#6. Biomaterials

##Results and conclusions

This week, we cooked and cast gelatin-based bioresin, biofoil and biofoam, and agar-based biofoil, as well as gelatin/agar-based biofoil. Using a variation of color additives and fillers (rice starch, wheat starch, tapioca, ground egg shells)

We prepared alginate plastic that we cured with calcium chloride, and lastly we grew some mycelium that we hope to cure and dry into fake leather (not vegan though!).

![](../images/)

*Conclusions:*

* Making/growing materials is not like making instant soup. It takes a good amount of time and each period or gesture requires dedication, due consideration, and careful observation (I found out after the fact, unfortunately).
* Time is like a box of chocolates: you never know what you're going to get or: how my voluptuous, satisfying blobs turned into dry wrinkled raisins (with some exceptions!)
* Making materials is a very sensual and satisfying, yet stinky experience. And then everything starts to shrink.
* I am now known as the left-over queen (and couldn't cast a bioplastic sheet to save my life)
* Biofoam with egg filler was my best surprise move this week
* Making a bioplastic bottle appear out of an erlenmeyer bottle is a pretty good party trick
* Forget cookies and cream: *cabbage & cream* is the word
* Blue is still the warmest color.

##Context and biomaterials basics

This paragraph is a mix of lecture notes from the [lecture by Cecilia Raspanti, slides and info here](https://class.textile-academy.org/classes/week04AAA/) and my own reflections.

###The Plastic Issue
How long does your product need to function? Let the material follow function. A throw-away cup does not need to live longer than 45 minutes, why is it made of a material that takes forever to break down?

"Plastic is a substance the earth cannot digest." The 8 issues with plastics:

>1. It never goes away
1. Its breakdown pollutes ground water
1. Threatens wildlife
1. Poisons our food chains
1. Affects human health
1. Attracts other pollutants
1. Piles up in the environment
1. Costs billions to abate

Source: www.plasticpollutioncoalition.org

So what we need are good alternatives. What I notice this week is that it's not easy to make or grow a material that lets itself be controlled easily. You can kind of see how plastic got very popular, you can quite literally bend it to your will, so when working with a design or engineering mindset, this is a pretty docile material. There's real urgency to developing techniques that allow us to use bio-based materials for a range of applications that also have aesthetic value. It seems like it's also still pretty experimental and/or relatively unknown amongst designers and industrial engineers. On the other hand, we can also learn to love the resistance of the materials we are trying to lead. Some will follow, others won't but this can have a beauty of its own we might start to be able to recognize (again). And maybe that will even make us realize how precious plastic really is.

First things first though, some definitions:

1. *Bio-based* materials: They are made of organic or inorganic materials. Are they biological? Then they are bio-based.

2. *Bio-degradable* materials: Can they be broken down by microbes under specific conditions that we - humans - create?

3. *Bio-compostable* materials: Can they be composted *within* 180 days?

There are different ways of categorizing: by what they imitate (leather, plastics etc), or by how they are made. You can also categorize them under RAW ingredients and MADE materials.

###Not new media, people
ALL of these are heritage techniques, they were used long before we started making plastics (polymers). Credit always, and be specific about your modifications and local specifity of the conditions under which you are cooking the materials, or specificity of your local ingredients. Room temperature in Amsterdam and New Delhi are not the same. Also tap water may or not have a neutral PH value, can be alkaline, which can breakdown some materials but not others.

###\#backtoschool: What is plastic?

Basis is of plastic is always a **polymer** with then added:
* plasticizer (for flexibility)
* filler (to avoid shrinkage)
* stiffener (e.g. fibers to structure and reinforce)
* expanding agent (to create foams)
* color/pigment (to modify color)

###Processes that can be used in combo with plastic

It's versatile.

* Machine it and assemble it
* Glue by polimerisation
* Stitch together later
* Casting or machining
* Manual or machine cutting
* Milling, drilling, turning
* Heat shaping
* Impressing 3D patterns
* Casting, mould casting
* Profiles tubes, rods
* Digital extrusion
* 3D mould

###Basics for bio-based & bio-degradable materials
We want stuff that is bio-based AND bio-degradable but ideally also bio-compostable (within 180 days).

