Fundamentals and applications of polymers designed for laser ablation

Lippert, Thomas; Hauer, M.; Phipps, Claude; Wokaun, Alexander

doi:10.1007/s00339-003-2111-y

Cited by 58 publications

(32 citation statements)

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“…Fourth, as discussed before, the photon density corresponding to the fluence is in our case much larger than in the other studies discussed here, and than that typically used in polymer ablation (9.7 Â 10 15 to 2.9 Â 10 17 photons/ cm 2 , corresponding to laser fluences of 10-300 mJ/cm 2 , respectively). [29][30][31][32]34 Despite the differences mentioned, the order of magnitude of the width of the projected initial velocity distributions estimated from our experiments is surprisingly similar to those measured by Feldmann for polystyrene, 33 and by other researchers in laser ablation of polymers. 33,38,39 An explanation for this is that, despite these dissimilarities and the fundamental differences of size and sample geometry, similar mechanisms and similar initial velocity distributions are present in all these cases.…”

Section: Ion Velocity Distributions From Excimer Laser Ablation Of Posupporting

confidence: 82%

“…29,30 The extent of material removal in polymer ablation from surfaces depends in a complex manner on a number of factors such as laser wavelength, fluence, pulsed or continuous irradiation, duration of the laser pulse, on the one hand, and light absorption efficiency and sample morphology and thickness, on the other. [29][30][31] It has been observed that ablation starts immediately after the beginning of the irradiation and proceeds during the total irradiation time. It is also established that the ablation rates saturate at large fluences, due mainly to screening of the radiation by the ablated products and the associated plasma.…”

Section: Mechanistic Dependence Of the Direction Of The Expanding Ablmentioning

confidence: 99%

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Initial velocity distributions of ions generated by in‐flight laser desorption/ionization of individual polystyrene latex microparticles as studied by the delayed ion extraction method

Vera

Trimborn

Hinz

et al. 2004

Rapid Comm Mass Spectrometry

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The delayed ion extraction method has been used to study characteristics of the initial velocity distributions of positive and negative ions produced simultaneously by laser desorption/ionization (LDI) from non-impacted single aerosol polymeric particles, using a bipolar time-of-flight (TOF) instrument (LAMPAS 2). Due to the geometry of the setup and the characteristics of the ablation process, only the projections of the velocities on the axis of the mass spectrometer can be directly studied. Additionally, since the mean initial velocity under these conditions should be close to zero, it was necessary to extend the method by taking into account higher order contributions of the velocity distribution. Theoretical expressions for these higher order terms are presented and discussed. The bipolar characteristics of the instrument permit evaluation and treatment of a possible instrumental artifact caused by small inclinations of the ionizing laser with respect to the ideal incidence direction. Results of a number of experiments are presented and discussed in relation to the theoretical expressions presented, and to possible ablation scenarios. Evidence pointing out that, under our experimental conditions, only partial ablation of the latex particles occurs was obtained. The variance of the distribution of the projection of the initial velocities can be directly estimated from these results. By assuming that the total initial velocities of the ions are developed completely according to a single-temperature adiabatic expansion mechanism, temperatures of approximately 50 K/Da can be assigned to the ion clouds from the variance estimations. If a two-temperature model is used, a radial temperature of about 100 K/Da results. These values are in reasonable agreement with results for polymer ablation from the literature.

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Section: Ion Velocity Distributions From Excimer Laser Ablation Of Posupporting

confidence: 82%

Section: Mechanistic Dependence Of the Direction Of The Expanding Ablmentioning

confidence: 99%

Initial velocity distributions of ions generated by in‐flight laser desorption/ionization of individual polystyrene latex microparticles as studied by the delayed ion extraction method

Vera

Trimborn

Hinz

et al. 2004

Rapid Comm Mass Spectrometry

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“…The employed laser source emits UV radiation (266 nm), which ensures a high absorption by the PI foils. Furthermore, due to the short wavelength used, the produced radiation have a high photon energy, leading to the photochemical ablation of the polymer with a negligible contribution of photothermal processes 46,47 .…”

Section: Resultsmentioning

confidence: 99%

Fabrication of inclined non-symmetrical periodic micro-structures using Direct Laser Interference Patterning

Alamri

El-Khoury

Aguilar‐Morales

et al. 2019

Sci Rep

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The direct fabrication of microstructures, having a non-symmetrical morphology with controllable inclination, presents nowadays a challenging task. Natural examples of surfaces with inclined topographies have shown to provide anisotropic functionalities, which have attracted the interest of several researchers in the last years. This work presents a microfabrication technique for producing microstructures with a determined and controllable inclination angle using two-beam Direct Laser Interference Patterning. Polyimide foils are irradiated with a 4 ns UV (266 nm) laser source producing line-like structures with a period varying from 4.6 µm to 16.5 µm. The inclinations, retrieved by tilting the sample with respect to the optical axis of the setup, are changed from 0° to 75°, introducing a well controllable and defined inclination of the structure walls. The structuring parameters (laser fluence, number of laser pulses and interference period) as well as the inclination of the microstructures are correlated with the global tilting of the sample. As a result, a determined laser fluence and number of pulses are necessary to observe a remarkable non-symmetrical morphology of the structures. In addition, the presence of structural undercuts is reported, which opens the possibility for developing new direction-dependent properties on polymeric materials. As an example, preliminary results on light diffraction are presented, showing a similar behavior as blazed diffraction gratings.

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“…The dynamics of the ablation by UV lasers have been investigated in great detail [3][4][5], including shadowgraphic imaging of the triazene flye [6,7]. The theoretical ablation mechanism for TP is not fully understood, but it is known to have a significan photochemical element [8]. In general, however, ablation is dominated by thermal factors, and even for TP an ablation model based exclusively on thermal factors has been demonstrated [9].…”

Section: Introductionmentioning

confidence: 99%

Laser-induced ablation dynamics and flight of thin polymer films

et al. 2011

Self Cite

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We investigated the ejection dynamics oftriazene polymer layers in the thickness range of 40 nm to 600 nm upon nanosecond laser ablation at a wavelength of 532 nm. The ablation is due to laser-induced thermal degradation of a small part of the polymer in contact with the silicon substrate. The subsequent dynamics of the flyin polymer layer are measured with sub-nanosecond time resolution. The evaluation ofthe initial velocity for different fil thicknesses gives insight into the energy transfer process during the acceleration of the films P. Frank (181) .

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Fundamentals and applications of polymers designed for laser ablation

Cited by 58 publications

References 0 publications

Initial velocity distributions of ions generated by in‐flight laser desorption/ionization of individual polystyrene latex microparticles as studied by the delayed ion extraction method

Initial velocity distributions of ions generated by in‐flight laser desorption/ionization of individual polystyrene latex microparticles as studied by the delayed ion extraction method

Fabrication of inclined non-symmetrical periodic micro-structures using Direct Laser Interference Patterning

Laser-induced ablation dynamics and flight of thin polymer films

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