Laser Ablation Research Articles

Comparing mechanochemical endovenous ablation using Flebogrif with endovenous laser ablation in the treatment of primary great saphenous vein incompetence: protocol for a multicentre, open-label, non-inferiority, observer-blinded, randomised controlled trial (REBORN trial)

IntroductionEndovenous laser ablation (EVLA) is associated with an excellent outcome in the treatment of great saphenous vein (GSV) incompetence. However, the use of thermal ablation requires tumescent anaesthesia and is...

The leaky chronometer: Evidence for systematic cryptic Pb loss in laser ablation U‐Pb dating of zircon relative to CA‐TIMS

AbstractU–Pb dating of zircon via laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) has become a primary method for determining the age of crystalline rocks and the provenance and maximum depositional age of (meta)sedimentary rocks. Although chemical abrasion has become a standard approach for mitigating Pb loss in zircon dated via high‐resolution thermal ionization mass spectrometry (CA‐TIMS), laser ablation dating is rarely accompanied by chemical abrasion. We evaluate the accuracy of U–Pb dates acquired via LA‐ICP‐MS relative to CA‐TIMS through analysis of a large database of paired analyses from the same zircon crystals. We show that laser ablation 206Pb/238U dates are systematically younger than their CA‐TIMS counterparts, with a greater shift in detrital zircon (−2.0%) versus igneous or metamorphic zircon (−0.9%). Although systematic biases related to “matrix effects” may be a contributing factor, our analysis suggests that unmitigated cryptic Pb loss is likely widespread in laser ablation U–Pb datasets.

Recent Advances in Carbon Nanotube Technology: Bridging the Gap from Fundamental Science to Wide Applications

Carbon nanotubes, as carbon allotropes distinguished by their intricate structures and exceptional physicochemical properties, have demonstrated substantial progress in recent years across diverse domains, including energy production, chemical synthesis, and environmental preservation. They exhibit notable attributes such as high thermal stability, superior adsorption capacity, and a substantial specific surface area, rendering them superb catalyst supports. Particularly in electrochemical energy storage, CNTs are extensively employed in supercapacitor electrodes owing to their elevated electrical conductivity, mechanical robustness, and electrocatalytic prowess, which facilitate significant energy storage capabilities. Their intricate pore architecture and reactive sites make functionalized carbon nanotubes well suited for synthesizing composite materials with diverse components, which are ideal for sequestering carbon dioxide from both atmospheric and indoor environments. This review presents a comprehensive examination of carbon nanotube synthesis methodologies, encompassing chemical vapor deposition, arc discharge, and laser ablation, and evaluates their impacts on the structural and functional properties of carbon nanotubes. Furthermore, this article underscores the applications of carbon nanotubes in fields such as fuel cells, photocatalysis, ammonia synthesis, dry methane reforming, Fischer–Tropsch synthesis, and supercapacitors. Despite the considerable potential of carbon nanotubes, their manufacturing processes remain intricate and costly, impeding large-scale industrial production. This review concludes by addressing the challenges in fabricating carbon nanotube composites and outlining future development prospects.

Petrographic and geochemical analysis of lunar meteorite NWA 11788: Parallels with Luna 20 and the Apollo magnesian granulites

AbstractThe first in‐depth geochemical and petrological analyses of new lunar meteorite Northwest Africa (NWA) 11788 were conducted with the aim of better understanding the diversity of lunar rock types. Petrography, microcomputed tomography, electron probe microanalysis, and laser ablation inductively coupled plasma mass spectrometry were employed to analyze mineralogic/elemental makeup, petrologic profile, melt history, and inferred composition of the lunar mantle from which the crystals in this sample originated from. Geochemical maps of the lunar surface were generated to constrain potential lunar launch locations for NWA 11788. Potential launch locations are concentrated in the outer rims of impact basins on the lunar Eastern nearside limb (e.g., Crisium, Fecunditatis, Marginis, Smythii) and around the South Pole–Aitken Basin. Similarities in the major, minor, and trace element chemistry of NWA 11788 along with its potential launch locations suggest a petrogenetic relationship with regolith samples returned from the Luna 20 mission and the Apollo 16 and 17 magnesian granulites. Additionally, the results of this study add to the growing body of evidence that KREEP (potassium, rare earth elements, phosphorous)‐poor, Mg‐suite‐“like” lithologies are common in non‐Apollo‐type locales, that KREEP may not be required to generate lithologies like the Mg‐suite, and that KREEP is not globally distributed at present.

