Every week a million more people move to live in cities. Can they cope with this constant expansion? Aleks explores whether 'Smart' cities are the answer or do they come with a hidden price of personal freedom. She visits the world's "smartest" city, Masdar in Abu Dhabi and explores the social engineering that's as much part of the design as the bricks and mortar.

Contributors: Physicist Geoffrey West, Urban Explorer Brad Garrett, Lean Doody from ARUP, Dr Iyad Rahwan, Architect and Artist Usman Haque.

Producer: Peter McManus.