In nature, the dragonfly wing is unmatched in its structural performance and exquisite formal variation. Its morphology can not be traced to any single biomathematical minima or optimum, but is rather the complex result of multiple patterning systems interweaving in response to force flows and material properties. Dragonfly wings consist of both honeycomb patterns which are flexible and exhibit membrane behavior and ladder-type patterns which are stiff and exhibit beam-like behavior. These patterns are characterized by their rule-based interaction in terms of cell density, cell shape, and cell depth, as well as other parameters affecting overall wing performance, such as out-of-plane pleating behavior and material distribution. A composite of distributed and linear structural formations, the dragonfly wings are fields of continuous variation and adaptation evolving toward overall robustness.
In this installation, dragonfly morphology and syntax are employed biomimetically rather than biomorphically, that is in terms of formal and behavioral logics rather than pure aesthetics. We know that that dragonfly wings in nature are generated by evolutionary processes involving aerodynamics, lightness, mechanical properties, composite performance, the smooth accumulation of organic material, and the active flow of dragonfly blood. Dragonfly is governed by a different set of parameters including gravity and seismic loads, specific support locations and quality of those supports, flat material increments, and buckling failure, differences which lead to an unpredictable hybrid morphology. Seen in a larger context, this project contributes to the recent contemporary discourse on cellularity in architecture as a departure from pure cellularity toward a tectonic based on emerging structural hierarchies within rhythmic cellular fields.
Dragonfly is a cooperative effort of EMERGENT and Buro Happold, part of a longer lineage of works by both firms exploring the relation of structure to form. It is an experiment on the fluid feedback of design sensibility, engineering innovation, and fabrication logic in a contemporary digital environment where these disciplines have become enmeshed like never before. Thanks to support from ANSYS, a structural optimization loop was used in the search for emergent characteristics that would improve performance and increase heterogeneity in the structure. This process redefines engineering, which is often about idealized problem solving and formal economy, as a messy evolutionary process closer to speciation in nature.
Populations of random structural mutations were generated and fitness-tested based on the given support and loading conditions in a feedback loop involving multiple generations. Using boundary conditions relating to overall structural shape, individual cell morphology, vein distribution and pleating, depth, and incremental material thickness, the geometry was evolved simultaneously toward performance and wild variation.
The fabrication procedures for Dragonfly reflect this adaptive model. A CATIA fabrication model was generated which parametrically linked hundreds of two-dimensional unfolded bands to ‘live’ three-dimensional geometry. As the design evolved and as engineering information was filtered into the fabrication model, these bands, including scoring, bending, drilling, and location information, were updated automatically. Bands were distributed onto 4’x8’ aluminum sheets automatically using nesting software which optimized material usage. These sheets were then cut and inscribed using CNC milling machines.
Because all of the information required for assembly of the structure was embedded into the bands, including relative cell position, the construction of the Dragonfly can be considered an aggressively bottom-up process and a relief from ‘construction documentation’ as it is currently understood by the architectural profession at large.
