scholarly journals Ablation of Bone Tissue by Femtosecond Laser: A Path to High-Resolution Bone Surgery

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2429
Author(s):  
Laura Gemini ◽  
Samy Al-Bourgol ◽  
Guillaume Machinet ◽  
Aboubakr Bakkali ◽  
Marc Fauçon ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Bone Tissue ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Biological Tissues ◽  
Thermal Loads ◽  
Bone Surgery ◽  
Fs Laser ◽  
Laser Sources ◽  
Fresh Bone

Femtosecond lasers allow for high-precision, high-quality ablation of biological tissues thanks to their capability of minimizing the thermal loads into the irradiated material. Nevertheless, reported ablation rates remain still too limited to enable their exploitation on a clinical level. This study demonstrates the possibility to upscale the process of fs laser ablation of bone tissue by employing industrially available fs laser sources. A comprehensive parametric study is presented in order to optimize the bone tissue ablation rate while maintaining the tissue health by avoiding excessive thermal loads. Three different absorption regimes are investigated by employing fs laser sources at 1030 nm, 515 nm and 343 nm. The main differences in the three different wavelength regimes are discussed by comparing the evolution of the ablation rate and the calcination degree of the laser ablated tissue. The maximum of the ablation rate is obtained in the visible regime of absorption where a maximum value of 0.66 mm3/s is obtained on a non-calcined tissue for the lowest laser repetition rate and the lowest spatial overlap between successive laser pulses. In this regime, the hemoglobin present in the fresh bone tissue is the main chromophore involved in the absorption process. To the best of our knowledge, this is the highest ablation rate obtained on porcine femur upon fs laser ablation.

Fabrication and Characterization of Si Nano-Columns by Femtosecond Laser

2012 ◽  
Vol 16 ◽  
pp. 15-20 ◽  
Author(s):  
Omid Tayefeh Ghalehbeygi ◽  
Vural Kara ◽  
Levent Trabzon ◽  
Selcuk Akturk ◽  
Huseyin Kizil
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Laser Beam ◽  
Chemical Etching ◽  
Silicon Surface ◽  
Laser Pulses ◽  
Laser Beam Profile ◽  
Fs Laser ◽  
Fabrication And Characterization

We fabricated Si Nano-columns by a femtosecond laser with various wavelengths and process parameters, whilst the specimen was submerged in water. The experiments were carried out by three types of wavelengths i.e. 1030 nm, 515nm, 343nm, with 500 fs laser pulses. The scales of these spikes are much smaller than micro spikes that are constructed by laser irradiation of silicon surface in vacuum or gases like SF6, Cl2. The Si nano-columns of 300 nm or less in width were characterized by SEM measurements. The formation of these Si Nano-columns that were revealed by SEM observation, indicates chemical etching with laser ablation occurred when surface exposed by laser beam. We observed 200 nm spikes height at the center of laser beam profile and the ones uniform in height at lateral incident area.

Optimizing controlled laser cutting of hard tissue (bone)

2018 ◽  
Vol 66 (12) ◽  
pp. 1072-1082 ◽  
Author(s):  
Lina M. Beltran Bernal ◽  
Iris T. Schmidt ◽  
Nikola Vulin ◽  
Jonas Widmer ◽  
Jess G. Snedeker ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Cutting ◽  
Laser Surgery ◽  
Healing Process ◽  
Ablation Rate ◽  
Movement Speed ◽  
Lateral Movement ◽  
Hard Tissue ◽  
Robot Assisted ◽  
Bone Surgery

Abstract Conventional bone surgery leads to unwanted damage to the surrounding tissues and a slow healing process for the patients. Additionally, physicians are not able to perform free cutting shapes due to the limitations of available systems. These issues can be overcome by robot-assisted contactless laser surgery since it provides less mechanical stress, allows precise functional cuts, and leads to faster healing. The remaining drawback of laser surgery is the low ablation rate that is not yet competitive with conventional mechanical piezo-osteotomes. Therefore, we aim at maximizing the efficiency in hard tissue laser ablation by optimizing the lateral movement speed for different irrigation conditions. The results of this study show a non-linear relationship between cutting rates, speeds, and depths that should be critically considered for integration in robotic laser surgery.

scholarly journals Laser ablation of silicon with THz bursts of femtosecond pulses: an experimental and theoretical investigation

2021 ◽  
Author(s):  
Caterina Gaudiuso ◽  
Pavel N. Terekhin ◽  
Annalisa Volpe ◽  
Stefan Nolte ◽  
Bärbel Rethfeld ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Thermal Load ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Pulse Mode ◽  
Femtosecond Laser Pulses ◽  
Photon Absorption ◽  
Burst Frequency ◽  
Two Photon Absorption ◽  
Theoretical Investigations

