Development of flash photographic system and 1D numerical model for drop-on-demand inkjet technology

Huicong Jiang

Flash photography has been widely used to study the droplet dynamics in drop-on-demand (DoD) inkjet due to its distinct advantages in cost and image quality. However, the whole setup, typically comprising the mounting platform, flash light source, inkjet system, CCD camera, magnification lens and pulse generator, still costs tens of thousands of dollars. To further reduce the cost of visualization for DoD inkjet droplets, we proposed to use a low-cost microcontroller board as the pulse generator in the flash photographic system. The temporal accuracy of the microcontroller was first measured by an oscilloscope and then the temporal stability was compared with a professional pulse generator by tracking a large number of droplet positions. To validate the effectiveness of the whole setup, the droplet ejection and the droplet impact on a silicon wafer were quantitatively analyzed and compared with theoretical predictions. Finally, sample images of droplet ejected from a commercial inkjet cartridge were presented to show the flexibility of the system. In recent years, physics-based computer models have been increasingly applied to design the drop-on-demand (DOD) inkjet devices. The initial design stage for these devices often requires a fast turnaround time of computer models, because it usually involves a massive screening of a large number of design parameters. Thus, in the present study, a 1D model is developed to achieve the fast prediction of droplet ejection process from DOD devices. A popular 1D slender-jet method is adopted in this study. The fluid dynamics in the nozzle region is described by a 2D axisymmetric unsteady Poiseuille flow model. Droplet formation and nozzle fluid dynamics are coupled and hence solved together to simulate the inkjet droplet ejection. The proposed methods are implemented in an in-house developed MATLAB code. A series of validation examples have been carried out to evaluate the accuracy and the robustness of the proposed 1D model. Our study has shown that 1D model can significantly reduce the computational time (usually less than one minute) yet with acceptable accuracy, which makes it very useful to explore the large parameter space of inkjet devices in a short amount of time.

Development of flash photographic system and 1D numerical model for drop-on-demand inkjet technology

Files and links (1)

Abstract

Metrics

Details