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Industrial Applications of Nanomaterials || Laser-driven nanomaterials and laser-enabled nanofabrication for industrial applications
摘要： Laser is one of the most important technologies invented in the 20th century. Nowadays, the applications of laser have stretched over a vast spectrum including information technology, optoelectronics, quantum computing, materials characterization, materials processing, advanced three-dimensional (3D) printing, biology, biomedical, etc. In the nanotechnology domain, laser can be used for synthesis, processing, and characterization. In this chapter, we will focus on applying laser for synthesis and processing of nanomaterials as well as nanofabrication.
关键词： nanofabrication,nanomaterials,laser ablation,laser pyrolysis,Laser,carbon-based nanomaterials,industrial applications
更新于2025-09-11 14:15:04
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[IEEE 2019 International Conference on Electronics Packaging (ICEP) - Niigata, Japan (2019.4.17-2019.4.20)] 2019 International Conference on Electronics Packaging (ICEP) - An Investigation of Compound Machining of Ceramic-LPM Package by Ultrafast Laser
摘要： It is well known that ceramic substrates provide excellent electrical insulation and protection from oxidation/ corrosion in addition to idea heat dissipation while allowing heat dissipation through controlled paths, e.g. integrated heat sinks. Low pressure molding (LPM) with polyamide and polyolefin (hot- melt) materials is a process typically used to injection molding for waterproof, to encapsulate and environmentally to protect electronic components. The purpose than epoxy encapsulation is to protect electronic components with finer pitch against moisture, dust dirt and vibration. There is a special need for SiP (System in Package) application utilizing both ceramic substrate and LPM package materials where ceramic serves as mechanical structure and thermal dissipation path and LPM for high density SMT (Surface Mount) package. The research of this paper is to apply nano UV (Ultraviolet) laser to machine the LPM and ceramic substrate (sapphire, Al2O3) and compare the results with nano green laser. The interactions of these two materials with laser are quite different and even conflicting for machining (LPM is ductile and hot-melt while ceramic is brittle), thus proper strategy has to be taken to satisfy needs for both materials. One of the major problem is the re-solidification of LPM material as temperature elevated during laser irradiation. It is necessary to provide a delay time between each laser pulsing. The laser ablation threshold (LAT) of green and UV laser for both materials is also investigated in this paper. The best parameters for processing ceramic substrates are speed 200 mm/s, frequency 95 kHz, delay time 450 ms, when processing LPM speed 700 mm/s, frequency 40 kHz, delay time 250 ms.
关键词： Low Pressure Mold (LPM) compound,laser ablation threshold (LAT),ceramic substrate,ultrafast Laser
更新于2025-09-11 14:15:04
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Laser based analysis of transition metal boride thin films using liquid standards
摘要： In this work the use of two laser assisted direct solid sampling methods, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and laser induced breakdown spectroscopy (LIBS) for the determination of the stoichiometry of novel diboride based materials is reported. To overcome the need for certified reference materials or matrix matched standards, which were usually required for quantitative investigations with LA-ICP-MS or LIBS, in this work liquid standards are employed. For LA-ICP-MS the concept of self-aliquoting micro-grooves and for LIBS conventional dried droplets were used. As a model for application of the developed analytical procedures the ternary system W1-xTaxB2-z was used. Fabrication of W1-xTaxB2-z thin films with varying stoichiometry was performed via magnetron sputtering. Reference compositions were obtained by liquid digestion of the samples and subsequent ICP-OES measurement. Both laser-assisted methods enabled fast and spatially resolved measurements, although the LA-ICP-MS method generally yielded more accurate results. It was shown that the method can easily be adapted for the stoichiometry determination of systems with different elemental composition.