Gelatine, agar, alginate, casein, cellulose, chitine or starch based plastics are a good start. These are the polymer replacements. Then we look for alternatives to modify the properties of the bioplastic, such as:

* Glycerine = plasticizer
* Egg shells, chalk = avoid shrinkage
* Fibers and natural debris = stiffeners
* Green soaps = expander (foaming)
* Natural dyes & pigments (like we did in biochrome week!)
* etc. etc.

Each have their own properties that can often be seen as both pros and cons.

####Documenting
* Tools
* Ingredients
* Procedure
* Properties

##Gelatine Plastics

The gelatine plastics will shrink a bit. More water means more shrinking. Additives might help. Gelatine bio foil and bio resin are strong but sensitive to heat. Gelatine silicon is super stretchy and totally compostable.

###Transparent/opaque bioresin and biosilicon: using cabbage as colorant

**Basic bioresin Recipe:**

* 48g gelatin powder
* 8g glycerine
* 240 ml water

Mix all ingredients at 60 degrees until smooth, then boil at 100 degrees for 5-10 mins, until it's like a syrup. This will make it harder but more brittle.

**Basic biosilicone Recipe**

* 48g gelatin powder
* 24g glycerine
* 240 ml water

Bring water to the boil. Add glycerine while stirring slowly, add gelatine. Gently mix, to avoid bubbles. Simmer for 15-20 mins at max 86 degrees (our stoves tend to be lower than the display suggests, so go a bit higher or use a thermometer). Let it thicken into syrup-like consistency.

*Additives:*

* Natural abbage ink (ethanol-based, neutral, modified with vinegar and modified with soda), and played with additional PH modifiers citric acid powder and soda ash that I sprinkled on top.
* Coffee cream to make mixture opaque.

I made 6 separate mixing bowls. I added coffee cream (a teaspoon) half the bowls to make them opaque, the rest would stay transparent, then I added the purple, pink and turqoise colorant. The blue/green one is the bioresin.

*Casting and releasing*
I cast both recipes into the lids of petri dishes and dried them while turning every now and then.

I released them from the mold when they cured a little bit. The acidic pink one was a lot harder to release, it remained snotty and wet, especially where I'd sprinkled the citric acid, it tore a little.

I kept a few pressed under a petri dish with weight on it to try keep them flat. These kept their form quite well, but some were a bit hard to release. The PH modifier gave interesting results and pretty much kept working as long as the plastic was still wet. The soda had more effects than the citric acid though, the pink faded very quickly.

**Shrinkage and deformation**

*Biosilicone*: it took quite some days to dry, and probably took even longer because I kept them pressed underneath some heavy books, probably the water couldn't evaporate so well. Apparently this is also how they tend to get moldy. These casts shrank about 25% without deforming much, compared to the foam and alginate experiments. They stayed relatively flat. I thought they'd cured enough after 3 days, but the baking paper I kept the samples between after the first days (when I pressed them under books) left an imprint, probably better to press between entirely smooth surfaces.

*Bioresin:* also took a long time to dry and was still going after 5 days. At this point it was already a bit firmer and had slightly more tendency to curl up. These shrank about 20% up to now (so less than the silicone).

**Texture and feeling**

Still cold and rubbery (after 5 days) the bioresin a bit more rigid but rubbery still. Let's see what happens in the next week. These have a nice bouncy elasticity.

The bioresin has a bit of texture: the soda ash I sprinkled on top immediately made a chemical reaction and started foaming a bit.

**Color changes**

The natural dye faded quite a lot in terms of saturation and definition: it became more "blurry" and less saturated. Still lovely pastels I think. Also the difference between the opaque casts (with the coffee cream) turned a little more transparent so the difference was not so big, in the end they looked alike quite a lot. The pink acidic ink lost a lot of color.

