7. BIOFABRICATING MATERIALS

INTRODUCTION / CONTEXT

Biomaterials are materials derived from biological sources — such as plants, animals, fungi, algae, & microorganisms — or made from natural polymers & minerals.

They can exist in their raw, natural form or be chemically processed & combined to achieve specific textures, strengths, or functions.

By experimenting with both crafted (formulated) & grown (cultivated) materials, this assignment invites us to understand the potential of living matter as a design medium — shifting our role from consumers of materials to active co-creators with nature.

BIO MATERIALS

BIO-BASED

Means the material is made from biological or natural sources. These can include bacteria, fungi, plants, minerals, or animal-derived components.

BIODEGRADABLE

These materials can break down into natural elements under specific conditions, often involving microorganisms, enzymes, temperature, or pH.

Degradation depends on the environment — not all “biodegradable” materials degrade everywhere or at the same speed.

BIO-COMPOSTABLE

Compostable materials go a step further: they decompose within a specific timeframe (typically 90 days) under composting conditions.

The result should be non-toxic & usable as compost.

Key message:

A bio-based material is not automatically biodegradable or compostable. A material can be made from biological resources but still be chemically stable & resist natural decomposition.

Understanding this distinction helps designers choose materials responsibly — balancing sustainability, durability, & end-of-life impact.

What does Fabrication mean?

The term Fabrication refers to the act of making — the transformation of raw materials into new forms through different techniques.

In the context of biofabrication, it includes both traditional craft methods & biological growth processes, merging design, science, & technology into one creative system.

It illustrates a wide range of actions that fall under fabricating, like:

• Crafting: Manually shaping or forming materials using recipes & molds.
• Casting: Pouring mixtures into molds to create solid forms.
• Extruding: Pushing materials through a shape or nozzle to form continuous structures.
• Laser / 3D Printing: Digital fabrication techniques to design precise geometries.
• Inoculating: Introducing living organisms (like fungi or bacteria) to grow materials.
• Autoclaving: Using heat & pressure to sterilize or modify biological matter.
• Growing: Cultivating living systems — such as mycelium, kombucha, or algae — into material form.

The goal of this assignment is to explore the full process of biofabrication in practice:

• Research: Gather inspiration from artists, designers, & projects working with biomaterials, as well as from local resources & ingredients.

• Experiment: Produce at least one crafted & one grown material, testing & adapting recipes.

• Document: Record ingredients, processes, observations, & unexpected discoveries.

• Present: Create a systematic material chart & contribute physical swatches to the lab’s material library.

This week bridges research, craftsmanship, & biotechnology — encouraging a deeper understanding of how materials can be designed, grown, & reimagined in more sustainable ways.

Change of Narrative

We need new material narratives that are regenerative, bio-based, & values-driven.

Instead of seeing waste as an endpoint, it can become a resource — connecting industries like food, textiles, & agriculture through circular systems. By transforming organic by-products such as fruit peels, shells, fibers, or plant residues into new materials like bio-leathers, bio-fibers, or biopolymers, we can design within nature’s logic.

It invites collaboration across sectors & encourages a mindset where materials are cultivated, reimagined, & continuously regenerated, rather than extracted & discarded.

RESEARCH & INSPIRATION

JULIA LOHNMANN - DEPARTMENT OF SEAWEED

Julia Lohmann is a German-born designer, researcher & educator whose work interrogates our material relationships with nature.

She explores the potential of seaweed as a sustainable, regenerative material. Through her platform Department of Seaweed, she develops ways to craft, shape, & design with algae — creating translucent, leather-like surfaces & sculptural forms. Her work redefines the relationship between humans & marine ecosystems, inviting collaboration with nature rather than extraction from it.

BILLIE VAN KATWIJK

Studio Billie van Katwijk – VENTRI Dutch designer Billie van Katwijk transforms overlooked animal by-products into refined materials. In her project VENTRI, she turns the four stomachs of a cow into unique leathers, each revealing distinct natural textures & patterns. By revaluing what is normally discarded, her work challenges perceptions of waste, beauty, & material origin.

BONE GLASS

Ella Einhell – Bone Glass

With Bone Glass, designer Ella Einhell transforms animal bone waste & recycled glass into a new, opaline material. The bone ash replaces industrial additives, giving the glass unique translucency & warmth. By revaluing local waste streams, Bone Glass bridges sustainability, craft, & poetic material innovation.

What do they have in common?

Julia Lohmann, Billie van Katwijk, & Ella Einhell share a deep interest in exploring how natural or waste materials can be transformed into valuable design materials.

They work between craft, science, & sustainability, rethinking resources like seaweed, animal by-products.

