Cross-Scale Analysis for the Growth of Light-Induced Plasmonic Nanobubbles

Light-induced plasmonic nanobubbles (PNBs) around noble metallic nanoparticles (NPs) have gained significant attention as a promising application in fields such as biomedicine and sensors. However, their nucleation and growth involve a wide range of space and time scales, making it challenging for a single traditional method to analyze both micro- and macroscopic processes simultaneously. For example, although near-field radiation theory combined with molecular dynamics (MD) simulation can model PNB formation, MD simulation requires high computational resources, which limits the system size and timescale. Meanwhile, the Rayleigh-Plesset equation (RPE) can analyze the evolution of large bubbles but cannot simulate the nucleation and growth of light-induced bubbles. To overcome these limitations, this study aims to develop a cross-scale MD-RP framework. Its key innovation is a pressure-volume (<i>P</i>-<i>V</i>) relationship derived from near-field-coupled MD simulations, which serves as a critical bridge translating microscopic nucleation physics into inputs for macroscopic bubble growth models. This approach involves two stages: First, an MD model combined with near-field radiation theory is used to simulate the nucleation of PNB under a resonant electric field (REF) induced by light interacting with metallic NPs, enabling precise calculation of pressure evolution during the process. Then, for the growing stage of PNB, the pressure and initial PNB radius from the MD model are used as inputs for the RPE to predict the kinetics of larger PNB. Crucially, the <i>P</i>-<i>V</i> function is parametrized by pulse duration, energy density, and NP size, enabling low-cost, accurate predictions across a range of conditions. Compared with traditional methods, this MD-RP cross-scale approach overcomes the limitations of single method and can simulate PNB evolution on a wide scale. It provides an efficient tool for studying the regulation of PNB and related applications.