7. BioFabricating Materials

Research

Biofabrication represents an innovative approach to sustainable material production, with ongoing research spanning areas such as biopolymers, microbial cultivation, plant-based composites, and sustainable dyeing methods.

Each area brings unique challenges and opportunities for creating eco-friendly materials that mimic or even surpass synthetic ones.

Biopolymers and Bioplastics: Research into biopolymers like polylactic acid (PLA) and polyhydroxyalkanoates (PHA) has paved the way for creating biodegradable alternatives to traditional plastics. These bioplastics, sourced from renewable agricultural products, are designed to decompose naturally. Studies on PLA and PHA’s performance have revealed strengths in their rigidity and suitability for food packaging, while ongoing research aims to improve flexibility and cost efficiency for broader applications.

Microbial and Fungal Cultivation (e.g., Mycelium): Microbial cultivation, especially with fungi like mycelium, offers a sustainable alternative for durable, lightweight, and biodegradable materials. Research into mycelium growth has led to innovative applications in fashion, construction, and packaging, where its natural rigidity and biodegradability provide eco-friendly solutions. Ongoing studies explore optimizing growth conditions and material properties to expand its applications.

Bacterial Cellulose (e.g., Kombucha SCOBY): Bacterial cellulose production through kombucha fermentation has proven to be an effective method for creating flexible, biodegradable bio-leathers. This cellulose has unique properties like breathability and strength, ideal for sustainable fashion. Researchers are exploring ways to alter its properties, such as thickness and durability, making it viable for broader applications in textiles and even biomedical fields.

Plant-Based Composites and Agricultural Waste: Researchers are harnessing agricultural byproducts, like orange peels, potato skins, and coffee grounds, to create biodegradable composites. These materials are used to develop lightweight, strong materials suitable for sustainable packaging, insulation, and more.

Sustainable Dyeing and Pigmentation: Research on natural dyes extracted from algae, food waste, and microbial cultures addresses the toxicity of traditional dyes. This field has led to non-toxic and eco-friendly coloring methods that can be adapted to a variety of bio-based materials. Advances in natural dye retention and color vibrancy promise to make bio-fabricated products more appealing and sustainable.

References & Inspiration

Biofabrication brings together innovative minds and organizations dedicated to transforming natural resources into sustainable materials. From trailblazing scientists to influential companies, the field draws inspiration from diverse sources:

Pioneers in Biofabrication:

Suzanne Lee: As the creator of Biocouture, Lee has championed the use of microbial cellulose (produced by bacteria) to develop biodegradable, leather-like materials for clothing and accessories. Her work illustrates how fashion can shift towards sustainable, lab-grown alternatives.

Neri Oxman: A professor at MIT Media Lab, Oxman merges design with biology in her groundbreaking projects like the Silk Pavilion, an architectural structure woven by silkworms. Oxman’s work in biodesign has expanded the boundaries of biofabrication in both the art and architecture worlds.

Influential Companies and Startups:

MycoWorks: Using mycelium, the root structure of mushrooms, MycoWorks develops sustainable leather alternatives for fashion, automotive, and consumer goods, offering a durable, environmentally-friendly replacement for animal leather.

Ecovative Design: Known for its eco-conscious packaging solutions, Ecovative Design also harnesses mycelium to create fully biodegradable materials that can replace Styrofoam and plastic in packaging, showing the potential for biofabrication to reshape consumer products.

Overview material research outcomes

In biofabrication, creating bioplastics or other bio-based materials involves a few essential components, each playing a specific role in achieving the desired properties. Here’s an overview of key components commonly used:

1. Polymers

Role: Provide the structural framework for bio-materials, contributing flexibility and strength.

Examples: Starch, cellulose, and gelatin, which are biodegradable and versatile.

1. Plasticizers

Role: Add flexibility, making materials softer and less brittle.

Examples: Glycerol and sorbitol, commonly used in films and packaging.

1. Crosslinkers

Role: Strengthen materials by bonding polymer chains, adding durability.

Examples: Citric acid and calcium chloride, used for structural integrity.

1. Fillers

Role: Add bulk, reduce costs, and improve biodegradability.

