Surface cleaning from laser-induced cavitation bubbles

Abstract

When bubbles expand and collapse close to boundaries, a shear flow is generated which is able to remove particles from the surface, thus locally cleaning it. Here the authors demonstrate experimentally with microparticle tracking velocimetry that the strongest forcing of particles occurs during a very brief time interval of the bubble oscillation period. During this interval a jet flow impacts and spreads radially along the surface, thus transporting the particles with it.

Evidence for hydrogen generation in laser- or spark-induced cavitation bubbles

“…Nevertheless, hydrogen concentration was found 2.7 times larger with the spark. 3 and surface cleaning, 4 where the phenomena occurring at the collapse of the bubble 2,5,6 are taken advantage of. To understand these phenomena, namely, shock waves, microjets, chemical reactions, luminescence, and nano/microbubbles, most experimental studies on the dynamics of cavitation bubbles in still water [6][7][8] use point-like hot plasma which is used to initiate thermal growth of a quasi-spherical vapor bubble in a controlled and repetitive way.…”

Analysis of the Micromachining Process of Dielectric and Metallic Substrates Immersed in Water with Femtosecond Pulses

“…Temperature-induced tensile stress is particularly a problem for micromachining brittle material, since absorption of the beam's peripheral region and plasma-material coupling [34] leads to local heat build-up and ultimately to cracking and shattering of the samples. Due to a portion of the energy being absorbed in the water and ablation processes occurring there, cavitation bubbles form that remove ablated particles upon collapse during fabrication, and prevent debris redeposition on the samples [35]. Moreover, the system is simple, and is comprised of only a few components making it easy to use relative to other femtosecond micromachining systems.…”

Cavitation bubble dynamics during pulsed laser ablation of a metallic glass in water

“…This intriguing phenomenon has versa-tile applications ranging from nanoparticle synthesis [1,2], surface cleaning [3] to luminescence [4]. The dynamics of cavitation bubble is of central importance since it reflects the fundamental response of liquid-plasma-solid system to laser ablation, and thus has drawn increasing interest [5][6][7][8].…”