Abstract In this work, we performed an experimental investigation supported by a theoretical analysis, to improve knowledge on the laser ablation of silicon with THz bursts of femtosecond laser pulses. Laser ablated craters have been created using 200 fs pulses at a wavelength of 1030 nm on silicon samples systematically varying the burst features and comparing to the Normal Pulse Mode (NPM). Using bursts in general allowed reducing the thermal load to the material, however, at the expense of the ablation rate. The higher the number of pulses in the bursts and the lower the intra-burst frequency, the lower is the specific ablation rate. However, bursts at 2 THz led to a higher specific ablation rate compared to NPM, in a narrow window of parameters. Theoretical investigations based on the numerical solution of the density-dependent two temperature model revealed that lower lattice temperatures are reached with more pulses and lower intra-burst frequencies, thus supporting the experimental evidence of the lower thermal load in Burst Mode (BM). This is ascribed to the weaker transient drop of reflectivity, which suggests that with bursts less energy is transferred from the laser to the material. This also explains the trends of the specific ablation rates. Moreover, we found that two-photon absorption plays a fundamental role during BM processing in the THz frequency range.

Ablation of Si and Ge Using UV Femtosecond Laser Pulses

1995 ◽  
Vol 397 ◽  
Author(s):  
G. Herbst ◽  
M. Steiner ◽  
G. Marowsky ◽  
E. Matthias
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Material Removal ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Bond Breaking ◽  
Intensity Enhancement ◽  
Silicon And Germanium

ABSTRACTLaser ablation of silicon and germanium was carried out in moderate vacuum with l00fs to 400fs pulses at 248nm and intensities up to 3x1013 W/cm2. Evidence for non-thermal material removal was found. Imaged multishot ablation patterns display the intensity dependent self-structuring effect, forming well-known columnar structures. It is shown that continued irradiation of these structures eventually results in comparatively clean ablation. An increase of ablation rate with depth was observed. The reason is an intensity enhancement inside the pits by reflective focussing to a level where bond-breaking takes place. Furthermore, it was noticed that ablation contours can be significantly improved by electrically grounding the target.

scholarly journals Micropatterning MoS2/Polyamide Electrospun Nanofibrous Membranes Using Femtosecond Laser Pulses

Photonics ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 3 ◽  
Author(s):  
Kelly T. Paula ◽  
Luiza A. Mercante ◽  
Rodrigo Schneider ◽  
Daniel S. Correa ◽  
Cleber R. Mendonca
Keyword(s):  
Laser Ablation ◽  
Composite Nanofibers ◽  
Electrospun Nanofibers ◽  
Scanning Speed ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Spectroscopic Techniques ◽  
Fs Laser ◽  
Nanofibrous Membranes ◽  
Scale Control

The capability of modifying and patterning the surface of polymer and composite materials is of high significance for various biomedical and electronics applications. For example, the use of femtosecond (fs) laser ablation for micropatterning electrospun nanofiber scaffolds can be successfully employed to fabricate complex polymeric biomedical devices, including scaffolds. Here we investigated fs-laser ablation as a flexible and convenient method for micropatterning polyamide (PA6) electrospun nanofibers that were modified with molybdenum disulfide (MoS2). We studied the influence of the laser pulse energy and scanning speed on the topography of electrospun composite nanofibers, as well as the irradiated areas via scanning electron microscopy and spectroscopic techniques. The results showed that using the optimal fs-laser parameters, micropores were formed on the electrospun nanofibrous membranes with size scale control, while the nature of the nanofibers was preserved. MoS2-modified PA6 nanofibrous membranes showed good photoluminescence properties, even after fs-laser microstructuring. The results presented here demonstrated potential application in optoelectronic devices. In addition, the application of this technique has a great deal of potential in the biomedical field, such as in tissue engineering.