###Gelatine-based biofoam with acrylic paint and food coloring

**Basic biofoam recipe:**

* 48g gelatine powder
* 12g glycerine
* 240 ml water
* 10 ml soap (we used LIDL dishwashing soap)
* Additives: acrylic paints (blues) and food colorant (red) for coloring

Bring water to the boil, add ingredients until dissolved. Then add a squeeze of soap and make it foam with a whisk. Keep whisking at max 68 degrees for 15-20 mins.

The foam was probably left too long before pouring so it started separating. One layer of foam and one layer of jelly. It was nice to play with and make shapes. The colors are very bright with these synthetic paints. The back was even more beautiful than the top: glossy and nice marmoring in the colors.

![](../imgs/)

**Casting and releasing**

I mostly cast into petri dishes again, but also kept the left overs from the mixing pots (the smaller, thicker ones). I released the casts from the petri dishes as soon as they would let go from the sides when pulled a little so they would not get stuck. I released the mixing pots at the end of the day, some still had stirring sticks in them so they have some damage. I did not plan this :)

**Color behaviors**

You can see quite well that the pigment had time to sink to the bottom in the mixing pot. Because there was more in it, it cured less fast, allowing the pigment to move a little longer. The colors are very deep and dark. You can see the speckles of pigment in most of them.

![](../imgs/)*Here you can see the difference between the mixing pot casts and the petri dish casts, Loes Bogers, 2019*

The thickness of the mixture even before curing allows you to create really nice shapes that blur together really nicely, especially when seen from the back where it also got a glossy jelly layer. It reminded me of planets and the galaxy ;)

![](../imgs/)*Front/back view from some biofoam samples where I played with shapes*

**Shrinkage: 20-35%**

When drying, *some* of these morphed a lot, curling up at the sides and getting a slightly dried out look. All samples shrank in thickness and size. What I don't understand completely is why they shrank different amounts, and why some stayed flat and other curled a lot.

The red sample colored with food coloring shrank less than the ones with acrylic paint. Interestingly, there was *one* that kept its shape really well so I was able to measure the exact amount of shrinkage. This was one that had a pretty even mix between red and blues poured in dots across the surface. Perhaps the reason why it behaved differently? When I noticed this one had not gotten rigid and curly like the other ones, started to press it underneath heavy books to keep it flat for the rest of the curing process (below).

The food coloring in the foam did not leave stains (unlike the other places I've used it later on....)

**Texture and feeling**

The thicker foam buds (from the mixing pots) feel squishy and soft. The thinner samples got more rigid, much less squishy but still a bit flexible.

![](../imgs/)

###Gelatine-based biosilocone

###Potluck gelatine-based foam with and without egg shell filler

You can keep adding liquid and heat and keep manipulating gelatine-based plastics (it's not heat- or waterproof), so we made a potluck gelatine left-over pot. It turned out to be very foamy so there was probably a good amount of foam leftovers in.

**Casting and releasing**
I cast into petri dishes. The thinner samples both with and without egg shells were rather hard to release. They need longer or they get a bit damaged in handling (which happened to the plain foam one). The thicker one came out pretty soon and pretty easily.

Damaging the foam a little might be a factor in keeping it a little more flat though. It breaks the integrity of the surface so perhaps releases some tension when the material starts shrinking. That's my hypothesis anyway.

**Shrinkage without filler**

I cast one in a petri dish that got wrinkly but otherwise stayed very nice and soft but shrank quite a bit (35%)

**Less shrinkage with egg shells as filler**

To the other part I added dried and powdered egg shells as a filler (36 gr of eggshell powder to 100 gr foam), which turned into a lovely fluffy lightweight brick-like texture with little shrinkage (10%). It turned a bit harder after curing a few days.

**Texture and feeling**

The thinner sample is a bit more rigid and brittle but flexible. It feels a bit like the flooring sometimes found in outside playgrounds: strong but a bit bouncy. Thee surface feels a bit like sanding paper.

The thicker sample feels more squishy and foamy, the egg shells feel a bit like the surface of a brick. So like a squishy foamy brick perhaps? I need more words here...

Because this was a potluck recipe it's unclear what does what. But adding egg shells to biofoam results in material that is firm yet soft, maybe something to apply in toys or furniture?