I chose them as inspirations because they show how design can emerge from respect, regeneration, & material curiosity.

BOOKS

The CHEMARTS Cookbook

Bioplastic Cook Book - Margaret Dunne

SASSCHA PETERS - HAUTE INOVATION

haute innovation

Dr. Sascha Peters is a materials & technology expert who explores sustainable & circular innovations through his agency Haute Innovation in Berlin.

His work focuses on future materials — from bio-based & recycled resources to new uses of CO₂ as a material — bridging design, science, & industry for a regenerative future.

Since 2016 he has been teaching about materials & innovation at HAWK Hildesheim, Germany.

During my time working on the development of the Materialarchiv, I occasionally collaborated with him on topics related to material research & acquisition.

I especially recommend his books on materials & technical product design, which provide a good overview & introduction to the topic.

PREVIOUS WORK

I have always been fascinated by alternative materials & their potential to reshape how we design & produce.

During my internship at TextileLab Amsterdam, I gained deeper insights into biobased & circular material innovation — including research on leather alternatives as part of my internship project. Resaerch about alternative Leathers

Later, in my BA thesis: SHOE WITH EXPIRATION DATE, I expanded this research by exploring regional & compostable materials for shoe soles.

Within this context, I collaborated with Fabricademy Alumnus Felipe Fiallo / Instagram & received a mycelium sole prototype from ConceptKicks Japan.

This ongoing interest continues to guide my work — combining material research, sustainability, and design experimentation.

SHOE WITH EXPIRATION DATE - compostable Sneaker-Set made from regional materials

A compostable, modular sneaker made from regional materials such as dandelion & hemp. After its use, the shoe can simply be composted in the garden. The project questions the idea that sustainability always means longevity.

Its short material lifespan is intentional — reflecting a balance between environmental responsibility & consumer culture.

The design follows a building-block principle, with elements held together by a strap instead of glue. This approach shows that footwear can be made without plastic, using renewable, local resources — leaving a thoughtful, rather than lasting, footprint.

youtube: SHOE WITH EXPIRATION DATE

fun fact: Snoop Dog, 50Cent & HaHa Davis post my concept as a Disstrack against: Kanye West

BIO GLASS

During the FABRICADEMY BOOTCAMP 2025 in Brussels, I experimented with different gelatin-based bioplastic recipes to explore their material properties and potential applications.

WORKSHOPS: BIO MATERIALS + BIO PLASTICS

As part of my InCollages project, together with Theresa Bäcker & later also within the context of experimental jewelry & body-related objects, I gave workshops on alternative materials & bioplastics** at HAWK – Faculty of Design in Hildesheim.

ASSIGNMENT:

WEEK 07: BIOFABRICATING MATERIALS

CONCEPTS

For the Biofabrication Assignment, I developed diffrent conceptual ideas that explore different bio-based materials & natural cycles.

I am aware that it will be difficult to realize all concepts to my satisfaction within just one week. Nevertheless, I wanted to record the ideas so that I might return to them & develop them further at a later time.

Jellyfish as Material - (only concept)

Jellyfish are made up of about 95% water & contain natural collagen, which can serve as a base for bio-based materials.

I’m interested in exploring how dried or processed jellyfish could be transformed into new, translucent biomaterials.

Seaweed (only concept)

Seaweed is a fast-growing, regenerative resource rich in natural polymers such as alginate.

It offers a sustainable basis for biofilms, coatings, or even textile-like structures.

“Ash to Ash – Bone to Bone”

A compostable urn made from bones – for bones.

The design takes inspiration from the natural structure of bones & aims to reconnect the human body with the earth.

The material could combine bone meal as a filler with gelatin-based bioplastic as a binder, creating a biodegradable composite.

Since I was 6 years old, I have been collecting animal skulls & bones. Over the years, this has grown into a considerable collection.

The themes of death, dying, & the body as material have always fascinated me. In school, I even chose burial rituals in different cultures as the topic for my senior-year project, & I accompanied my great-grandmother through her passing.

Right now, here in Mexico, during the Days of the Dead / Día de los Muertos, this theme feels especially present.

I find it beautiful how death is approached here— visible, honored, celebrated, instead of hidden or silenced.

The project / concept:

Ashes to ashes: bone to bone

is an idea I have wanted to realize for a long time: to create a translucent urn made from bone material (bone flour or gelatin) that reveals the ashes within— not hiding them, but showing & honoring them. At the same time, the material would be ephemeral & biodegradable—

( though the word compostable feels somehow inappropriate here.)

