These bubbles won’t burst
Jan 11, 2010

One of the Beijing 2008 Summer Olympic venues, the National Aquatic Centre, certainly lives up to its other name, the Water Cube. It seems to be sliced from a giant cube of soap-bubble foam, an effect that is enhanced when it glows blue against the night sky. To achieve this effect, the engineers at ARUP and the architects at PTW based their design on the work of two Irish physicists, Denis Weaire and Robert Phelan. In 1993, Weaire and Phelan found a new solution to the problem of dividing a space into cells of equal volume in the most efficient way but with a minimal surface area.

"We soon found a curious feature about this foam. Despite its absolute regularity, when viewed at an arbitrary angle it appears totally random and organic," comments Arup staff member Tristram Carfrae explaining why they based the Water Cube's design on the Weaire/Phelan structure. "We realized that a structure based on this unique geometry would be highly repetitive and could be built, but would nevertheless appear very organic and random. Indeed such expansive patterns are regularly observed in biological cells and mineral crystals, and are probably the most common structures in nature. Moreover, the ductile space frame that is generated using this geometry is ideally suited to the seismic conditions in Beijing."

This prestigious project comprises over 300,000 sq.m. of ETFE foils, meaning it is the single largest ETFE structure in the world to date. The manufacturer AGC (Asahi Glass Co., Ltd.) has invented the fluororesin ETFE film. Vector Foiltec has pioneered the use of Texlon ETFE as a climatic envelope and as an innovative architectural solution world-wide. Texlon ETFE consists of pneumatic cushions in an extruded aluminum frame and supported by a lightweight structure. The cushions are inflated with low-pressure air to provide insulation and resist any wind load. Originally developed for the space industry, the ETFE is unique in that it does not degrade under ultra-violet light or atmospheric pollution.

Photo © MCMILLAN, Natural Aquatics Centre Beijing, China
Photo © MCMILLAN, Natural Aquatics Centre Beijing, China
Cell structure for the most efficient way of dividng space but with a minimal surface area. Discovered by the Irish physicists, Denis Weaire and Robert Phelan in 1993.
Closeup view on the facade construction.
The design of the „Water Cube" is based on the geometric structure of soap bubbles.