Research Papers

Laser-Induced Plasma Micromachining Process: Principles and Performance

[+] Author and Article Information
Kumar Pallav

Department of Mechanical Engineering,
Northwestern University,
Evanston, IL 60208
e-mail: kumarpallav2008@u.northwestern.edu

Ishan Saxena, K. F. Ehmann

Department of Mechanical Engineering,
Northwestern University,
Evanston, IL 60208

1Corresponding author.

Contributed by the Manufacturing Engineering Division of ASME for publication in the JOURNAL OF MICRO- AND NANO-MANUFACTURING. Manuscript received January 20, 2015; final manuscript received May 27, 2015; published online June 24, 2015. Assoc. Editor: Nicholas Fang.

J. Micro Nano-Manuf 3(3), 031004 (Sep 01, 2015) (8 pages) Paper No: JMNM-15-1008; doi: 10.1115/1.4030706 History: Received January 20, 2015; Revised May 27, 2015; Online June 24, 2015

Laser-induced plasma micromachining (LIP-MM) is a novel multimaterial and tool-less micromachining process. It utilizes tightly focused ultrashort laser irradiation to generate plasma through laser-induced dielectric breakdown in a dielectric material. The plasma facilitates material removal through plasma–matter interaction spot through vaporization and ablation. The paper introduces the LIP-MM process, discusses the underlying principles behind plasma generation and machining, and proves its feasibility by describing the experimental conditions under which plasma generation and machining occur. Upon successful commercial realization of this novel process, the key benefits envisaged are micromachining with better accuracy and better surface integrity, minimal subsurface damage, relatively smaller heat-affected zone (HAZ) and low roughness in a wide range of materials including those that are difficult to machine by some of the most successful micromachining processes such as micro-electrodischarge machining (EDM) and laser ablation.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.


Pallav, K., Malhotra, R., Saxena, I., Ehmann, K., and Cao, J., 2014, “Laser 522 Directed Plasma Micro-Machining (LDPMM) With Magnetic and Optical Control,” U.S. Patent Filed.
Saxena, I., and Ehmann, K. F., 2014, “Multimaterial Capability of Laser Induced Plasma Micromachining,” ASME J. Micro Nano–Manuf., 2(3), p. 031005. [CrossRef]
Saxena, I., Malhotra, R., Ehmann, K., and Cao, J., 2015, “High-Speed Fabrication of Microchannels Using Line-Based Laser Induced Plasma Micromachining,” ASME J. Micro Nano–Manuf., 3(2), p. 021006. [CrossRef]
Noack, J., and Vogel, A., 1999, “Laser-Induced Plasma Formation in Water at Nanosecond to Femtosecond Time Scales: Calculation of Thresholds, Absorption Coefficients, and Energy Density,” IEEE J. Quantum Electron., 35(8), pp. 1156–1167. [CrossRef]
Vogel, A., Nahen, K., Theisen, D., and Noack, J., 1996, “Plasma Formation in Water by Picosecond and Nanosecond Nd:YAG Laser Pulses. I. Optical Breakdown at Threshold and Superthreshold Irradiance,” IEEE J. Sel. Top. Quantum Electron., 2(4), pp. 847–860. [CrossRef]
Sacchi, C. A., 1991, “Laser-Induced Electric Breakdown in Water,” J. Opt. Soc. Am. B, 8(2), pp. 337–345. [CrossRef]
Hammer, D. X., Thomas, R. J., Noojin, G. D., Rockwell, B. A., Kennedy, P. K., and Roach, W. P., 1996, “Experimental Investigation of Ultrashort Pulse Laser-Induced Breakdown Thresholds in Aqueous Media,” IEEE J. Quantum Electron., 32(4), pp. 670–678. [CrossRef]
Pallav, K., 2013, Laser Induced Plasma Micro-Machining Process (LIP-MM), Ph.D. Dissertation, Northwestern University, Evanston, IL.
Pallav, K., and Ehmann, K. F., 2010, “Laser Induced Plasma Micro-Machining,” ASME Paper No. MSEC2010-34242, pp. 363-369.
Pallav, K., Saxena, I., and Ehmann, K., 2013, “Comparative Assessment of the Laser Induced Plasma Micro-Machining (LIP-MM) and the Ultra-Short Pulsed Laser Ablation Processes,” ASME J. Micro Nano–Manuf., 2(3), p. 031001. [CrossRef]
Steen, W., and Majumdar, J., 2005, Laser Material Processing, Springer, London, Chap. 2.
Vogel, A., Schweiger, P., Frieser, A., Asiyo, M. N., and Birngruber, R., 1990, “Intraocular Nd:YAG Laser Surgery: Laser–Tissue Interaction, Damage Range, and Reduction of Collateral Effects,” IEEE J. Quantum Electron., 26(12), pp. 2240–2260. [CrossRef]
Pallav, K., and Ehmann, K., 2010, “Feasibility of Laser Induced Plasma Micro-Machining (LIP-MM),” Precision Assembly Technologies and Systems, S.Ratchev, ed., Springer, Boston, pp. 73–80. [CrossRef]
Vogel, A., Noack, J., Nahen, K., Theisen, D., Busch, S., Parlitz, U., Hammer, D. X., Noojin, G. D., Rockwell, B. A., and Birngruber, R., 1999, “Energy Balance of Optical Breakdown in Water at Nanosecond to Femtosecond Time Scales,” Appl. Phys. B, 68(2), pp. 271–280. [CrossRef]
Nagahanumaiah, Ramkumar, J., Glumac, N., Kapoor, S. G., and DeVor, R. E., 2009, “Characterization of Plasma in Micro-EDM Discharge Using Optical Spectroscopy,” J. Manuf. Processes, 11(2), pp. 82–87. [CrossRef]
Stolarski, D. J., Hardman, J. M., Bramlette, C. M., Noojin, G. D., Thomas, R. J., Rockwell, B. A., and Roach, W. P., 1995, Integrated Light Spectroscopy of Laser-Induced Breakdown in Aqueous Media, S. L.Jacques, ed., Proc. SPIE, San Jose, CA, Feb. 1, pp. 100–109. [CrossRef]
Jamieson, T. A., 1981, “Thermal Effects in Optical Systems,” Opt. Eng., 20(2), pp. 156–160. [CrossRef]
Singh, K. P., 2004, “Electron Acceleration by a Circularly Polarized Laser Pulse in a Plasma,” Phys. Plasmas, 11(8), pp. 3992–3996. [CrossRef]
Steiger, A. D., and Woods, C. H., 1972, “Intensity-Dependent Propagation Characteristics of Circularly Polarized High-Power Laser Radiation in a Dense Electron Plasma,” Phys. Rev. A, 5(3), pp. 1467–1474. [CrossRef]
Sprangle, P., Esarey, E., Krall, J., and Joyce, G., 1992, “Propagation and Guiding of Intense Laser Pulses in Plasmas,” Phys. Rev. Lett., 69(15), pp. 2200–2203. [CrossRef] [PubMed]


