Molecular Dynamics-Based Approach for Laser-Induced Cavitation Bubbles: Bridging Experimental and Hybrid
Sasan Rezaee1, Ebrahim Kadivar1, Ould El Moctar1
1Institute of Sustainable and Autonomous Maritime Systems, University of Duisburg-Essen, Duisburg 47057, Germany.
Langmuir : the ACS Journal of Surfaces and Colloids
|July 18, 2025
Summary
This study introduces a laser-based molecular dynamics (MD) model to simulate nanobubbles, revealing cavitation dynamics from nucleation to collapse. The findings confirm the model
Area of Science:
- Computational Physics and Chemistry
- Materials Science
- Fluid Dynamics
Background:
- Cavitation phenomena are crucial but challenging to study at the molecular level.
- Existing experimental, analytical, and computational methods have limitations in capturing detailed cavitation dynamics, including phase transitions.
Purpose of the Study:
- To introduce and validate a laser-based molecular dynamics (MD) approach using a coarse-grained (CG) model for investigating molecular-level cavitation dynamics.
- To simulate and analyze the nucleation, growth, collapse, and phase transitions of laser-induced nanobubbles.
Main Methods:
- Development of a laser-liquid interaction model based on experimental observations of millimeter-scale cavitation.
- Implementation of the analytical model into a coarse-grained molecular dynamics (CGMD) simulation.
- Simulation of nanobubble formation and evolution induced by a 1 fJ laser pulse in water.
Main Results:
- Laser pulse generates hot plasma, leading to nanobubble formation and spherical expansion via collision cascades.
- Simulated nanobubbles reached a maximum radius of 5.26 nm, collapsing within 17 ps, with subsequent regrowth/collapse cycles observed.
- Characterization of the vapor-liquid interphase (0.8 nm thickness, 0.105–0.840 g/cm³ density), cold evaporation (300–315 K), and vapor density (4.5×10⁻⁵ g/cm³).
Conclusions:
- The proposed MD-based algorithm effectively simulates laser-induced cavitation nanobubbles, aligning with experimental data.
- The model provides molecular-level insights into cavitation dynamics, including phase transitions and interphase properties.
- The algorithm's potential for extension to all-atom simulations of radical species and chemical reactions under laser radiation is highlighted.
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