J. Lienhard & J. Knippers
Institute of Building Structures and Structural Design (ITKE),
University of Stuttgart, Germany


Deployable systems in nature are often based on flexibility; this can be observed especially in plant movements. Here growth or change of turgor pressure are the most common causes for a change in dimension of fibres, tissues, organs and whole plants. In some instances, these deformations can be reversible. Bending of the structure is an unequal contraction and elongation of the tissues and the fibres within the tissues which is caused by an asymmetrical distribution of turgor pressure.

Based on this simple principle plants have developed a multitude of kinematics which are used for opening and closing, positioning and anchoring etc.

From an engineering point of view most of these deformations are within a visco elastic range. New construction materials such as fibre reinforced polymers can combine high tensile strength with low bending stiffness, allowing large elastic deformations. These characteristics enable us to think about a completely new interpretation of convertible structures which work on reversible deformation. This potential has not yet found its use in building and construction. In a current research project in this field a group of engineers and biologists are trying to close this gap by developing a new type of convertible structures. The kinematics of these pliable structures will be based on the flexible deformation principles found in nature.

The object of this paper is to describe the bionic working progress in the selection of plant movements with a high potential for transfer in technical applications, and the abstraction and modification of these movements in order to develop elastic kinematics for deployable structures in architecture.