**Morphogenetic Design Experiment 05**

This morphogentic design experiment aims to evolve a differentiated surface structure consisting of a dense network of interlocking members from a basic array of simple, straight elements. To achieve complexity in the resultant material system the exploration focuses on advanced digital generation techniques in concert with relatively common computer numerically controlled production processes. The basic system constituent is defined as a jagged, planar strip cut from sheet material on a 3 axis CNC router. In a parametric software application a generic digital component is established through the geometric relationships that remain invariant in all possible instances of the material element and the variable production constraints of the intended machining technology and process. Each particular implementation of the parametric component in the system to be digitally constructed is then based on three interrelated inputs: Primary input influencing the particular geometry of a specific system type is given by a gestalt envelope that describes the systemâ€™s overall extent and shape. This envelope is defined by a geometric surface grown in a digitally simulated environment of forces.

The digital growth process employed for the generation of the surface is based on extended Lindenmayer Systems, which derive form through the interaction of two factors: a geometric seed combined with rewriting rules which specify how elements of the shape change and a process that repeatedly reinterprets the rules with respect to the current shape. In this particular case the surface is represented by a graph data structure constituted by a set of edges, vertices and regions. Since all edges are constantly rewritten during the digital growth process all parts of the surface continuously change until the ontogenetic drifts settle into a stable configuration. Based on the growing surface another input for the implementation of the material elements is generated. In response to particular geometric surface features, as for example global undulation and regional curvature, a variable distribution-algorithm establishes a network of lines on the surface indicating the position of each element and the related node type. Digital components then populate the system accordingly and derive a virtual solid model.

In the resultant organisation crossing members only intersect if they are perpendicular due to the embedded manufacturing constraints. If not, they pass under or over crossing elements, not dissimilar to a birds nest, and thereby form a geometrically defined, self-interlocking, stable structure. This complex correlation of geometric definition, structural behaviour and production logics does not only remain coherent in a single system, as for example the tested prototype with almost 90 members and 1000 joints, but it is integral to the generation process itself. This is of particular importance if one considers that the surface defining the critical morphogenetic input is constructed through a bottom-up process in which all parts respond to local interactions and the environment. As these internal and external interactions are complex and the interpretation of the L-systems is non-linear, the outcome of the growth process remains open-ended. This continual change combined with the long chain dependencies of the subsequent generation methods enables the growth of different system types of member organisation, system topology and consequent performative capacity.

Morphogenetic Design Experiment 05 – Fibrous Surface

Sylvia Felipe, Achim Menges, Jordi Truco with Emmanuel Rufo, Udo Thoennissen