Examples: Natural fibers and calcium carbonate, which add strength and reduce plastic use.

1. Colorants

Role: Add natural color for aesthetic appeal.

Examples: Beetroot powder and charcoal, which provide red and black tones.

1. Stabilizers & Preservatives

Role: Extend the lifespan of organic materials by preventing decay.

Examples: Vinegar and lemon juice, which inhibit mold and microbial growth.

1. Binders

Role: Hold materials together, providing consistency and firmness.

Examples: Agar-agar and egg white, useful for flexible films.

1. Emulsifiers

Role: Help blend incompatible substances for smooth consistency.

Examples: Lecithin and beeswax, which stabilize mixtures in bio-composites.

These components work together to tailor biofabricated materials for specific applications, balancing flexibility, strength, texture, and sustainability. Depending on the desired end product, adjusting the proportions of each component allows for a wide range of customizations and functional properties.

Tools

Basic Tools

1. Measuring Tools:
   • Digital Scale: For accurate measurement of ingredients.
   • Graduated Cylinder or Measuring Cups: For measuring liquids.
2. Mixing Tools:
   • Mixing Bowls: For combining ingredients.
   • Hand Mixer or Blender: For pureeing fruits or mixing ingredients uniformly.
3. Spoons and Spatulas: For stirring and scraping mixtures.

Processing Equipment

• Dehydrator: Essential for drying out materials like fruit leather (lavashak) or alginate foils efficiently and at controlled temperatures.
• Oven: May be used for drying or curing certain materials that require heat, such as bioresins or silicone.
• Blender or Food Processor: For pureeing fruits or combining polymers and additives thoroughly.
• Syringe or Pipette: For precise application of materials, especially when extracting alginate threads or filling molds.

Molding and Shaping Tools

• Molds: Depending on the desired shape, silicone or plastic molds are essential for casting materials like bioresins or biosilicone.
• Rolling Pin: Useful for rolling out dough for biofoam or other dough-like materials.
• Cutting Tools: Scissors or Knife: For cutting finished products to the desired size.

Safety Equipment

• Gloves: To protect hands while working with chemicals or materials that can irritate skin.
• Face Mask or Respirator: Important when working with powders or materials that may release harmful fumes, especially when heating or curing.
• Safety Goggles: To protect eyes from splashes or reactions, especially when using chemicals.

Additional Tools

• Hot Plate or Heating Pad: For gentle heating of materials when necessary.
• Drying Rack or Surface: A flat, clean surface for laying out materials to dry properly.
• Storage Containers: For keeping finished products, ingredients, and mixtures organized and free from contaminants.

Process and workflow

1. Preparation: Assemble ingredients (polymers, plasticizers, etc.) and necessary equipment.

2. Material Selection:

   • Choose Base Material: Select a primary polymer (e.g., alginate, starch).
   • Additives: Decide on additional ingredients to enhance properties.

3. Mixing:

   • Measure Ingredients: Accurately quantify components.
   • Mix: Combine base material and additives until uniform.

4. Molding:

   • Prepare Molds: Select or create molds for shaping.
   • Pour/Spread Mixture: Transfer the mixture into molds or spread it out.

5. Curing/Drying: Allow the material to dry or cure in a controlled environment (e.g., dehydrator or oven).

Ingredients & Recipes for crafted materials:

Here are my recipes:

Biosilicone

A sustainable, flexible silicone substitute. This project was a collaborative effort, with Anoush.

ingredientsrecipe

• Gelatin 7 gr
• Water 21 gr
• Glycerin 3 drops

1. Dissolve gelatin in hot water, add glycerin for flexibility.
2. Pour into molds and allow to set for a flexible, rubbery material.

