Hybrid Continuous-Discrete Repetitive Process Modeling of Meniscus Dynamics in Electrohydrodynamic Jet Printing

Abstract

Electrohydrodynamic jet (E-Jet) printing is a micro-/nano-manufacturing process in which a liquid ink is jetted from a micron-scale nozzle through the actuation of an electric field applied between the nozzle and a grounded substrate. Because the jetting behavior is driven by electrohydrodynamics and is capable of producing printed features with length scales ranging from nanometers to microns, E-Jet printing is a promising manufacturing tool for printed electronics and bioengineering applications. However, a significant hurdle in adoption of E-Jet printing for these applications is the lack of appropriate process modeling and control methodologies to improve printing performance and robustness to process disturbances. Here, a model describing the dynamics of the meniscus and the onset of jetting in E-Jet printing is given. The model is posed as a repetitive hybrid continuous-discrete process where the continuous meniscus dynamics are interrupted by the discrete jetting behavior and are dependent on previous trial information. The developed model is compared to a set of experimental results and the model exhibits good quantitative agreement with time-to-jetting from a step voltage input and good qualitative agreement in the dynamic response after jetting has ceased.