Femtosecond laser-induced transformation mechanism from 1D groove structure to 2D microholes structure on the surface of Zr-based metallic glasses

This study presents the contact angle prediction model of a trapezoidal groove structure based on the laser irradiation on polymethyl methacrylate (PMMA). The trapezoidal groove structure was designed and proposed according to the characteristics of a femtosecond laser. First, the complete wetting model and incomplete wetting model which were compatible with the characteristics of the laser mechanism were constructed based on the Gibbs free energy and the structural parameters of the trapezoidal groove structure. Then, based on the contact angle prediction models constructed, the samples were divided into two groups according to the designed structural parameters, and the experimental investigations were carried out. The result demonstrated that the incomplete wetting prediction model was more in line with the actual situation. The convex width and the top edge length of spacing of the trapezoidal groove structure both affected the contact angle prediction results. From both the experimental contact angles and the contact angles predicted by the incomplete wetting model, it could be known that the contact angle reached 138.09° when the ratio of the convex width to the top edge length of spacing was 0.25, indicating that the smaller the ratio of the convex width to the top edge length of spacing, the better the hydrophobicity of PMMA.

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Reduced bacterial adhesion on zirconium-based bulk metallic glasses by femtosecond laser nanostructuring

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411919898011 ◽

2019 ◽

Vol 234 (4) ◽

pp. 387-397 ◽

Cited By ~ 1

Author(s):

Cezhi Du ◽

Chengyong Wang ◽

Tao Zhang ◽

Xin Yi ◽

Jianyi Liang ◽

...

Keyword(s):

Femtosecond Laser ◽

Laser Irradiation ◽

Metallic Glasses ◽

Bacterial Adhesion ◽

Bulk Metallic Glasses ◽

Surface Structures ◽

Femtosecond Laser Irradiation ◽

Adhesion Properties ◽

Nanostructured Surfaces

As high-performing materials, bulk metallic glasses have attracted widespread attention for biomedical applications. Herein, the bacterial adhesion properties of femtosecond laser-nanostructured surfaces of four types of zirconium-based bulk metallic glasses are assessed. Laser-induced periodical surface structures and nanoparticle structures were fabricated by femtosecond laser irradiation under different energy intensities (0.23 and 2.3 J/mm2). Surface topography, roughness, wettability, and surface energy were investigated after femtosecond laser irradiation and the surface bacterial adhesion properties were explored using Escherichia coli and Staphylococcus aureus as respective representatives of Gram-negative and Gram-positive bacteria. 4′,6-Diamidino-2-phenylindole fluorescence staining was used to characterize and assess the bacterial surface coverage rate. The in vitro cytotoxicity of polished and laser-nanostructured surfaces was investigated using MC3T3-E cells. The obtained results demonstrate that femtosecond laser surface nanostructuring retained the amorphous structure of zirconium-based bulk metallic glasses and led to an obvious decrease in bacterial adhesion compared with polished surfaces. The inhibition of bacterial adhesion on laser-induced periodical surface structures was greater than on nanostructured surfaces after 24 h of bacterial incubation. In addition, femtosecond laser nanostructuring did not have an apparent effect on the cytotoxicity of zirconium-based bulk metallic glasses.

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Initial Morphology and Feedback Effects on Laser-Induced Periodic Nanostructuring of Thin-Film Metallic Glasses

Nanomaterials ◽

10.3390/nano11051076 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1076

Author(s):

Mathilde Prudent ◽

Florent Bourquard ◽

Alejandro Borroto ◽

Jean-François Pierson ◽

Florence Garrelie ◽

...

Keyword(s):

Thin Film ◽

Femtosecond Laser ◽

Surface Topography ◽

Metallic Glasses ◽

Physical Vapor Deposition ◽

Thermomechanical Properties ◽

Femtosecond Laser Irradiation ◽

Columnar Microstructure ◽

Morphological Response ◽

Feedback Effects

Surface nanostructuring by femtosecond laser is an efficient way to manipulate surface topography, creating advanced functionalities of irradiated materials. Thin-film metallic glasses obtained by physical vapor deposition exhibit microstructures free from grain boundaries, crystallites and dislocations but also characterized by a nanometric surface roughness. These singular properties make them more resilient to other metals to form laser-induced nanopatterns. Here we investigate the morphological response of Zr65Cu35 alloys under ultrafast irradiation with multipulse feedback. We experimentally demonstrate that the initial columnar microstructure affects the surface topography evolution and conditions the required energy dose to reach desired structures in the nanoscale domain. Double pulses femtosecond laser irradiation is also shown to be an efficient strategy to force materials to form uniform nanostructures even when their thermomechanical properties have a poor predisposition to generate them.

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Surface smoothing of bulk metallic glasses by femtosecond laser double-pulse irradiation

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2020.126803 ◽

2021 ◽

pp. 126803

Author(s):

Tie Li ◽

Yang Guo ◽

Masayoshi Mizutani ◽

Shaolin Xu

Keyword(s):

Femtosecond Laser ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Double Pulse ◽

Pulse Irradiation ◽

Surface Smoothing

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Metallic glasses: Some kind of order

NPG Asia Materials ◽

10.1038/asiamat.2011.117 ◽

2011 ◽

Keyword(s):

Metallic Glasses

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Nanosecond laser-induced breakdown assisted by femtosecond laser pre-ionization in air: the effect on spatial resolution and continuous radiation

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200258 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20701

Author(s):

Bo Li ◽

Xiaofeng Li ◽

Zhifeng Zhu ◽

Qiang Gao

Keyword(s):

Femtosecond Laser ◽

Spatial Resolution ◽

Laser Induced Breakdown Spectroscopy ◽

Nanosecond Laser ◽

Breakdown Threshold ◽

Powerful Technique ◽

Breakdown Spectroscopy ◽

Continuous Radiation ◽

Laser Induced Breakdown

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.

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