Picosecond Laser Ablation of Polydimethylsiloxane (PDMS)

2009 ◽  
Author(s):  
Hansong Zeng ◽  
Yi Zhao ◽  
Benxin Wu ◽  
Chris Taylor ◽  
Ronald L. Jacobsen ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Fluence ◽  
Picosecond Laser ◽  
Ablation Rate ◽  
Pulse Number ◽  
Hole Diameter ◽  
Replica Molding

Picosecond laser ablation of Polydimethylsiloxane (PDMS) has been studied experimentally. The measurements show that laser ablation rate per pulse increases with laser fluence and pulse number. The laser-drilled hole diameter increases with pulse number, and it saturates above certain pulse number for low fluence. The study shows that picosecond laser ablation may provide a good solution for micromachining PDMS, which is more flexible and versatile than the replica molding technique.

Micromachining of Metals, Alloys and Ceramics by Picosecond Laser Ablation

2008 ◽  
Author(s):  
Wenqian Hu ◽  
Galen B. King ◽  
Yung C. Shin
Keyword(s):  
Electron Microscope ◽  
Laser Ablation ◽  
Picosecond Laser ◽  
Ablation Rate ◽  
Optical Microscope ◽  
Recast Layer ◽  
Laser Machining ◽  
Percussion Drilling ◽  
Scanning Electron

Microhole drilling and microstructure machining with a picosecond (ps) Nd:YVO4 laser (pulse duration of 10 ps) in metals, alloys and ceramics are reported. Blind and through microholes were drilled by percussion drilling as well as trepanning drilling. The diameters of the holes were in the range from 20 μm to 1000 μm. Microfeatures were machined and the flexibility of ps laser machining was demonstrated. The quality of drilled holes, e.g., recast layer, microcrack and conicity, and that of the microstructures, were investigated by optical microscope, surface profilometer, or scanning electron microscope (SEM). Ps laser ablation rate was investigated by experiments as well as a simplified laser ablation model.

Real-Time Monitoring of Indium Tin Oxide Laser Ablation in Liquid Crystal Display Patterning

1998 ◽  
Vol 526 ◽  
Author(s):  
M.H. Hong ◽  
Y.F. Lu ◽  
M. Meng ◽  
T.S. Low
Keyword(s):  
Laser Ablation ◽  
Acoustic Wave ◽  
Laser Fluence ◽  
Indium Tin Oxide ◽  
Glass Substrate ◽  
Ablation Threshold ◽  
Liquid Crystal Display ◽  
Pulse Number ◽  
Spectral Lines ◽  
Spectral Intensities

AbstractAudible acoustic wave detection is applied to investigate KrF excimer laser ablation of Indium Tin Oxide (ITO) thin film layer for Liquid Crystal Display (LCD) patterning. It is found that there is no acoustic wave generation if laser fluence is lower than ITO ablation threshold. For laser fluence higher than the threshold, audible acoustic wave will be detected due to shock wave generation during ITO laser ablation. The amplitude of the acoustic wave is closely related to the laser ablation rate. With more laser pulse applied, the amplitude is dropped to zero because the ITO layer is completely removed. However, if laser fluence is increased higher than ablation threshold for glass substrate, the amplitude is also dropped with pulse number but not to zero. It is due to laser ablation of ITO layer and glass substrate at the same time. Since the thickness of ITO layer is in a scale of 100 nm, laser interaction with glass substrate will happen even at the first pulse of high laser fluence irradiation. Laser ablation induced ITO plasma emission spectrum in visible light region is analyzed by an Optical Multi-channel Analyzer (OMA). Specific spectral lines are In I (325.8, 410.2 and 451.1 nm) and In II 591.1 nm. Spectral intensities of 410.2 and 451.1 nm lines are selected to characterize the evolution of ITO plasma intensity with laser fluence and pulse number. It is found that the spectral intensities are reduced to zero with laser pulse number. It is also found that spectral lines other than ITO plasma will appear for laser fluence higher than ablation threshold for glass substrate. Threshold fluences for glass and ITO ablation are estimated for setting up a parameter window to control LCD patterning in real-time.

Ablation study of laser micromachining process with molecular dynamics simulation

2016 ◽  
Vol 231 (3) ◽  
pp. 415-426 ◽  
Author(s):  
Angelos P Markopoulos ◽  
Dimitrios E Manolakos
Keyword(s):  
Molecular Dynamics ◽  
Laser Ablation ◽  
Laser Fluence ◽  
Three Dimensional ◽  
Ablation Rate ◽  
Dynamics Simulation ◽  
Entire Duration ◽  
Micro Hole ◽  
System Temperature ◽  
Ablation Study

A three-dimensional molecular dynamics model is presented for the simulation of the creation of a micro-hole on a thin film metal substrate via laser ablation. For the presented analysis, molybdenum and aluminium specimens are selected and short pulses are assumed. The laser fluence takes several values between 0.5 and 20 J/cm2. The proposed models include significant laser ablation phenomena such as plasma shielding. However, they are not computationally intense. In this study, the Morse potential is used for the interactions of the atoms of the specimens. The analysis is carried out in order to investigate the ablation rate, the ablation depth and the mean temperature of molybdenum and aluminium targets under their heating by the laser beam, for several different values of fluence. Results for molybdenum indicate that as fluence increases, it takes less time for the atoms to be ablated. For low-fluence pulses, more than one pulse may be required for the ablation of all atoms. For high-fluence pulses, the ablation is not uniform across the entire duration of the pulse and the specimen is overheated. A fluence value around 2–3 J/cm2 is suggested for uniform ablation. From the analysis, it is evident that the evolution of ablation and system temperature is different for molybdenum and aluminium, for the same laser fluence. This is attributed to different crystalline structures and absorptivity of each material. It may be said that molecular dynamics prove to be a powerful tool for the simulation of nanomanufacturing processes and useful conclusions are drawn from the analysis.

