The amphotericpH sensitive gel possesses both the ionized acidic group and the basic group.Compared with the conventional gel

it has better swelling properties and biocompatibility.It is widely used in many aspects such as biomedical science

drug delivery systems

micro-fluid control and so forth.However

there is still a lack of the FEM method for the amphoteric pH sensitive gel.Therefore

we use the equilibrium swelling theory of amphoteric pH sensitive gel

andFEM methodwhich is developed to describe the mechanical behavior of gel swelling

to calculatemechanical behavior of pH sensitive gel in homogeneous and inhomogeneous swelling.The results shows a very good agreement between results of FEM calculation and the analytical solution of the gel swelling theory.It can provide important parameters and mechanical theoretical guidance for some key indexes in biology

and also provide an important reference for the design of micro fluid control valve.