Today, the focus of physical scientists is shifting more to biology than ever before. A biological tissue is typically an ionised porous medium saturated with a solution of ions and neutral solutes. Because classical porous media theories do not account for ionisation, the present paper addresses this issue. The characteristic pore size in most biological applications is close to the molecular level and hence below the Debye-Hueckel scale. Not only pressure gradients and concentration gradients, but electrical gradients as well are intimately linked to fluid flow, ion flow and deformation.
swelling; shale; cartilage; finite deformation; equipresence
