Adaptive Façade Shading Systems inspired by Natural Elastic Kinematics

This paper aims to present a novel approach to conceptualize basic mechanics for exterior façade shading systems by investigating kinematics of complex plant movements that are based on reversible elastic deformations. In an interdisciplinary collaboration between architects, engineers, and biologists; autonomous and non-autonomous flower opening and leaf folding processes were tested for their potential to act as concept generators for deployable structures in architecture. By introducing two case studies, the paper will exemplify how kinematical relationships can be successfully derived from pliable structures in nature. While, for example, the Flectofin® façade is based on the valvular pollination mechanism of the Bird-Of Paradise flower, the curved-line folding kinematics in the second case study was informed by the rapid trap closure mechanism of the carnivorous waterwheel plant. Both systems couple surface deformations to a cascading movement such that a small and simple actuation in one part of the structure is translated into a large yet stable deflection of another. For a better understanding of the principles involved, the paper will firstly introduce the inspirational phenomenon and explain the plants’ functional-morphological relationships. Secondly, the paper will present first abstractions of the underlying geometrical and structural features by using physical and digital models. Thirdly, FE-simulations will be used to validate the possibilities to scale and distort the kinematics and to transfer them into technical constructions. Finally, an outlook in which these adaptive façade shading systems are applied as parametric components to free-form geometries will close this paper.