6. BioFabricating Materials

Research & Ideation

This is another exciting week for me. I had never made bioplastics myself, although I co-taught a basic design course where students prepared bioplastic samples to cast as modules. So it was a different perspective and first-hand experience for me.

Going into this week, I wanted to explore changes in material/finish/structural properties of base bioplastic recipes with different fillers, creating composites.

References & Inspiration

My researched of this week focused on making sense of experiment processes and outcomes. So I observed how data is made explicit in various sources.

I find Materiom as a good recipe and resource site for finding different bioplastic recipes. If you login/create an account, you can view different bioplastics recipes, make queries with different filters and compare some of them according to material properties. You can also contribute to grow their database.

Materiom

Other material websites which I find inspiring as well as a good resource to understand how to expliticize material properties. One of them is Future Materials Bank and the other one is Material District.

Left: Future Materials Bank, Right: Material District

A few other references:

• How to test the strength of bioplastics, a video tutorial. I haven't used this method, however it is a good reference for the future.
• Here is a really short recap of bioplastics, if you are in the mood for just a small dose.
• Bioplastic Cook Book
• The Chemarts Cookbook
• Bioplastic Tools and Recipes: I liked the extent of physical attributes explored.

Here is an interior design studio, undergraduate project which explores local materials and bioplastics made with them:

Tools

Biobased plastics ingredients:

• Polymer: Gelatine, Agar Agar, Sodium Alginate
• Solvent: Water
• Plasticizer: Gylcerine
• Filler & Stiffener: Wool, Eggshells, ground and recycled Coffee, Bamboo Leaves
• Expander: dish soap
• Colorant: mica powder, pigment from biochromes, bought ink (contains arabic gum)
• For curing alginate: Calcium chloride

Biobased plastics tools:

• Stove
• Pot
• Teaspoon, tablespoon, ladle, wooden spoon
• Kitchen scale
• Sensitive pharmacy scale
• Containers and bowls of various sizes
• Whisk
• Hand blender
• Petri dish
• Dehydrator
• Syringe

Fish leather ingredients and tools:

• The skin of a fish (I used eel skin)
• Egg
• Olive oil
• Dish soap
• Bowl

Kombucha leather ingredients and tools:

• Unpasteurized kombucha drink
• A form of sugar: glycerine, fructose, granulated sugar, dextrose
• Brewing content: various teas (rooibos, green tea, etc.), beer
• Water
• White vinegar
• Rubbing alcohol
• Containers with lids
• Heating pads

Process and workflow

Base bioplastics of gelatine, agar agar and sodium alginate

In the lab, we prepared 4 pots with gelatine and agar agar as well as three mixtures of sodium alginate with different compositions.

Fish leather

There are a few recipes to tan a fish skin. We used 3 different recipes in the lab. I used the following recipe from Lotta Rahme:

Ingredients:

• The skin of a fish
• 1dl grapeseed oil or olive oil
• 1 egg yolk
• 1 teaspoon of soap

Method:

Remove all the flesh and scales from the fish skin. I used an eel skin for my leather. I found tablespoon as a good tool to remove flech and scales. Squeeze all the water out. Add the above ingredients in a bowl. This mixture can be used for 3-4 skins. Put the fish skin in the mixture and work it 10-15 minutes, rubbing the mixture on the skin. Hang the skin. During the drying, work your skin frequently for better results.

After 3 days, wash the skin in soap and water mixture at 20 degree celcius. The skin is very stiff at this point. You need to work your skin against a sturdy frame to soften it. Ideally, put the skin on a board flat to dry. I did not have a proper place and board so I hung it again to dry.

From left to right: cleaning the fish skin, working and rubbing the skin in tanning mixture, working the skin against a sturdy frame, hanging it to dry.

In the lab, people also used salmon skin. I think salmon skin is a better option than eel skin, because:

1. it has a wider width
2. The scale side has a better looking finish
3. The overall feel of the leather is better than eel.

Kombucha leather

This is still a work-in-progress as kombucha leather making process takes around 1 month. We prepared 3 batches of kombucha mixtures during the biofabricating materials week to harvest our materials later.

	Batch 1	Batch 2	Batch 3
Sugar	250gr fructose, 300 gr granulated sugar	300 gr glycerine	200 gr glucose
Brewing content	3lt beer	1,5 lt water, 50 gr green tea	1,5 lt water, 100 gr rooibos tea
Water	3lt	1,5 lt	2 lt
Unpasteurized kombucha	500 ml	500 ml	500 ml

Clean the containers with lids with rubbing alcohol. Any contamination is your enemy while growing kombucha bacteria, therefore it is really important to sterilize the containers.

