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Bridging Synthetic and Organic Materiality: Gradient Transitions in

Material Connections Hironori Yoshida Digital Fabrication Laboratory (dFAB), Computational Design Lab (CoDe lab) at Carnegie Mellon University, Pittsburgh, Pennsylvania ABSTRACT The recent movement from mass production to mass customization enabled by digital fabrication has opened the door for new typologies in architecture and design. The author brought the idea of mass customization to material connection, which normally appears as orthogonal seams that are dominant in man-made objects. This chapter introduces gradient material transitions that seamlessly bridge synthetic and organic matter. Using digital image processing of organic forms, the fabrication process generates 3D tooling paths, culminating in the concept of ‘bio customization’ rather than mass customization; a new prospect of digital fabrication. Index Words  Mass customization, Digital craft, Robot manufacturing, Materiality, Digital fabrication, Image processing   INTRODUCTION If mass produced parts and components are the atoms of modern design, jointing techniques are the bonds between these atoms, the nucleus of today’s built world. “The art and technology to build is based on the skill to combine, to connect and to join similar, various or different parts, materials or components in order to construct a new whole” (Emmitt, Olie & Schmid, 2004). Seams between standardized parts and components are everywhere in our physical environment from products to buildings. These lines reveal how built objects are assemblies of standardized parts and components. There is a well established tradition of assembling structures according to this method in human history: Building with adobe bricks has over 9,000 years of history and the Egyptian pyramids are made of millions of standardized stones. It is no exaggeration to say that throughout history, people have continuously flattened and standardized the diverse natural materials into regular, uniform, repeatable, measurable forms. Our living environment today consists mainly of mass produced artifacts, which is typically considered to be the consequence of industrialization and subsequent mass production. The nature of mass production to create uniformity, which became a dominant aesthetic trend: Functionalism. Adolf Loos claimed in his essay ‘Ornament and Crime’ (1908) that “the evolution of culture is synonymous with the removal of ornamentation from objects of everyday use”, and expressed his “passion for smooth and precious surface” (Rykwert, 1973). In part due to new materials and tectonics, Functionalism created a dialogue that questioned standard perceptions of the built environment. Although the means of standardization have evolved, there has been continuous criticism to this process by organizations such as the Luddites in early 19th century and the Arts and Crafts Movement. This criticism of anti-machine trends is today continued in the form of organic fluid shapes enabled by recent digital tools, resulting in 'blobby' reforms. “The biomorphic structures and organic designs

 

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referred as "blobitecture" have their roots in the postmodernist rebellion against the perceived mechanistic dryness of modernism, with its well-known emphasis on function, scientific analysis, and order.” (Walters, 2003). CAD/CAM technologies realize efficient construction process of such structures; mass customization rather than mass production. “Mass customization of buildings means that all produced building components have a unique identity, are individuals that can be addressed independently. Each building component is different, and fits only in one place” (Oosterhuis and Biloria, 2008).   MATERIAL CONNECTIONS Before humans, nature discovered jointing techniques long ago. Organisms developed biological forms and jointing techniques such as the suture joint on skulls and the connection of a tooth to the jawbone. Later, humans got inspirations from those connections and developed standardized joining techniques such as mechanical fasteners to hold man-made structures together. In the design process, designers and engineers subdivide a required function into parts and components ultimately built with mono-materials. They specify materials to fulfill assigned requirements taking advantage of material properties; for example a window component with a transparent sheet glass and a well insulated frame. As long as man-made structures are fabricated as complex assemblies of parts and components, whether mass produced or digitally mass customized or one-off hand crafted, connections between components are inevitable. “From a philosophical and practical stance we can see that where materials or building components meet each other - at the points, at the lines or at the planes or surfaces - there is nothing” (Emmitt et al., 2004). Thus, assembled objects typically have pronounced seams between parts and components. Designers and architects do not have many choices to cope with these seams: To accentuate the contrast between components by using parting lines as graphical elements, or to disguise them from the eye using complex tooling, surface finishing or processing methods. The technological limitation of standardized parts and components is represented by their seams and appears as orthogonal seams that are predominant in man-made objects. Konrad Wachsmann, a forerunner in architectural details, “emphasized the need in any age to understand technical possibilities — in terms of machine-made standardized elements” (Creighton, 1969). Consequently his focus on architectural details such as joints and mechanical fasteners contributed to detail qualities of modern architecture. Mies van der Rohe (1959) famously said that God is in the details. The details do influence how people perceive the quality of a built structure or fabricated product. We simply appreciate to the quality of details and connections such as well-fitted stone works from Inca civilization or Japanese wood joinery. The number of books and magazines focusing on details illustrates how much people pay attention to detail. “Details - connections, joints and knots- have an extraordinarily crucial place and meaning, both technologically and culturally” (Emmitt et al., 2004).  GRADIENT MATERIAL TRANSITION What if materials are gradually connected one another instead of pronounced seams between them? Is it possible to construct contiguous product forms with gradual material transitions between types of materials or components? Gradient effects are frequently used in architecture and design, but historically served only as graphical visual transitions. “Gradation is found everywhere in our environment. — Frequently found in nature, gradation is, however, little used in architecture. More regular rhythms are preferred for obvious reasons of economy of building methods” (Van Meiss, 1990). Patterning of floor tiles and wall panels is a popular design technique to personalize spaces; however these are mechanically assembled using adhesives or

