7. BioFabricating Materials¶

I. References & Inspiration¶

A. Recycled eggshells Inspiration¶

One particularly interesting example of biomaterial fabrication I came across is Carrelé, an ecologically sustainable collection of wall tiles created by Nature Squared. Every year, around 250,000 tonnes of chicken eggshell waste are generated worldwide, most of which ends up in landfills. In response, Carrelé transforms this overlooked waste into beautifully handcrafted wall tiles, showcased as part of an installation at the Rossana Orlandi Gallery in Milan.

B. Bio Leather Inspiration¶

II. Introduction to Biofabricating Materials¶

This week began with an inspiring lecture by Cecilia Respanti, guiding us through the timeline and foundational concepts of biofabricating materials. Biofabricated materials are grown, cultivated, or formed through biological processes, rather than being fully produced using conventional industrial manufacturing methods.

But how could that process happen?

Growing :

Inoculating: the process of introducing a living microorganism (such as bacteria, fungi, yeast, or spores) into a material or environment to initiate biological growth or a desired biological process.

Autoclaving: used to sterilize tools, substrates, growth media, and containers before inoculation, ensuring that only the intended microorganisms grow.

Crafting : Extruding, Casting, Laser 3D Printing, Assembling, Spraying, Mixing, etc.

Important to notice that

There is a common misconception that bio-based, biodegradable, and bio-compostable materials are the same, however, it is important to note that they are fundamentally different at their core.

Bio-based Materials: Materials that do not necessarily benfit the environment but have a biological base whether bacterial, fungal, vegetal, mineral, bio-manmade and animal.

Bio-degradable Materials: Materials that degrade only in specific conditions, could be PH-sensitive, thermo-sensitive or need certain enzymes to degrade.

Bio-compostable Materials: Materials that are composted within 90 days, Bacteria, Mycelium, Animal, etc.

III. Class Research and Experimentation¶

The aim this week was to biofabricate materials through a value-driven approach, materials that our planet can naturally digest. Accordingly, our class experimentation went as follows:

A. Bioplastics¶

Bioplastics are custom made material systems built by combining a base polymer with specific additives such as plasticizers, fillers, stiffeners, expanding agents, and pigments to control flexibility, strength, shrinkage, structure, foaming, and color of the final material.

1. Agar Agar Biofoil¶

Agar-agar powder is a fine, plant-based powder derived from red seaweed that dissolves in hot water and forms a strong gel when cooled, commonly used as a gelling agent in food, laboratories, and bioplastic fabrication.

Workflow

Ingredients:

Agar Agar: 5 gm 
Glycerine: 15 gm
Onion Water: 250 gm

Tools:

Pot (non-reactive), spoon, whisk, and stove
Textiles, moulds, or casting surfaces
Scale

Preparing Process

Warm up the water in a pot on your stove (plain or dyed) at a maximum of 80°C. A starting temperature between 30–50°C is recommended.
Add your plasticizer; the more glycerine you add, the more flexible the material will be. Adding too much glycerine will cause it to remain sticky.
Add the agar. Some types of agar have larger flakes and take a long time to dissolve.
Mix until smooth.
Simmer for another 30 minutes (you can start at 60–70°C and slowly increase to 86°C max). Time depends on the agar typology, room temperature, and humidity.
Pour onto your chosen surface.
Let it dry in a dry room. Turning your piece will affect deformation due to water loss, which characterizes agar bioplastics.
De-mould when completely dry. You will notice that agar bioplastic loses a lot of water and therefore shrinks. It can shrink up to 20%, depending on the water-to-agar ratio used during casting.

Result Analysis

Heat Resistance : The material becomes sweaty in warm room temperature especially if rubbed by hand, completely dissolving if microwaved for over 20 seconds.

Water Resistance : Submerges directly in hot water, sumberges after hours in room temperature water.

Properties : Bendable, Medium level of stretchability, lightweight, rubbery.

Surface : Medium Smoothness, Translucent.

2. Gelatine Bioplastic¶

Gelatine powder is a protein based gelling agent derived from collagen, typically sourced from animal byproducts, that dissolves in warm water and forms a flexible, thermo-reversible gel when cooled.

Workflow

Ingredients:

Gelatine: 48 gm 
Glycerine: 12 gm
Water: 240 gm
Additive (Coffee Grounds): 3gm

Tools:

Pot (non-reactive), spoon, whisk, and stove
Textiles, moulds, or casting surfaces
Scale

Preparing Process

Warm up water in a cooking pot on your stove (water can be plain or dyed).
Add the filler (Coffee Grounds).
Add first your plasticiser. Remember: the more glycerine, the more flexible the material will become — do not exceed 1:1.
Add the gelatine while gently whisking.
Mix slowly until smooth.
Simmer for 15–30 minutes (86°C max). Time depends on the typology of heat applied, room temperature, and humidity. Aim for a liquid honey consistency.
Pour while hot onto your chosen surface (surfaces help texturise your material; choose accordingly).
Let it dry in a dry room. First wait until it is solid to the touch but still cold, then start turning your piece until it is dry. This helps prevent mould formation during long drying, but may affect deformation due to water loss.

Result Analysis

Heat Resistance : The material is not very heat resistant, yet it doesn't sweat when rubbed with hand.

Water Resistance : Submerges directly in hot water, sumberges after hours in room temperature water.

