The bio-photovoltaic panel consists of a battery in which energy is harvested from bacteria inside the soil to release electrons. Installed at the Valldaura campus of the Institute for advanced architecture of Catalonia, the system has sensors that display its status, as well as make it self sufficient. The bacteria is fed through by-products from the photosynthesis of plants, and by introducing an anode and cathode (battery) into the soil, the free electrons can be extracted and put into the circuit.

Bacteria living in the soil takes these plant nutrients and metabolizes them, releasing hydrogen protons and electrons – the introduction of a microbial fuel cell, anode and cathode means a redox process occurs, transferring the free electons in the soil from anode to cathode. By connecting a circuit with a capacitor or step-down converter into the fuel cell, it is possible to use this source of flow to power appliances or any other electrical device.

Each of the components that form the BPV have certain parameters that may be changed to control the processes and efficiency of the output – the type of plant that grows, whether its edible or decorative, the soil characterístics that enable microbial growth, the type of soil that makes the electron transfer, and the battery’s materials and composition all help to determine the efficiency for the way the electrons are gathered and transferred.

Based on the results of the experiment, the following relationships where found:

1. 100% saturated soil produces the best results since the water in the medium promotes electrolysis within the soil.
2. The closer the anode and cathode are placed the more efficient the electron transfer is.
3. The relationship between the soil volume and the cathode’s area does not grow as volume grows.
4. A triangle container is more efficient.
5. The coil cathode maximizes the surface for the bacteria to gather around, hence it is the most efficient electron collector.
6. All soil types yield similar results, hence have similar bacteria count.

Voltage and amperage were measured in all the experiments, and even though voltage was always present, no amperes were observed. The containers were connected in series to increase the voltage and still there was no amperage. To get amperage, the batteries must be connected to a capacitor or step down converter.

The maximum voltage had to be conserved, while at the same time allowing enough space for the plant’s roots to grow. To achieve both results, a voronoi tessellation was applied, which allowed for the cells to contain the batteries and keep the triangular proportion, while giving the plant more volume to spread it’s roots.

The irrigation system incorporates a voronoi tessellation, making it possible to reach more plant cells (batteries) with only once cell of water. To ensure that all of these were kept at a 100% saturation, a water base was created to connect the plant cells with the water cells via a tube, and also keep the water bed height constant throughout.

Having tested the different components and networks in previous prototypes, the final one incorporates an automation system that controls the irrigation and a data logger to monitor the variables that affect the plant’s growth. A customized design was also developed where the user can create his/her own panel design and send it to be fabricated to the fablab. The fabrication procedure consists of milling the panel in polysteryne and applying coats of ruber and epoxy resin to stiffen and waterproof it. Afterwards, the wiring and electronics are assembled and the soil and moss placed. finally, the finishing is laser cut and glued to the exposed surfaces.

The prototype incorporates the voronoi pattern in three different levels of the leaf – each vary in size, the first one is big and gives rigidity to the piece, the second subdivides the different battery clusters, and the third, the smallest, contains the battery cells. an arduino is powered by the batteries and controls the sensors for the data and water pump of the irrigation. Each panel is 2x1m and 10cm thick made of polystyrene coated in epoxy resin. A wood finishing is applied to give coherence and rigidity to the whole.

The fabrication process starts with the design of the panel and 3D model, which is sent to the milling machine to turn it into a polysteryne panel of 2x1m and 10cm thick – a process that takes 9 hours. When the polysteryne is milled, it can move along to be coated in latex, firstly close to the pores so that less epoxy resin is needed.

After the resin is applied, the circuit is connected with each of the small voronoi cells, containing a galvanized steel wire coil as anode and a copper wire coil as cathode. These are joined in a series with the surrounding the cells. after the irrigation system is applied, the wires and plumbing are sealed on the bottom with a layer of fiber and two epoxy resin coats – adding rigidity to the base, while holding the wires and cables in place. Once everything is sealed and water proofed, the saturated soil is placed to make contact with the anode and cathode. Once the soil is in place, the moss is then planted into it in the different individual cells.

