TY - JOUR
T1 - High throughput microfabrication using laser induced plasma in saline aqueous medium
AU - Saxena, Ishan
AU - Ehmann, Kornel
AU - Cao, Jian
N1 - Funding Information:
The authors would like to acknowledge National Science Foundation (awards CMMI #1234491 and #0960776 ), and DARPA for funding this ongoing research. Research was sponsored by the U.S. Army Contracting Command – New Jersey, Emerging Technologies Contracting Center (ACC-NJ, ET) , Benet Laboratories on behalf of the US Army Armament Research, Development & Engineering Command's (ARDEC) Benet Laboratories (BL) and the Defense Advanced Research Projects Agency (DARPA) and was accomplished under Grant Number W15QKN-12-1-0001 . The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the ACC-NJ, ET on behalf of the ARDEC/BL and DARPA, or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation hereon.
Publisher Copyright:
© 2014 Elsevier B.V. All rights reserved.
PY - 2015/3
Y1 - 2015/3
N2 - We report a novel micro-fabrication process that achieves high material removal rate by utilizing thermal ablation by a laser-induced plasma inside an aqueous medium with added salinity. The process involves focusing a pulsed laser beam of visible wavelength within the saline solution, leading to optical breakdown and subsequent formation of a localized plasma plume. Therefore higher material removal rates and greater aspect ratios of machined features can be obtained as compared to laser ablation, while preserving its resolution and precision of machining. The underlying phenomenon behind the process is the enhancement of plasma energy density due to availability of dissociated ions from salt, combined with an increase in optical attenuation coefficient of the medium, leading to an optimum salinity level for maximum material removal. Micro-channels were machined on 6061 Aluminum mirror-finish flat samples by this process, and the material removal rate was found to be higher by up to 97% for an optimized salinity level of 2-4 g/100 ml, as compared to that obtained by pure aqueous media (distilled water). Moreover, the machining characteristics correlated with the experimentally determined plasma generation thresholds for the corresponding salinity levels. In this paper, the experimental results for plasma generation thresholds, plasma fluence and material removal parameters (depth, width, and material removal rates) are presented.
AB - We report a novel micro-fabrication process that achieves high material removal rate by utilizing thermal ablation by a laser-induced plasma inside an aqueous medium with added salinity. The process involves focusing a pulsed laser beam of visible wavelength within the saline solution, leading to optical breakdown and subsequent formation of a localized plasma plume. Therefore higher material removal rates and greater aspect ratios of machined features can be obtained as compared to laser ablation, while preserving its resolution and precision of machining. The underlying phenomenon behind the process is the enhancement of plasma energy density due to availability of dissociated ions from salt, combined with an increase in optical attenuation coefficient of the medium, leading to an optimum salinity level for maximum material removal. Micro-channels were machined on 6061 Aluminum mirror-finish flat samples by this process, and the material removal rate was found to be higher by up to 97% for an optimized salinity level of 2-4 g/100 ml, as compared to that obtained by pure aqueous media (distilled water). Moreover, the machining characteristics correlated with the experimentally determined plasma generation thresholds for the corresponding salinity levels. In this paper, the experimental results for plasma generation thresholds, plasma fluence and material removal parameters (depth, width, and material removal rates) are presented.
KW - Laser induced plasma
KW - Laser material processing
KW - Saline water plasmaa
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U2 - 10.1016/j.jmatprotec.2014.10.018
DO - 10.1016/j.jmatprotec.2014.10.018
M3 - Article
AN - SCOPUS:84910608334
VL - 217
SP - 77
EP - 87
JO - Journal of Materials Processing Technology
JF - Journal of Materials Processing Technology
SN - 0924-0136
ER -