Properties : Rigid, Not Stretchable, Lightweight

Surface : Rough Surface, Medium Translucency

B. Bio-Leathers¶

Bio-leathers are leather-like materials made from biological or bio-based sources, such as plant fibers, fungi (mycelium), algae, or fermented polymers, designed to replicate the look and performance of animal leather while reducing environmental and ethical impacts.

1. Kombucha Leather¶

Workflow

Ingredients:

1 ltr boiled water
3 black tea bags
100 gm sugar
Previously grown scoby
1 ml 100% concentrated vinegar

Tools:

Large plastic tray
Mixing utensils
Beaker
Scale

Preparing Process

Sterilize beakers, tray and all utensils using hot water.
Boil 1 ltr black tea with 3 tea bags.
Add 100 gm sugar to the tea.
Stir the tea till sugar melts.
Filter the tea to avoid any possibility for future mold formation.
Pour the tea in the tray, let cool down and check the PH of the liquid.
Measure the temperature, you are looking for ±30°C. Then add the kombucha SCOBY and its liquid to the tray.
Put 1 ml of concentrated vinegar and mix the liquid around.
Cover with cloth very well.
Let it grow for ±30 days at 30°C, or until you have at least 1 cm thickness. Then remove the wet grown mat, wash it, treat it, and place it to dry on a 3D shape or on a flat tray.

Result Analysis

Heat Resistance : The material is not very heat resistant, it doesn't sweat when rubbed with hand, yet it softens, warps, or shrinks when exposed to heat

Water Resistance : Absorbs water easily, swells, softens, and loses strength in high humidity.

Properties : Bendable, Not Stretchable, Lightweight

Surface : Medium Smoothness, Medium Translucency

C. Bio-Sheet and Yarns¶

1. Alginate Bio-Sheet and Yarns¶

Sodium Alginate is the sodium salt form of alginic acid and gum mainly extracted from the cell walls of brown algae. Brown seaweeds are usually large, and range from the giant kelp Macrocystis pyrifera that is often 20 m long, to thick, leather-like seaweeds from 2–4 m long, to smaller species 30–60 cm long. Alginate is a compound know as a polysaccharide.

Workflow

Ingredients:

12 gr   Sodium Alginate
40 gr   Glycerine
400 ml  Water
250-300 ml  Ca Chloride Solution 
400 ml  Water
1 drop Food colorant

Tools:

Pot/Beaker, spoons 
Meshes, textiles, nets, molds
Blender
Syringes and Squeez Bottles
Spray Bottle

Preparing Process

Start:

Mix the alginate with water and glycerine. The best way of getting a smooth mixture is to use a hand held mixer or blender. If you are planning to make a batch of multiple colours, prepare your colors in a jar or small container, to which you will add the mixture.
Once the mixture is smooth and completely dissolved, let it sit for some time, this will allow all the bubbles to leave the mixture.

Next steps would be seperate for each the sheet and the Yarns.

Process for the Bio-sheet:

Prepare a solution of water and calcium chloride, adding 10% (from water volume) of Ca Chloride to the water, and fill a small spray bottle with it.
Prepare your the surfaces and moulds to be filled, by spraying the calcium chloride mixture on the surfaces. You can use 3d textured coated fabrics that are waterproof, to transfer the texture to your bioplastic foil.
Cast the alginate mixture onto the surface or mould. Once you start pouring, try to cast slowly, without inglobating air, and by carefully pouring on the liquid itself. Spread the material into a thin film using a very wide spatula or by moving the mould.
After a couple of minutes spray the casted alginate with the calcium chloride mixture, the casted material will shrink both in thickness and width.
Once the alginate mixture is cured, rinse it thoroughly or dip in it water to eliminate any residue of calcium chloride.

Process for the Bio-yarns:

Prepare a solution of water and calcium chloride, adding 10% (from water volume) of Ca Chloride to the water, and fill a small size jar with it.
Fill the squeezable bottle and the syringes of different sizes with the alginate mix (for different thicknesses of yarns).
Squeeze the alginate mixture consistently into the Calcium Chloride solution jar.
Remove the yarns from the solution , wash then rinse and let dry completely.

Result Analysis

Heat Resistance : The material is heat resistant, however it does sweat when rubbed with hand.

Water Resistance : Submerges within couple of hours in Alkaline water, waterproof in Ph neutral or Acidic water.

Properties : Bendable, Stretchable, Lightweight

Surface : Soft Surface, Medium Translucency

IV. Personal Research and Experimentation¶

Pending

V. Results: Overview material research outcomes¶

Documenting and comparing experiments¶

Material name	polymer	plastifier	filler	Stabilizer	Solvent
Agar Agar Biofoil	Agar Agar 5 gm	glycerine 15 gm	N/A	N/A	Onion Water 250 gm
Gelatine Bioplastic	Gelatine Powder 48 gm	glycerine 12 ml	Coffee Grounds 3gm	N/A	Water 240 gm
Alginate Biosheet and Bioyarn	Sodium Alginate 12 gm	glycerine 40 gm	N/A	Ca Chloride Solution	Water 400 gm

Material pic	Material name	Ingredient 1	Ingredient 2	Ingredient 3	Ingredient 4	Ingredient 5
	Kombucha Leather	Black Tea 1 ltr	SCOBY	Concentrated Vinegar 1 ml	N/A	N/A