Ben Van Berkel: Polyurea over rubber base (hot fluid-applied roof membrane?) over 2 layers bendable plywood. Says he would have liked 3-4 more layers on the New Amsterdam Pavilion to make it smoother.
A supplier http://www.versaflex.com/
http://www.versaflex.com/images/polyurea.pdf.pdf
Some Polyurea projects:
UN Studio: http://www.archdaily.com/34788/new-amsterdam-pavilion-unstudio/
MVRDV: http://www.modeloos.nl/?p=602
Not Polyurea, but a similar idea by MooMoo:
http://archide.wordpress.com/2009/07/31/house-by-moomoo-architects-lodz-poland/
