Constitutive modeling of pH-sensitive hydrogel: Multi-physics coupling of electromagnetics with mechanics and thermodynamics

The field theory of pH-sensitive hydrogel deformation is presented coupling electro-magnetic (EM) field (external or internal) and diffusion (Poisson–Nernst–Planck and Maxwell equations) of mobile ionic species through irreversible thermodynamics. The evolution of fixed-charge in the hydrogel is modeled by Langmuir monolayer adsorption theory. The important contribution of present work is a derivation of Cauchy stress tensor constitutive...