![](../images)

##Biofoils

###Agar biofoil

**Basic agar biofoil recipe:**

* 4g agar powder
* 3g glycerine
* 400ml water

Warm up the water, add the glycerine, then the agar. Mix gently. If the agar doesn't dissolve add some heat (up to 80 degrees). Our cooker doesn't reach that temperature so I went up and down a bit so it would boil down into a syrup-like texture. This stays very liquid so i also played with some stiffeners.

**Additives used:**

* colorants: alkanet ink (gray samples)
* filler/stiffener: (raw) rice flour, (raw) wheat flour, (raw) tapioca.

**Casting and releasing**

I cast samples onto textured synthetic surfaces (which totally disappeared in the curing process) and poured some into petri dishes. It stays cold and rubbery for quite a while when you can still release it very easily. I left it to dry on baking paper.

**Color behavior**
The alkanet turns gray but stays the same throughout.

**Shrinkage/deformation**
Wow, these just turned into coral pretty much. The thinner samples shrank a lot in thickness and size and deformed into wicked seacreatures. Thicker casts kept their shape a lot better: the thicker round one with the big bubbles was left in a mixing pot and then released, it shrank since then but didn't deform. I did not cast in petri dishes so cannot measure well how much the shrank.

**Notes on the stiffeners: raw or cooked, pre-mixed or thrown right in**

Rice flour and tapioca can be mixed into the recipe raw and they will dissolve without further cooking. Dissolve it into a mixing pot using a little bit of liquid before pouring the rest of the liquid in. Otherwise for sure it will get lumpy (like you would when cooking with starches to make a sauce for example).

I forgot to do this when using the wheat flour and got huge lumps. I thought it was a total fail but actually turned into a wonderful blistery textured surface that I released from the mixing pot and treasured anyway.

The raw rice flour made the mixture thicker and easier to pour without making elaborate frames, but also shrank loads. This could be because of the rice flour, or because I poured it out onto a bigger surface, and a bit thinner, I'm not sure.

We also made a leftover pot with tapioca that we mixed into the recipe and then continued cooking a little longer so the tapioca was no longer raw. We added some natural inks that we didn't mix and Bela and I had a glorious pouring experience in purple. The next day it turned a light blue. It's now partially rock solid and partically sticky, so it's still curing...

**Texture and feeling**

Thicker ones are still moist and cold, squishy/rubbery. The thinly casted foils with rice flour are rigid, and pretty brittle, whilst still a little flexible.

###Agar/gelatin biofoil

**Basic agar biofoil recipe:**

* 4g agar powder
* 3g glycerine
* 400ml water
* colorants used: food coloring (turqoise/blue),
* fillers/stiffeners: raw rice flour, raw tapioca.

**Casting and releasing**

I cast these two mixtures onto textured synthetic surface (a table cover I think). Which made a beautiful imprint and released really well relatively quickly. I think the gelatin/agar mix is easier to pour.

**Shrinkage and deformation**

I left these to dry after releasing them from the surface. They curled and shrank so much! I could try some different variations in the drying process here to see what else it can do.

The imprint shrank with it but it kept its definition (unlike the agar foil with rice flour, which was much less present after drying.

**Texture and feeling**

Brittle and rigid, very little flexibility. The tapioca sample dried a lot slower, but is also surprisingly strong. I can break the rice flour sample easily but the tapioca one is a tough cookie!

##Alginate Plastics

##Growing Mycelium

###Algae inspiration

Eric Klarenbeek & Maartje Dros - Algae plastic 3D print filament

Austeja Platukyte - Foodsafe Algae packaging (fully compostable)

Amam - Bioplastics and agar packaging (90% of plastics are packaging)

Margarita Follert - Alginate top, packaging in natural colors

Carolyn Raff - agar beads: casted, cut and used for embroidery. She also makes amazing textures and patterns.

Jasmine Linington - alginate sequins (somewhat waterproof, but not soapproof, soap tends to be too alkaline).

Stephanie Santos - agar composite and gold leaf. She used bioplastics as glue instead of sewn seams.

Catherine Euale - alginate top, lasercut.

