Multi-scale modeling of the replication of submicron-structures by micro injection molding

The replication accuracy of submicron surface structures by micro injection molding control the replicated part functionalities, such as tissue engineering. In this work, we propose a multi-scale model for the replication quality of laser-induced periodic surface structures by micro injection molding of different bio-based polymers. The model decouples the macro cavity flow, investigated through a numerical simulation, from the micron-scale flow, that is modeled with a novel analytical approach. The macro model determines the boundary conditions for the filling of the sub-micron surface structures. An in-depth characterization of the mold topography of the polymer thermal, rheological, and wetting properties was carried out to feed the model. Injection molding tests were performed, varying the mold temperature to manufacture sub-micro textured parts for the model validation. The sensitivity of the replication accuracy to mold temperature and polymer selection was captured. The multi-scale model showed a maximum deviation of 8% from the experimental results.