An Area-Depth Approximation Model of Microdrilling on High-Density Polyethylene Soft Films Using Pulsed Laser Ablation

Effect of nanosecond pulse laser ablation on the surface morphology of Zr-based metallic glass

Ultra-short pulsed laser ablation of highly oriented pyrolytic graphite

Effect of ultraviolet irradiation on the optical properties and biological activity of silver nanoparticles prepared by pulsed laser ablation

Mechanism of laser-chemical process to remove of oxide layer and formation of periodic microstructures for drag reduction

Superconducting thin films of Y1Ba2Cu3 O7 −x have been deposited on (100) Y-ZrO2 substrates by pulsed excimer laser ablation from anunreacted mixture of Y2O3, BaCO3 and CuO. The films deposited at substrate temperature of 680°C and oxygen partial pressure of 200 mtorr were found to be superconducting with zero resistive transition temperature of 89 K and critical current density of over 3 × 105 A/cm2 at 77 K. These results are compared with those obtained by laser ablation from a sintered superconducting pellet.

Micromachining of silicon by short-pulse laser ablation in air and under water

Numerical and experimental investigation on pulsed nanosecond laser ablation processing of aluminum alloy

Degradation of TiAlN coatings by the accelerated life test using pulsed laser ablation

Thermal model for nanosecond laser ablation of alumina

Background and Objective To determine the survival of in vitro retinal pigment epithelium (RPE) cells subjected to laser-generated stress transients (shock waves) and compare it to that of other cell lines. Study Design/Materials and Methods Normal and transformed human retinal pigment epithelium cell lines were used. The cells were imbedded in a gel to prevent motion and cavitation and located in a thin layer at the bottom of a pipette tube closed at one end by a polyimide film. Stress transients were generated by pulsed excimer laser (193 nm and 248 nm wavelength) ablation of the polyimide film. Cell survival, compared to that of unirradiated cells, was assessed by counting surviving cells. The stress was varied from 300 to 740 bars and the number of shock wave pulses applied varied from 5 to 150. Results Cell survival decreased sharply at the higher stresses but some cells always survived. The lowest survival rate was 50%. Increasing the number of shock wave pulses did not increase cell killing after 20 pulses, demonstrating a saturation effect. In contrast to the transformed cell line, normal cells could not be killed at the highest stress available to us. Conclusion The susceptibility of RPE cells to damage by stress waves varies with cell line. Transformed retinal pigment epithelium cells are more susceptible than normal ones. Saturation of the damage versus number of pulses is observed and a threshold-like behavior for cell killing versus stress is found. Because at least 50% of the cells survived, normal cell growth can serve to replenish damaged cells. © 1996 Wiley-Liss, Inc.

Antibacterial efficiency of cadmium thin films deposited by the thermionic vacuum arc

Pulsed laser ablation (PLA) is a unique method used to obtainatoms, ions, and small molecules from solid targets because ofits high-energy output, the ability to adjust the power of thelaser, and the purity of the final product.1,2 Most experiments onpulsed laser-solid interaction have been carried out in vacuum(10−4 Pa)3 or in a low pressure background gas,4 aiming at thin film fabrication and cluster formation.1 One of the advantages ofthe PLA method is that stoichiometric thin films can be preparedwith the same composition as the target materials. In addition,metals, semiconductors, and ceramics with high melting point canbe obtained at lower temperatures. However, this method has somedisadvantages, such as the size of the granules on the surface ofthin films is not even, big particles exist in the surface, and ahigh vacuum environment raises the preparation cost. Also, it isdifficult to obtain a thin film with big area using the PLA method.Some researchers have attempted to produce new materials by PLAin a static liquid medium. Figure 11.1 shows a typical schematicdiagram of the experimental apparatus of PLA in static liquid.5Mafune´ and coworkers prepared small silver, gold, and platinumclusters by laser ablation of ametal plate in the aqueous solution of asurfactant, where the clusters are encapsulated by the surfactant. Atthe same time, they also researched the influence of the preparationconditions, such as the concentration of the surfactant and thepower of laser ablation, on the stability of the nanoparticles in thesolution.5−8 Yang and coworkers prepared nanocrystalline diamond and cubic C3N4 by laser ablation of a graphite target in acetonesolution and ammonia solution, respectively.9,10,11 Iwabuchi et al.12prepared nanosized titania particles by PLA of a rutile single-crystaltarget in water. Compagnini et al.13 reported PLA of gold andsilver in several liquids (mainly water, ethanol, and chloroform).They observed the formation of metal sols by laser ablation inwater and ethanol and the formation of chloride compound solsby laser ablation in chloroform. This revealed that the chemicalstate of the formed nanoparticles depends mainly on the chemicalreactivity of the liquid. Liang et al.14 synthesized ultrafine SnO2−x nanocrystals by PLA of a tin metal plate in aqueous solutions ofsodium dodecyl sulfate and in pure water. Yeh and coworkers15also prepared aluminum hydroxides by laser ablation of an Al rodimmersed in water solvent. During aging, bayerite, gibbsite, andboehmite particles were formed simultaneously.

Realization of Y 1Ba 2Cu 3O 7−δ/Y-ZrO 2 epitaxial configuration on silicon (100) by pulsed laser ablation without chemical removal of native surface oxide

The pulsed laser ablation in liquid (PLAL) technique can produce high purity nanoparticles, it is a top-down physical method based on the principle of dividing metal ion bulk precursors into metal atoms, this method was used in this work to synthesize silver nanoparticles (AgPNs) by using Nd: YAG laser with two wavelengths (355 nm) and (532 nm) at energies (500 mJ) and (600 mJ) respectively, with the number of pulses (500, 600, 700, 800, and 900 pulses) for each wavelength. The properties of the prepared nanoparticles were investigated by UV-Vis, XRD, SEM with EDX, AFM, and FTIR analysis and then tested for antibacterial activity against two Gram-positive bacteria (Staphylococcus aureus, Streptococcus mutans) and two Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa) isolated from the oral cavity. The findings demonstrated that AgNPs generated via the PLAL method have antibacterial activity and could be employed to kill dangerous and pathogenic bacteria.

Optical absorption studies of pulsed-laser-engineered silver nanospheres and their enhanced catalytic performance in the degradation of toxic methylene blue dye