Teaching / Thesis LAM-CLUPM

Parametrization and simulation of laser-induced material transfer processes

PhD Candidate: Juan José Moreno Labella (LAM-CLUPM)

Juan José Moreno Labella is doing his thesis in Mechanical Engineering at Universidad Politécnica de Madrid. He received his degree in Industrial Engineering in the specialty of Materials Science in 2016 at the same university. Currently, he is Graduate Teaching Assistant at Escuela Técnica Superior de Ingenieros Industriales in Madrid, at Universidad Politécnica de Madrid. His research line includes laser processing, LIFT applications in Additive Manufacturing and Finite-Elements Method modeling.

His Thesis is focused on understanding the dynamics that rule the Laser-Induced Forward Transfer (LIFT) processes. The transference of material through laser direct writing techniques avoid the nozzle clogging problems that comprise the main disadvantage of inkjet-like techniques. Despite the existence of many variants of the setup, two main groups branch out from LIFT regarding the induction of the movement of the fluid: In the first one, mainly represented by direct LIFT and Absorbing-Layer LIFT, the interaction of the laser pulse on the fluid generates a bubble whose expansion moves the fluid towards the acceptor –either directly or indirectly, through an intermediate layer that vaporizes the fluid by heating–. In the second LIFT group, named Blister-Assisted LIFT (BA-LIFT), the fluid is deposited onto a polymeric deformable layer. The interaction of the laser pulse with that intermediate layer vaporizes a small portion of it, which pushes away the remaining polymer and the fluid on it.

The transference of both low-viscosity and high-viscosity fluids are being studied. Among the low-viscosity fluid, three kinds of fluid stand out: metallic conductive inks for metallization and flexible electronics, experimental fluids, as water-glycerol mixtures, whose properties are easily modified to study specific phenomena, and biocompatible fluids applied to bioprinting.

Several Finite-Element Method (FEM) models are being set to study these two processes in COMSOL Multiphysics. Diverse fluid computational consideration has been considered (Level Set and Phase Field) to replicate the transference of fluids. BA-LIFT and direct LIFT models have been developed to understand the hydrodynamics of the transference and the characteristics of the transferred material. The simulation results are compared with the experiments by shadowgraphy image acquisition.

By this time, a paper is under review with the title: “Simulation of cavitation effects in blister-assisted laser-induced forward transfer of fluids” (https://doi.org/10.31224/osf.io/6dkv2), and a second one is on writing stage.