In this work, we present the Poroelastic Relaxation Indentation (PRI) testing approach for quantifying the mechanical and transport properties of thin layers of poly(ethylene glycol) hydrogel materials with thicknesses on the order of 200 m. Specifically, PRI characterizes poroelastic relaxation in hydrogels by indenting the material at fixed depth and tracking the contact area-dependent load relaxation process as a function of time. With the aid of a linear poroelastic theory developed for thin polymer gel layers, we demonstrate that PRI can quantify the shear modulus and diffusion coefficient of water transport within the hydrogel layers. This measurement approach provides a simple methodology to quantify the material properties of thin swollen polymer networks relevant to transport phenomena.
Citation: Soft Matter
Pub Type: Journals
poroelasticity, diffusion, transport, polymers, hydrogels, modulus, pore size, mechanics