Smart Materials and Technologies in Architecture

Michelle Addington, Daniel Schodek

• Publisher: Routledge
• Year: 2012
• ISBN:
  9781136366086
• Edition: 1
• Topic: Architecture
• Subtopic: Architecture Methods & Materials

Today, architects and designers are beginning to look toward developments in new
"smart" or "intelligent" materials and technologies for solutions to long-standing problems
in building design. However, these new materials have so far been applied in a diverse
but largely idiosyncratic nature, because relatively few architects have access to
information about the types or properties of these new materials or technologies.
Two of the leading experts in this field - Addington and Schodek - have solved this
problem by incorporating all the relevant information of all the latest technologies
available to architects and designers in this one volume. They present materials by
describing their fundamental characteristics, and go on to identify and suggest how
these same characteristics can be exploited by professionals to achieve their design
goals. Here, the wealth of technical understanding already available in the materials
science and engineering literature is at last made accessible to a design audience.

1	Materials in architecture and design

Smart planes – intelligent houses – shape memory textiles – micromachines – self-assembling structures – color-changing paint – nanosystems. The vocabulary of the material world has changed dramatically since 1992, when the first ‘smart material’ emerged commercially in, of all things, snow skis. Defined as ‘highly engineered materials that respond intelligently to their environment’, smart materials have become the ‘go-to’ answer for the 21st century's technological needs. NASA is counting on smart materials to spearhead the first major change in aeronautic technology since the development of hypersonic flight, and the US Defense Department envisions smart materials as the linchpin technology behind the ‘soldier of the future’, who will be equipped with everything from smart tourniquets to chameleon-like clothing. At the other end of the application spectrum, toys as basic as ‘Play-Doh’ and equipment as ubiquitous as laser printers and automobile airbag controls have already incorporated numerous examples of this technology during the past decade. It is the stuff of our future even as it has already percolated into many aspects of our daily lives.

Figure 1-1 NASA's vision of a smart plane that will use smart materials to ‘morph’ in response to changing environmental conditions. (NASA LARC)

In the sweeping ‘glamorization’ of smart materials, we often forget the legacy from which these materials sprouted seemingly so recently and suddenly. Texts from as early as 300 BC were the first to document the ‘science’ of alchemy.¹ Metallurgy was by then a well-developed technology practiced by the Greeks and Egyptians, but many philosophers were concerned that this empirical practice was not governed by a satisfactory scientific theory. Alchemy emerged as that theory, even though today we routinely think of alchemy as having been practiced by late medieval mystics and charlatans. Throughout most of its lifetime, alchemy was associated with the transmutation of metals, but was also substantially concerned with the ability to change the appearance, in particular the color, of given substances. While we often hear about the quest for gold, there was an equal amount of attention devoted to trying to change the colors of various metals into purple, the color of royalty. Nineteenth-century magic was similarly founded on the desire for something to be other than it is, and one of the most remarkable predecessors to today's color-changing materials was represented by an ingenious assembly known as a ‘blow book’. The magician would flip through the pages of the book, demonstrating to the audience that all the pages were blank. He would then blow on the pages with his warm breath, and reflip through the book, thrilling the audience with the sudden appearance of images on every page. That the book was composed of pages alternating between image and blank with carefully placed indentions to control which page flipped in relation to the others makes it no less a conceptual twin to the modern ‘thermochromic’ material.

Figure 1-2 Wireless body temperature sensor will communicate soldier's physical state to a medic's helmet. (Courtesy of ORNL)

What, then, distinguishes ‘smart materials’? This book sets out to answer that question in the next eight chapters and, furthermore, to lay the groundwork for the assimilation and exploitation of this technological advancement within the design professions. Unlike science-driven professions in which technologies are constantly in flux, many of the design professions, and particularly architecture, have seen relatively little technological and material change since the 19th century. Automobiles are substantially unchanged from their forebear a century ago, and we still use the building framing systems developed during the Industrial Revolution. In our forthcoming exploration of smart materials and new technologies we must be ever-mindful of the unique challenges presented by our field, and cognizant of the fundamental roots of the barriers to implementation. Architecture heightens the issues brought about by the adoption of new technologies, for in contrast to many other fields in which the material choice ‘serves’ the problem at hand, materials and architecture have been inextricably linked throughout their history.

1.1 Materials and architecture

The relationship between architecture and materials had been fairly straightforward until the Industrial Revolution. Materials were chosen either pragmatically – for their utility and availability – or they were chosen formally – for their appearance and ornamental qualities. Locally available stone formed foundations and walls, and high-quality marbles often appeared as thin veneers covering the rough construction. Decisions about building and architecture determined the material choice, and as such, we can consider the pre-19th century use of materials in design to have been subordinate to issues in function and form. Furthermore, materials were not standardized, so builders and architects were forced to rely on an extrinsic understanding of their properties and performance. In essence, knowledge of materials was gained through experience and observation. Master builders were Smart Materials and New Technologies those who had acquired that knowledge and the skills necessary for working with available materials, often through disastrous trial and error.

