microfluidics, medical devices, scaffolds, and more. In this research, hierarchical textures were generated on steel mold inserts using femtosecond laser ablation to transfer on plastic parts surface via injection molding. Different textures were designed to study the effects of various hierarchical geometries on the wetting behavior. The textures are designed to create wetting functionalization while avoiding high aspect ratio features, which are complex to replicate and difficult to manufacture at scale. Nano-scale ripples were generated over the micro-scale texture by creating laser-induced periodic surface structures. The textured molds were then replicated by micro-injection molding using polypropylene and poly(methyl methacrylate). The static wetting behavior was investigated on steel inserts and molded parts and compared to the theoretical values obtained from the Cassie–Baxter and Wenzel models. The experimental results showed correlations between texture design, injection molding replication, and wetting properties. The wetting behavior on the polypropylene parts followed the Cassie–Baxter model, while for PMMA, a composite wetting state of Cassie–Baxter and Wenzel was observed.

The ablation phenomena in silica glass were investigated using a visible femtosecond laser and time-resolved pump-probe imaging. A pump pulse with a wavelength of 400 nm was employed. Only gentle ablation occurred at a peak fluence of 6.88 J/cm2, and gentle ablation and strong ablation occurred at a peak fluence of 8.23 J/cm2. At both peak fluences, reflectivity increased owing to excitation at a delay time of ~1 ps. At a delay time of ~30 ps, a decrease in reflectivity due to melting was observed only at the local fluence that generated strong ablation. The ablation that occurred after melting was considered to correspond to strong ablation. Similar changes in reflectivity were observed for two values of the local fluence that corresponded to gentle ablation. [ABSTRACT FROM AUTHOR]

We study the properties of laser-induced periodic surface structures (LIPSS) formed on titanium-doped diamond-like nanocomposite (DLN) a-C:H:Si:O films during ablation processing with linearly-polarized beams of a visible femtosecond laser (wavelength 515 nm, pulse duration 320 fs, pulse repetition rates 100 kHz-2 MHz, scanning beam velocity 0.05–1 m/s). The studies are focused on (i) laser ablation characteristics of Ti-DLN films at different pulse frequencies and constant fluence close to the ablation threshold, (ii) effects of the polarization angle rotation on the properties of low spatial frequency LIPSS (LSFL), and (iii) nanofriction properties of the ‘rotating’ LIPSS using atomic force microscopy (AFM) in a lateral force mode. It is found that (i) all LSFL are oriented perpendicular to the beam polarization direction, so being rotated with the beam polarization, and (ii) LSFL periods are gradually changed from 360 ± 5 nm for ripples parallel to the beam scanning direction to 420 ± 10 nm for ripples formed perpendicular to the beam scanning. The obtained results are discussed in the frame of the surface plasmon polaritons model of the LIPSS formation. Also, the findings of the nanoscale friction behavior, dependent on the LIPSS orientation relative to the AFM tip scanning direction, are presented and discussed.

The performance and long-term durability of dental implants hinge on the quality of bone integration and their resistance to bacteria. This research aims to introduce a surface modification strategy for zirconia implants utilizing femtosecond laser ablation techniques, exploring their impact on osteoblast cell behavior and bacterial performance, as well as the integral factors influencing the soft tissue quality surrounding dental implants. Ultrafast lasers were employed to craft nanoscale groove geometries on zirconia surfaces, with thorough analyses conducted using x-ray diffraction, scanning electron microscopy, atomic force microscopy, and water contact angle measurements. The study evaluated the response of human fetal osteoblastic cell lines to textured zirconia ceramics by assessing alkaline phosphatase activity, collagen I, and interleukin 1 β secretion over a 7 day period. Additionally, the antibacterial behavior of the textured surfaces was investigated using Fusobacterium nucleatum , a common culprit in infections associated with dental implants. Ciprofloxacin (CIP), a widely used antibacterial antibiotic, was loaded onto zirconia ceramic surfaces. The results of this study unveiled a substantial reduction in bacterial adhesion on textured zirconia surfaces. The fine biocompatibility of these surfaces was confirmed through the MTT assay and observations of cell morphology. Moreover, the human fetal osteoblastic cell line exhibited extensive spreading and secreted elevated levels of collagen I and interleukin 1 β in the modified samples. Drug release evaluations demonstrated sustained CIP release through a diffusion mechanism, showcasing excellent antibacterial activity against pathogenic bacteria, including Streptococcus mutans, Pseudomonas aeruginosa , and Escherichia coli ., (© 2024 IOP Publishing Ltd.)

Nanofillers are added to polymeric insulating materials in order to modify the electrical, mechanical and thermal properties. This study investigates silicone rubber filled with hydrophilic and hydrophobic silica nanoparticles with respect to their resistance to laser ablation and to arc discharges, as well as their mechanical properties. The laser ablation is performed with single femtosecond laser pulses at wavelengths of 520 nm and 1040 nm. This way, the influence of the nanoparticles on the ablation by laser pulses with defined energy is investigated. The energy absorbed in the ablated volume is determined by taking into account the absorption for various fluences above the ablation threshold. For the silica nanocomposites, the energy specific ablation volume (ESAV), i.e., the ablated volume per absorbed energy, is significantly reduced compared to the unfilled polymer. The reduction is more pronounced for hydrophilic nanoparticles than for hydrophobic nanoparticles. Furthermore, the resistance to arc discharges and the mechanical strength of the nanocomposites are higher compared to the unfilled polymer. In particular, for nanocomposites with different types of silica filler particles the resistance to laser ablation, expressed by the ESAV, the resistance to arc discharges and the mechanical strength, expressed by Shore A hardness and the Young's modulus, show a strong correlation. From this, it is concluded that the modifications of the material properties are caused by interactions between the polymer and the nanoparticle surface, i.e., an interphase. The different extent of this interphase becomes obvious in the different degrees of impact on various electrical and mechanical properties. [ABSTRACT FROM AUTHOR]