Implantable medical devices have experienced a major development in the past years due to the super-miniaturization of mechanical structures and electronic circuits. Among the most innovative medical technologies, "Neural Dust" and "Body Dust" are two key concepts in the field of neural bio-implants for brain recording and spreadable bio-electronics for marker sensing respectively. Moreover, neurostimulation is a promising method to address several neurological and mental disorders. Toward this end, the project carried at Medtronic Chair in Neuroengineering (EPFL, Genève) and Integrated Circuits Laboratory (EPFL, Neuchâtel) aims to restore the sense of vision in blind patients. Brain implantation is challenging and the main target is to design a device less invasive as possible.