Prepare your mixtures for each batch in containers by adding brewing content, sugar and water. Wait until the the temperature in each container is not more then 30 degree celcius. Kombucha bacteria are also very sensitive to heat: if temperature is high, they die; if temperature is low, they cannot grow. Add unpasteurized kombucha in each container and put the containers on heating pads. Amsterdam is cold nowadays. You need constant 30 degree celcius and heating pads help.

Approximately 84 hours after preparing the mixtures, we discovered mold growth on the surface of the mixtures. We added white vinegar (the amount does not matter, but we added a lot) to kill the mold bacteria as per suggested by Cecilia.

From left to right: sterilizing and preparing mixtures in the containers for the three batches, creating a warm and cozy environment on the heating pads for kombucha growth with optimum heat, killing contamination with white vinegar.

Creating reinforced composites (personal experiment)

I took on the personal exploration of creating composites with different reinforcement by adding different fillers and stiffeners as well as colorants to base bioplastic recipes that we created together. The aim was to achieve different material, visual and structural properties.

Reinforcement based classification of composites

I used wool, bamboo leaves, eggshell and recycled ground coffee as fillers and stiffeners. Comparing with the above chart, eggshell and coffee act as large particles, wool act as continuous fiber reinforcement and bamboo leaves act as discontinuous-random reinforcement.

Wool composites

Eggshell composites

Coffee composites

Bamboo leaves composites

---

Notes from the Classroom

notes from the classroom

BIOFABRICATING MATERIALS lecture by CECILIA

Bio - plastics, yarns&fabrics, leathers

Bio - based (bacterial, fungal, vegetal, mineral, biosynthetic and animal), degradable (degrade in specific conditions - pH-sensitive, thermo-sensitive, enzymes), compostable (composted within 90 days - bacteria, mycelium, animal, etc.)

BIOBASED

• Animal - gelatine, collagen, fat, silk, spider-silk, (fish) skin, leather, hair
• Vegetal - glycerine, lignin, alginate, cellulose, food waste, seed-oil, plants, fruits, seeds
• Microbial - cellulose, bacteria, bioshades, pigments
• Fungal - fungii, mycelium
• Biosynthetic - cellulose, ...

WHY BIO?

synthetics seem to seep into environment. plastic is a substance the earth cannot digest.

PLASTICS is a word that originally meant "pliable and easily shaped". Polymer + plasticizer (to create flexibility)/filler(to avoid shrinkage)/stiffening(to structure and reinforce)/expanding(to create foams) + color (pigment)

BIOPLASTICS

Agar & Alginate Bioplastics Gelatine Vegetal Waste

Alternative Leathers

• Microbial
• Mycelium
• Vegetal
• Animal waste
• Fruit
• Hi-tech or lab grown

BIOFABRICS & YARNS

• Plant Matters
• Rooted in nature
• ....

HOW TO CRAFT BIO-PLASTICS?

polymer (alginate, gelatine, starch...) + glycerine / egg shells, chalk, fibers, oils, etc. / fibers, natural debri / green soaps, emulsifiers

BIOMATERIALS DESIGN PROPERTIES

• Structural
• Structural decorative
• Sensorial texture, visual texture
• Structural color (with refraction sheets)
• Structural color & augmented properties (with holographic charcoal activated)
• Color, texture and transperancy

AGAR & ALGINATE BIOPLASTICS

Agar: Agar agar, glycerol, water (not heat resistant)

Alginate: sodium alginate, glycerol, water, calcium chloride hydrate (water resistant, but pH sensitive, heat resistant)

GELATINE BIOPLASTICS

Gelatine(buy the powered not the sheet), glycerol, water (not very water and totally not heat resistant, but you can recast it and it makes the plastic sturdier)

VEGETAL BIOPLASTICS

Cellulose recipes: Aalto chemarts, the Chemarts Cookbook

WASTE BIOPLASTICS

Fishscale plastics, blood waste, carrot waste, casein whey waste (marieke's bio scoring system)

ALTERNATIVE LEATHERS

Grown: Microbial (scoby - kombucha starter 25-30 degree celcius), mycelium

Crafted

• vegetal leathers, fruit leathers
• animal waste leather
• fish-skin leather

BIO FABRICS & YARNS

Grown: root fabrics, spider silk

Crafted: leaf & flower yarn

• Plant matters... chemarts recipe book (fiber extraction)
• Rooted in nature
• Algae fabrics and yarns
• Animal & human resource
• Spider silk