Session: Research Posters

Paper Number: 119867

119867 - Experimental and Numerical Study of Energy Absorbing Layer on the Jet Formation in Laser-Induced-Forward-Transfer (Lift) Printing 

Laser-Induced-Forward-Transfer (LIFT) printing is a non-contact laser direct writing technology known for its high printing resolution and wide range of compatible printing materials. In LIFT printing, the printed pattern, which is crucial to the printing quality, relies heavily on the stability of the ink jet. One effective method of achieving jet stability is by utilizing an energy absorbing layer (EAL).

In our experimental study, we investigated the use of graphene, gelatin, and gold as EALs in LIFT printing and examined the jet formation process for each EAL. We found that the interaction between the laser and EAL materials can result in different jet behaviors due to various dominant interaction mechanisms. For instance, graphene EAL exhibits strong absorption in the infrared range, gelatin EAL experiences significant scattering loss, and the gold for demonstrates strong absorption in the ultraviolet range but weak absorption in the infrared range. Besides, we believe that the thermal effect should be the leading effect of the bubble generation process in LIFT, while we also found the evidence of mechanical impact for some EALs.

In our ongoing numerical study, an existing computational fluid dynamics (CFD) model developed by our group will be utilized. By considering the mechanical characteristics, such as the absorption rate, reflection rate, and scattering rate of the EAL materials, we can determine the total energy transferred from the laser beam to the liquid layer based on the conservation of energy. In the first step of this study, we will ignore the energy loss and assume that all the transferred energy is converted into thermal energy, which leads to the generation of bubbles. The initial conditions of the bubbles, including the temperature and pressure, can be derived from the conservation of energy. Subsequently, the further development process of the jet can be simulated using our previously developed initial-bubble development model. The simulation results will be compared with experimental data for all three EALs. Since the experimental results have indicated the occurrence of mechanical impact during the LIFT process when using the gold EAL, in the following simulation we will introduce a coefficient representing the transferred thermal energy to the total laser energy, by adjusting the coefficient and running the simulation iteratively and comparing the results with experimental data, we aim to determine the precise energy transferred to generate the mechanical impact, which may help better understand the laser-gold EAL interaction during the LIFT process. This knowledge will aid in refining our numerical model and potentially applying it to other metal EALs that exhibit similar performance characteristics to the gold EAL.

Presenting Author: Shuqi Zhou University of Houston

Presenting Author Biography: Shuqi Zhou is a PhD student and Graduate Research Assistant in Dr. Ben Xu's lab at University of Houston. He earned his Master degree from Mississippi State University and his B.S. degree from East China University of Science and Technology。

Authors:

Shuqi Zhou University of Houston
Ben Xu University of Houston