A method of manufacturing an implantable pump includes providing an upper layer comprising a dome structure for housing a drug chamber and a cannula in fluid communication with the drug chamber. A middle deflection layer is provided adjacent the drug chamber. A bottom layer is provided comprising either electrolysis electrodes or a permeable membrane. The upper layer and middle deflection layer are thermally bonded to form the drug chamber of the pump. The bottom layer is bonded to the drug chamber to form the pump.