Laser irradiation-induced surface-enhanced Raman scattering of Sn@SnO composite films

In this work, Sn@SnO composite films were obtained by Nd:YAG fiber pulsed laser ablation at room temperature. The effects of laser ablation on the microstructure, optical properties, and Raman scattering properties of the films were investigated. Tunable Localized Surface Plasmon resonance(LSPR)of Sn nanoparticles was realized in the wavelength range of 380–450 nm by varying the scanning rate to modulate the degree of oxidation of Sn nanoparticles. Surface enhanced Raman scattering (SERS) was also observed in the composite structure, which was demonstrated excellent stability and SERS sensitivity with the detectable concentration of methylene blue (MB) as low as 10−9 M and an enhancement factor of 1.75 × 105 as well as a good uniformity. Finally, the electric field distribution of the samples before and after the laser treatment is simulated by the finite difference in time domain (FDTD) method, and the results are consistent with those of experimental ones.

Organic synaptic transistor showing ultralow energy consumption with a microscale channel by laser ablation

Low energy consumption per synaptic event is important for artificial synapses in applications of highly integrated and large-scale neuromorphic computing systems. Reducing the channel length of a synaptic transistor is an effective method to achieve this goal because such devices can work under low operating voltage and current. In this Letter, we use femtosecond laser ablation to fabricate a microscale slit in an Ag film as the channel of an organic synaptic transistor to obtain low energy consumption. The length of the shortest channel is only 1.6 μm. As a result, the device could be driven by a 50 μV drain bias voltage while output 855 pA excitatory postsynaptic current under a gate spike of 50 mV and 30 ms. The calculated energy consumption per synaptic event is 1.28 fJ, which is comparable to that of a biological synapse (1–10 fJ per synaptic event). Femtosecond laser ablation has been demonstrated a rapid and effective process for the fabrication of microscale channel with high resolution for synaptic transistor, showing large potential for the development of neuromorphic electronics.

Composite Liquid Media Influence on the Optical and Bactericidal Properties of Silver Nanoparticles Synthesized by Pulsed Laser Ablation in Liquids

Composite Liquid Media Influence on the Optical and Bactericidal Properties of Silver Nanoparticles Synthesized by Pulsed Laser Ablation in Liquids

Quantitative Measurement of Multiple Elements in Micro‐Quantities of Crude Oil Using In Situ Analysis by Laser Ablation‐ICP‐MS

Multi‐element quantification in small amounts of material and in situ measurements at the micrometre scale are essential aspects of geological sample investigation. A direct and rapid simultaneous multi‐elemental determination of metals in crude oil samples was carried out by combining direct laser ablation of the oil inserted in silica capillaries with inductively coupled plasma‐mass spectrometry. The accuracy of LA‐ICP‐MS determination was demonstrated by analysing CONOSTAN reference material oils, certified for multiple elements, and by comparing LA‐ICP‐MS measurement results with those obtained by ICP‐OES using microwave‐assisted sample digestion. The results obtained by both methods were in agreement with certified values. The LA‐ICP‐MS method showed an adequate precision with a mean relative standard deviation of less than 10% for multi‐element determination, and was sufficiently sensitive to determine the majority of elements. LA‐ICP‐MS was also applied to the determination of elements in crude oils of different origins. LA‐ICP‐MS is a good alternative method allowing the determination of elements in organic fluids (oil and bitumen) in shorter times, involving less material consumption, smaller test portion size and with higher throughput compared with protocols using, for instance, sample digestion. It validates the possible application of metal analysis in hydrocarbon‐containing fluid inclusions for metallogenic purposes.