###Gelatine inspiration

Miriam Ribul - bioplastics, check out her [issuu book!](https://issuu.com/miriamribul/docs/miriam_ribul_recipes_for_material_a/7)

Juliette Pepin - amazing analysis of different bioplastics. Nice description and comparisons between the materials. Check out her documentation [here](https://issuu.com/juliettepepin/docs/bookletbioplastic)

Aagje Hoekstra - Coleoptera (insect shells and bioplastics)

Mayan Pesach - Food waste mixed with gelatin, creating beautiful colors!

Textile Lab Amsterdam - Material archive

Maria Viftrup - gradient going from bio-silicon to bio-resin. To study how materials react to one another where they meet.

Maria Viftrup - dye your plastics with bacterial dye!

Tessa & Maria @Textile Lab Amsterda - Fish scale plastics: food waste, fish skin, scales, bones and pigments. Super durable.

Clara Davis - Laser cut bags and booklet made with modular stitches, no seams. Also made a booklet!

Great Dalessandro - bioplastic dress that changes over time, based on the lifespan of each material. Fades and decomposes layer by layer.

###Questions and tips:

* How do you avoid mold?
It depends a lot on the moisture in the air in the environment where you work. If you work in a dry room you experience this less. The amount of water in the recipe is also a factor. Less water will dry faster so less chance for mold growing, but also harder to cast.
* Use everything the same to replicate the same environment, down to the spoon you use to stir the pot :)
* There are no mistakes, look at the mistake with love and discover a new application for it. Someone will be looking for exactly that.

##New leathers

###Microbial leather: kombucha
A fermented tea drink. A symbiotic colony of bacterial yeast (SCOBY), it feeds on the sugars and tea to create layers of cellulose that can be dried up. Treated with different techniques and recipes. Results sit somewhere between leather and paper. There are many different strings of these, they are microbial so they behave similarly but there are also variations in how they behave.

The bacteria turn the environment acidic very quickly but some experiment with adding vinegar. [THR34D5](https://thr34d5.org/research/) has interesting recipes and methods for after-treatments.

Kombucha is sensitive to humidity and water. It laser cuts beautifully. You can easily stitch it wiht sewing machine, dye it with any acidic dye. Lots of pinks and reds! Alkaline dyes don't work so well, ut you can use it with pigments just before drying it.

It smells a bit like honey and vinegar mixed. Things get stinky when you grow big pieces. It grows between 25-30 degrees Celcius best and quickest.

####Kombucha inspiration!

Suzanne Lee - Microbial Leather 3D moulded top and jackets. GORGEOUS! Stamped patterns with bio-inks. So nice.

Kwasaki Kazuya - kombucha mixed with digital fabrication. Created a jacket, 3D scanned it, CNC'd a mold and grew kombuha on top of it, for it to grow in the 3D shape directly. Whoa!

Moya Hoke - Green tea kombucha suit. She made a molding tray in the shape of a suit! Hilarious. Haha. Made of *coated* metal, would not work in uncoated metal.

Sammy Jobbins - lasercut structure.

Zionium - green and black tea wallet. Semitransparent so you can see within your wallet! Lovely contrast stitching, really looks and feels like leather. But if you stitch this, moisture can access the material. Hmmm.

Emma van der Leest - kombucha and pigments bag for Biocouture London. Laser cut and laser engraved, speckled with powdered pigments to color the surface before drying.

Emma Sicher - kombuch and food waste, e.g. little sugar bags.

Barbara Arteaga - Kombucher: electrospinning machine, to spin cellulose from kombucha instead of growing it in layers.

###Fish skin leather (spoiler alert: not an innovation)

The Inuits have been working with this forever. Hundreds of years of experiments with local materials happening there. Boom. Be aware of your surroundings, see what is already easily found around you.

Maria Hees - carp leather dyed and naturally tanned. Tanning chemicals tend to be very polluting. Can be done with tea, bark and nuts or tara pulver, whatever contains large amounts of tannins.

Nienke Hoogvliet - salmon skin stool. Leather is probably stronger than the metal frame.

