Capillary-Induced Solvent Transport in Hydrogels with Large Swelling

Capillary forces induced by droplets can deform a soft substrate. When the soft substrate is made of poroelastic materials such as hydrogels which consist of polymer networks that can be swollen by solvent, the deformation is coupled with the transportation of the solvent. We implement a large deformation model to investigate this coupled dynamic process. We formulate the total free energy of the system including the stretching of the polymer network and the mixing of the network with small molecules. The dissipation caused by the viscoelasticity of the gel is also included. Our work sheds light on some recent experiments.