Discussion

• Shrinkage and Deformation: Shrinks approximately 25%, with minimal warping when dried under gentle weight. Prolonged drying prevents mold formation.
• Elasticity: Highly flexible and rubber-like, similar to commercial silicone.
• Surface Finish: Smooth, matte, and slightly sticky at first; tackiness decreases over time.
• Transparency: Semi-transparent, with a slight opacity that softens colors.
• Durability: Durable and resistant to tearing, with a high resilience to bending and stretching.
• Drying Time: Slow to dry; can take several days, especially in thicker casts.
• Handling Requirements: Requires careful pressing to avoid surface irregularities; should be dried on a smooth, non-porous surface.
• Reaction to Additives: Compatible with natural colorants, though heavy additives may interfere with curing.
• Color Retention: Maintains vibrant colors due to its inherent UV stability.
• Strength Under Pressure: Resilient and maintains flexibility; can stretch and return to form under moderate pressure.
• Tactile Qualities: Soft and rubbery, providing a satisfying bounce when pressed.
• Weathering Properties: Water-resistant, maintaining flexibility in both hot and cold weather.
• Biodegradability: Limited biodegradability; decomposes slowly but can be repurposed or upcycled.

Gelatin Foil

A flexible, biodegradable film. This project was a collaborative effort, developed alongside the participants of our lab.

ingredientsrecipe

• Gelatin 7 gr
• Water 21 gr
• Glycerin 3 drops

1. Dissolve gelatin in warm water and add a few drops of glycerin
2. Pour onto a flat surface, spreading thinly.
3. Leave to dry completely for a flexible, transparent film.

Discussion

• Shrinkage and Deformation: Shrinks around 20%, with slight curling at edges if not dried flat. Even drying results in a smoother appearance.
• Elasticity: Flexible and stretchy when freshly made; hardens over time but retains some pliability.
• Surface Finish: Smooth and semi-glossy, with some tackiness initially.
• Transparency: Partially transparent, adding an interesting depth to colors.
• Durability: Not highly durable; sensitive to moisture and may soften when re-exposed to water.
• Drying Time: Usually takes 1–2 days, depending on thickness and ambient conditions.
• Handling Requirements: Sensitive to handling while drying as it is tacky. Requires even, flat drying to prevent curling.
• Reaction to Additives: Compatible with some natural pigments, but acidic additives can affect texture.
• Color Retention: Colors may appear muted, with pastel tones. Susceptible to fading with UV exposure.
• Strength Under Pressure: Flexible when fresh but becomes brittle as it ages.
• Tactile Qualities: Soft, pliable, with a smooth, slightly sticky surface initially.
• Weathering Properties: Loses rigidity in humid conditions, as it reabsorbs moisture.
• Biodegradability: Biodegradable, breaking down easily when reintroduced to moisture-rich environments.

Alginate Foil

A thin, flexible alginate film.

ingredientsrecipe

• Sodium alginate 10 gr
• Water 250 ml
• Calcium chloride 5 gr

1. Dissolve sodium alginate in water and pour onto a flat surface.
2. Spray lightly with a calcium chloride solution.
3. Let dry to form a thin, transparent film.

Discussion

• Shrinkage and Deformation: Shrinks around 20% and remains flat if dried evenly. Edges may curl if not pressed down.
• Elasticity: Smooth and flexible, with moderate elasticity.
• Surface Finish: Smooth and slightly glossy, which reflects light well.
• Transparency: Translucent, especially in thin layers.
• Durability: Fairly durable but sensitive to humidity and water, which can soften or deform it.
• Drying Time: Dries within 1–2 days.
• Handling Requirements: Best dried flat to avoid curling.
• Reaction to Additives: Compatible with light pigments, but heavy dyes may make it brittle.
• Color Retention: Colors remain but may develop a slight haziness.
• Strength Under Pressure: Somewhat delicate but holds its shape if handled gently.
• Tactile Qualities: Smooth and flexible with a semi-gloss finish.
• Weathering Properties: Prone to softening in high humidity.
• Biodegradability: Fully compostable, breaking down in moist conditions.

Alginate String

A strong, flexible string of alginate for bio-based textiles.This project was a collaborative effort, developed alongside the participants of our lab.

ingredientsrecipe

• Sodium alginate 10 gr
• Water 400 ml
• Calcium chloride 40 gr

1. Mix 400mL of water with alginate to create an emulsion.
2. Allow the mixture to rest to release any trapped air bubbles.
3. Prepare a 10% calcium chloride solution.
4. Draw sodium alginate solution through a thin nozzle into a calcium chloride bath.
5. Leave the threads in the solution for 5 minutes.
6. Rinse the threads in water.
7. Stretch the threads out to dry.

