CFD-based numerical modeling to predict the dimensions of printed droplets in electrohydrodynamic inkjet printing

Abstract

Electrohydrodynamic (EHD) inkjet printing is a type of potential non-contact micro/nanoscale manufacturing technology. The printed droplet dimension plays an important role in EHD inkjet printing due to its significant influence on printing quality and the resolution of patterns. The complexity of the mechanism and the limited process optimization techniques present a challenge in obtaining the desired printing resolution, eventually becoming an expensive and time-consuming endeavor. In this study, a CFD model is proposed to investigate the mechanism of the cone-jet printing process in EHD inkjet printing. The complete cone-jet printing process is successfully simulated. A further analysis predicts the jetting diameter and printed droplet diameter with different operating parameters and substrates. The simulation has a satisfactory agreement with experiments in predicting the printing behavior and printing quality (jetting diameter, printed droplet diameter). Such advancement in modeling can be utilized to guide the quick determination of operation parameters for the desired printing resolution when given a new ink. • Electrohydrodynamic inkjet printing is a non-contact micro/nano manufacturing technique that utilizes electric force to generate droplets. • A computational fluid dynamics (CFD) model is proposed to investigate the cone-jet printing mechanism in EHD printing. • A complete cone-jet printing cycle with four phases is simulated: cone formation, jet generation, jet break and droplet expansion. • A further analysis predicts the jetting diameter and printed droplet diameter using different operating parameters and substrates. • The modeling advancement can guide the quick determination of operation parameters for desired printing resolution given a new ink. Electrohydrodynamic (EHD) inkjet printing is a type of potential non-contact micro/nanoscale manufacturing technology. The printed droplet dimension plays an important role in EHD inkjet printing due to its significant influence on printing quality and the resolution of patterns. The complexity of the mechanism and the limited process optimization techniques present a challenge in obtaining the desired printing resolution, eventually becoming an expensive and time consuming endeavor. Recent developments in computational fluid dynamics (CFD) bring an effective alternative to alleviate the aforementioned challenges. In this study, a CFD model is proposed to investigate the mechanism of the cone-jet printing process in EHD inkjet printing. The complete cone-jet printing process is successfully simulated with four phases: Taylor cone formation, cone-jet generation, jet break and droplet expansion. A further analysis predicts the jetting diameter and printed droplet diameter with different operating parameters and substrates. The simulation has a satisfactory agreement with experiments in predicting the printing behavior and printing quality (jetting diameter, printed droplet diameter). Such advancement in modeling can be utilized to guide the quick determination of operation parameters for the desired printing resolution when given a new ink.