IAAC C-Biom.A Thesis: Additive Manufacturing of Seaweed as a Biocomposite Material

AMBER L AMINA R IA Additive Manufacturing of Seaweed as a Biocomposite Material

Thesis Author: Ilaena Mariam Napier Thesis Advisors: Marcos Cruz & Kunaljit Chadha

AMBER LAMINA R IA Additive Manufacturing of Seaweed as a Biocomposite Material

Thesis Author: Ilaena Mariam Napier Thesis Advisors: Marcos Cruz & Kunaljit Chadha Thesis Studio: C-Biom.A

Institute for Advanced Architecture of Catalonia Master in Advanced Architecture II (MAA02)

Barcelona, Spain September 2021

Thesis presented to obtain the qualification of Master Degree from the Institute of Advanced Architecture of Catalonia

SEAWEED IN WATER Photo credit: Lachlan Gowen - Unsplash Images

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AB ST R AC T This research aims to develop and understand kelp as a biocomposite material within the built environment. The research is motivated by current issues of global warming, the problem of material waste, and the need to create more sustainable manufacturing processes. The use of seaweed brings attention to organic, underutilized resources that are in abundance in the world and should be used to create more renewable materials. Seaweed doesn't require land, fresh water or fertilizer, only sunlight and nutrients within the ocean.

In ideal conditions kelp grows extremely fast at a rate of almost 30 times faster than land plants. Seaweed-based bioplastics can alleviate the effects of global warming through its production as it encompasses a carbon sink, as well as create an alternative material system from an organic resource, creating a closed loop.

There are few architectural projects that incorporate seaweed as a construction material, however eelgrass - a type of seagrass - has been established as a natural material for roofing and wall insulation due to its large salt content which restricts mold and ultimately preserves the material for centuries. Seaweed is also naturally fire-resistant, deeming it a suitable material for architecture. There have been recent developments in seaweed-based applications in biofuels, soil bioremediation and biomaterials which all provide sustainable solutions. Sodium alginate, a derivative from brown seaweed, is a multifunctional material with the ability to homogenize with other materials to create a bioplastic.

The approach of the research focuses on the development of a water-based biocomposite material made from sodium alginate. This water-based recipe made only from renewable and non-toxic materials, combines sodium alginate powder and cellulose powder as the biopolymers, glycerin as the plasticizer, and kelp powder as an additive. Once dried, the outcome material creates unique aesthetic qualities that can be compared to leather and can be incorporated as a membrane or skin within the built environment. By creating a biodegradable, biocomposite material, one can determine new ways to design and fabricate it.

A set of methodical experiments were conducted and recorded, with the aim of creating a bioplastic material with adaptable material properties based on strength, translucency

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and flexibility. The shrinkage due to water content as well as viscosity of the material steered the progression of the research towards a specific type of manufacturing process.

A progression of techniques range from pouring the material into frames to 3D extrusion printing the material into flat sheets. This change in production method allows for the ability to control the shape of the material being printed as well as the deposition of material across the shape. This is beneficial in order to reduce the shrinkage and deformation, however each print remains organic and unique. A further incorporation of a robotic arm gave the opportunity to show how the material has the ability to be scaled.

By creating, designing and fabricating using renewable and biocompatible polymers, one is able to design an architectural strategy that would not contribute to carbon emissions but have the ability to create a natural resource cycle. Therefore, the material can decay and return to the earth, for the purpose of remediating soils and fueling new growth. This water-based kelp biocomposite material additionally has the ability to be fully recovered and reused, relieving the strain on non-renewable resources. The project aims to devise a system that encourages the protection and nourishment of the ecosystems, while at the same time providing humans with a new material system.

Key wo rds

Seaweed Biocomposite Material / Bio-based Polymer / Kelp Bioplastic / Sodium Alginate / Robotic Additive Manufacturing / Material Ecology / Material-informed Design / Water-based Fabrication

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P RE FAC E The key aspects of this investigation are material experimentation and physical prototyping through digital fabrication. The practical material research has been conducted in a controlled laboratory environment, with care and precision taken to ensure accurate results. All experiments shown in this document are carried out by the author. The goal of this research is to create a novel biocomposite material from seaweed and develop a custom manufacturing process to create large sheets in order to bring awareness to the problem of petroleum-based materials and their environmental effects.