In Germany, I would have several bones that I could potentially use for mold making. But here, it’s difficult (for me, within the given time) to find the types of bones suitable for creating molds. Additionally, the mold would need to be water-resistant, since I’ll be pouring liquid / hot bioplastic into it.

SLUSH -A Quick & Easy Casting Method

Form Exploration – Bone Structures & Vertebra Inspiration

For the form development, I was inspired by organic bone shapes, particularly the structure of a vertebra.

To explore these forms, I experimented with several approaches. Initially, I scaled & distorted existing 3D models downloaded from Thingiverse, adapting them to achieve more fluid, anatomical proportions.

Since the available models still did not fully match my concept, I generated custom reference images using OpenAI / ChatGPT, focusing on urn-like forms with bone-inspired features.

The final concept image was then converted into a 3D model using TripoStudio, which allowed me to continue my exploration in three dimensions.

However, the resulting geometry contained complex undercuts, which made a conventional multi-part mold difficult to produce.

To overcome this, I decided not to create a traditional multi-section mold (which would have required around 3 outer & 3 inner parts to define the wall thickness), but instead to experiment with a simplified casting technique inspired by classical plastic manufacturing methods — namely, a rotational or slush casting process.

Rotational Casting Process

In the rotational casting method, a liquid or powdered plastic is poured into a closed mold, which is then rotated continuously along multiple axes. Through this motion, the material evenly coats the interior surface, gradually forming a uniform wall thickness as it begins to cure. This approach allows complex hollow forms to be produced without the need for internal support structures or multi-part inner molds — making it particularly well suited for organic, soft-robotic-inspired geometries.

Type	Material	Properties / Use	Temperature
Thermoplastic Powders	Polyethylene (PE)	Durable, impact-resistant, easy to mold	200–300 °C
	Polypropylene (PP)	Rigid, heat-resistant	200–300 °C
	PVC	Flexible, smooth surface (less used today)	150–250 °C
Reactive Systems (Cold Casting)	Polyurethane (PU)	Adjustable hardness, strong surface	25–60 °C
	Silicone (RTV / Platinum)	Flexible, elastic, ideal for soft robotics	25–60 °C
	Epoxy Resin	Rigid, precise thin shells	25–60 °C

Although undercuts still pose a challenge during demolding, I decided to take the risk. From previous experiments, I know that gelatin-based bioplastics — whether used as a rigid, flexible, or foamed material (with - without glycerin - with added soap) — remain flexible enough immediately after curing to be removed from molds with undercuts without breaking or tearing.

Mold Making with Dual Extrusion: PETG & PVA

For the mold fabrication, I decided to print with 2 filaments simultaneously — PETG for the outer shell of the mold & PVA (polyvinyl alcohol) as a water-soluble infill.

Why PETG inste of PLA

Property	PLA	PETG
Material Base	Biodegradable (made from corn starch, sugarcane, etc.)	Non-biodegradable (derived from PET, like plastic bottles)
Printing Temperature	~190–210 °C	~230–250 °C
Strength & Toughness	Brittle – can crack easily	Tough and impact-resistant
Water Resistance	Absorbs moisture, softens	Waterproof and moisture-resistant
Heat Resistance	Low (~55 °C)	Higher (~75–85 °C)
Post-processing	Easy to sand, glue, paint	Slightly harder, but more durable
Transparency	Usually opaque	Can be very clear or translucent

Why You’d Use PETG Instead of PLA

• Higher heat resistance: PETG won’t deform as easily when exposed to warmth — ideal if you’re pouring hot or liquid bioplastic into a mold.
• Water & chemical resistance: Great for molds that come into contact with moisture or liquids.
• More flexible & durable: PETG is less likely to crack — useful for reusable or thin structures.
• Smooth finish: Produces a clean, slightly glossy surface — perfect for casting molds or design objects.

Since I needed the inner negative form & wanted to minimize material usage while avoiding uneven surfaces caused by traditional support structures, I chose to split the mold vertically & replace the supports with soluble PVA infill instead.

This approach allowed me to achieve smooth internal surfaces & create complex inner geometries that could easily be revealed after dissolving the PVA.

Material Properties – PVA

• Water-soluble: fully dissolves in warm water (30–50 °C)
• Compatible: adheres well to PLA during dual extrusion
• Precise: enables clean internal cavities without support residues
• Sensitive: hygroscopic — must be stored in a dry environment

Step by Step: Removing the PVA

• Finish the print and carefully remove it from the build plate.
• Place the part in warm water (around 40 °C).
• Gently agitate or stir the water to accelerate the dissolving process.
• Wait several hours, depending on the infill density, until the water becomes cloudy and the PVA is gone.
• Rinse the part in clean water and remove any remaining residue with a soft brush.
• Allow the part to air dry completely before further processing.