Discussion

• Shrinkage and Deformation: Shrinkage around 10%; strings hold shape well if tension is applied during drying.
• Elasticity: Slightly firm with mild flexibility, feels durable yet pliable.
• Surface Finish: Smooth and string-like, with a firm surface.
• Transparency: Semi-transparent, offering a subtle visibility.
• Durability: Fairly strong for threading or lightweight applications.
• Drying Time: Usually dries within 24 hours.
• Handling Requirements: Needs to be stretched out during drying to maintain length.
• Reaction to Additives: Limited compatibility with additives; can become stiff.
• Color Retention: Holds color moderately well but fades with time.
• Strength Under Pressure: Flexible but can snap if pulled too tightly.
• Tactile Qualities: Smooth and flexible, with a slight gloss.
• Weathering Properties: Sensitive to moisture, becoming soft if rehydrated.
• Biodegradability: Breaks down quickly in compost

Agar Foil

A biodegradable, flexible film from agar.

ingredientsrecipe

• Agar-agar 10 gr
• Water 50 gr
• Glycerin 3 drops

1. Dissolve agar powder in hot water, add a few drops of glycerin.
2. Pour onto a flat surface, spreading thinly.
3. Let it cool and dry to form a flexible, transparent film.

Discussion

• Shrinkage and Deformation: Approximately 15% shrinkage, drying relatively flat with minimal curling.
• Elasticity: Flexible initially but firms up over time with a slightly brittle edge.
• Surface Finish: Smooth and semi-glossy, providing a gentle shine.
• Transparency: Translucent, giving a soft, delicate appearance.
• Durability: Sensitive to moisture but stable in dry conditions.
• Drying Time: Dries within 1–2 days.
• Handling Requirements: Requires even drying for a smooth finish.
• Reaction to Additives: Accepts some dyes, but these may reduce flexibility.
• Color Retention: Retains colors well initially but may fade with sunlight.
• Strength Under Pressure: Fairly rigid; can crack if bent.
• Tactile Qualities: Smooth, with a slightly glassy feel.
• Weathering Properties: Sensitive to water; rehydrates easily.
• Biodegradability: Decomposes quickly in compost.

Fruit leather

In Persian culture, Lavashak occupies a cherished space as a traditional fruit leather, predominantly made from sour or sweet-sour fruits. This delightful treat is not only a nostalgic snack but also a testament to the region's agricultural heritage and preservation techniques. Similarly, Armenian "fruit lavash," known as Ttu Lavash (which translates to "sour lavash"), mirrors this practice, embodying the art of natural fruit preservation.

The creation of both lavashak and Ttu Lavash begins with the selection of ripe, flavorful fruits, such as apricots, plums, and various berries. These fruits are carefully pureed, allowing their natural flavors to shine through. The puree is then spread in a thin layer and sun-dried, a process that concentrates the fruit's sweetness while enhancing its flavor profile. This method results in a chewy, leathery snack that is free from added sugars and preservatives, highlighting the essence of the fruits used.

The final product boasts not only a delightful taste but also a unique texture, making it a nutrient-dense option that can be stored for extended periods. Both Lavashak and fruit lavash are celebrated for their rich flavors and versatility, serving as nutritious snacks, energy boosters, or even culinary ingredients. They encapsulate the essence of the region's fruit bounty while embracing a sustainable approach to food preservation, reflecting a deep-rooted appreciation for nature’s gifts and traditional craftsmanship.

Many modern methods for producing lavash—including both traditional Armenian lavash and Persian lavashak—now incorporate heaters or dehydrators as part of the drying process. While the traditional method often relies on sun-drying, the use of heaters provides several advantages:

Advantages of Using Heaters for Lavash Production:

• Controlled Environment: Heaters allow for better control over temperature and humidity, ensuring consistent drying conditions regardless of weather. This control can improve the quality and safety of the final product.