The following research focuses on finding an alternative material option not only within the construction industry but other industries that are continuously polluting and using up precious resources. With growing concerns about global warming and the effects of climate change, the growing of seaweed (more specifically kelp) is one of the most effective and natural ways that we as humans can implement in order to reduce the rising temperatures.

Not only does it sequester large amounts of carbon from the atmosphere and ocean, it cleans the surrounding ocean water, provides habitat for thousands of marine species, and once harvested, can provide humans, animals and soils with a magnitude of benefits.

This research is guided by a growing interest and curiosity towards this multifunctional organism which began with Professor Tim Flannery's TED talk on how seaweed can help curb global warming as well as his 2017 book titled "Sunshine and Seaweed: An Argument for How to Feed, Power and Clean Up the World".

The main benefit of bio-based materials within an architectural scope is that they originate from renewable resources and therefore enable resource-efficient components. By creating new ways to fabricate these new materials, as well as how to apply them within the engineering, product or architectural industries, we can reduce the reliance on renewable resources. This in turn can reduce our environmental mark and reduce the effects of climate change. If not now, when?

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ACK N OW L ED GME NT S Firstly, I would like to express my sincere gratitude to my thesis advisor, Marcos Cruz, for his guidance, dedication and continuous inspiration throughout this thesis project. His remarks were vital to the outcome of this thesis and will always be deeply appreciated. His virtual crits were constructive and positive, even when it was difficult for him to not be physically present to see, feel and smell the material prototypes.

Additionally, I would like to thank Kunaljit Chadha for his dedication, digital fabrication support, and encouragement throughout the project.

I would also like to thank: Mathilde Marengo for her continuous advice and theoretical support which laid the foundations for the thesis to be built upon, Nikol Kirova for her support in terms of organizing and managing everything from behind the scenes, as well as Ricardo Mayor and the IAAC fabrication team for their patience and fabrication assistance.

Lastly, I would like to thank my family and friends for their support and encouragement throughout the two years as a student at IAAC.

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I N D EX Abstract

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Preface

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Acknowledgments

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Index

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Introduction

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Thesis Statement Aims & Objectives Methodology

Context: Carbon Sequestration

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Carbon Cycle & Biosequestration Blue Carbon Regenerative Ocean Farming

Seaweed State of the Art

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Seaweed Material Research

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Seaweed Properties & Characteristics Seaweed Extraction: Sodium Alginate Bioplastic Research Impact of Bioplastics Initial Material Experiments Recipe Development & Behavioral Attributes

Kelp Biocomposite Additive Manufacturing

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Extrusion Printing Strategies & Parameters Catalogue of Explorations Unforeseen Outcomes & Solutions

Material Informed Design

129

Design for Shrinkage Geometric Studies Design Development

Kelp Biocomposite Application

149

Material Driven Design Biodegradability

Conclusions

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Bibliography

159

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01 INT R OD UCT ION

KELP ON SANDY BEACH, CALIFORNIA Photo credit: James Lee - Unsplash Images

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Reduce Ocean Acidification

Carbon Drawdown

“

Oceans absorb about 30% of carbon

dioxide produced by humans, buffering the impacts of global warming.

“

“

To limit global warming to 1.5 degrees celsius, as called for in the Paris Agreement, greenhouse emissions must fall by 7.6% each year starting in 2020.

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Regenerate Natural Systems

“

“

The global material footprint grew by 17.4% in 2017 as compared to 2010.

“

I nt ro d u c ti o n

The global challenges we are facing due to climate change and the depletion of natural resources is forcing us to radically change the way we construct our built environment and to take a new critical stance in how we design and construct. The construction industry plays an important role in all industrial sectors, as it currently is responsible for a large share of resource consumption, energy use, carbon dioxide emissions and waste generation (Bekkering, Nan, and Schröder, 2021). This is having a catastrophic effect on our surrounding environment which can be seen within the ecosystems around us. With growing concerns about the effects of global warming on the environment, there needs to be a shift in the way we interact with our natural environment by integrating nature-based solutions into all sectors of our daily lives.

