Numerical modeling of heterogeneous stimuli-responsive hydrogels

In this paper, we introduce a computational technique for modeling heterogeneous thermoresponsive hydrogels. The model resolves local fluid-solid interactions in hydrogel pores during the deswelling process. The model is a Lagrangian particle-based technique, which benefits from computational grids that represent polymer beads inside hydrogel scaffolds. The results show that the mechanical properties of hydrogels during deswelling, e.g., shrinkage ratio and elastic modulus, have a direct effect on the development of the front of expelled fluid. It is also observed that in certain parameter regimes the hydrogel may generate inertial fluid jets at the early stages of deswelling. Finally, simple heterogeneous designs are developed using Menger sponge-inspired shapes to investigate the effect of design heterogeneity on promoting directional release.