Brain stimulation is an effective technique to restore impairing neural functions, such as deafness and blindness. Despite the progresses in leaps and bounds in these technologies, several limitations are still present, such as wiring connection to implants, bulky batteries and invasiveness of surgical procedure. For these reasons, neuroengineering research is moving towards the development of miniaturized and wireless implantable devices for selective and specific neurostimulation. This, inevitably, brings up new issues to face, such as mechanical and electrochemical stability of microelectrodes after integration. This aspect is the core of my mas- ter’s thesis, conducted at EPFL (École Polytechnique Fédérale de Lausanne) at the Integrated Circuits LABoratory (ICLAB) in Neuchâtel and at the Center of Micronanotechnology (CMi) in Lausanne.