9.


Site specific Installation / Residency: Centre for Creative Solutions / Lovinac
2020 Photo Microbial Fuel Cell


My connection to the natural world has always been a very physical and intimate experience. Over the past year, alongside Natalia Gima and Miriam Felici, I have been using technology as a means to learn about this connection in further depth, allowing it to form a part of this intimacy and enhance it.

Through having access to the open-source community I have the ability to research, requestion and visualize many aspects surrounding the concept of plants intelligence, information that otherwise I would not come across without having to meet the right people.

As an audiovisual artist with an interest in the natural world, my perspective has always been slightly naive and poetic regarding the subject of non-human intelligences, allowing me to slip away from my anthropocentric education and envision future possible scenarios.

"The machine is not an IT to be animaled, worshipped and dominated. The machine is us, our processes, an aspect of our embodiment. We can responsible for machines, they do not dominate or threaten us. We are responsible for boundaries, we are they."
- Donna Haraway


During my residency at C4CS, a sustainable-permaculture farm in Lovinac, Croatia, where my closest access to wifi is a 3km bike ride-away, and electricity is available only if the sun is to allow it, I was given the opportunity briefly set aside this easy access to constant information and depend on the knowledge I had stored over the past year to be able to reflect and develop a permanent and sustainable installation, enhancing an experience for both the human and non-human intelligences.

Re-calibrating the equilibrium between the physical and non physical areas of my work process in order to be able create something beneficial for both parts based on the given environment setting was the starting point of what was to come.

I explored this concept surrounded by a permaculture garden for 20 days, where thanks to the biodiversity available through the range of variation found among microorganisms, plants, fungi and animals, the richness of the species of living organisms creates a balance in the environment.

For over a year, throughout my practice whilst developing ephemeral and interactive installations, electricity has always been a fundamental element in every project. Taking forward a now permanent installation without a stable source of electricity was the first challenge I was to overcome. Leading me to begin my research by how I could generate my own flow of electrons, and potentially my own source of electricity.

Here I made a recap of what I had learnt up until now regarding the concept of non-human intelligence to see how to go by this.

Plants can sense your electromagnetic field - Joe Patitucci

Plants have memory and are able adapt to new circumstances - Monica Gagliano

Plants communicate and share resources, even more so with their offspring. - Stephano Mancuso

Plants can hear - University of Missouri - US

Plants can distinguish each other one from another - Monica Gagliano

Plants work as a network - Stephano Mancuso

It was the last statement that stuck with me, as a fundamental part of my own work process, as I previously mentioned, functions as a network with the resources shared online by fellow users. Here I am nurtured and I am able to progress in my research in a similar way a plant will share resources with its surrounding environment and communicate with one another in a beneficial way.

The idea of being enriched by the world wide web where all humans are connected via electricity, consuming our own content and our own dialogue, allowed me to wonder would that occur if plants were also given an electrical via connecting one another, how would they interact with it? Would it allow them to communicate and share resources in different manner? Would it enhance their growth and progress? What would be the outcome?

It was here that I was able to visualize the project I was going to be taking forward: I was going to replicate this self-created cycle, creating an electrical loop generated by a set of interconnected plants and for them.

As I started to investigate on the subject, occurring to the open-source community, I came across a large number of scientific experiments focused on the possibilities of utilizing photosynthesis as a source of electricity, discovering that this mechanism is a sustainable energy source yet to be developed known as Photo Microbial Fuel Energy.

The further I researched, the more questions I had. As an artist trying to break down scientific paper after paper, there is a lot I am not able to understand, not only at a first glance, but after days of reading the same article, which brings me to question, why is all this knowledge so unaccessible, available to only a very niche community? This information could change how we interact with the natural world completely, yet it is reserved for only a few.

"The idea is not the plant, in the same way that the idea I have of you is not actually you, but a simplified, broken down version of you"
- Monica Gagliano

Drawn by the idea of being able to create electricity through photosynthesis, something that any person can do from their own home- given the right materials, set me on my mission to create a Photo Microbial Fuel Cell, and thereby creating the source of electricity by the set of interconnected plants I had previously imagined.