Energy is at the centre of the development of the contemporary urban landscape, however we are facing a situation where the energy structures of these cities are often segregated, hidden from the places of urban life. The bio-technological Prototypes presented aimed to subvert this paradigm of segregation, through the study of morphology, materiality and aesthetic novelty generating the emergent qualities of specific flows of energy and information.

Step 1: Generating a shape for the prototype

Our first design trial was based on experiences we did to increase the effect of a light similar to the light created by bioluminescence. We used for this the liquid found in glowing sticks: a mix of Phenyl oxalate and fluorescent dye solution that react when in contact with Hydrogen peroxide solution.

Experience 1          Experience 2     Experience 3

In glass                       With water        With mirror

The presence of mirrors and water around the source of light increases its effect. We therefore decided to create a double recipient in Plexiglas, the inner part would contain the bacteria, and the outer part water surrounding the source of light, as well as mirrors on the back side as to increase its effect, the angular shape was based on an hexagon.

A section of the prototype

In order to implement the prototype in Valldaura, we took a cropped satellite image of the site and extracted a gradient image from it:

The distribution of these hexagons represents the density of the trees it also corresponds to the way each prototype is placed on site.

Problems related to this trial:

We could not justify the choice of this shape for the volume, more than an intentional design decision; this choice was more based on the available icosahedron in the programs.

The design did not take into account the different functional needs, necessary to maintain the bacteria alive and glowing: the nutrients, the conditions etc..

Step 2 Design of a system based on functional need

In order to create a system that would maintain the bacteria alive, and ideally be self-sufficient, we studied in details the different needs necessary to maintain the bacteria alive and glowing.

The functional needs

The Vibrio Fischeri can live in both a gel agar or in liquid salty water. It also needs to get continuous input of nutrient, but also of oxygen, and in order for the oxygen to reach the bottom, the liquid or agar need to be stirred.

We ideally would like to have some kind of interaction between the users and the bioluminescent installation. We still are researching to know if compost material resulting from the user food waste could be a good source of nutrient for the bacteria.

If this is the case, the methane generated by the compost can be directed into the agar or bacterial liquid, it will form bubbles that will provoke movements and will thus allow the oxygen to penetrate the bacterial environment.

These different components, if put in different units, need to communicate:

1-Compost can be source of nutrients for the bacteria; the compost will be situated higher than the agar unit as to have the resulted juice continuously going down by gravity to fill the agar unit.

2- The agar unit is then connected to the bacteria unit and linked to inner skin through pipes which opening can be controlled from outside.

3- The methane unit is also connected to inner bacteria unit through continuously opened pipes. When methane enters the bacterial liquid it transforms into bubbles that agitate the liquid and thus allow regeneration of oxygen and agar inside the bacterial liquid.

4- The bacteria unit is double skinned as to give some temperature insulation to the bacterial liquid which is contained in an opaque recipient. Holes in this skin allow the oxygen to enter the recipient and fiber optics to go out of it and transmit the light.

These different connections require a shape that can be tessellated.

The following diagram shows how each 4 functional units form one whole unit, and how those units tessellate:

At a theory level, the organization and function of this system are successful and present a credible draft for a more high tech installation.

Future development concerning the functions:

However, in order to achieve a fully self-sufficient system the units would need to improve as following:

1-Compost would need to be under UV light in order to be sterilized and not contaminate the vibrio Fischeri culture.

2- The agar unit would have to be linked to measuring tools in order to control the needed quantity and balance of the ingredients and extract the extra quantity of ingredients

3- The methane if directly introduced into the bacterial liquid will displace the oxygen which is not ideal for the bacteria which is aerobic and needs oxygen to live.

Rather, the methane can be burned in this unit and serve as energy supply to power an air bubbler that would be connected to the bacterial unit.

Implementation on site and shape design

We were inspired by the ruins site in Valldaura

The evanescence quality of bioluminescence seemed to connect with the feeling of nostalgia that such a site can provoke.

The parallelism between old and solid stones scattered all around and a lighter installation was also inspirational to us.

This site also represents a potential public area where people could picnic and spend some time. It is an opportunity to establish an interaction between the users and the installation. The users would throw their waste in the compost unit, which will feed the bacteria that in return could be maintained alive and glow.