Processing Characteristics and Parametric Effects on Picosecond Laser Nanoscaled Patterning of Poly(methyl methacrylate)

2020 ◽  
Vol 20 (8) ◽  
pp. 5142-5146
Author(s):  
Ching-Yen Ho ◽  
Zui-Wei Liu ◽  
Xian-Liang Chen ◽  
Dongkai Qiao ◽  
Chang-Wei Xiong ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Laser Fluence ◽  
Electronic Devices ◽  
Pulsed Laser ◽  
Picosecond Laser ◽  
Ablation Rate ◽  
Poly Methyl Methacrylate ◽  
Nanoscale Patterning ◽  
Parametric Effects ◽  
Noncontact Processing

Characteristics of picosecond laser processing for poly(methyl methacrylate) (PMMA) are studied in this text. Poly(methyl methacrylate) (PMMA) can be applied to micro- or nano-scale electronic devices. Short-pulsed laser is usually used for noncontact processing of nanoscale patterning of poly(methyl methacrylate) (PMMA). This study considers optical energy of laser to be transferred into decomposition energy of poly(methyl methacrylate) (PMMA). Using the condition of the energy balance at the decomposition interface, the variation of the ablation rate with the logarithm of the laser fluence is calculated for poly(methyl methacrylate) (PMMA) and agrees with the measured data. This study also discusses parametric effects of poly(methyl methacrylate) (PMMA) on the variation of the ablation rate with the logarithm of the laser fluence.

scholarly journals Picosecond Laser Ablation of Polyhydroxyalkanoates (PHAs): Comparative Study of Neat and Blended Material Response

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 127 ◽  
Author(s):  
Rocío Ortiz ◽  
Pooja Basnett ◽  
Ipsita Roy ◽  
Iban Quintana
Keyword(s):  
Tissue Engineering ◽  
Laser Ablation ◽  
Food Packaging ◽  
Laser Energy ◽  
Picosecond Laser ◽  
Ablation Rate ◽  
Ablation Efficiency ◽  
Medium Chain Length ◽  
Micro Structuring ◽  
Convenient Technique

Polyhydroxyalkanoates (PHAs) have emerged as a promising biodegradable and biocompatible material for scaffold manufacturing in the tissue engineering field and food packaging. Surface modification is usually required to improve cell biocompatibility and/or reduce bacteria proliferation. Picosecond laser ablation was applied for surface micro structuring of short- and medium-chain length-PHAs and its blend. The response of each material as a function of laser energy and wavelength was analyzed. Picosecond pulsed laser modified the surface topography without affecting the material properties. UV wavelength irradiation showed halved ablation thresholds compared to visible (VIS) wavelength, revealing a greater photochemical nature of the ablation process at ultraviolet (UV) wavelength. Nevertheless, the ablation rate and, therefore, ablation efficiency did not show a clear dependence on beam wavelength. The different mechanical behavior of the considered PHAs did not lead to different ablation thresholds on each polymer at a constant wavelength, suggesting the interplay of the material mechanical parameters to equalize ablation thresholds. Blended-PHA showed a significant reduction in the ablation threshold under VIS irradiation respect to the neat PHAs. Picosecond ablation was proved to be a convenient technique for micro structuring of PHAs to generate surface microfeatures appropriate to influence cell behavior and improve the biocompatibility of scaffolds in tissue engineering.

Micromachining of Metals, Alloys, and Ceramics by Picosecond Laser Ablation

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Wenqian Hu ◽  
Yung C. Shin ◽  
Galen B. King
Keyword(s):  
Electron Microscope ◽  
Laser Ablation ◽  
Picosecond Laser ◽  
Ablation Rate ◽  
Optical Microscope ◽  
Recast Layer ◽  
Laser Machining ◽  
Percussion Drilling ◽  
Scanning Electron

Microhole drilling and microstructure machining with a picosecond (ps) Nd:YVO4 laser (pulse duration of 10 ps) in metals, alloys, and ceramics are reported. Blind and through microholes are drilled by percussion drilling as well as trepanning drilling, where the diameters of the holes are in the range of 20–1000 μm. Microfeatures are also machined and the flexibility of ps laser machining is demonstrated. The quality of drilled holes, e.g., recast layer, microcrack, and conicity, and that of the microstructures, are investigated by an optical microscope, a surface profilometer, or a scanning electron microscope. Ps laser ablation rate is studied by experiments and a simplified laser ablation model.

Effect of pulse number on the ablation rate of metals in PLA multipulse regime

2010 ◽  
Author(s):  
C. Negutu ◽  
I. Vladoiu ◽  
M. Stafe ◽  
A. Rizea ◽  
N. N. Puscas ◽  
...  
Keyword(s):  
Ablation Rate ◽  
Pulse Number
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