Simultaneous Bulk‐Rock Elemental and Boron Isotope Ratio Measurement Using LA‐ICP‐MS on Silicate Micro‐Particulate Pellets

We have established a method for the simultaneous measurement of element abundances and boron isotopic compositions of bulk‐rock silicate samples by laser ablation coupled to two different ICP‐MS instruments. Fifteen silicate reference materials were prepared as micro‐particulate pressed powder pellets (MP) for analysis. Approximately 1/5th of the ablated material was transported to a single‐collector ICP‐MS for elemental measurement, while 4/5ths were sent to a multi‐collector ICP‐MS for boron isotope ratio measurement. Compositions of different milling materials (agate, zirconium oxide, tungsten carbide, sintered corundum and silicon nitride) were measured for the evaluation of potential contamination during sample preparation. Determined element mass fractions are in agreement with literature values within ±20%. For boron isotope ratios, the matrix‐dependent background elevation across the m/z from 9.9 to 11, and the effect of ablation mass was quantified. Measured δ11B values of most reference materials are consistent with literature values within ±1‰. The intermediate measurement precision is ±0.3‰ for JB‐2 with 30 μg g−1 B and ±0.4‰ for JA‐2 with 21 μg g−1 B. A publically available, web‐based streamlit app was developed for data processing (https://zenodo.org/doi/10.5281/zenodo.11150471). This paves the way for combined, accurate and precise elemental and boron isotope ratio measurements of geological materials.

Hot Embossing to Fabricate Parylene-Based Microstructures and Its Impact on the Material Properties

This study aims to establish and optimize a process for the fabrication of 3D microstructures of the biocompatible polymer Parylene C using hot embossing techniques. The different process parameters such as embossing temperature, embossing force, demolding temperature and speed, and the usage of a release agent were optimized, utilizing adhesive micropillars as a use case. To enhance compatibility with conventional semiconductor fabrication techniques, hot embossing of Parylene C was adapted from conventional stainless steel substrates to silicon chip platforms. Furthermore, this adaptation included an investigation of the effects of the hot embossing process on metal layers embedded in the Parylene C, ensuring compatibility with the ultra-thin Parylene printed circuit board (PCB) demonstrated previously. To evaluate the produced microstructures, a combination of characterization methods was employed, including light microscopy (LM) and scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). These methods provided comprehensive insights into the morphological, chemical, and structural properties of the embossed Parylene C. Considering the improved results compared to existing patterning techniques for Parylene C like plasma etching or laser ablation, the developed hot embossing approach yields a superior structural integrity, characterized by increased feature resolution and enhanced sidewall smoothness. These advancements render the method particularly suitable for diverse applications, including but not limited to, sensor optical components, adhesive interfaces for medical wearables, and microfluidic systems.

One-step fabrication of multifunctional superhydrophobic copper surfaces via laser-assisted ablation PDMS solution

The super-hydrophobic surfaces have been greatly restricted in multi-functional applications because of the poor surface durability and multi-step processes such as preparing rough structures and low surface energy modification. In this work, a multifunctional wear-resistant super-hydrophobic surface (SHS) was primarily developed by one step laser etching polydimethylsiloxane (PDMS) i.e. the uncured PDMS layer was laser-ablated just after it was coated on the surface of copper. The wettability, morphology and chemical composition of the surfaces were characterized by a contact Angle measuring instrument, scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR). The results show that the developed SHS has the high contact angle (WCA) of 156.8° and low sliding angle (WSA) of 4.6°; which presents a regular linear grating array and a large number of coral-like rough structures, and the developed SHS can withstand at least 120 tape stripping tests, 40 sandpaper friction abrasion tests, 60 h of high temperature treatment (100 °C∼300 °C) or 240 h of ultraviolet light exposure tests, respectively. The self-cleaning rate and anti-fouling rate of the SHS were 94.2 % and 91.8 %, respectively, and the freezing time of droplets on the SHS is 162 s longer than that on the original copper surface, and almost 3 times longer than that on the smooth surface. In all, the non-polluting wear-resistant multifunctional SHS was primarily developed by laser ablation of metals and polymers, which has strong potential usage in the fields of anti-fouling of industrial pipeline systems and anti-icing of outdoor power transmission systems.

Enhanced MALDI-2 Sensitivity with Reflecting Post-Ionization Laser for High-Resolution MS Imaging Combined with Real-Time Microscope Imaging.