The revival of that place and the life of the bacteria become intertwined.

In order to anchor the installation on the site, we used the 123d catch autodesk program to construct the mesh of an existing surface constituted of stones and vegetation.

From this mesh we extracted a surface on which we applied a hexagonal grid, and created our installation by applying a grasshopper definition that transforms this grid into volumes.

From these volumes we extracted one unit and applied on it contour lines in order to fabricate it with the laser cut.

The problems we encountered with this prototype are the following:

-The scale was too big for one unit and seemed bulky

- The design of this unit did not help in the development of connections with the neighboring units

- The material (Plexiglas) was too expensive

Step 3 Reducing the hexagonal grid

The second trial in the design development consisted of reducing the size of the grid, to obtain smaller units.

Also, instead of using the contour function for the fabrication of the unit, we rather unfold it for the laser cut.

The problems that arose from this method are the following:

-The material (Plexiglas) and method of fabrication were incompatible; we could not fold the plexiglas without breaking it, it was also impossible to make the unit waterproof.

-The connections between the different units were still not easy to figure out

Step 4  Changing the material and fixing the connection

We changed the material from plexiglas to polypropylene.

After some research, we confirmed that his material is compatible with both the methane and the compost.

This material turned out to be much more compatible with the folding method of assemblage.  We extracted 4 units from the whole installation to start with:

We separated the sides, bottom, and top in rhino and added a tabbing to the different sides through a grasshopper definition.

These tabbings  allowed us to assemble each unit and the different units with one another. We did that using punch pliers and eyelets.

We still need to try closing the compost units with magnets, to be able to open, and have it well sealed when closed.

The holes in the bacteria unit, that allow the oxygen to enter the bacterial liquid and the optic fibers to stick to the outside, follow the patterns that represent a bio-luminescent cell.

Our intention by choosing these patterns is to give a hint on the nature of bioluminescence by revealing what could not be seen but through a microscope.

We projected the patterns on the whole installation prior to the unfolding of the different units.

We would like to thank Dr. Silvia Bures for the help she provided us with, and her contact Dr. Peters for his time and information and  Luis Fraguada for his availability.

GreyLess designers hiked to Valldaura for a pre-installation site visit to determine an ideal location to place the phytodepuration system. The ideal location would be adjacent to: crops that need to be irrigated, water tank, and visible from the house. After the site visit we acquired more information about the tanks that can be accessed. Currently, two rain water basins about 2 meters from the back end of house provide the house with clean water. Farther into the forest resides a black and gray water tank that are combined and unaccessable. In the future, the residents of Valldaura plan to separate black and grey water tanks. For this installation we will use the existing water tank to simulate grey water that will flow through our system.

Final Form:
The 4th prototype was a single, linear form incorporating the slow sand filter, algae slide within the high and low pools to create one coherent system. Arriving to our final form, we depart from the single slope design we have used in our past prototypes to developing it in section, giving us a more refined geometry to optimize the water vectors as they flow through the system. In the past each prototype was developed based on discrete paramaters and developments and changes in those parameters. In this prototype we will fully integrate all of the lessons learned from previous prototypes as well as the full scope of parameters into eachother.

[Image below depicts the mapping of parameters for the final prototype, prior to integration and site strategy.]

Parameters:
Post Midterm Review, we stepped back from the prototype to analyze which parameters were successful, need to be improved, and new parameters to be implemented.

What was successfull?
-Increase surface area for hosting biofilm: after extracting contour lines from the digital model surface, the contours of each tooth are distorted from each other by increasing the apex point offset from the centerline of the tooth.

What needs to be improved?
-Using diameter of the teeth to replicate effective aggregate size instead of depending on the Venturi effect to drive the perimeter of the flumes.

-Improve entrance/exit curve oscillation in perimeter of the flumes in order to get the water to reach the outer extents of the slide. This will be done by developing each flume in section.

-Ensure that the profiles of the final contouring of the form doesn’t negatively effect the water pathways.

-Centerline of the water flow in each row needs to be offset from those of the row before and after instead of being aligned. In the upcoming prototype enhanced by using curved interruption vector lines rather than straight lines, this is something we did in the 2nd prototype, and want to re-incorporate in our new form.

