Actuation waveform auto-design of drop-on-demand inkjet for ejection droplet without satellite

Designing the actuation waveform is a key step for the piezoelectric inkjet printing technology, which controls the deposition quality of the material. However, the current design of actuation waveforms remains laborious and reliant on repetitive experimentation, resulting in a suboptimal match between the actuation waveform and ink properties, which may cause material deposition defects such as satellite. In this study, the influences of the ink physical properties, nozzle diameter, and ejection behavior on the kinetics of droplet formation were investigated. Further, the transition boundaries of three droplet formation modes for different types of inks, namely, no droplet, single droplet, and satellite droplet, were determined. An actuating waveform auto-design method for creating a single droplet without satellite was constructed based on the physical properties of the ink, which can easily achieve the formation and volume control of a single droplet. The efficacy of the method was validated through monitoring the droplet forming processes of four standard reagents. Moreover, the printing of an interdigitated electrode and micro-patterns was precisely controlled under well-formed droplets. This study could facilitate a comprehensive understanding of droplet formation dynamics, enabling the rapid creation of actuation waveforms for high-quality deposition of functional inks and enhancing the performance of piezoelectric inkjet-based fabrication equipment.