BIO PLASTIC YARN: Based on Alginat

For this assignment, I explored the creation of a bioplastic yarn using an alginate-based recipe. The goal was to produce a flexible bio yarn that could later be braided and used for small textile objects.

RECEPIE

500 ml       Water
20  g        Sodium Binder
45  gr       Glycerin
             Pigment (preferable powder)

100 ml       Water
7%           calcium chloride

1. Recipe Overview

Component	Quantity	Purpose
Water	500 ml	Base liquid for alginate mixture
Sodium alginate	20 g	Main biopolymer / binder
Glycerin	45 g	Plasticizer for flexibility
Pigment (powder)	As needed	Coloring
Water (solidifying bath)	100 ml	Solvent for calcium chloride
Calcium chloride	7 g (7%)	Crosslinking agent for solidification

Process

First, We prepared the solidifying solution for the bio yarn. Using a digital scale, We measured 100 ml of water & dissolved 7 g of calcium chloride in it. The mixture was stirred until fully homogenized. In a separate bowl, We prepared the alginate mixture by combining water, sodium alginate, glycerin, & (if wanted) pigment. The ingredients were mixed thoroughly until a smooth & uniform consistency was achieved. Once ready, the alginate mixture was transferred into a syringe. Care was taken to avoid air bubbles, as these can cause the bio yarn to break during extrusion, resulting in short fragments instead of continuous strands. The mixture was slowly extruded from the syringe into the calcium chloride solution, where it immediately solidified into bio yarn.

2. Workflow Summary

Step	Description
Prepare solidifying solution	Dissolve 7 g of calcium chloride in 100 ml of water and stir until fully homogenized
Prepare alginate mixture	Mix 500 ml water, sodium alginate, glycerin, and optional pigment until smooth
Load syringe	Transfer the alginate mixture into a syringe, avoiding air bubbles
Extrusion	Slowly extrude the mixture into the calcium chloride bath
Solidification	The yarn immediately solidifies upon contact with the solution
Drying	Allow the bio yarn to dry completely
Post-processing	Experiment with braiding techniques

Results

After producing the yarn, I experimented with different braiding techniques. Using these techniques. An important observation was that the bio yarn shrinks by approximately 60% once completely dry. This significant shrinkage should be considered during the design & fabrication process.

Reflection

This experiment demonstrated the potential of alginate-based bioplastics for textile applications. The material is flexible, biodegradable, & suitable for handcrafted techniques such as braiding. Future experiments could explore different pigment concentrations, yarn thicknesses, & drying conditions to better control shrinkage & final texture.

3. Key Observations

Aspect	Result
Material behavior	Flexible & suitable for textile applications
Shrinkage	Approx. 60% shrinkage after complete drying
Workability	Well suited for braiding & handcrafted techniques

Bioplastic Yarn – Recipe & Workflow Overview

Category	Phase / Step	Material / Action	Quantity / Specification
Materials	Recipe	Water	500 ml
Materials	Recipe	Sodium alginate	20 g
Materials	Recipe	Glycerin	45 g
Materials	Recipe	Pigment (powder)	As required
Materials	Solidifying bath	Water	100 ml
Materials	Solidifying bath	Calcium chloride	7 g (7% w/v)
Methods	Preparation	CaCl₂ solution	Calcium chloride dissolved in water and stirred until homogeneous
Methods	Preparation	Alginate mixture	Water, sodium alginate, glycerin, and pigment mixed until smooth
Methods	Processing	Syringe loading	Mixture transferred into syringe, avoiding air entrapment
Methods	Processing	Extrusion	Mixture extruded into CaCl₂ bath
Methods	Processing	Solidification	Immediate fiber formation upon contact
Methods	Post-processing	Drying	Fibers air-dried; approx. 60% shrinkage observed
Methods	Post-processing	Braiding	Yarn braided using manual techniques

MYCELIUM

The Oyster Mushroom (Pleurotus ostreatus) is a fast-growing & resilient species that thrives on a wide range of organic substrates.

It is commonly used for mycelium cultivation & material experiments because its dense, fibrous network grows quickly, binds well, & can be easily shaped or dried — making it ideal for bio-based materials & design applications.

Semilla seta gris - Pleurotus Ostreotus

Oyster Mushroom Cultivation — Using a 2-Part 3D-Printed Mold

1. Prepare & Pasteurize the Substrate Chop straw into 2–5 cm pieces. Heat water to 70–80 °C & submerge straw fully for 60 minutes (pasteurization). Drain & cool until hand-warm. Moisture check: squeeze — only 1–2 drops should come out.