The role of materials changed dramatically with the advent of the Industrial Revolution. Rather than depending on an intuitive and empirical understanding of material properties and performance, architects began to be confronted with engineered materials. Indeed, the history of modern architecture can almost be viewed through the lens of the history of architectural materials. Beginning in the 19th century with the widespread introduction of steel, leading to the emergence of long-span and high-rise building forms, materials transitioned from their pre-modern role of being subordinate to architectural needs into a means to expand functional performance and open up new formal responses. The industrialization of glass-making coupled with developments in environmental systems enabled the ‘international style’ in which a transparent architecture could be sited in any climate and in any context. The broad proliferation of curtain wall systems allowed the disconnection of the façade material from the building's structure and infrastructure, freeing the material choice from utilitarian functions so that the façade could become a purely formal element. Through advancements in CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) technologies, engineering materials such as aluminum and titanium can now be efficiently and easily employed as building skins, allowing an unprecedented range of building façades and forms. Materials have progressively emerged as providing the most immediately visible and thus most appropriable manifestation of a building's representation, both interior and exterior. As a result, today's architects often think of materials as part of a design palette from which materials can be chosen and applied as compositional and visual surfaces.

It is in this spirit that many have approached the use of smart materials. Smart materials are often considered to be a logical extension of the trajectory in materials development toward more selective and specialized performance. For many centuries one had to accept and work with the properties of a standard material such as wood or stone, designing to accommodate the material's limitations, whereas during the 20th century one could begin to select or engineer the properties of a high performance material to meet a specifically defined need. Smart materials allow even a further specificity – their properties are changeable and thus responsive to transient needs. For example, photochromic materials change their color (the property of spectral transmissivity) when exposed to light: the more intense the incident light, the darker the surface. This ability to respond to multiple states rather than being optimized for a single state has rendered smart materials a seductive addition to the design palette since buildings are always confronted with changing conditions. As a result, we are beginning to see many proposals speculating on how smart materials could begin to replace more conventional building materials.

Cost and availability have, on the whole, restricted widespread replacement of conventional building materials with smart materials, but the stages of implementation are tending to follow the model by which ‘new’ materials have traditionally been introduced into architecture: initially through highly visible showpieces (such as thermochromic chair backs and electrochromic toilet stall doors) and later through high profile ‘demonstration’ projects such as Diller and Scofidio's Brasserie Restaurant on the ground floor of Mies van der Rohe's seminal Seagram's Building. Many architects further imagine building surfaces, walls and façades composed entirely of smart materials, perhaps automatically enhancing their design from a pedestrian box to an interactive arcade. Indeed, terms like interactivity and transformability have already become standard parts of the architect's vocabulary even insofar as the necessary materials and technologies are far beyond the economic and practical reality of most building projects.

Figure 1-3 The ‘heat’ chair that uses thermochromic paint to provide a marker of where and when the body rested on the surface. (Courtesy of Juergen Mayer H)

Rather than waiting for the cost to come down and for the material production to shift from lots weighing pounds to those weighing tons, we should step back and ask if we are ignoring some of the most important characteristics of these materials. Architects have conceptually been trying to fit smart materials into their normative practice alongside conventional building materials. Smart materials, however, represent a radical departure from the more normative building materials. Whereas standard building materials are static in that they are intended to withstand building forces, smart materials are dynamic in that they behave in response to energy fields. This is an important distinction as our normal means of representation in architectural design privileges the static material: the plan, section and elevation drawings of orthographic projection fix in location and in view the physical components of a building. One often designs with the intention of establishing an image or multiple sequential images. With a smart material, however, we should be focusing on what we want it do, not on how we want it to look. The understanding of smart materials must then reach back further than simply the understanding of material properties; one must also be cognizant of the fundamental physics and chemistry of the material's interactions with its surrounding environment. The purpose of this book is thus two-fold: the development of a basic familiarity with the characteristics that distinguish smart materials from the more commonly used architectural materials, and speculation into the potential of these characteristics when deployed in architectural design.

1.2 The contemporary design context

Orthographic projection in architectural representation inherently privileges the surface. When the three-dimensional world is sliced to fit into a two-dimensional representation, the physical objects of a building appear as flat planes. Regardless of the third dimension of these planes, we recognize that the eventual occupant will rarely see anything other than the surface planes behind which the structure and systems are hidden. While the common mantra is that architects design space the reality is that architects make (draw) surfaces. This privileging of the surface drives the use of materials in two profound ways. First is that the material is identified as the surface: the visual understanding of architecture is determined by the visual qualities of the material. Second is that because architecture is synonymous with surface – and materials are that surface – we essentially think of materials as planar. The result is that we tend to consider materials in large two-dimensional swaths: exterior cladding, interior sheathing. Many of the materials that we do not see, such as insulation or vapor barriers, are still imagined and configured as sheet products. Even materials that form the three-dimensional infrastructure of the building, such as structural steel or concrete, can easily be represented through a two-dimensional picture plane as we tend to imagine them as continuous or monolithic entities. Most current attempts to implement smart materials in architectural design maintain the vocabulary of th...