Hybrid modeling and identification of jetting dynamics in electrohydrodynamic jet printing

Electrohydrodynamic jet printing (e-jet) is a micro additive manufacturing process in which polarizable liquid inks are extracted from a microcapillary nozzle by an electric field and deposited onto a substrate. This process can be broken into two discrete phases: build up to jetting, and jetting of material. This decomposition allows e-jet to be modeled as a hybrid dynamical system. In order to develop a single model with both discrete phases, knowledge of their continuous dynamics and the transition condition between them is needed. This paper proposes and empirically verifies a physics-based inequality on cone angle for modeling the transitions between phases. Additionally, a practical model of the continuous jetting dynamics is generated from measurements taken using high speed video of the e-jet process.