CONICET | Buscador de Institutos y Recursos Humanos

The development of new polymeric materials, like those used in the manufactureof OLED screens and similar devices, enabled the use of traditional printing technologies in the production process: inkjet/drop-on-demand printing, direct-write,gravure printing, among others. The latter one in particular is a continuous,high-resolution and high-throughput production process, with working fluids in awide range of viscosity values. In order to model this process at the scale of asingle cavity ?whose size is in the order of ten microns? the dynamics of viscousflows must be solved, considering the presence of liquid?solid and liquid?gas interfaces, as well as dynamic contact lines. The flow domain deforms continuouslybetween two solid surfaces ?the cavity and the printing substrate? in relativemotion. Important advances in the modeling of the process have been achieved inrecent years. The complexity of the problem, however, demands further improvements in the modeling. Previous publications have shown that 2D models canadequately capture the general dynamics of the process, demanding far less computational resources than costly 3D simulations. Thus, this work presents ourmost recent advances in the modeling and simulation of the 2D liquid transferbetween a micron-sized cavity and a substrate in relative motion. Specific contributions are a detailed inclusion of inertial effects and an enhanced description ofthe dynamic contact angle. The former allowed us to show that inertial effectscan be important, in spite of the small size of the flow domain. The latter provedto be key in achieving a better description of the wettability and roughness of different substrates used in applications The results obtained in this work enabledthe computation of different quantities of great importance in this process, as thefraction of liquid transferred to the substrate, or the fidelity of transfer of thepattern, as a function of the parameters that characterize the process.