Applying 2760 air-cooled membrane cushions to the plastic envelope of the Munich Allianz Arena built by ALPINE was no different. With 66.500 sqm this membrane envelope is the largest of its kind in the world. Additionally, 25.000 fluorescent tubes integrated into the cushions allow the soccer stadium to be lighted according to the colours of the competing clubs.
However, aesthetics alone was not the decisive factor: Outstanding achievements in material research enabled these building envelopes to automatically adjust according to light and temperature characteristics and thereby create a comfortable living and working environment. These building envelopes influence light transmittance, energy balance (absorption, reflection, storage), indoor environment quality, characteristics of ventilation, acoustic and colour and thereby create a variable and adjustable unit.
The Stuttgart based ILEK Institute (Institut für Leichtbau Entwerfen und Konstruieren – ILEK Institute for lightweight design and construction) actually is an interface between architecture and engineering. One of the research areas of the ILEK Institute is the “design of adaptive systems”. Excellent innovations resulted from using chemical and physical functional principles of multi-layered systems.
The materials used in room and building envelopes consist of autonomous or controlled systems with different functions and different possible reactions. For instance, thermotrope layers as used in glass fronts as sun screens. These layers change their optical characteristics from transparent to translucent as temperature increases. In an autonomous and reversible process they switch from clear to a strongly diffusing and misty-white condition. This ensures a strong multiple scattering and diffuse transmission of light.
Electrochrome material is placed in a gap between sheets of glass. It changes its colour when electrical charge is applied. This process can be reversed as well. This electrochrome material changes its transmittance of light depending on what amount of d.c. voltage is applied. This effect is utilized. Electrical charge is applied to a microscopically-small coating on a glass surface. This changes its colour.
The transmission characteristics and energy absorption of a window module may also be changed with liquid crystals. Prototypes have already been produced to test the usability of infinitely variable elements on the basis liquid crystals. These prototypes are currently undergoing field tests.
The exhibition
„Sketches for the Future“ (until October 16, 2009)
forschen // entwerfen // konstruieren (research // design // construction)
by Werner Sobek, head of ILEK and professor at the Mies van der Rohe professorship at the Illinois Institute of Technology currently displays at the Wiener Ringturm. Sobek is a “researching, designing and constructing engineer”. In cooperation with other famous architects he has often drawn attention when presenting spectacular concepts. The same is true for his work as an architect and and his own projects and buildings.
Image source:
Post Tower Bonn, 1999–2000 © HG Esch, Hennef
