algae textile: bio-façade
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What if buildings could breathe?—producing oxygen for urban centers.
The algae textile demonstrates how the growth of algae can be deployed as a lightweight component within conventional building systems—combating C02 emissions and global warming.
Bio-Façade Design
M.Arch thesis, University of Waterloo, School of Architecture
year: 2012-2014 | category: research
what is the algae textile?
A bio-façade which acknowledges both the productivity and the aesthetic of algae.
The algae textile is a building-integrated photobioreactor that is designed as a flexible membrane. Polymeric materials and parametric geometry are used to generate porosity and flexibility— something rarely seen in algal bio-façades. These techniques introduce an ability to modulate light and view into adjacent interior spaces without compromising the occupant’s interior experience, or expanding the wall assembly.
the bioreactor in architecture
While recent developments in bioreactor technology focus mainly on industrial applications, there is evident potential in translating the engineering principles of a bioreactor into the architecture of a building—making it possible for algae to act as a productive component within a building envelope, while emulating the oxygenating benefits of hectares of forestland.
why algae?
Urban algae production should focus on the visual and experiential impacts it can provide. Algae is also capable of producing valuable products for society, and makes it an important technology to assess when evaluating renewable resources for the built environment.
Algae produces 70-80% of all oxygen on earth, making it one of the best strategies for achieving a sustainable and carbon-neutral future.
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For the architect, adjusting qualitative parameters such as form, light or occupant comfort take priority over quantitative parameters such as maximizing biomass yields.
Qualitative parameters include: the ability to modulate light and shade, or the visual interest provided by its transformation and movement between growth cycles. For this, an ease in generating a networked path within the reactor around irregular contextual conditions is required and, therefore, geometries offering plasticity are desirable.
Algal facades must benefit the character of the space they surround.
The algae textile uses parametric design algorithms to generate these forms. First as a set of points that are mapped over a surface, then connected using a voronoi grid. Spheres are then mapped onto these points— larger spheres are programmed to aggregate around denser point locations—and connected to form the algae textile’s meshwork.
variable geometries
Geometric Plasticity
In mathematics, plasticity is used to describe discrete differential geometry: random triangulation and emergent conformal patterns, like in the study of fractals. In neuroscience, it describes how neural structures in the brain change through experience, and in biology, it describes how organisms can change their phenotype in accordance to their environmental surroundings: the branching structure of corals to optimize sun and shade conditions for photosynthesis. In all cases, they are derived through evolved physiological or morphological mechanisms used to cope with contextual fluctuations, and a major component in achieving geometric plasticity.
The Aesthetics of Plasticity
Models of plasticity are prevalent in adaptive systems and can be seen to benefit aspects of design relating to variability. Consequently, the aesthetic it may produce should be studied—suggesting a new paradigm in design which moves away from Cartesian geometries, and towards triangulated and conformal geometries which efficiently alter according to spatial fluctuations given by a context.
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1. An inoculation and harvest system:
For starting a culture, the inoculation system fills the textile with growth medium (blue line) and then injects a concentrated algae culture (orange line). This is left to grow and photosynthesize.
To maintain an existing culture once it has grown, a portion of the culture is extracted from the textile and directed to a harvesting tank (green line). The inoculation system then injects only fresh growth medium into the textile to dilute the culture and start a new growth cycle.
2. An air system:
Pressurized air is injected at floor level and travels upwards through the textile. This feeds the algae with CO2 as it photosynthesizes and circulates the culture to promote its growth. The resulting oxygen produced by the algae is exhausted at ceiling level and can be fed into the building’s ventilation system thereafter.
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The algae textile can be applied using the same logic as a frit pattern (an opaque pattern commonly applied to glass buildings to control light), but has the added benefits of,
supplying a source of alternative ecology to purify air, recycle water, and uplift an occupant’s well-being,
supporting the growth of a renewable resource in an urban setting, and
controlling light and shade over an expanse of glass, using gradients and variation to achieve subtle effects within streamlined dimensions.
By embedding productive functions within material, the desire for emergent qualities within traditionally rigid systems, incites a method of design where geometry is optimized and where material is machine.
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If an algal–urbanism were to be implemented, the proposal envisions how material surfaces could be designed with an agency in mind, to perform productive tasks (filtration, harvesting, energy production, etc.), and introduce alternative modes of ecology in highly dense urban environments.
It has been important to identify the challenges associated with using photobioreactors in an urban context, and to establish what characteristics are desirable when used in a building. As the proposal has shown, materials developed for living organisms must not only define a form specifically tailored to the growth mechanics of that organism, but they must also satisfy demands given by building construction to ensure their prolific use. For algae, circulation, agitation, surface–to–volume ratio and light penetration are all important factors, and is what the textile strives to explore, challenge and test.
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UNIVERSITY OF WATERLOO, M.ARCH THESIS, 2014
Petra Bogias, “Algae Textile: A Lightweight Photobioreactor for Urban Buildings” M.Arch Thesis, (University of Waterloo, 2014)
FACADE TECTONICS 2016 WORLD CONGRESS
Peer Reviewed Paper & Conference Speaker (October 9-11, 2016)
For the paper entitled, “Algae Textile: A Lightweight Photobioreactor for Urban Buildings”, pg. 437
