scholarly journals Influence of energy fluence and overlapping rate of femtosecond laser on surface roughness of Ti-6Al-4V

2019 ◽  
Vol 58 (10) ◽  
pp. 1
Author(s):  
Yong Yang ◽  
Wenhui Fan ◽  
Rui Lou ◽  
Xu Chen ◽  
Jing Bai ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Energy Fluence

Femtosecond laser single step, full depth cutting of thick silicon sheets with low surface roughness

2021 ◽  
Vol 138 ◽  
pp. 106899
Author(s):  
Zhaoqing Li ◽  
Olivier Allegre ◽  
Qianliang Li ◽  
Wei Guo ◽  
Lin Li
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Single Step

scholarly journals Femtosecond Laser Fabrication of Engineered Functional Surfaces based on Biodegradable Polymer and Biopolymer/Ceramic Composite Thin Films

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 378 ◽  
Author(s):  
Albena Daskalova ◽  
Irina Bliznakova ◽  
Liliya Angelova ◽  
Anton Trifonov ◽  
Heidi Declercq ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Femtosecond Laser ◽  
Surface Functionalization ◽  
Biodegradable Polymer ◽  
Photoelectron Spectroscopy ◽  
Laser Energy ◽  
Surface Characteristics ◽  
Laser Pulses ◽  
Xrd Analysis

Surface functionalization introduced by precisely-defined surface structures depended on the surface texture and quality. Laser treatment is an advanced, non-contact technique for improving the biomaterials surface characteristics. In this study, femtosecond laser modification was applied to fabricate diverse structures on biodegradable polymer thin films and their ceramic blends. The influences of key laser processing parameters like laser energy and a number of applied laser pulses (N) over laser-treated surfaces were investigated. The modification of surface roughness was determined by atomic force microscopy (AFM). The surface roughness (Rrms) increased from approximately 0.5 to nearly 3 µm. The roughness changed with increasing laser energy and a number of applied laser pulses (N). The induced morphologies with different laser parameters were compared via Scanning electron microscopy (SEM) and confocal microscopy analysis. The chemical composition of exposed surfaces was examined by FTIR, X-ray photoelectron spectroscopy (XPS), and XRD analysis. This work illustrates the capacity of the laser microstructuring method for surface functionalization with possible applications in improvement of cellular attachment and orientation. Cells exhibited an extended shape along laser-modified surface zones compared to non-structured areas and demonstrated parallel alignment to the created structures. We examined laser-material interaction, microstructural outgrowth, and surface-treatment effect. By comparing the experimental results, it can be summarized that considerable processing quality can be obtained with femtosecond laser structuring.

Characterization of Electrical Contacts on Silicon (100) after Ablation and Sulfur Doping by Femtosecond Laser Pulses

2013 ◽  
Vol 205-206 ◽  
pp. 358-363 ◽  
Author(s):  
Philipp Saring ◽  
Anna Lena Baumann ◽  
Stefan Kontermann ◽  
Wolfgang Schade ◽  
Michael Seibt
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Laser Pulses ◽  
Sample Surface ◽  
Femtosecond Laser Pulses ◽  
Electrical Contacts ◽  
Single Shot ◽  
Excess Charge ◽  
Silicon Sample ◽  
Etching Depth

This paper investigates the influence of different number of laser pulses on contact behavior and conductivity of the surface layer of femtosecond laser microstructured, sulfur-doped silicon. Single shot laser processed silicon (Pink Silicon) is characterized by low surface roughness, whereas five shot laser processed silicon (Grey Silicon) has an elevated sulfur content with a surface roughness low enough to maintain good contacting. To laterally confine the laser induced pn-junction part of the Grey Silicon sample surface is etched off. The etching depth is confirmed to be sufficient to completely remove the active n-type sulfur layer. While Pink Silicon shows little or no lateral conductivity within the laser processed layer, Grey Silicon offers acceptable conductivity, just as expected by the fact of having incorporated a higher sulfur dopant content. Recombination dominates the irradiated regions of Pink Silicon and suppresses excess charge carrier collection. Grey Silicon, while showing sufficient lateral conductivity, still shows regions of lower conductivity, most likely dominated by the laser irradiation-induced formation of dislocations. According to our results, the optimum laser pulse number for electrical and structural properties is expected to be in the range between one and five laser pulses.

