In their emphasis on process, Deleuze and Guattari take into account not only the materiality of forms, but also other process-based considerations. They draw upon the notion of \u201cdouble articulation\u201d through which geological, biological, and even social strata are formed. As Manuel DeLanda puts it in his essay \u201cDeleuze, Materialism and Politics,\u201d \u201cThe first articulation concerns the materiality of a stratum<\/em>: the selection of the raw materials out of which it will be synthesised (such as carbon, hydrogen, nitrogen, oxygen and sulphur for biological strata) as well as the process of giving populations of these selected materials some statistical ordering. The second articulation concerns the expressivity of a stratum\u2026<\/em> This second articulation is therefore the one that consolidates the ephemeral form created by the first articulation and that produces the final material entity defined by a set of qualities expressing its identity.2<\/sup><\/a><\/span> 2 <\/a> - Manuel DeLanda, \u201cDeleuze, Materialism and Politics,\u201d in Deleuze and Politics<\/em>, ed. Ian Buchanan and Nicholas Thoburn (Edinburgh: Edinburgh University Press, 2008), 162-63 (emphasis in original).<\/span>. ” <\/p>\n\n\n\n DeLanda is drawing upon Deleuze and Guattari\u2019s notion of expressivity, which has to do with the colour, sound, texture, movement, and geometrical forms of matter. He refers to these qualities as \u201cfingerprints\u201d that can be used to identify and determine the properties of a given material through the process of spectroscopy. First developed in the nineteenth century, spectroscopy refers to the study of the interaction between matter and electromagnetic radiation, which produces an expressive result for a given material through emission, absorption, or other processes. These expressive patterns are what scientists call information. This information has nothing to do with semantics but consists of linguistically meaningless physical patterns in which matter expresses itself. <\/p>\n\n\n\n Besides the material expressivity of a single atom producing a distinctive pattern, these finger\u00adprints can express themselves in more complex forms, such as a genetic code or DNA. As DeLanda elaborates, \u201cGroups of three nucleotides, the chemical components of genes, came to correspond in a more or less unique way to a single amino acid, the component parts of proteins. Using this correspondence, genes can express themselves through the proteins for which they code.”3<\/sup><\/a><\/span> 3 <\/a> - Manuel DeLanda, loc.<\/span>. <\/p>\n\n\n\n <\/p>\n\n\n\n What is worth noting here is that the underlying patterns of information found in living organisms lead to the emergence of certain expressive behaviours that are actually functional \u2014 such as when a bird puffs up its feathers in order to protect its body from the cold or to impress a potential mate.<\/p><\/blockquote><\/figure>\n<\/div>\n<\/div>\n\n\n\n Material expressivity is also to be found in muscle functions. Muscles are made of an elastic fibre-like material that can contract and expand. As animals change their gait, from walking to trotting to galloping, the muscles express themselves in different ways through contraction and expansion. Similarly, when humans change their expressions from smiling to frowning, the muscles of the face express themselves in different ways through micro-muscle contractions. In this case, the form and behaviour of an organism at a macro-scale are a reflection of material expressivity and muscle functions at a micro-scale. Focused attention on material expressivity could open up novel approaches to art and design practices that would transform our experience of them. As such, materials which are typically seen as static, rigid, and solid, could become dynamic, active, and shape-changing. For instance, Hylozoic Soil<\/em> (2009), an interactive art installation by Canadian architect Philip Beesley, senses human occupants and responds accordingly. Similar to how the Mimosa pudica reacts to being touched, this installation, with its lightweight feather-like elements, moves organically when someone is approaching. Made of tens of thousands of delicate components, and with its embedded machine intelligence, the installation comes to life, allowing the occupants to interact and trigger various behaviours by the work, such as breathing, caressing, and swallowing. The movement is triggered by a series of SMAs embedded within the installation. To coordinate its movements, arrays of proximity sensors inform networks of microcontrollers. The installation is never in a finished state but is constantly evolving and changing as it interacts with users. Beesley describes this environment as being similar to a coral reef, following cycles of opening, clamping, filtering, and digesting. Indeed, by implementing principles inspired by natural systems and exploring dynamic material expressivity, Beesley has developed interactive systems that change the relationship between human bodies and materials in the surrounding environment. <\/p>\n\n\n\n One of the remarkable examples of material expressivity in non-biological materials can be seen in the emergence of smart materials \u2014 materials that can change their properties in a controlled fashion under the influence of external stimuli, such as stress, temperature, moisture, electricity, pH level, and magnetic fields. SMAs, also known as \u201cmuscle wires,\u201d are among the most frequently used types of smart materials; they go through morphological changes and behave similarly to biological muscles. This material can be deformed but then \u201cremember\u201d its original shape when triggered by a specific activation temperature, in a behaviour known as shape memory effect (SME). Commonly made of nickel-titanium, SMAs display a solid-to-solid phase transition, during which molecules reshuffle their structural configurations and consequently affect the material properties of the SMA. This is typically known as the austenite state (at higher temperatures) and the martensite state (at lower temperatures). As Michelle Addington and Daniel Schodek explain, \u201cThe material in the austenite state is strong and hard, while it is soft and ductile in the martensite phase. The austenite crystal structure is a simple body-centered cubic structure, while martensite has a more complex rhombic structure4<\/sup><\/a><\/span> 4 <\/a> - Michelle Addington and Daniel Schodek,Smart Materials and Technologies: For the Architecture and Design Professions<\/em> (Oxford, UK, and Burlington, MA: Architectural Press, 2005), 105.