Particle-Based Numerical Modelling of Liquid Marbles: Recent Advances and Future Perspectives

Abstract

A liquid marble is a liquid droplet coated usually with hydrophobic particles that can hold a very small liquid volume without wetting the adjacent surface. This combination gives rise to a set of unique properties such as resistance to contamination, low-friction mobility and flexible manipulation, making them appealing for a myriad of engineering applications including miniature reactors, gas sensing and drug delivery. Despite numerous experimental studies, numerical modelling investigations of liquid marbles are currently underrepresented in the literature, although such investigations can lead to a better understanding of their overall behaviour while overcoming the use of cost- and time-intensive experimental-only procedures. This paper therefore evaluates the capabilities of three well-established and widely-used particle-based numerical frameworks, namely Smoothed Particle Hydrodynamics (SPH)-based approaches, Coarse-Grained (CG)-based approaches and Lattice Boltzmann Method (LBM)-based approaches, to investigate liquid-marble properties and their key applications. Through a comprehensive review of recent advancements, it reveals that these numerical approaches demonstrate promising capabilities of simulating complex multiphysical phenomena involved with liquid-marble systems such as their floatation, coalescence and surface-tension-surface-area relationship. The paper further elaborates on the perspective that benefiting from particle-based numerical and computational techniques, liquid marbles can become an even more effective and exciting platform for many cutting-edge large-scale engineering applications.