Grahic Jump Location
Fig. 2

Image of plasma as obtained by a CCD camera (a) super-threshold pulse energy level of 9.63 μJ, (b) near-threshold peak power density of 6.07 μJ, diffraction limited focal spot size 10.44 μm at 10 kHz pulse repetition rate

Grahic Jump Location
Fig. 1

Schematics of plasma formation in the focal volume through laser-induced dielectric breakdown

Grahic Jump Location
Fig. 3

Microscopic image and transverse depth profile of a typical crater machined by four plasma discharges in stainless steel (ASTM A276)

Grahic Jump Location
Fig. 4

Process schematic for plasma generation and machining

Grahic Jump Location
Fig. 6

Dependence of the average power and the ratio of average power to pulse repetition rate on the pulse repetition rate of the incident laser beam

Grahic Jump Location
Fig. 5

Images of plasma generated in distilled water, kerosene, and EDM oil, respectively

Grahic Jump Location
Fig. 9

Plasma images obtained by the high-speed camera at different delay intervals (Δt = 0–30 ps) (9.63 μJ pulse energy and 10 kHz repetition rate)

Grahic Jump Location
Fig. 7

Experimentally determined dependence of the plasma formation probability on pulse energy at a pulse repetition rate of 10 kHz

Grahic Jump Location
Fig. 8

Plasma images obtained by the high-speed camera for each laser pulse at 9.63 μJ and 10 kHz repetition rate

Grahic Jump Location
Fig. 10

Schematics of the formation of (a) single-pass microchannel through overlapping of craters, (b) multi-pass microchannels through lateral overlapping of single-pass microchannels, and (c) formation of 3D microfeature through machining of multipass microchannels in layers

Grahic Jump Location
Fig. 11

(a) Transverse depth profile, (b) SEM image, (c) 3D depth profile of a typical microchannel machined in stainless steel, (d) Longitudinal depth profile, and (e) Histogram of the longitudinal depth profile

Grahic Jump Location
Fig. 12

Microscopic image and depth profile (transverse and longitudinal) of a typical microchannel based surface textured stainless steel specimen



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In