Bundling Pavilion

Prof. Achim Menges, Prof. Jan Knippers, Universität Stuttgart, 2010-2011

In botany, the principle of bundling allows for transitional surface morphology while maintaining continuous structural patterns. The grass leaf for example consists of both a basal sheath and a flattened blade. At the apex of the sheath, the leaf retracts from a column of tightly bundled supportive layers and transforms into an independent tensile surface with the task of photosynthesis. The seamless juncture between sheath and blade is not a connection of two separate parts, rather a morphological transition.

The leek plant follows the same principles of leaf bundling and surface transition found in grass, yet the directional continuity of its cellular structure is distinguishingly apparent to the naked eye. The natural principle of bundling applies to the anisotropic continuity of structural fibers at the cellular (micro) level and to the telescopic, sequential growth and expansion at the overall morphological (macro) level. In designing a biomimetic material system, the principle of bundling may be applied to the definition of a continuous, transitional connection system as well as the constellation of its parts.

Investigation into the particular transition between the sheath and blade reveals that the overall three-dimensional leaf surface is attained through a specific connection detail. The sheath, which provides compressive support throughout the stalk, transforms into a blade that is capable of supporting itself independently. When unrolled and severed at the ligule, the surfaces of both the sheath and the blade are completely flattenable. The geometry of the transition allows the cylindrical sheath to convert into a V-shaped blade with inherent lateral stability.

The unique shape of the architectural prototype originates from an optimized, two-dimensional pattern cut into the wood, which was wrapped and bent into its final shape. Its cylindrical base mimics the leek leaf sheath, and the expansive portion of the prototype resembles the blade. The prototype, like the leek leaf, is not an independent architectural element. Its success depends on cooperation with kindred building components to stand and to expand. The material system is capable of performing bundling at the architectural scale.

The pavilion is a constellation of transitional surface prototypes. A branching algorithm produces the plan, and a function gives rise to the stalks. Through its recursive process, the model creates connections and generates leaves between the stalks at moderated random heights. The result is a lightweight network of transitioning architectural surfaces.