scholarly journals Micromachining of Transparent Biocompatible Polymers Applied in Medicine Using Bursts of Femtosecond Laser Pulses

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1093
Author(s):  
Evaldas Kažukauskas ◽  
Simas Butkus ◽  
Piotr Tokarski ◽  
Vytautas Jukna ◽  
Martynas Barkauskas ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Contact Lenses ◽  
Laser Pulses ◽  
Laser Micromachining ◽  
Femtosecond Laser Pulses ◽  
Intraocular Lenses ◽  
Great Promise ◽  
Biocompatible Polymers ◽  
Mechanical Methods

Biocompatible polymers are used for many different purposes (catheters, artificial heart components, dentistry products, etc.). An important field for biocompatible polymers is the production of vision implants known as intraocular lenses or custom-shape contact lenses. Typically, curved surfaces are manufactured by mechanical means such as milling, turning or lathe cutting. The 2.5 D objects/surfaces can also be manufactured by means of laser micromachining; however, due to the nature of light–matter interaction, it is difficult to produce a surface finish with surface roughness values lower than ~1 µm Ra. Therefore, laser micromachining alone can’t produce the final parts with optical-grade quality. Laser machined surfaces may be polished via mechanical methods; however, the process may take up to several days, which makes the production of implants economically challenging. The aim of this study is the investigation of the polishing capabilities of rough (~1 µm Ra) hydrophilic acrylic surfaces using bursts of femtosecond laser pulses. By changing different laser parameters, it was possible to find a regime where the surface roughness can be minimized to 18 nm Ra, while the polishing of the entire part takes a matter of seconds. The produced surface demonstrates a transparent appearance and the process shows great promise towards commercial fabrication of low surface roughness custom-shape optics.

Influence of femtosecond laser on the osteogenetic efficiency of polyetheretherketone and its composite

2016 ◽  
Vol 29 (9) ◽  
pp. 997-1005 ◽  
Author(s):  
Jing Guo ◽  
Lijun Liu ◽  
Hong Liu ◽  
Kang Gan ◽  
Xiuju Liu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Biological Activity ◽  
Femtosecond Laser ◽  
Femtosecond Lasers ◽  
Cone Beam ◽  
Test Results ◽  
Bone Implant ◽  
Peek Composite ◽  
Trabecular Bones ◽  
Push Out

Objective: This study aimed to evaluate the effect of a femtosecond laser on the osteogenetic efficiency of polyetheretherketone (PEEK) and its composite for clinical applications. Methods: One hundred pieces of PEEK and its composite (6 × 4 × 2 mm3) were randomly divided into four groups and treated as follows: group A1, PEEK; group A2, PEEK + femtosecond laser; group B1, PEEK composite; and group B2, PEEK composite + femtosecond. The surface morphology of the pieces of each group was observed through scanning electron microscopy. The surface roughness and wettability, which were considered as the main parameters affecting cell adhesion characteristics of implants, were measured. The animals whose mandibles were implanted with the four groups of materials were killed at the end of 6 and 12 weeks. Various characterization tests, such as Cone Beam Computed Tomography (CBCT), push-out test, microscope test, and bone implant contact , were conducted to investigate the healing effect between materials and bones. Results: In group B1, the nanoparticles in PEEK were uniformly distributed. In groups A2 and B2, many periodic nanostructures were observed. The surface roughness and wettability of group B2 were significantly increased compared to those of the other groups ( p < 0.05). At each time point, the number of trabecular bones, contact strength, and BIC of group B2 were higher than those of the three other groups ( p < 0.05). Compared with those of group A1, the test results of group B1 were significantly improved. Conclusion: Femtosecond lasers can effectively enhance the biological activity of PEEK and its composite; PEEK composite exhibits better biological activity than PEEK.

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