Nienke Hoogviet - laser cut salmon leather sequins

Jurii Kasao - jelly fish leather dried on 3D mould into the shape of a bag.

###Mycelium leather

Vegan leather: very soft and thin material. Thickness depends on amount of substrates and how long you let it grow. Also a recipe for a composite.

Maurizio Montalti - mycelium leather bag & shoes (high pressurized).

Maurizio Montalti - Mogu: Industry of natural processes

Aniela Hoitink - Mycelium Dress. Patches grown in petri dishes. No seams

Gradozero - Muskin (mycelium leather). It feels amazing, like a thick suede: hairy and smelling good.

Mycoworks - Check out their [resources page!](https://www.mycoworks.com/resources-1)

###Fruit leather

Starting with food waste. Rotterdam students went to market and looked at stuff disposed at supermarkets. Often vendors have to pay to dispose of e.g. fish waste. Also for fruit waste.

Fruit leather Rotterdam - samples and concept bag

Aurore Bourguignon - Fabtextiles - coffeewaste bag

Barbara Sanchez - Fabtextiles booklet on issue

###Algae leather

Using algae without turning it into powder first.

Violaine Buet - the master of algae leathers and seaweed layers. Woven algae strips into fabrics.

Tjeerd Veenhoven - Algae fibers and yarn. Algae covering sea in China so the light could not come through. This is not great for the sealife below the surface. Let's take out the algae and use it.

Julia Lohmann - leather stretched into architecture. She stretches it out onto large constructions, masks, collargs etc. She uses giant algae, and treats/tans them the way you would leather.

Nina Edwards Anker - Chlorophyta algae dried into shape, crunched up transucent lamp shades by Studio Nea. Lovely.

###High-tech lab grown materials

Lab grown skin - "Pure Human", Tina Gorjanc made bags grown from Alexander McQueen's skin.

Modern Meadow - Zoa's lab grown leather. Apparently very nice.

Elisa Brunato - cellulose extraction sequins. Beautiful! Uses crytallization of cellulose to create reflective material, where cellulose turns into crystals that act as a prism diffracting light.

###Silks

Simon Peers and Nicholas Godley - silk spun by spiders from Madagascar, dyed, woven into a cape.

Spider silk is also done by Adidas (industrially engineered, so not natural collected by spiders).

Bolt Threads' Spider silk - industrially engineered spider silk.

##Cooperation with nature

Tamara Orjola - Forest wool (pine tree fibres), made of "tree waste", the tree sheds them anyway. They can be softened and spun into yarn or by felting it.

Carole Collet - Domesticated Roots (lace-like root structures). I love love love this project so much.

Sarmite Polakove - Bark fabrics: studiosarmite.com produced quite soft material. When you cut wood and take layer between the bark and wood, which can be cut into strips or just used as a whole (which is difficult to attain). You can use these strips for knitting and weaving. Leather-like.

Billie van Kwatwijk - tanned cow stomach leather. www.billievankatwijk.com/ventri. Cow stomach has very beautiful textures. Goes from white to dark brown. These textures cannot be designed.

Austeje Platukyte - pine tree resin composites. Very smooth beautiful resins. In Japan they used to use pine tree resin to create lacquers that can be sanded done very finely. Age-old.

Diana Scherer - Rootsystem domestication:

Shellworks - Ed Jones, Insiya Jafferjee, Amir Afshar and Andrew Edwards. Carbshell extract (*chitosan*) to create waterproof plastics. Not completely biodegradable. Great patterns and colors, translucencies for different uses. They made their own machines for everything! OMG yesssssss. The recipes are quite well-known. The machines are probably not open-source.

##Material archives

There are so many out there. They are so interestinggggg.

* Material Archive Amsterdam Textile Lab
* Fab Textiles Barcelona
* Material Experience Politenico Milano
* ZHDK Material
* Material Connexion
* Materfad Barcelona
* Surfacematter London
* Materio
* many many more, see slides.

These are not only about the materials but also about finishings!

##Assignment

1. Experiment with grown materials
1. Experiment with crafted materials
1. Stick a go-pro to your forehead and record **everything**