2. Mix with Spawn Work clean (washed hands, gloves, disinfected area). Mix pasteurized straw with oyster mushroom spawn at about 1 : 3 – 1 : 5 (spawn : substrate). Do not over-mix or compress — keep it airy.

3. Fill the Mold Fill each half of the 3D-printed mold separately. Cover loosely (plastic wrap or lid with small holes / micropore tape) to allow gas exchange. Do not seal airtight — the mycelium needs oxygen.

4. Incubation Phase Keep at 22–25 °C, dark or low light, stable humidity (~60–70 %). Wait until both halves are fully white & firm (approx. 1–2 weeks). Avoid opening frequently; check visually for contamination.

5. Combine the Two Halves Once fully colonized, gently press or stack the halves together. Allow small gaps or ventilation holes — never airtight. Let the mycelium fuse across contact surfaces (“mycelial fusion”).

OPTINAL:

6. Fruiting Phase After full colonization, move to cooler conditions (17–20 °C). Provide fresh air, indirect light, & 85–95 % humidity. Mushrooms will grow through openings or small slits naturally.

Key Notes

Oxygen ↑ = healthy mycelium. Too wet → bacterial contamination. Too compact → slow or stalled growth. Clean hands + stable temperature = success.

THE MOLD

For the construction of the mold used to grow the mycelium, I reused a 3D file that I had already worked with during WEEK 2: DIGITAL BODIES, which I originally found on Thingiverse. I edited & scaled the back part of the body of the Ant & then split the model into a left & a right half.

After preparing the positive form, I used it to create a negative mold by carving (booling) the material. Both negative molds were then 3D printed used to fill & grow the mycelium.

THINGIVERSE - The Red Bull Ant by Kintall_John Gosper

Mycelium Processing

Since I joined the LAB at a later stage, the initial preparation of the substrate was already completed.

The straw had been washed, cut into small pieces, sterilized in boiling water with calcium carbonate (CaCO₃) as a pH regulator, & left to cool in a sterile environment.

When I started working with the material, the Mycelium was already well colonized inside a small container.

I prepared additional sterilized straw & carefully mixed it with the existing Mycelium to ensure an even distribution. The mixture was then packed into the prepared mold, taking care to compact it evenly. This step aimed to provide enough nutrients & structure for the Mycelium to continue growing & binding the material inside the mold.

24.10.2025

28.10.2025

After 4 days, a white fluffy layer began to form, covering the straw.

31.10.2025

18.11.2025

After approximately 20 days, the mycelium had fully colonized the substrate. At this stage, I decided to remove the individual parts from the molds, assemble them using toothpicks, & place the object inside a sterilized plastic bag. The assembled piece was left to grow together for an additional 27 days. 09.12.2025

Once small fruiting bodies started to appear, the mycelium object was removed from the bag & placed in direct sunlight to dry & stop further growth.

CONCLUSION: MYCELIUM

Mycelium, as a composite material, is environmentally friendly, lightweight. It can grow into almost any form & is relatively affordable. Production is natural & low-tech & even generates edible mushrooms as a by-product. Very little additional material is needed, & waste substrates (coffee grounds, straw etc.) can expand volume significantly.

However, its long & irregular growth time, contamination risks & low flexibility are notable disadvantages. The material is not yet suitable for high-stress applications — unless extremely thin or segmented — since abrasion resistance & durability are limited.

Mycelium Cultivation – Recipe & Workflow Summary

Phase	Material / Step	Quantity / Conditions
Organism	Oyster mushroom (Pleurotus ostreatus)	Fast-growing, resilient mycelium
Substrate	Straw	Chopped to 2–5 cm pieces
Substrate treatment	Pasteurization	70–80 °C water for 60 min
Moisture control	Drain & cool	Hand-warm; 1–2 drops when squeezed
Additive (optional)	Calcium carbonate (CaCO₃)	pH regulation during sterilization
Inoculation	Mushroom spawn	Ratio 1:3–1:5 (spawn : substrate)
Mixing	Substrate + spawn	Mixed gently, kept airy
Molding	3D-printed mold (2-part)	Each half filled separately
Gas exchange	Covering	Loose cover; not airtight
Incubation	Growth phase	22–25 °C, dark/low light, 60–70 % RH
Colonization time	Mycelium growth	Approx. 1–2 weeks (initial)
Assembly	Combine mold halves	Mycelial fusion across contact surfaces
Extended growth	Post-assembly growth	Additional ~27 days
Fruiting (optional)	Fruiting phase	17–20 °C, 85–95 % RH, fresh air
Drying	Growth termination	Direct sunlight to stop growth
Result	Final material	Fully colonized, lightweight mycelium composite