The water Cube's membrane structure is under construction (photo credit: newsphoto)

(BEIJING, September 22) -- Starting Thursday, installation of membrane structures at the National Aquatics Center is in full swing, and the work is expected to be completed at the end of the year.

The membranes comprise over 3,000 pneumatic cushions which are restrained in aluminum extrusions and supported by lightweight structures. The cushions are inflated with low-pressure air to provide insulation and resist wind loads.

The cushions are manufactured from multiple layers of a modified co-polymer called ethylene-tetra-fluoro-ethylene, or ETFE.

The National Aquatics Center, dubbed the "water cube", comprises over 100,000sqm of ETFE foils, making this the single largest ETFE structure in the world to date.

The center will host swimming, diving, water polo and synchronized swimming competitions for the 2008 Olympic Games.