For twenty years industrial leaders and scientists have discovered the "nanoworld" - the organization of matter at the nanometer scale - the millionth of a millimeter. Applications of all kinds have emerged that are changing technical capabilities in a wide variety of fields - from building, textiles, telecommunications and digital technologies to health and nano-medicines. The products of daily life - food, cosmetics, cleaning products, etc ... - do not escape these evolutions: they make an extensive use of nanomaterials as additives. These uses rightly raise questions about the health risks they may pose, questions made difficult by the uncertainties that remain about the biological activity of nanomaterials. This symposium in which we brought together chemistry experts, physicists, biologists, academics and industry, aims to illustrate the richness of the nanoworld by presenting the continuous discovery of new natural or artificial nano-objects and new properties, which mobilizes both scientific and industrial circles. The symposium will present perspectives for the development of nanotechnologies in current fields (such as the development of batteries for electric cars or that of sensors of the state of the environment), but it will also illustrate the care that is provided by all actors to evaluate the toxicity of nano-objects through the development of specific characterization methods of the nanoscale. This conference is open to a wide audience, with special attention to high school students, students and their teachers. The level of interventions is meant to be accessible to all to allow a wide debate. We wish you a fascinating exploration of these new fields of knowledge. More info here.