Laser-induced matrix-assisted laser desorption/ionization post-ionization (MALDI-2) could improve the MALDI sensitivity of biological metabolites by over 1 order of magnitude. Herein, we demonstrate that MALDI-2 sensitivity can be further enhanced with reflecting post-ionization laser that multiplies the intersection times between laser and MALDI plume. This method, which we named MALDI-2+, typically brought over 2 times sensitivity improvement from conventional MALDI-2. Advancing in sensitivity thereby prompted us to pursue higher mass spectrometry imaging (MSI) spatial resolution. A dedicated T-shaped ion guide was designed to allow perpendicular incidence of ablation laser in reflection geometry MALDI. Although 8-10 μm pixel was used in MALDI imaging due to the limited precision of the motorized stage, the laser spot diameter could be down to 2.5 μm for potentially higher spatial resolution. In addition, this ion source enabled real-time and high-quality microscope imaging from backward of the sample plate. Beneficially, we were able to monitor the actual laser spot condition in real time as well as obtain high-resolution microscopic sample images that inherently register with MSI images. All of these benefits have been demonstrated by analyzing standard samples and imaging of cells. We believe that the enhancement in sensitivity, spatial resolution, and microscope capacity of our design could facilitate spatial omics studies.

Improved precision at high-spatial resolution of strontium isotope analysis in apatite and apatite inclusions by LA-MC-ICP-MS with 1013 Ω amplifiers

Recent advancements in in situ analytical techniques have generated new interest in measuring strontium (Sr) isotopes in rock-forming apatite and apatite inclusions in zircon, because they can bring new insights into the primary signatures of magmatic sources. This paper introduces a novel approach based on laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), which allows to achieve higher precision in situ analysis of Sr isotopes in small volumes of samples. The use of 1013 Ω current amplifiers for the acquisition of the signal on m/z 83, 83.5, 84, 85, 85.5, 86, 86.5, 87 and 88, along with a specific data reduction protocol, enhance both the internal precision and the external reproducibility of the 87Sr/86Sr ratio by a factor of four, presenting a significant improvement over the conventional use of 1011 Ω amplifiers. An internal precision better than 0.45‰ (i.e. 450 ppm; 2 s.e.) on the 87Sr/86Sr ratio can be achieved on the Durango apatite standard with a 13 μm square-shaped laser beam and a laser ablation pit of 60 μm depth. With a 5 μm beam, the precision is 2.2‰ on average with a 10 μm ablation pit depth for this standard. This analytical procedure was applied to investigate Sr isotopes in apatite and apatite inclusions within zircons from seven high BaSr magmatic rocks in the Northern Highland Terrane, Scotland. For these well-characterised, geochemically undisturbed samples, the data reveals similar Sr isotope compositions between apatite inclusions armoured in zircon, matrix apatites, and the bulk rock. This highlights the ability of apatite inclusions to faithfully record primary signatures of host magmas, elucidating their utility as reliable indicators in petrological studies of ancient samples.

A laser-induced superhydrophobic surface with multiple microstructures for stable drag reduction

To address the issue of water resistance in ship navigation, we developed a drag-reducing surface based on the microstructure of shark skin and a superhydrophobic coating. First, grooves with various microstructures were fabricated on the substrate surface using laser processing. Then, a mixture of octadecyltrichlorosilane, water, and silica solution was uniformly sprayed onto the grooved substrate surface to achieve superhydrophobicity. To enhance and stabilize the drag reduction effect, we optimized the width and spacing of the grooves by adjusting the laser processing parameters, achieving a high drag reduction rate under various flow conditions. In the Reynolds number range of 2 × 105 to 5 × 105, the drag reduction rate of the superhydrophobic coated surface with grooves reached over 66.57 %, which is an improvement of 7 % to 26.51 % compared to the superhydrophobic coated surface without grooves. Additionally, the oxides accumulated on the ribs after laser ablation can slow down the wear of the superhydrophobic coating, significantly enhancing the surface's mechanical durability. This simple and cost-effective surface provides a new approach for laser preparation of drag-reducing surfaces.

Fabrication of rGO-bridged TiO2/g-C3N4 Z-scheme Nanocomposites via Pulsed Laser Ablation for Efficient Photocatalytic CO2 Reduction.