• Faster Drying: Using heaters can significantly reduce the drying time compared to natural sun-drying, making the production process more efficient and scalable, especially in regions with less favorable weather conditions.

• Reduced Risk of Contamination: Drying indoors with heaters minimizes the risk of contamination from insects, dust, or other environmental factors that can affect sun-dried products.

• Year-Round Production: Heaters enable producers to create lavash throughout the year, regardless of seasonal changes in climate, thus increasing supply consistency.

IngredientsProcedure

• Fruits: Typically sour or sweet-sour fruits.
• Optional Sweeteners: Though traditional recipes do not include added sugars, some variations might incorporate honey or sugar to adjust sweetness, depending on the tartness of the fruit used.
• Flavor Enhancers: Some recipes may add spices (like cinnamon) or citrus juice to enhance the flavor profile.
• Oil or Butter: Occasionally included for a richer taste and softer texture.
• Salt: Salt enhances the flavor of the bread and helps to strengthen the dough.
• Yeast: While traditional lavash may not always require yeast, many modern recipes use either active dry yeast or instant yeast to help the dough rise, resulting in a softer texture. Some versions use sourdough starter for a more complex flavor.
• Water: Warm water is essential for hydrating the flour and forming the dough.

1. Fruit Selection and Pureeing: Ripe, juicy fruits are selected for their flavor and nutritional value. These fruits are often pitted.
2. Pureed into a smooth consistency without any added sugars or artificial ingredients.
3. Spreading and Sun-Drying: The fruit puree is then spread in a thin layer on a smooth surface—traditionally a cloth or large tray—forming a flexible, leather-like sheet when dried.
4. Drying process is typically done under the sun or in heaters, with the open air contributing to a unique depth of flavor while preserving the fruit's natural nutrients.
5. Natural Preservation: The drying process removes most of the water content, preventing bacterial growth and thus preserving the puree naturally for long periods.
6. The resulting fruit lavash has a distinct sweet-sour taste, ideal for storage and long-term use.

Discussion

This process and product provide an exciting model for biofabrication and sustainable materials:

• Durability and Flexibility: The leathery, bendable nature of fruit lavash makes it akin to a naturally created biopolymer, with qualities similar to leather substitutes and flexible films.
• Edibility and Safety: Since it’s purely made of fruit, it’s safe and edible, providing inspiration for bio-materials in food-safe applications or temporary packaging.
• Natural Dyes and Pigments: The vibrant colors of fruit lavash can also inspire natural dye applications, as the pigments of the fruit remain visible, offering a sustainable, chemical-free coloring option.

Result

1. Laser Cutting Process
   • Parameter Testing:Since fruit leather is a non-standard material for laser cutting, I began by experimenting with high-speed, low-power settings to avoid burning or melting
   • I gradually adjusted the parameters, testing small sections of the material to refine the settings.

1. Assembly and Finishing
   • Forming the Pieces
   • Joining and Detailing

Documenting and comparing experiments

TEST SERIE BIO-PLASTIC

Material pic	Material name	polymer	plastifier	filler	emulsifier
	Biosilicone	Gelatin 7 gr	Glycerin 3 drops	Silica - increases tensile strength and reduces costs	Not usually applicable
	Gelatin Foil	Gelatin 7 gr	Glycerin 3 drops	Starch - can be added to enhance strength and reduce costs	Lecithin - assists in the dispersion of other ingredients
	Alginate Foil	Sodium alginate 10 gr	Glycerin 3 drops	Natural fibers (e.g., cellulose) - can be incorporated for added strength	Lecithin - may assist in creating a uniform mixture
	Alginate String	Sodium alginate 10 gr	Glycerin 3 drops	None typically used	None required
	Agar Foil	Agar-agar 10 gr	Glycerin 3 drops	Natural fibers can be added to improve strength	Lecithin - can assist in mixing

Conclusion

My initial attempt at creating a beautiful biomaterial didn’t go as planned, but it was a valuable learning experience that significantly improved the next recipes. Each setback taught me more about refining my approach, ultimately allowing me to achieve better results in later iterations.

