It is disclosed an implantable electrical/electronic biomedical device comprising: a) a reservoir (100) comprising an inlet (101) at a first end and a mechanical support (200) at a second, opposed end, and b) at least one electrode structure (300) deployable by eversion, said electrode structure (300) comprising: i) an elastic polymeric support (301) operatively connected to the reservoir's inlet (101) through a first end (302) and to the mechanical support (200) at a second end (303), and ii) at least one conductive track (400) disposed on a surface (S) of said elastic polymeric support (301).