Walter Haase

Plants and Animals as Source of Inspiration for Energy Dissipation in Load Bearing Systems and Facades

From the manifold strategies that nature offers to materials under overload conditions, we describe two: the fibrous and multi-layered system of the bark of the Giant Sequoia, which possesses an impressive damping mechanism, and the spines of pencil and lance sea urchins. The latter introduce a new concept to energy dissipation in brittle construction materials, namely quasi-ductility by multiple local fracturing. The potential for transfer as bioinspired technical solutions is high as the biological role models combine several advantages such as lightweight, recyclability and high protective efficiency. We demonstrate that, in principle, the concepts found in the biological role models can be transferred to concrete-based building materials.

Fabrication of Biomimetic and Biologically Inspired (Modular) Structures for Use in the Construction Industry

The transformation of biological paradigms into building construction involves the transfer of structure and system-defining properties from biological role models to construction-specific and innovative non-construction-specific systems and processes. The challenge of manufacturing biomimetic and bio-inspired structures includes the provision of methods and procedures that allow the mapping of biological features on a production-related description. The methodological approach requires the validation and verification of existing production methods at the small scale (model, elementary cell) in order to transfer findings to the production of components at the construction scale. Additionally, the biological features that cannot be reproduced by existing methods require further adjustment or the development of new methods for appropriate transfer. A basic condition for the further development of such production procedures is the possibility of manufacturing complex structures based on biological strategies concerning resource and energy consumption, waste production and greenhouse gas emissions.

Adaptive glazing systems - survey of systems

Glazed facade units must satisfy numerous criteria. In addition to allowing an unobstructed view of the exterior they should also provide protection from direct sunlight and the associated heat transfer. In order to optimize the performance of glazed facades under varying conditions, much effort has been directed towards the development of adaptive glazing systems based on smart materials or smart mechanism. This article will outline the functional principles and visual properties of one self-adjusting, thermochromic glazing, two controllable electrochromic systems and one liquid crystal based system.

Potential of origami-based shell elements as next-generation envelope components

Building envelopes manage several crucial functions, including structural, thermal, hygric and aesthetic functions. Classic façade concepts usually work with static elements like glass, metal or composite panels that primarily provide protection against the elements, and an additional layer of active systems that manage dynamic tasks like light protection or thermal regulation. Kinematic shell elements offer new ways to incorporate multiple dynamic functionalities into cladding elements, and thus can help to generate new active, efficient and aesthetic envelopes. We will introduce the concept of origami-inspired multifunctional shell elements and discuss potential applications.

Cost-efficient manufacturing process of switchable glazing based on twisted nematic LC cells

Large-area glass facades are widely spread in contemporary architecture. They meet demands for natural light illumination of rooms and satisfy esthetic requirements of modern architecture. However, larger glass facades increase transfer of energy into the building. Since this has to be compensated by the intense use of air conditioning, modulation of the energy passing through the glazing is essential. The authors have been developing a corresponding system. It consists of a modified twisted nematic (TN) liquid crystal (LC) cell which is embedded in a double glazing. Since a conventional outside film polarizer is susceptible to heat, the authors substituted this component for an inside coatable polarizer. Long term outdoor weathering tests demonstrated that the concept is viable. Part of the current research is the integration of the TN LC cell into double-glazing. A further demand for such a system is a cost-efficient manufacturing process. It has been investigated to use the coatable polarizer at the same time as an alignment layer for the liquid crystal. Aluminum zinc oxide (AZO) is to be used for the electrode material substituting conventionally used indium tin oxide (ITO) which is expensive. Currently the authors are looking into the coating process for the inside polarizer.