So, how do plants create electricity?

Plants, algae and cyanobacteria, also known as photoautotrophs, are the only organisms capable of performing photosynthesis, a multi-step process in which they can synthesize their own food by generating carbohydrates and oxygen from carbon dioxide, water and light energy.

Photoautotrophs are able to capture the sunlight through a process that takes place in the mesophyll of the leaves, inside the chloroplasts. Chloroplasts contain disc-shaped structures called thylakoids which contain the pigment chlorophyll. Chlorophyll absorbs certain portions of the visible spectrum and captures energy from sunlight.

With the combination of the CO2 and water, the photoautotrophs release Oxygen through the leaves, and Gyceraldehyde-3-phosphate - G3P or GA3P (simple carbohydrate molecules that are high in energy and can subsequently be converted into glucose, sucrose or other sugar molecules) through the roots.

These sugar molecules contain covalent bonds that store energy. Part of this organic matter is used for the plant´s growth, but up to 70% ends up in a soil layer known as rhizosphere where active microorganisms found in soil, lake sediment or compost naturally surround the roots, and break down these bonds as part of their own metabolism, breaking it down into CO2.

In this process electrons are released as waste products. By harnessing and converting the excess electrons produced by the plant during this process and converting them to electricity we create what we call a Photo Microbial Fuel Cell (P-MFC), a device that converts light energy into electrical energy. Unlike a battery that stores electricity through a chemical reaction, a Microbial Fuel Cell produces electricity through biology.

By containing the microbes and their medium in such a way to deprive them of oxygen, we can orientate the electrons to go where we need them to, this is due to the fact oxygen molecules are hungry for electrons, playing a key role in the process. Because these electrons are cut off from direct contact with oxygen they are drawn towards the oxygen like magnets through the path of least resistance.

This is done by placing a proton permeable membrane into the soil, separating our two main areas:

Firstly, we have what we call our anode: An anode is an electrode through which conventional current (positive charge) flows into the device from an external circuit. Our anode in this case will be placed at the root of the plant where our microbes will be releasing protons H+ and electrons E-. It's a very positive sign if the microorganisms grow directly on the anode surface, creating a biofilm, having great potential to improve the system. The electrons will flow into our anode and be transferred via a copper (positive) wire to a power harvester, like a LED light or ideally something that requires small amounts of electricity over large periods of time, whereas the protons diffuse to the cathode, passing through the membrane where they react with oxygen to form water. 

The electron source in the anodic compartment is the main difference between PMFC's (with plant) containing phototropic and MFC (no plant, just soil / compost / etc.)containing heterotrophs. In a PMFC, as the bacteria colony grows, voltage will increase until it reaches its potential, the fuel cell will continue to produce as long as the plant lives, providing more nutrients to the soil, expanding the lifetime of the bacteria. Whereas in an MFC, the  soltage reduction during the evolution is due to the fact that the substrate is depleting and is in need of nutrients to continue producing electricity.

The power harvester connected to our anode is also connected via another cable taking to our second compartment where we have what we call our cathode: A cathode is an electrode through which conventional current flows out of. In this case, the electrons are released at the cathodes surface, drawn back to the oxygen through the wire, where together with protons passing through from the anode side, water is formed.

Here all cycles are closed and electricity is produced without harming the environment or affecting the plants growth in any way, creating a naturally occurring sustainable and renewable process. As can be imagined, the system's electrical peak occurs whilst the plants are performing photosynthesis, especially at mid-day whilst the UV rays are their strongest. The electrical charge can go from 2.9 V (with 5 plants connected) to approximately a total of 1V at midnight, as microorganisms are able to donate electrons to the anode whilst respiring in the dark.

Materials:

The nature of both the anode and cathode material is critical for device efficiency. Material wise, an excellent electrode should have qualities such as high conductivity, low corrodibility, high specific surface area and porosity, suitability for microorganism growth, and low cost. Many carbon-based materials such as carbon paper, activated carbon, carbon cloth, graphite granules and carbon-fiber brushes, have all of these qualities, nowadays they are widely used as MFC electrodes.