<\/span>. ” <\/p>\n\n\n\n In my own work, I have also been exploring material expressivity using SMAs. For instance, The Living, Breathing Wall<\/em>(2013) is an interactive tensile-surface installation that responds to the visitor\u2019s spoken words with a range of morpho\u00addynamic behaviours. It is covered by a single stretchable Spandex textile membrane, the surface of which can be modulated by a series of inner mechanisms, similar to how the human skin can be modulated by the micro-contractions of muscles. The installation is an attempt to see how a membrane can respond dynamically to various people\u2019s emotive words (such as \u201chappiness,\u201d \u201csadness,\u201d and \u201cbeautiful\u201d), which trigger certain movements through a Kinect device that registers and interprets those words. As the surface is distorted by the fifty-six hidden addressable SMA actuators, it finds its optimal form according to the position of each actuator. Illuminated from the space in-between the fabric and wooden surface, aluminum straps reflect the light and give the installation a mesmerizing jellyfish-like effect. <\/p>\n\n\n\n Other materials also have the capacity to change their physical properties in an unconventional manner. Coworo<\/em> (2018) is an installation designed by Takuya Matsunobu and Yasuaki Kakehi of the University of Tokyo. The installation uses a shape-changing liquid that is constantly changing texture, as it appears to switch from solid to liquid states; bubbles appear and disappear on the surface, as if it were breathing, creating an ever-changing, undulating landscape. When the installation starts operating, the liquid surface rises and various dynamic behaviours and textures emerge on the surface. As non-Newtonian fluid is stirred by motors installed inside a tank, various impressions emerge on the liquid surface, which responds instantaneously with fascinating transformations that overcome many limitations of traditional solid materials, such as wear and tear and restriction of movement. This stunning dance of materials is captured by a spotlight on top of the tank, to create a sense of wonder and foster a new kind of experience for viewers.<\/p>\n\n\n\n By addressing the notion of material expressivity in terms of both biological and non-\u00adbiological materials, we can immediately see how their characteristics can afford new possibilities. In our daily lives, we are constantly encountering and extracting information from our environment. For instance, we can perceive the softness of a piece of fabric simply by looking at it. Or we can immediately detect someone\u2019s aggression through a series of non-verbal bodily cues. It is also possible that different forms of material expressivity in our environment inform our behaviour. But what if the colour and texture of our environment changes? What if the shape of an art piece transforms as you stand in front of it? I argue that we have to pay close attention to material expressivity in the creative process in order to develop new engaging experiences. Rather than forcing a material to behave in a certain way (as seen in most conventional mechanical systems), we should try to work with its inherent material properties to unleash its potential and allow forms to emerge through their intrinsic \u201cmaterial behaviour.\u201d As such, we can make non-biological materials display shape-changing and dynamic behaviours that could open up the possibility of radical approaches to art and design. It is therefore important to investigate the active, dynamic, and morphogenetic capacities of materials, to ensure that they express themselves in ways that go beyond the limitations of visual representation. <\/p>\n\n\n\n In more general terms, this also might help to counter the seemingly excessive emphasis on the textual and the visual rather than the material and performative, a problem that seems to compromise the art world as a whole. While representation and process are themselves locked into a mechanism of reciprocal presupposition, a strategic emphasis on process over representation might serve to thwart the prevailing hegemony of representation in contemporary art. Last, but not least, a process-based approach to active matter allows the relationship between viewer and art work to become dynamic and \u00adparticipatory.<\/p>\n<\/div>\n<\/div>\n\n\n\n <\/p>\n![\"\"](\"https:\/\/esse.ca\/wp-content\/uploads\/2021\/07\/101-DO5-IMG1-IM_Farahi_Beesley_Hylozoic-soil_kissing-pores_CMYK-1024x705.png\")
Hylozoic Soil<\/em>, installation view, Mus\u00e9e des beaux-arts de Montr\u00e9al, 2007.
Photo : \u00a9 Philip Beesley Studio Inc., courtesy of the artist <\/figcaption><\/figure>\n<\/div>\n\n\n\n![\"\"](\"https:\/\/esse.ca\/wp-content\/uploads\/2021\/07\/101-DO5-IMG2-IM_Farahi_Farahi_Living-breathing-wall_02_CMYK-1024x575.png\")
The Living, Breathing Wall<\/em>, 2013, installation view, Los Angeles, 2015.
Photo : Laura Cechanowicz, courtesy of the artist<\/figcaption><\/figure>\n\n\n\n![\"\"](\"https:\/\/esse.ca\/wp-content\/uploads\/2021\/07\/101-DO5-IMG3-IM_Farahi_Kakehi_Matsunobu_Coworo_025_CMYK-C-1024x683.png\")
Coworo<\/em>, detail, 2017.
Photo : courtesy of the artists<\/figcaption><\/figure>\n<\/div>\n\n\n\n