Nanosecond Laser Ablation of Silicon Carbide at Infrared Wavelength

2010 ◽  
Author(s):  
Yibo Gao ◽  
Yun Zhou ◽  
Benxin Wu
Keyword(s):  
Silicon Carbide ◽  
Laser Ablation ◽  
Electrical Discharge Machining ◽  
High Hardness ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Nanosecond Laser ◽  
Infrared Wavelength ◽  
Nanosecond Laser Ablation ◽  
Mechanical Machining

Silicon carbide, due to its unique properties, has many promising applications in optics, electronics and other areas. However, it is difficult to process using mechanical machining or electrical discharge machining due to its electrical insulation, high hardness and brittleness. Laser ablation can potentially provide a good solution for silicon carbide micromachining. However, the study on silicon carbide ablation by nanosecond laser pulses at infrared wavelength is limited, and will be presented in this paper. The laser ablation rate, laser-induced plasma, the ablated surface morphology and chemical composition change have been studied, and the results are discussed.

scholarly journals Femtosecond laser ablation of brass: A study of surface morphology and ablation rate

2012 ◽  
Vol 30 (3) ◽  
pp. 473-479 ◽  
Author(s):  
Mohamed E. Shaheen ◽  
Brian J. Fryer
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Surface Morphology ◽  
Fine Particles ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Ambient Air ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Nanosecond Laser

AbstractThe interaction of near infrared femtosecond laser pulses with a Cu based alloy (brass) in ambient air at atmospheric pressure and under different laser conditions was investigated. The effects of laser fluence and number of pulses on surface morphology and ablation rate were studied using scanning electron microscopy (SEM) and optical microscopy. Ablation rates were found to rapidly increase from 83 to 604 nm/pulse in the fluence range 1.14–12.21 J/cm2. At fluence >12.21 J/cm2, ablation rates increased slowly to a maximum (607 nm/pulse at 19.14 J/cm2), and then decreased at fluence higher than 20.47 J/cm2 to 564 nm/pulse at 24.89 J/cm2. Large amounts of ablated material in a form of agglomerated fine particles were observed around the ablation craters as the number of laser pulses and fluence increased. The study of surface morphology shows reduced thermal effects with femtosecond laser ablation in comparison to nanosecond laser ablation at low fluence.

scholarly journals Laser ablation of silicon with THz bursts of femtosecond pulses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caterina Gaudiuso ◽  
Pavel N. Terekhin ◽  
Annalisa Volpe ◽  
Stefan Nolte ◽  
Bärbel Rethfeld ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Thermal Load ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Pulse Mode ◽  
Femtosecond Laser Pulses ◽  
Photon Absorption ◽  
Burst Frequency ◽  
Two Photon Absorption ◽  
Theoretical Investigations

AbstractIn this work, we performed an experimental investigation supported by a theoretical analysis, to improve knowledge on the laser ablation of silicon with THz bursts of femtosecond laser pulses. Laser ablated craters have been created using 200 fs pulses at a wavelength of 1030 nm on silicon samples systematically varying the burst features and comparing to the normal pulse mode (NPM). Using bursts in general allowed reducing the thermal load to the material, however, at the expense of the ablation rate. The higher the number of pulses in the bursts and the lower the intra-burst frequency, the lower is the specific ablation rate. However, bursts at 2 THz led to a higher specific ablation rate compared to NPM, in a narrow window of parameters. Theoretical investigations based on the numerical solution of the density-dependent two temperature model revealed that lower lattice temperatures are reached with more pulses and lower intra-burst frequencies, thus supporting the experimental evidence of the lower thermal load in burst mode (BM). This is ascribed to the weaker transient drop of reflectivity, which suggests that with bursts less energy is transferred from the laser to the material. This also explains the trends of the specific ablation rates. Moreover, we found that two-photon absorption plays a fundamental role during BM processing in the THz frequency range.

Morphological Changes and Plume Deflection Effect during Pulsed Laser Ablation Deposition of Al

2007 ◽  
Vol 546-549 ◽  
pp. 789-792
Author(s):  
A. Perrone ◽  
L. Cultrera ◽  
S. Duhalde
Keyword(s):  
Laser Ablation ◽  
Morphological Changes ◽  
Digital Camera ◽  
Target Surface ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Columnar Structure ◽  
Beam Direction ◽  
Si Substrates ◽  
Laser Fluences

The morphological changes and corresponding plume deflection effect during long laser (XeCl excimer laser, λ=308 nm, τ=30 ns) irradiation of Al target have been investigated,and results showed that, a the number of laser pulses per site increases, the target morphology changes and produces a visible deviation of the plasma plume up to 5º. Scanning electron spectroscopy analys of the target surface related the plume deflection angle to the target morphology and the number of laser pulses per site. Typically well-defined columnar structures oriented along the laser beam direction were observed on the target surface. The plume created during the laser ablation was clearly visible to the naked eye and was recorded by a digital camera. Detailed studies were also performed on the ablation rate at different laser fluences (4.6 J/cm2-12.5 J/cm2). The morphologies and the thickness of the Al thin films deposited on Si substrates during the present laser ablation experiments were also studied. Finally, the scenario explaining the formation of columnar structure on target surface responsible for the plume deflection effect will be discussed.

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