DIY Gelatin Solar Cell

Gelatin

Solar Cell Elisabeth Lorenzi & Jeffrey Yoo Warren

December 2020

Los autores Elisabeth Lorenzi I live in Madrid (Spain) and I am interested in research in materials as a reective practice on technology, gender and the environment. By training I am a social anthropologist and textile designer and I have long experience in developing design projects and collaborative prototyping

Jeffrey Yoo Warren I design open source objects, activities, and interactions that re-organize ideas about expertise, identity, equity, and our environment.

I'm interested in how people build identity and strength through their interactions with objects, and the ways that objects can tell stories that people can be part of.

Licencia: CC-BY-SA

Bioplastic Solar Cell

This tutorial shows the steps needed to build a biodegradable solar cell that uses similar principles as “dye-sensitized� solar cells (DSSCs).

Bioplastics are polymers created from materials present in nature and extracted with low social and environmental impact. They are also highly biodegradable. In this recipe we will use gelatin as a base bioplastic to build the layers of the solar cell.

The biodegradable solar cells are build by stacking layers of different materials added to a base mix.

Sunlight induced chemical reactions between the layers, produce the energy.

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Anthocyanin is a natural pigment that is activated by sunlight. You can ďŹ nd it in raspberries, blueberries, cranberries, grapes, red berries, hibiscus, beets, red cabbage ...

You can: - make hibiscus or red cabbage infusion, and use this water to create the basic mix -

squeeze the juice directly from the raspberry, cranberry etc. and add it to the base mix (recommended)

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If you want to make large quantity of solar cells, you have two options: 1.

Make each cell in a different mold (like muffins)

2.

Make a single large mold and then, when it becomes solid, cut it into squares, (like a sponge cake). While cutting the mold with a knife be extremely careful to not mix the layers.

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Make a base mix of bioplastic with two properties: transparency and resistance. In our recipe we will use gelatin, but you can use agar, methylcellulose ... or mix them. The advantage of gelatin is that you control the layering process very well Base mix recipe: G / g Gelatin: 12gr Glycerin: 0.5 gr Hot water: 60 ml While mixing the glycerin with gelatin, slowly add the hot water.

Keep the mixture warm, so it will not solidify before adding the other ingredients.

Afterwards, you will prepare each of the layers, and you can chill them the in the fridge.

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Base mix ingredients: (G / g) Gelatin: 12gr Glycerin: 0.5 gr Hot water: 60 ml While mixing the glycerin with gelatin, slowly add the hot water. Keep the mixture warm, so it will not solidify before adding the other ingredients.

Afterwards, you will prepare each of the layers, and you can chill them the in the fridge.

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Once you have the base mixture, gather the ingredients with which you are going to ‘dope’ each layer: salt, activated carbon, iodine, pigment, titanium dioxide ...

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Assemble the solar cell layer by layer.

It is crucial to keep in mind that the layers should not mix with each other. If they do, the recipe won’t work.

You can try either of the following techniques: 1. When pouring in the first layer, allow it to completely cool and solidify before pouring the next one. Check If the solidifying layer stains the fingertips. If it does, it is not ready yet.

2. Chill all of the layers separately in the fridge. Stack them gently. Try not to mix them while trimming them to the same size. If the layers are mixed the experiment will not work.

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4. Ingredients of each layer (bottom layer ďŹ rst) 1.

Basic mix + salt NaCl (electrode)

2.

Basic mix + activated carbon (cathode)

3.

Basic mix + iodine (electrolite)

4.

Basic mix + pigment****

5.

Basic mix + titanium dioxide TiO2 (anode/semiconductor)

6.

Basic mix + salt NaCl (electrode)

The amount of the doping ingredients are not speciďŹ ed in this tutorial. We recommend making layers with enough to create a full, rich color.

Be careful with layers 1 and 6. Too much salt causes salted waves when it dries, which makes it hard to work with.

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pigmento pegado a titaneo

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ujo de electrones

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The 1st layer is transparent and conductive: the Electrode.

The 2nd layer contains Titanium Dioxide which works as semiconductor. This layer receives the electrons from the 3rd layer, that of the anthocyanin pigment, which reacts to sunlight.

When reacting, it loses electrons, but recovers them through the electrolyte of the 4th layer, containing iodine, from the counter-electrode, which is the 5th layer that contains activated carbon, together with the 6th which is again a transparent and conductive layer.

Sunlight causes the titanium to react with the pigment receiving electrons, initiating the electric current in a cycle.

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Remove the solar cell from the mold and measure its voltage (volts) and intensity (amps) with a multimeter. Stick the probes in the ďŹ rst and last layers.

Check how the multimeter reacts when you turn it on and off the sunlight.

You can get up to 0.8 volts.

Leave the cell in a dry, shaded place. Let it dehydrate completely before using it in sunlight. You will see that when it is dehydrated it will have reduced its original size .

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