 

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fasteners. This is different than transitioning a weave pattern in a rug. Moreover, our perception of three-point perspective and diminishing views creates a gradation effect. A repetition of columns gradually scales down towards the vanishing point and as the columns recede from the viewer, the eye perceives them to move closer to each other. Recent advances in 3D printing technology can construct mono-structures with multi-material transitions. “Complete electromechanical devices can be made entirely by printing with a single fabrication system” (Alonso, Malone, Moon, & Lipson, 2009). Taking a look at organic structure like the human body, tendons connect bones and muscles with gradient transitions from mineral (bone) to organic collagen (muscle). This transition aids in its functionality and thereby affects its form. Functionally Graded Material (FGM) is an emerging research area in material science and nano science. The concept is to make composite materials by varying the microstructure from one material to another with a specific gradient pattern or structure.

DEVELOPMENT OF GRADIENT MATERIAL TRANSITIONS

The author launched a project aiming to construct a recognizable gradient material transition in place of standardized connections. Comparing the visually apparent transition of parting lines and assemblies versus a multi-material mono-structure without apparent seams provided the basis for experimentation. The transition in micro scale like FGM is not relevant, because the transition is not obvious for human eyes. On the other hand, at human scale, visually recognizable gradient effects could be achieved by tiling of components, however, there is a risk of ending up with just an exploration of gradient patterns. For those reasons, this project envisions to fabricate a mono-structural piece composed of different materials with gradient transitions. Moreover, creating the correct amount of gradient transitions where different materials are equally hybridized. The project fabricates two-dimensional surfaces projecting interior applications e.g. table surfaces and wall panels. The development of gradient material transitions was an iterative process of fabrication and reflection.  

 

Prototype 1: Selecting different materialities

To observe how gradient material transitions mediate contradicted materialities, plywood (organic, opaque, subtractive) and castable polyester resin (synthetic, transparent, additive) are selected. Figure 1 illustrates the first prototype of gradient transition between plywood and polyester resin. Transition patterns cited from material texture was used for visually apparent transitions. For a smooth transition of different materialities, the straight incisions referred to the layers of the plywood (Figure 2). The result demonstrates a smooth transition from plywood to polyester resin without any gaps due to the castable nature of polyester resin.

 

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 Figure 1. [Prototype of Gradient Material Transition between plywood and polyester resin]. (© [2010], [Hironori Yoshida].).

Figure 2. [A transition pattern refers to material texture integrates different materialities]. (© [2010], [Hironori Yoshida].).

Prototype 2: Various transition patterns  Prototype 2 explores generating various transition patterns aiming to fabricate mass customized connections. The bowed veneer strips refer to the elasticity of the material and helped to create a gradient transition (Figure 3). As Figure 4, prototype 2 successfully fabricated several transition patterns by controlling the amount of compression or pinching of the veneer strips.

 

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Figure 3. [Process of bowing veneer strips]. (© [2010], [Jeremy Ficca, Hironori Yoshida]. Used with permission.).

Figure 4. [Uniformed veneer strips and castable resin by a pattern of bowed shape]. (© [2010], [Jeremy Ficca, Hironori Yoshida]. Used with permission.).

Prototype 3: Mass customization of gradient material transitions

Aiming for mass customized connection, prototype 3 automates the process of generating transition patterns. For mediating different materialities, a plywood panel and polyester resin were selected and the wood grain pattern was used for the transition pattern. The grain pattern was first scanned (Figure 5) and then analyzed by a developed algorithm that converts the 2D image into 3D tooling paths. The algorithm simplifies the scanned image by pixelating and thresholding color values (Figure 6). The algorithm transforms the 2D image to 3D model by converting the color values to depths of each pixel and connecting them with vector lines. Figure 7 illustrates the generated tooling path and Figure 8 shows the CNC tooling process.  

 

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Figure 5 (Left). [Original grain image]. (© [2010], [Hironori Yoshida].). Figure 6 (Middle). [Processed original grain image by the algorithm]. (© [2010], [Hironori Yoshida].).

Figure 7 (Ledt). [Generated tooling path by the algorithm]. (© [2010], [Hironori Yoshida].). Figure 8 (Right). [A CNC router tooling a plywood panel]. (© [2010], [Hironori Yoshida].). Result Figure 9 shows a 24” x 48” fabricated board with a gradient material transition. The developed algorithm automatically converts a 2D image to 3D tooling paths by image processing. Since wood grain is a biologically developed structure unique to wood, the generated tooling paths from the grain pattern identifies the original wood panel thus can only be used for that particular wood

 

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panel. This automation process of tool path generation and the usage of organic materials realized mass customization of gradient material transitions. In terms of the quality of gradient material transition, a visually apparent transition effect was achieved by leveraging the inherent material quality of the wood and its organic grain pattern. At the same time, the transparency of the polyester resin emphasizes the contrast of materialities of wood and polyester. Since the fabricated piece presents a uniformed surface between wood and resin, the piece has a continuous mono-structure made of different materials, which is an essential element of gradient material transition, declared in the beginning of this section.  

