4. Nanotechnologies for a sustainable city

Concentrating people, services and exchanges in a limited space – is the very essence of the city – without this concentration destroying the social fabric, without increasing the vulnerability of residents, without reducing accessibility and impeding the flow of traffic, without squandering energy, without degrading air and water quality, and without solving its problems by dumping all nuisances outside - these are just some of the challenges facing the designers of a sustainable city. Among all these challenges, there are at least three in which NT and NM have a role to play. These are environmental health, traffic fluidity and energy management. In all three cases, there is likely to be massive recourse to ICST, thanks to on-board or fixed devices, which already make extensive use of NT.