Analysis of drop-on-demand printing characteristics and stability driven by inertial forces

Abstract

As the core technology in the field of microdroplet related applications, researchers have been striving to develop new driving methods and improve the stability of inkjet printing technology to meet the diverse needs of various materials and applications. In this study, a novel, simple, and cost-effective droplet printing method based on inertial force driving is proposed, and its printing characteristics and stability are investigated through experimental and numerical simulation studies. A numerical model was developed to explore the effects of operating parameters and fluid properties on the printing process. The results showed that for a given fluid, it is easier to form satellite droplets when driven from a smaller nozzle with higher voltage and pulse width. The hydrophilic nature of the nozzle can suppress the formation of satellite droplets, but it is prone to retain liquid, thereby affecting the next printing effect. Under certain operating conditions, fluids with lower density, higher viscosity, and higher surface tension are difficult to be driven but can suppress the formation of satellite droplets and promote printing stability. Finally, a parameter space composed of dimensionless numbers Op representing operating parameters and Z representing fluid properties (reciprocal of the Oh number) was established to investigate the comprehensive influence on the printing. The correctness of this parameter space in guiding the selection of parameters for stable droplet printing was validated through experiments.