This research describes a studio experiment developed with the aim of exploring the bio receptivity of ceramics taking advantage of the porosity of the material that allows it to retain water and using natural fibers as complement elements to benefits other properties. This research was made in the OTF program, at the Institute for Advanced Architecture of Catalonia. IAAC.
We know that species like moss and other organism have the capacity to growth in different kind surfaces, specially those ones where we can identify high levels of moisture and acceptable pH levels. Ceramics like roof tiles become suitable places for reproduction of this organism, providing even more benefit to material performance in terms of thermal and acoustic parameters, beside this, photosynthetic organism help to improve the air quality, alleviate urban heating among others.
Is important to understand that material suffer different physical changes depending on the environment and climate conditions, moss and other plants can also be responsible to increase the moisture levels and with high rise of temperature water can damage significantly a normal ceramic peace.
Testing Material Phase 1 [TM1]
In order to start testing the material I had been researching about previous work in ceramic fields taking in account components to test different levels of porosity and roughness. By nature of its microstructure, traditional ceramic material can function as a buffer for both heat and moisture. I am using bentonite white clay because it has been proven that it has an equilibrium moisture content of 13 percent under 50 percent standard humidity conditions, whereas the equilibrium moisture content of kaolinite under the same conditions is only 0.7 percent.
Introducing porosity into any material will improve the thermal insulating characteristics (decreasing the conductivity) of the material. Porous materials consist of solid matrix and gas inside the pores. Their good insulation properties are achieved due to the very small thermal conductivity in gases compared to solids or liquids. Therefore this first testing I am using pine sawdust in different proportion and chamotte to produce a rough finish to help the growing process.
Moss growing acceleration [MGA]
Botanically, mosses are non-vascular plants in the land plant division Bryophyta. They are small (a few centimeters tall) herbaceous (non- woody) plants that absorb water and nutrients mainly through their leaves and harvest sunlight to create food by photosynthesis. They differ from vascular plants in lacking waterbearing xylem tracheids or vessels. As in liverworts and hornworts, the haploid gametophyte generation is the dominant phase of the life cycle. This contrasts with the pattern in all vascular plants (seed plants and pteridophytes), where the diploid sporophyte generation is dominant. Mosses reproduce using spores, not seeds and have no flowers.
Since moss gametophytes have no vascular system to transport water through the plant or waterproofing systems to prevent tissue water from evaporating, they must have a damp environment in which to grow, and a surrounding of liquid water to reproduce. Since mosses are autotrophic they require enough sunlight to conduct photosynthesis. Shade tolerance varies by species, just as it does with higher plants. In most areas, mosses grow chiefly in areas of dampness and shade, such as wooded areas and at the edges of streams; but they can grow anywhere in cool damp cloudy climates, and some species are adapted to sunny, seasonally dry areas like alpine rocks or stabilized sand dunes. Since life cycle moss can take couple of months to be stabilise I am using a method of mixing different components in order to accelerate the growth.
Once I take a multispectral photograph of the materials, I am able to post-process the images, compositing the infrared and visible data to generate new images which displays the moss healthy, photosynthet- ically active areas as bright regions. In these case Im using QGIS1 to analize regions but I am working in grasshopper definition to explore new potentital data. Near-infrared photography has been a key tool for planning at the industrial and governmental level: it is used on airplanes and satellites by vineyards, large farms, and even NASA for sophisticated agricultural and ecological assessment.
1. Filter created by Public Lab
2. Code designed by Dr. Agustin Lobo
Near infrared/ Normalized Difference Vegetation Index [NIR/NDVI]
In order to analyse the bio receptibility of the BCS I am using the NIR NIR and NDVI technology to see and detect first evidence of living moss in the ceramics, this will let me know which samples is more suitable for growing the photosynthetic organism in controlled conditions. Using a modified digital camera in these case the Canon A810 by replacing the original filter from the lens and adding a specific blue filter1. This new filter capture near-infrared and blue light in the same image, but in different color channels. Images are processed with a code1 designed in Studio R, a language designed for processing images and Quantum Gis a open source geographic information system.
Conceptual Prototype [CP1]
As a first conceptual prototype, the design is base in two layers of ceramics with different properties. The first layer will be responsible to contain the organisms, in these sense this layer must have high levels of moisture but also a texture geometry that help structurally to avoid possible cracks. Besides of these characteristics this layer is will also contain rockwool.
Second layer is a less porosity ceramic combined with enamel or vanis. This layer is design in order to retain water and responsible to add rigidity to the system. To produce these peace is important to analyse the percentage of contraction when the loose water before and after cocking. Other construction protocols will be tacking account.
Improving NVDI methodology [NIR/NDVI]
The observations through the practice of this method I had show that normalised difference vegetation index can change as a consequence of different factors, as in the final image result. For this reason the protocol was improved in order to get a better image quality. One of the factors that can modify the image and the values is the direction and the amount of direct sun light, for this reason the pictures were taken between 12:00 and 14:00, as well as good weather conditions. To verify these values and to compare this index a black background, a green color (to prove if this color is not producing NDVI) and a healthy sample of moss were also analyzed with the same method.
Reyner Banham states that “Of all the factors involved in environmental management, humidity has, for most of architectural history, been the most pestiferous, subtle, and elusive of control”. By Nature of its microstructure, traditional ceramic material can function as a buffer for both heat and moisture. The intention of the project with this second group of prototypes was to control moisture levels with different porosity levels. The conclusion of the observation of the NVDI pictures was that photosynthetic organism grows progressively in ceramic of G3, unlike G2 and G1 where water absorption is higher, but also dries faster. To measure and understand the moisture levels better the ceramic formula used was from piece 3CL from group 3, not only because it seems to be one of the best samples with better bioreceptibility but also because Chamotte C and Rockwool creates low levels of frangibility compared to the rest.
Multiple Moisture Details [MM-D]
In order to prove and compare the difference in terms of porosity, I’m developing a multiple moisture sensor using an Arduino MEGA controller capable to read data from ten different regions inside of the clay. This measurement will help me to understand better the capacity of water retention and time absorption. Code and projection data is designed in MATLAB.
TEMP/SOUND Buffer [HSB]
While the moss is providing high levels of humidity because the capacity to keep water to survive this will generate a passive heat buffer, where the water will be retain by the three layers in the clay making a natural exchange cycle from the moss to the medium and vice versa. At the same time this levels of density can be test it as a sound and temperature buffers.