关键词： laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS),liquid calibration,Laser-induced breakdown spectroscopy (LIBS),borides,thin films
更新于2025-09-11 14:15:04
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Influence of Aluminum Laser Ablation on Interfacial Thermal Transfer and Joint Quality of Laser Welded Aluminum–Polyamide Assemblies
摘要： Laser assisted metal–polymer joining (LAMP) is a novel assembly process for the development of hybrid lightweight products with customized properties. It was already demonstrated that laser ablation of aluminum alloy Al1050 (Al) prior to joining with polyamide 6.6 (PA) has significant influence on the joint quality, manifested in the joint area. However, profound understanding of the factors affecting the joint quality was missing. This work investigates the effects of laser ablation on the surface properties of Al, discusses their corresponding impact on the interfacial thermal transfer between the joining partners, and evaluates their effects on the joint quality. Samples ablated with different parameters, resulting in a range from low- to high-quality joints, were selected, and their surface properties were analyzed by using 2D profilometry, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). In order to analyze the effects of laser ablation parameters on the interfacial thermal transfer between metal and polymer, a model two-layered system was analyzed, using laser flash analysis (LFA), and the thermal contact resistance (TCR) was quantified. Results indicate a strong influence of laser-ablation parameters on the surface structural and morphological properties, influencing the thermal transfer during the laser welding process, thus affecting the joint quality and its resistance to shear load.
关键词： laser ablation,laser welding,metal–polymer,thermal contact resistance
更新于2025-09-11 14:15:04
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Metal ablation study with a 10 picosecond laser under low and median fluence
摘要： Single shot 10 ps laser ablation on aluminium and gold at a wavelength of 1064 nm under low and median laser fluence was studied theoretically and experimentally. Simulations have been performed by using an optimized two temperature model. It is revealed that electron-phonon coupling ability of the target metal affected both the ablation depth and target metal’s morphology. Under low fluence, melting could well be the relevant ablation mechanism. With laser fluence rising, vaporization or phase explosion happens thereafter, depending on material’s electron-phonon coupling ability.
关键词： Metals and alloys,Picosecond laser processing,Modeling of laser ablation
更新于2025-09-11 14:15:04
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Laser interstitial thermal therapy in drug-resistant epilepsy
摘要： MRI-guided stereotactic laser interstitial thermal therapy (LiTT) has been utilized in the surgical treatment of discrete, small epileptogenic lesions. This review summarizes the current literature and addresses the clinical application of this technique. LiTT has the potential to reduce the morbidity and discomfort of epilepsy surgery. Review of data from retrospective, uncontrolled studies suggests that LiTT may offer benefit when treating drug-resistant epilepsy because of mesial temporal sclerosis, hypothalamic hamartoma, cavernous hemangioma, and small cortical dysplasias and malformations. It is now being offered as initial therapy in place of anterior temporal lobectomy in many centers, and a prospective study is underway to compare it with historical temporal lobectomy reports. LiTT appears promising and has potential for reduced morbidity and improved tolerability compared with open surgery. Studies must be done to compare efficacy and safety of LiTT with open surgery, and further investigation is needed to optimize this technique.
关键词： magnetic resonance-guided laser interstitial thermal therapy,epilepsy surgery,laser ablation,temporal lobe epilepsy,drug-resistant epilepsy
更新于2025-09-11 14:15:04
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Applications of Laser Ablation - Thin Film Deposition, Nanomaterial Synthesis and Surface Modification || Surface Modification of Polymer Materials Induced by Laser Irradiation
摘要： We report on the surface modification effects using allyl‐diglycol CR39 polymer induced by laser irradiation at 157?nm F2 laser (VUV) and 248?nm KrF laser. The motivation is to investigate the ablation effects on this polymer in optical waveguides application the ablation effects on this polymer in optical waveguides. Fabrication of waveguides has been observed using continuous wave (CW) at 244?nm argon ion laser. Ablation effects on the surface of this polymer have been characterized including ablation threshold at different wavelengths from the assorted depth of craters formed from UV pulsed laser. Application of this polymer in optical waveguide application is corroborated by the refractive index value on the CR39 channels that varied as fluences changed when using the continuous wave UV irradiation. A limit for upper fluence at the point where laser ablation originates on this polymer has also been determined.