Figure 9. [A board with gradient material transition]. (© [2010], [Hironori Yoshida].).   CONCLUSION   We began by reflecting on the history of standardization and the dominance of material connections with joints and mechanical fasteners in man-made structures. This observation formed the concept of ‘gradient material transition’ and the fabricated board. In the fabrication process of gradient material transition, computation was used to extract the biologically developed structure of wood grain. Now the digital fabrication process interacts with organic structures, and materials automatically defining the tooling process. As a consequence, they form as if they already knew how they were supposed to be composed. This fabrication process could be described as bio customization rather than mass customization.

 

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The built piece raises a question: What is the boundary between organic and inorganic? Since the degree of hybridization of organic/inorganic materialities varies, the boundaries will blur. Apparently a tree in the forest is natural, but once cut down, is it artificial just because the human hand is involved? Further, is a 90%-10% wood-resin piece artificial? We label many artifacts in our living environment as strictly ‘organic’ or ‘natural’. These artifacts may have organic shapes built with natural materials through natural fabrication processes or may be synthetic man-made forms with very “inorganic” materials. Although artifacts are temporally distinguished from natural objects through the different methods by which materials are connected, our notion of nature will be transformed because the boundary between natural and artificial will blur. We need a new category for the new nature; objects formed or fabricated through biologically inspired processes.

REFERENCES Alonso, M., Malone, E. Moon. F., Lipson. H. (2009, August). Reprinting the Telegraph: Replicating the Vail Register using Multi-materials 3D Printing. Paper presented at Solid Freeform Fabrication Symposium (SFF'09). Austin, TX. Creighton, T. (1969). Building for Modern Man. Manchester, NH: Ayer Publishing. Emmitt, S., Olie, J., & Schmid, P. (2004). Principles of Architectural Detailing. Oxford, UK: Wiley-Blackwell. Loos, A. (1998). Ornament and Crime Selected Essays. (Mitchell, M, Trans.). Riverside, CA: Ariadne Press. (Original work written 1908). Oosterhuis, K. Biloria, BN (2008). Interactions with Proactive Architectural Spaces: the Muscle Projects. Communications of the ACM, Volume 51, Issue 6. doi:10.1145/1349026.1349041 Rykwert, J. (1973). Adolf Loos: the new vision. Studio International, Volume 186, Number 957. Triggs, O. L. (1909). Chapters in the History of the Arts and Crafts Movement. Chicago, IL: Bohemia Guild of the Industrial Art League. Van Meiss, P. (1990). Elements of Architecture. London, UK: Taylor & Francis. Wake, W. (2000). Design Paradigms: A Sourcebook for Creative Visualization. Hoboken, NZ: John Wiley and Sons. Walters, J. (2003). Blobitecture: waveform architecture and digital design. Boston, MA: Rockport Publishers, Inc. ADDITIONAL READING SECTION Gramazio, F. Kohler, M.(2008). Digital Materiality in Architecture. Lars Müller Publishers. Pye, D. (1995). The Nature and Art of Workmanship. Fox Chapel Publishing. Weiser, M. (1996). The Coming Age of Calm Technology. Palo Alto: Xerox PARC

 

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Willis, K. Xu, C. Wu, KJ. Levin, G. Gross, M. (2011). Interactive Fabrication: New Interfaces for Digital Fabrication. TEI’11, Proceedings of the fifth international conference on Tangible, embedded, and embodied interaction. Funchal, Portugal.

 

KEY TERMS & DEFINITIONS KEYWORDS

Material connections: Where materials, parts and components are connected to hold structures together.

Standardized connections: Simplified joining techniques to connect mass produced standardized parts and components. Typically these connections are already embedded in parts and components for economical and productive construction.

Joining techniques such as joinery, mechanical fasteners, adhesives, glues and so forth to connect machine-made standardized parts and components to construct a new whole.

Customized connections: Joining techniques to connect raw materials together. Typically fabricators customize such joining to connect such non-standardized raw materials by manual analysis of material conditions.

Mass customized connections: Joining techniques customizing their typologies by automated analysis of material conditions.

Materiality: Materiality is defined with the most dominant properties among sensual properties (sight, touch, smell, taste, and hearing), technical properties (e.g. strength and elasticity) and expressive characteristics (organic, artificial).

Standardization: transforming diverse natural materials into regular, uniform, repeatable, measurable forms for rational construction and quality of artifacts.

Parts and components: standardized construction units typically mass produced by machine.

Mass customization: producing goods and services to meet individual customer's needs with near mass production efficiency.

Materiality: the most dominant properties of a material among sensual properties (sight, touch, smell, taste, and hearing), technical properties (e.g. strength and elasticity) and expressive characteristics (organic, artificial).

FGM (Functionally graded material): composite materials by varying the microstructure from one material to another with a specific gradient pattern or structure to improve functionality of materials.