A model for nature inspired interactive building envelope design based on pattern

The use of the pattern in the field of the architecture has been controversial so far, its usage in computer science, biology and artificial intelligence as shapes and forms which emerge from series and repeating sequences has caused to rethink the role of pattern in the architecture and create a new point of view regarding its applications. After, Alexander implies that production of building can be called the assembly of patterns, the rejection of pattern from architecture has shifted to understand pattern as a contributor to make architecture more profound. By means of this new perspective, a pattern has not only been seen as a repetition of identical geometries or elements, it has also been seen as a result of random or emergent behaviours which are defined by rules. The shift in discussion is from the notion of pattern-making alone to pattern recognition (Castle, 2009). This two sided discussion about patterns which includes the pre-Modernism, Modernism and digital age is explained in historical background (Chapter 2) of this thesis with several examples in architecture. This thesis has two main parts which are the theory and application. As a theorical part, the definition of the pattern is discussed in Chapter 3 which has changed in time regarding the types of iterations which a pattern has. How the notion of the regularity and chaos has shaped the definition of pattern. The rules behind pattern formations have exposed to examine the complex systems in nature. In a pattern definition and classification chapter of this thesis, the examination of patterns goes under two headings as natural and artificial (man-made) patterns. First, it is explained that the rules behind formations in nature with the help of biology, chemistry, mathematics and computer sciences and exhibited some algorithms which are generated by rule sets to produce biomimetic models. Next, man-made patterns are analysed through the relation between material, geometry and production which are the most prominent criteria of this kind of patterns. From regular to complex, man-made patterns have different kind of generative methods which are discussed under heading of periodic, aperiodic and random patterns whose classification is borrowed from mathematics. Owing to analysing and defining natural patterns, functionality and materiality has exposed behind the formal. This situation has affected patterns in architecture from micro to macro scale. In the scope the thesis, patterns in architecture is explained under the chapters of urban, structural (building) and tiling patterns considering the pattern classifications in regards to the part of the city or building that pattern is applied to considering the material, additional systems ad pattern formation method of the projects. This classification has the methodology of showing the different scales and degrees of the application regarding patterns and their relation with concept of the projects. Patterns on the body of animal which yield adapting to the environment, mating as a communication or protecting himself from threats is related to building façade or envelope, in this thesis. Understanding the adaptations of animals leads to ensuring the building envelope to be seen as an expression, negotiation and performance entity aside from dividing interior and exterior. Thus, building envelope is not seen a completed element and is understood as a system which can be transformed according to stimulus like in nature. In today's dynamic world, it is important to have the ability of the adaptation by means of transformation. The thesis is based on the development of the analogue pattern generation methods in the help of digital technologies and use them to produce a responsive and interactive building envelope by using the method of biomimicry as a application part of this thesis. While doing this, the camouflage by means of blending with its surroundings and accentuation of the building envelope by means of becoming apparent which are also characteristics of the animal' bodies, is discussed through the proposed model for the thesis. In the scope of the thesis, after analysing the natural and artificial patterns, a model is produced integrating patterns on bodies of animals (natural) and patterns of weaving (man-made). One of these animals which is analysed and mimicked for this thesis is chameleon whose skin changes in colour according to its mood. If the chameleon is excited its skin colour turned out to warm colours, in opposition to calm mood. The other animal is cuttlefish which has sophisticated skin adaptation system both in colour and form thanks to its multi-layer skin. The colour filters which are called chromatophores varies in colour define the colour of skin by inflating and deflating. If the chromatophores are inflated they colour the skin to their own colours by reflecting light which is changed by these cells. If they are deflated, light which comes through the skin is reflected as a white colour. These pigment-like cells work as muscles and help the adaptation of the animal to its environment. To generate the model which is proposed for this thesis, two layers of a hexagonal grid is chosen as an initial shape like in the cuttlefish. This two layers are interwoven and have ability to change in colour and shape by using pneumatic and LED systems like in the chromatophore cells. Thus, the model is a pattern based model inspired by the mechanisms of colour and form changing animals which can be transformed according to stimulus as the sun orientation, the movement of people and change in the environment and produced as a building envelope, façade or installation by using of several parametric design tools. By means of the stimulus, several pattern formations occurs owing to this generative model. This pattern formation which is carried to the architectural discourse called "responsive interactive architecture". Here, responsive stands for being activated by stimulus while interactive represents the human interaction of the model. The kinetic pattern which is proposed for this thesis responses to the stimulus as blending with its surroundings (camouflage) or communicating with the environment (accentuation) like in natural adaptations of animals. All these characteristic changes in the pattern based model are enriched by the combinations of agents which affects the character of the building envelope which are gathered together at the end of this chapter in a table of patterns. Inflation/deflation of system is enhanced by colour makes the model communicative as well as performative in terms of architecture. In the conclusion chapter of this thesis, the potentials of the model is discussed regarding architecture and sustainability. Owing to responsive and interactive character of the model, it can be applied in different scales like building envelope, façade or installation and combined with different functions of the building. The sun orientation of the model yields to sustainable architecture by providing heat gain and light optimization. The human interaction provides dynamic relationship with the inhabitants of the building while defining a surface of communication with its environment. Besides, thanks to the colour adaptation of the model, it blends with its surroundings. Combinations of these agents can create more transformations in the pattern based model thanks to the generative algorithm. In regards to application of the model, the integration of the pneumatic modules which are produced with PVC based materials and LED systems is suggested for the future applications. Thus, it can be observed that the contribution of integrating the material with the electrical and mechanical systems to the sustainability of the building considering the future of our world.