The Swiss Pavilion EXPO 2010 | Buchner Bründler Architekten

The Swiss Pavilion at EXPO 2010 in Shanghai is enclosed in a semi-transparent façade that produces electricity using cutting-edge solar technology and turns solar radiation into a visible form of energy. The electricity is drawn from by light-emitting diodes that flash in varying quantities, constellations and durations depending on the available light and its intensity. The diodes flash individually, throwing coloured shadows on to the wall behind, and together light up the whole façade, sweeping across the curtain in swarms or other patterns. As a result of this special light display and the reaction of the façade, visitors will be able to perceive Switzerland as an innovative, technologically advanced and ecologically aware country even before they enter the Pavilion. As they approach and enter the Pavilion, the Swiss city concept becomes gradually clear: a hybrid, interconnected urban area in which nature and technology, innovation and sustainability function and interact in symbiosis. The façade is suspended from a height of 20 m and is made up of a coarse metal netting to which 11,000 cells are attached in a random fashion. Each cell contains – based on a pattern inspired by a map of Switzerland – an electronic circuit board that feeds the interactive light-play on the façade: solar cells, two double-layer condensors (highperformance energy accumulators), a light-emitting diode and sensors that react to light and activity in neighbouring cells. The solar cells produce electricity that is then stored in the condensor and used when the lightemitting diode flashes. As a result of the sensors the cells react to light regardless of its intensity. If the light falling on one part of the façade increases, the light sensors transmit an impulse, thus causing the light-emitting diodes on that part of the façade to flash. The cells light up for a longer or shorter period of time, depending on the intensity of the light they receive. The intensity of the light emitted by the diodes varies according to the energy stored and the level of ambient light. During the night they react in the same way due to the energy stored in the accumulators. Each cell is autonomous and, as it were, has a life of its own. The micro-controller produces a reactive form of behaviour among the cells, however. Electro-magnetic impulses influence the light behaviour of each cell, which in turn influence neighbouring cells when they light up. This causes a chain reaction which results in a swarm of flashes across the façade. The front side of the cell represents the view of Switzerland from outside: a white outline of Switzerland, representing rural areas, can just be made out behind the surface. The electronics and the circuits are visible from the same side and symbolise the urban parts of the country – the cities with their modern infrastructure and complex networks. Once the Expo is over, the cells will be sold as innovative gadgets and souvenirs. The façade will therefore be directly “recycled” and will spread its message among the Chinese population, leaving a lasting reminder of an innovative and sustainable Switzerland.