An ideal anode is biocompatible and facilitates direct electron transfer from the microorganisms with no need for an electron mediator, it should not prevent light from perfusing through the photosynthetic cells.

The cathode should facilitate the rapid reaction of protons and oxygen to form water so as not to rate limit the device. Ideally the design integrates something called a biocathode, providing a passive oxygen supply. An efficient biocathode promotes electrocatalytic activity and biofilm formation, packed and brush material structures provide high surface area and porosity. Combining different materials improves the surface properties of the biocathode.

PEM: A proton exchange membrane or polymer electrolyte membrane, is a semipermeable membrane generally made from ionomers and designed to conduct protons while acting as an electronic insulator and reactant barrier. It is important we have this membrane in our device dividing our sections, because if not, both electrodes are turned into anodes. As the membrane is the electrolyte, it must be hydrated to work efficiently.

Overall only about 0.1 % of electrons are captured, there is huge potential in using nanotechnology making the device even more efficient. Otherwise, current generation can be increased by increasing the surface area for the bacteria and oxygen reduction reaction. If the exoelectrogenic bacteria can be enriched that would further enhance current generation, providing substrates that are easy for bacteria to break down quickly

First Prototype: No Membrane

Materials: 1 plastic bottle, 1 piece of mesh the size of the diameter of the bottle approximately, aluminium foil, 2 electrode wires, scissors, 1 plant.

1. Cut off the top of a bottle. In my case I used a 6L water bottle.

2. Make aprox. 8 small holes in the base of the bottle for drainage.

3. On the vertical side of the bottle, make a hole 2cm above the base. And 3cm above that hole, make another. These holes are where our cables will be passing through, so bear this in mind when thinking about size.

4. Cut your metal mesh to the size of the bottles base, and fold in at least 1cm each on the side. Connect your first electrode wire and place the mesh covering the base of the bottle. Pass the cable out through the first hole we made on the vertical side of the bottle. I saw a number of examples online using "metal mesh" the metal was never specified, and given the circumstances I used what I could, but if you can use any of the materials mentioned in the cathode description above, i'm sure results will improve.

5. Cover the base with soil until you reach the height of the second hold we made on the vertical side of the bottle.

6. Place a piece of folded aluminium foil over the soil and attach your second wire passing through the second hole. Again, I used what I had at hand, but following the indications above, I'm certain the results will improve.

7.  Place your chosen plants on top, covering both the roots and foil with soil until your reach the top of the bottle. I started working with Milefoie, a plant that grows in abundance here at the permaculture farm I was researching at.  It is for this reason, I tried to plant it with it's permaculture guild, taking into consideration the environment it grows in naturally, but as it grows amongst grass and weeds, it was difficult for them to adapt with the heated weather.

8. Connect both electrodes to your power harvester and leave the plant to adapt to its new surrounding, allowing the microbial to create the energy.

Outcome:
I interconnected 5 plant devices, reaching a máximum of 2.98 V at midday over a period of 7 days. The voltage in each plant began with a range of 0.2 - 0.5 aprox, increasing each day up to 0,5 - 0,9 each plant. Sadly I was not able to light my LED light, so I carried on trying and changing the different variables, coming to discover I had to focus on augmenting the amps.

After a week of adapting the system to improve results, I currently have one plant maintaining the initial set up, with a voltage of 0,48 and 160 microamps aprox.

Second Prototype: Membrane

Materials: 1 plastic bottle, 1 piece of mesh the size of the diameter of the bottle approximately, aluminium foil, 2 electrode wires, scissors, 1 plant, glass wool.

1. Cut off the top of a bottle

2. Make aprox. 8 small holes in the base of the bottle for drainage.

3. On the vertical side of the bottle, make a hole 2cm above the limit to where your stones reach. And 3cm above that hole, make another. These holes are where our cables will be passing through, so bear this in mind when thinking about size. In this prototype I discovered that the closer the anode and cathode are on either side of the membrane, the better.

