An intraocular implantable magnetically actuated micropump for drug delivery is proposed. A magnetic nanoparticle-PDMS composite membrane assembly in the micropump can be actuated in magnetic field, and it causes drug release. The membrane assembly is composed of thin elastic PDMS membrane and thick magnetic nanoparticle-PDMS composite (MNPC) to obtain maximum deflection of membrane within the confined room of micropump. A micro check valve composed of two PDMS layers is integrated to realize on-demand drug delivery and effectively prevent drug diffusion without magnetic field.