New Parameters:
modular structure strategy
water flow vectors superimposed with interruption (curved) vectors as was done in our 2nd prototype.

-Arduino Outputs

Output Ranges:
Converting outputs in ardruino code to get the numerical data in a form we can translate to a projection. In order to do this, we will send the arduino translations to grasshopper via firefly where we will use the data to manipulate the geometry of the water flow vectors for the projection data visualization before being visualized in processing.

Water cells are optimized for water distribution to plant cells.

This was the idea that drove further prototypes to be tessellated by Voronoi with subsequent modification in terms of shape, height variation, tiling, etc. As these prototypes where developed though, the impracticality of this irrigation system in vertical surfaces became evident. The system works well by creating a water bed all with the same level around the water cell yet, when placed vertical, the level of this water bed turned and so neither all plant cells where receiving water nor did it keep the proper water level for those it did.

Water level distribution horizontal and vertical.

Hence, this irrigation system was discarded and substituted by a drip irrigation system powered by a submergible water pump and a tube running along the cells to water them. By substituting the water system, the Voronoi tessellation of the surface was rendered useless since there is no other aspect of it that is beneficial for the system. This freed the design consideration and opened up new possibilities for the prototype. The first being the tessellation method, the surface could be subdivided in ways that are more beneficial to the plants themselves. Second, the rigidity of the system, the surface doesn’t need to have fixed stiff walls to contain the water. Finally, the new irrigation system allows for free flowing tubes to extend through a surface which allows surface flexibility rather than achieving the height difference by making the walls higher or lower. The idea then is to transfer a generic surface with photovoltaic panels into any surface, independent of the shape.

Taking a generic surface to a modified surface

To find the surface to apply the generic surface to, the first step was to find the location in Valldaura. The site that was selected contains four trees to develop a cable surface in between them with which the path that goes undernearth will be covered.

After this, the site was recreated in Rhino and four cables connected in between the four trees. A mesh is created in between this cables and a grasshopper/kangaroo scrip is run to simulate the gravity affecting it.

Once the mesh is simulated, it is tesellated in a inner polygon subdivision which gave us inner cells in between the “cables” of the mesh. This inner cells are the ones to become the photovoltaic panels. After having this, through a weaverbird/grasshopper definition, the cells where inserted.

Modeled terrain and gravity mesh

The fabrication process will be done by milling the mold of the individual cells and casting it in pigmented rubber due to its flexibility and water resistance. It will be suspended by tension steel cables and raised into position.

Design Approach

An interactive water diversion system, linking Valldaura’s plants and residents to its grey water.  The interactive system will, via the GreyLess App, allow users to make decisions based on real information of their plants soil humidity levels.  The model will also be used as a screen to project live data on the soil conditions.  Combining experiments, research, and lessons learned from previous prototypes, the GreyLess system is ready to clean grey water and turn it into irrigation water.

Prototype

The midterm Greyless prototype is a 1:1 object scaled phyto-depuration system ideal for low volumes of water.  This is a formal version of a slow sand filter, maximizing surface area for future bio-film (algae) build up and aeration two things that are critical when cleaning water.  The GreyLess system will communicate the needs of Valldaura’s plants using a wifi application available to residents and guests as well as creating energy.

The 4th prototype is made up of  a high and low pool with a algae slide in between.

The high pool is a mixing and circulating pool.  The high pool is attached to the algae tank where algae is exposed to light and photosynthesis allows it to grow.  Once this water enters the high pool the algae-grey water slowly circulate and the mixture is evenly distributed as biofilms are deposited on the pools teeth, before flowing down the slide and into the settling pond.

The GreyLess system works similar to a sand filter, as water passes through the system it travels through various sized sand particles.  This change in size of the sand particles as well as the change in water flow and pressure drove our design for the algae slide walls.  The algae slide connects the two pools, accelerating water, creating turbulence while orthogonal tooth tessellations interrupt water flows creating more oxygenated water.  Within the algae slide there are 4 flumes, these are oxygenating forms that boost water aeration as it flows through each pond.  The flume form has been designed to mimic venturi tunnels, where pressure changes as water flows from higher speeds to lower speeds through constricted areas.  The 4 flumes each have gradual water flow entrance and a sharp more orthagonal water flow exit with protruding teeth to break up the water vectors.    The first flume’s teeth are exaggerated, heightened, and reed-like in order to catch debris before it goes through the rest of the slide and flows to the settling pool.