4. Place a metal mesh covering the base of the bottle with your first electrode wire attached. The cable will come out through the first hole we made on the vertical side of the bottle.

5. Fill bottle with soil until your reach mid way to the height of the second hole we made on the vertical side of the bottle. Place your membrane. I found the materials were very hard to find, but I came across an experiment which used glass wool and took it forward, resulting to be efficient.

6. Place a piece of folded aluminium foil over the membrane and attach your second wire passing through the second hole. I made another prototype evaluating the results with a copper anode instead of aluminum, and the results were notoriously lower, as well as harmful for the roots of the plants.

7. Place your plants on top of the foil and cover with soil until your reach the top of the bottle.

8. Connect both electrodes to a LED light or energy harvester and leave the plant to adapt to its new surrounding, allowing the microorganisms to create electricity.

Outcome:
After a first day of evaluation, each plant has the following results:

Plant 2.1:  0,30V - 65 Micro amps

Plant 2.2: 0,54V - 85 Micro Amps

Plant 2.3: 0,49 V - 180 Micro Amps

Plant 2.4: 0,35 V - 40 Micro Amps

Plant 2.5: 0,40 V - 60 Micro Amps

Following days:

Plants interconnected Day 1: 12pm / 1,57 V - 90 MicroAmps

Plants interconnected Day 2: 12 pm / 2,34 V - 117 Micro Amps

Plants interconnected Day 3: 12 pm / 2,94 V - 180 Micro Amps

After realising that the amount of amps I was receiving from the system was not enough to light my LED due to the materiales I had developed my prototypes with. I made a sonified voltmeter with arduino, modulating the pitch of the piezo buzzer with the electricity made by the plants. The change in voltage / pitch is observed throughout the day as the plants receive sunlight:

Arduino code:

int sensorValue;

int piezo = 12;

int sensorLow = 0;

int sensorHigh = 3;

void setup() {

  Serial.begin(9600);

  pinMode (piezo, OUTPUT);

}
void loop() {

  int sensorValue = analogRead(A0);

  float voltage = sensorValue * (5.0 / 1023.0);

  int buttonState = digitalRead (piezo);

  if (voltage > sensorHigh) digitalWrite (piezo, HIGH);

  else digitalWrite (piezo, LOW);

  int pitch = map(voltage, sensorLow, sensorHigh, 50, 10000);

  delay (200);

  tone (piezo, pitch, 50);

  Serial.println(voltage);

}


As my stay at C4CS comes to ends, I connected an extra anodic cable to each plant as an open ending to the outcome of the possible appropriation and adaptation towards the infinite feedback loop of electricity between the plants in their network. I am curious to see what the outcome will be over the next few weeks as the plants continue to grow in a now electroculture setting nurtured by their own exchange.

I was hoping to be able to source the arduino with the electricity produced by the plants in my time at C4CS, but I wasn't able to due to the materials I was working with. Leaving me to bring the project back with me to Barcelona and continue studying the possibilities of this naturally occurring sustainable and renewable process alongside my colleagues (www.akyute.com).

The overall experience of my residency at C4CS was immensely positive, being able to take the time from my city routine to concentrate and research in depth how photosynthesis and the creation of energy functions in nature whilst surrounded by amazing company in a sustainable environment, is an experience I can't put to words.

Seeing how both Kruno and Lana have developed this project is very inspiring, it is something I would love to take forward in the near future. Being able to disconnect, and live a self-sustainable lifestyle, where food is sourced almost completely from the permaculture garden, and everything is built by hand, is a life changing experience.

Here I have been able to relax and take a deep breath to recalibrate my ideas and priorities as well as meeting an enormous amount of people from completely different backgrounds, alongside comprehending how electricity functions in depth, and I learning how to develop the system for a Microbial Fuel Cell, I leave C4CS with a whole new amount of skills acquired and ready to take forward.






















Mark