关键词： refractive index modification,surface modification,channel waveguide,CR39 laser ablation
更新于2025-09-11 14:15:04
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Fabrication of chemical composition controlled YbFe <sub/>2</sub> O <sub/>4</sub> epitaxial thin films
摘要： The crystal growth of YbFe2O4 requires oxidant-poor conditions, thus YbFe2O4 usually contains a large number of iron deficiencies even in the bulk single crystal. The use of an ArF laser for laser ablation is effective to reduce the amount of active oxygen species and a wide process window to form the YbFe2O4 epitaxial films becomes available. By using the widened process window and an iron-rich target, the chemical composition of the YbFe2O4 epitaxial thin films is successfully controlled. The effect of the iron composition on the charge ordering transition can be discussed using the nonlinear I–V behavior. The threshold electric field changes depending on the iron composition owing to the broadening of the 3-dimensional (3D) charge order region, which affects the robustness of the 3D charge order against an electric field in YbFe2O4 thin films.
关键词： YbFe2O4,laser ablation,epitaxial thin films,chemical composition control,charge ordering
更新于2025-09-11 14:15:04
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In vivo evaluation of safety, biodistribution and pharmacokinetics of laser-synthesized gold nanoparticles
摘要： Capable of generating plasmonic and other effects, gold nanostructures can offer a variety of diagnostic and therapy functionalities for biomedical applications, but conventional chemically-synthesized Au nanomaterials cannot always match stringent requirements for toxicity levels and surface conditioning. Laser-synthesized Au nanoparticles (Aunp) present a viable alternative to chemical counterparts and can offer exceptional purity (no trace of contaminants) and unusual surface chemistry making possible direct conjugation with biocompatible polymers (dextran, polyethylene glycol). this work presents the first pharmacokinetics, biodistribution and safety study of laser-ablated dextran-coated Aunp (Aunpd) under intravenous administration in small animal model. our data show that Aunpd are rapidly eliminated from the blood circulation and accumulated preferentially in liver and spleen, without inducing liver or kidney toxicity, as confirmed by the plasmatic ALAT and ASAT activities, and creatininemia values. Despite certain residual accumulation in tissues, we did not detect any sign of histological damage or inflammation in tissues, while IL-6 level confirmed the absence of any chronic inflammation. The safety of AuNPd was confirmed by healthy behavior of animals and the absence of acute and chronic toxicities in liver, spleen and kidneys. our results demonstrate that laser-synthesized Aunp are safe for biological systems, which promises their successful biomedical applications.
关键词： gold nanoparticles,biodistribution,pharmacokinetics,toxicity,laser ablation
更新于2025-09-11 14:15:04
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Preparation and characterization of graphene sheet prepared by laser ablation in liquid
摘要： Graphene sheets prepared successfully by Nd: YAG laser ablation of carbon target immersed in deionized water. The structural, optical and morphological properties investigated using Fourier transform infrared spectroscopy, X-ray diffraction, UV–VIS spectrophotometry, photoluminescence spectroscopy, and Transmission electron microscopy. The result of FTIR spectra conform C?C and C@C bonds, which yield to carbon nanoparticles (CNPs) suspend in liquid. After re-irradiation, new peaks appear at 1723 cm(cid:1)1 and 2697 cm(cid:1)1 caused by the disordered arrangement and irregular layer thickness of graphene sheets. The XRD pattern observed sharp peaks at 2h (cid:3) 24(cid:1), 26.6(cid:1), and 43(cid:1) with higher intensity after the re-irradiation process. The absorption result shows a shoulders peaks among 260 and 320 nm relates to transition in C@O and C@C bands. The PL spectra have a peak in the visible region at 597 nm and increased as laser energy increased. TEM images show straight isolated long multiwall carbon nanotubes MWCNT with the hollow core in different dimensions. While graphene sheet it takes the shape of a ?at transparent layer with small wrinkles and folding sheet, appeared after re-irradiation the suspensions with same laser energy.
关键词： Carbon nanoparticles,Carbon nanotubes,Laser ablation,Graphene sheet
更新于2025-09-11 14:15:04