1. Speed of Drying

   • Impact on Structure: Faster drying can lead to uneven moisture distribution, resulting in cracks or warping, while slower drying allows for more uniform moisture removal.
   • Control of Properties: The drying speed affects the mechanical properties of the material. For instance, rapid drying can create a denser structure, while slower drying may enhance flexibility.

2. Amount of Water

   • Viscosity and Consistency: The water content in mixtures affects the viscosity, influencing how well materials can be shaped or molded. Higher water content generally leads to a softer, more pliable material, while lower water content can create a firmer structure.
   • Hydration of Polymers: In materials like alginate and gelatin, the amount of water is critical for proper hydration and gel formation. Insufficient water can prevent the polymer from achieving its desired texture.

3. Temperature: The temperature during drying and curing can greatly influence the final properties of the material. Higher temperatures can speed up drying but may also lead to thermal degradation or unwanted chemical reactions.

4. Humidity: The relative humidity of the environment affects the drying process. High humidity can slow drying, while low humidity can accelerate it, potentially leading to cracks or deformation.

5. Airflow: Proper airflow around drying materials helps prevent moisture accumulation and supports even drying, reducing the risk of mold and ensuring uniformity.

6. Thickness of Material: The thickness of the material layer affects drying time. Thicker layers take longer to dry, which can lead to issues like mold growth if not monitored.

7. Type of Filler or Additive: The addition of fillers or plasticizers can affect water retention and drying properties. For example, certain fillers may absorb moisture, influencing the overall water content and drying dynamics.

8. Chemical Composition: The specific polymers and additives used in each material can react differently to water and drying conditions. Understanding these interactions is crucial for optimizing formulations.

Ingredients & Recipes for grown materials:

Bacterial Cellulose (e.g., Kombucha Leather):

Kombucha is a fermented beverage made by fermenting sweetened tea with a symbiotic culture of bacteria and yeast (SCOBY). Beyond its role as a drink, kombucha is also significant in the field of biofabrication due to its production of bacterial cellulose—a versatile, biodegradable material with unique applications.

Kombucha's Role in Biofabrication

When kombucha ferments, the bacteria in the SCOBY consume sugars in the tea, producing a layer of cellulose on the surface. This cellulose is what biofabricators use to create kombucha leather or bacterial cellulose. With proper treatment and drying, this cellulose layer can be used as an alternative to traditional leather and plastic.

How Kombucha Leather is Made

1. Fermentation: Sweet tea is combined with a SCOBY in a large, open container. Over several weeks, the bacteria produce a thick layer of cellulose on the tea’s surface.

2. Harvesting: After a sufficient thickness is achieved, the cellulose is harvested from the liquid. This layer resembles a gelatinous sheet that can be further processed.

3. Rinsing and Boiling: To remove any residual acidity and ensure cleanliness, the cellulose is typically rinsed and sometimes boiled.

4. Drying: The rinsed cellulose is stretched and dried to form a flat, flexible material with a texture resembling leather. This drying step is crucial, as it determines the flexibility, thickness, and final texture of the kombucha leather.

5. Finishing and Treating: Depending on its intended use, kombucha leather can be treated with oils or coatings to enhance durability and water resistance, as it can otherwise remain sensitive to moisture.

Key Parameters in Kombucha Leather Production

• Growth Duration: The longer the fermentation period, the thicker the cellulose layer. Typical growth periods range from 1-4 weeks, depending on conditions.

• Temperature and Humidity: Kombucha thrives in a warm, humid environment. Temperatures around 25-30°C are ideal for rapid growth.

• pH Levels: A slightly acidic environment promotes bacterial growth. Adjusting pH is essential to prevent contamination from unwanted microorganisms.

Properties and Uses of Kombucha Leather

• Flexible and Biodegradable: Kombucha leather is flexible and can be cut, sewn, or molded. Unlike traditional leather, it’s biodegradable, making it a sustainable alternative.

• Customizable Texture: Through dyeing, embossing, or adding surface finishes, kombucha leather can achieve different textures and appearances, making it suitable for fashion and design applications.

• Limitations: Kombucha leather can be sensitive to water, though treatments (such as waxing or oiling) can improve its durability and water resistance.