The settling pool is an essential step for cleaning water.  The algae-water needs about 2 hours to separate before the now clean water can put into the irrigation system and the algae can be recycled back into the algae tank.

A Phytodepuration system cleans water.  Hydroelectric generation is one of the “greenest” energy alternatives will create a more dynamic system.  Using graphite, we installed 3 separate anodes and cathodes at different locations to produce energy as water flows through the system.  These pairs protrude similar to the vector interrupting teeth as seen throughout the rest of the prototype.  In the future the energy collected will be used to power a motor to mix algae within the algae tank.

Projection

A 2D animation will be projected on our GreyLess system showing a map of vectors representing the water flow through the slide.  The projection will help the residents of Valldaura understand what is going on within the system.  From the 2D animation the users will see: 1) The flow through the system, 2)Water Levels in the Grey and Rain water tanks, 3) Soil Humidity Levels; low water levels = agitated lines and 4) Water is present on slide.  The users will be able to understand all of this information and view actual data using the application, but over time, they will also be able to understand the system using the projection.

https://vimeo.com/80735582

Application

Connecting a phytodepuration system to Valldaura residents.  First, water diversion: GreyLessconverts existing grey water to irrigation water through an interactive system connecting the house and its residents to the plant network.  The app will facilitate the re-scheduling of occupants habits  through learning about the system.  Next, because of the re-allocation of grey water as well as the users schedule optimization, the irrigation system does not need exterior sources of water or water from rain water tanks.  Through the use of this system, users can better plan for the future, not only can their actions can adjust due to the needs of the plant network, but changes and/or additions to the plan network can be incorporated easily.

]]> http://legacy.iaacblog.com/maa2013-2014-when-energy-becomes-form/2013/12/bio-photovoltaics-midterm/feed/ 0 http://legacy.iaacblog.com/maa2013-2014-when-energy-becomes-form/2013/11/hygroscopic-morphology/ http://legacy.iaacblog.com/maa2013-2014-when-energy-becomes-form/2013/11/hygroscopic-morphology/#comments Fri, 29 Nov 2013 15:08:52 +0000 Karl Francalanza http://legacy.iaacblog.com/maa2013-2014-when-energy-becomes-form/?p=3207

Within this architectural context, hygroscopic morphology is defined by the study of forms made from materials that tend to absorb moisture from air. The goal is to produce kinetic energy by nature itself, without any artificial mechanical assistance.The proposal seeked to celebrate the hygroscopic behavior of wood, particularly wood veneer, composed of wood fibre in one direction.

We seeked alternative ways to eliminate absorption from both sides, mainly through plastics and wood varnish. Experiments showed that water particles were being retained on plastic. We started questioning if we could collect these water particles, and began to explore the idea of a passive water collecting systems.

Our testing showed that water particles expand the exposed fibres of the wood, causing bending and warping into the opposite side. If wood is wet from both sides, no deformation appears.

During our first visit to the site, we found ourselves in the middle of a thick mist. The phenomenon seems to be common in the area, as the mountains and hills around gather large amounts of humidity when the sun is absent. Humidity in its usual form, as well as in the form of fog and rain is the “machine” that provides the kinetic energy we are called to use. But rain and fog are also water. Pure water, in fact, that can be consumed after minimal purification procedures. It can also be collected and stored. Some hygroscopic materials are able to trap the water droplets of rain on their fibrous structure. In fact, installations of simple mesh materials have been used successfully on this purpose in many cases. So, hygroscopic morphology is much more than the kinetic energy produced by specific materials like wood.

We decided to focus on combining these two hygroscopic behaviors and creating some kind of mechanism that would be able to collect water. A kinetic water collector that would adapt to the humidity conditions by changing its shape.

Final Prototype in Valdaura Labs