Highly efficient photocatalysts can be fabricated using favorable charge transfer nanocomposite channel structures. This study adopted pulsed laser ablation in liquid (PLAL) to obtain rGO-bridged TiO2/g-C3N4 (rGO-TiO2/g-C3N4) photocatalytic Z-scheme without the need for noble metals. In addition to evaluating the resulting nanocomposite's (comprising rGO nanosheets, TiO2 nanotubes, and g-C3N4 nanosheets) CO2 reduction effectiveness, its chemical, morphological, structural, and optical characteristics were examined using various analytical techniques. The findings revealed a synergistic interaction between g-C3N4 and TiO2, suggesting the presence of unique interfacial bonding, as well as enhanced visible light absorption. Notably, the ternary rGO-TiO2/g-C3N4 Z-scheme exhibits an excellent photocatalytic performance by photocatalytically converting CO2 into CO and CH4, with 81% selectivity towards the CO and 1.91% apparent quantum efficiency at 420 nm. Thus, the findings can pave the way for various Z-scheme systems in wide photocatalytic applications.

Comparative Study between Endovenous Laser Ablation (EVLA) with 1940 nm versus EVLA with 1470 nm for Treatment of Incompetent Great Saphenous Vein and short saphenous vein: A Randomized Controlled trial

BackgroundTo date, the most commonly used endothermal ablation method is endovenous LASER ablation (EVLA). The objective of the present work is to assess the initial and short-term outcomes of a 1940 nm diode LASER compared to 1470 nm diode LASER utilization for the treatment of lower limb varicose veins. Patients and methodsThis is a randomized, controlled prospective study that included patients with varicose veins. The allocated patients were randomized according to the technique used: Group I, which was treated using EVLA with a 1940 nm diode LASER, and Group II, which was treated using EVLA with a 1470 nm diode LASER. ResultsThis study initially included 216 patients. After the exclusion of patients lost during follow-up, Group I consisted of 105 patients, and Group II consisted of 101 patients. There were high rates of anatomical success in the two groups with obliteration of the treated vessels at the 1-month follow-up (100% and 99%, respectively) and the 6-month follow-up (100% and 99%, respectively). A very low rate of adverse events was encountered (1%). Group II showed obviously longer median days to return for usual activities (11.5 compared to 7). They showed significantly higher pain scores, which was evident at the 7-day and 1-month follow-ups (p < 0.001). ConclusionBoth LASERS provided excellent outcomes in terms of anatomical success and low rates of adverse events. The 1940 nm diode LASER was associated with lower median days to return for usual activities and significantly lower pain scores. Evidently, lower power and LEED were required for this LASER.

Extreme ultraviolet laser ablation and time-of-flight mass spectrometry of gold, aluminum, and copper targets

Extreme ultraviolet laser ablation and time-of-flight mass spectrometry of gold, aluminum, and copper targets

Assessing spatial distribution of bioindicator elements in various cutaneous tumors using correlative imaging with laser-ablation-based analytical methods

Correlative imaging of cutaneous tumors provides additional information to the standard histopathologic examination. However, the joint progress in the establishment of analytical techniques, such as Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) in clinical practice is still limited. Their combination provides complementary information as it is also shown in our study in terms of major biotic (Ca, Mg, and P) and trace (Cu and Zn) elements. To elucidate changes in the elemental composition in tumors, we have compiled a set of malignant tumors (Squamous Cell Carcinoma, Basal Cell Carcinoma, Malignant Melanoma, and Epithelioid Angiosarcoma), one benign tumor (Pigmented Nevus) and one healthy-skin sample. The data processing was based on a methodological pipeline involving binary image registration and affine transformation. Thus, our paper brings a feasibility study of a practical methodological concept that enables us to compare LIBS and LA-ICP-MS results despite the mutual spatial distortion of original elemental images. Moreover, we also show that LIBS could be a sufficient pre-screening method even for a larger number of samples according to the speed and reproducibility of the analyses. Whereas LA-ICP-MS could serve as a ground truth and reference technique for preselected samples.

Fabrication of Plasmonic Microcubes by Laser Ablation of Au‐Nanoparticles‐Loaded Acrylate

Fabrication of Plasmonic Microcubes by Laser Ablation of Au‐Nanoparticles‐Loaded Acrylate

Synthesis and Characterization of Double Core-shell Au@Ag@Au Nanoparticles by Pulsed Laser Ablation in Liquid and Analysis of Their Antibacterial Properties

Synthesis and Characterization of Double Core-shell Au@Ag@Au Nanoparticles by Pulsed Laser Ablation in Liquid and Analysis of Their Antibacterial Properties