The research is framed within the same aspects as the Sustainable Development Goals (SDG) or Global Goals which are a collection of 17 interlinked goals that are designed to be a starting point in order to achieve a better and more sustainable future for all. The SDGs were set up in 2015 by the United Nations General Assembly and are aimed to be achieved by 2030. This research focuses on three interrelated goals of the SDGs namely goal 12: to ensure sustainable consumption and production patterns, goal 13: to take urgent action to combat climate change and its impacts, and goal 14: to conserve and sustainably use the oceans, seas and marine resources. The challenge is to reduce non-renewable resource consumption by turning to renewable resources that alleviate the effects of climate change in their production instead of contributing to it. Looking to the ocean for renewable resources from blue carbon solutions, such as regenerative ocean farming of seaweed, is one solution to tackling these goals. By producing and harvesting seaweed in a sustainable manner, we will be able to alleviate the effects of climate change through carbon sequestration, provide habitat for marine ecosystems, and most importantly produce and harvest a renewable biomass that can be used on a multitude of platforms.

"Today's industrial manufacturing processes are usually wasteful and their products are generally difficult to recycle" - Neri Oxman, 2015

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The use of renewable bio-based materials for large-scale applications within the built environment is still not widely acknowledged or accepted despite an urgent need for alternatives to non-renewable materials as natural resources are depleting. This is in spite of the fact that recent studies have proven that organic materials display high mechanical properties (Mogas-Soldevila, Duro-Royo and Oxman, 2014). Organic compounds embody more efficient and adaptable properties compared to synthetic materials, and leave no environmental mark. Natural resources such as polymers and polysaccharides, which include chitosan, cellulose, pectin and alginate, are all found naturally in abundance compared to many man-made synthetic materials (Mogas-Soldevila, Duro-Royo and Oxman, 2014). These organic ingredients are renewable, available in abundance, biocompatible and environmentally friendly. Then why are we not focusing our attention on developing these materials at a large scale?

Modern human-made structures are largely inefficient when comparing them to nature based structures, which are in turn complex and use functionally-graded material properties which are able to adapt and be reused within the same environment (Lesna and Nicholas, 2020). By introducing these renewable polymers into the built environment by creating new bio-based composites will have a significant impact on the environment and still provide it with the same benefits. By having the ability to carefully construct the composition of these composites, we are able to tailor these materials with specific characteristics for specific applications and come in a variety of shapes, sizes and colours, very similar to plastics. The abundance and utility of natural polymers to create and fabricate structural biopolymers is no secret to the scientific community. Cellulose is the world’s most abundant organic polymer, giving wood its mechanical properties, and has been used to make a range of products such as pharmaceuticals, building materials and food additives. An oceanic equivalent is chitin, the second most abundant polymer in the world, and similar polymers made from oceanic plants such as alginate and carrageenan, are largely overlooked because of their water-reliant dependencies.

These bio-based polymers have been found to be promising as base ingredients when making bioplastics or biocomposites. Bioplastics still have a long way to go until they are

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able to compete with widely-used petroleum-based plastics, which is largely due to the fear of losing land, water use and soil erosion in order to produce them (Kretzer et al., 2020).

However in this case of using seaweed as a base ingredient for bioplastics, these concerns are diminished as seaweed does not require land, fresh water or fertilizer to grow.

Recent development in tissue engineering using sodium alginate (due to its biocompatibility and low-toxicity) as a base material to create biodegradable scaffolds shows huge promise in mechanical and biological properties (Mogas-Soldevila, Duro-Royo and Oxman, 2014). Polymers such as chitosan and sodium alginate have been shown to enable the manufacturing of three-dimensional objects, therefore showing a platform for large-scale additive manufacturing of components that are fully compostable to be created. Research carried out by Neri Oxman and her team at MIT Media Lab (Mediated Matter) presents water-based robotic fabrication as an enabling technology for additive manufacturing for biodegradable composites of chitosan and sodium alginate. This is done in order to produce large-scale 3D shapes for the reduction of the need of molds when creating components.

This additive manufacturing of functionally-graded hydrogel composites is done through a multi-chamber extrusion system, creating an adaptable and controlled platform to print with. The research poses water as the 'core' from which the whole project emerges from and dissolves into, creating a temporary structure that forms a closed loop system. Without it, polysaccharides such as chitosan would remain brittle. The fabrication in conjunction with the surrounding controlled environment play a vital role in the general outcome of the printed material in terms of curing, water-storage, and hydration-induced shape change.

Bekkering, J., Nan, C. and Schröder, T. (2021), 'Circularity and Biobased Materials Evaluation of the Status Quo and Defining Future Perspectives in Architecture and ­Design', p. 5.

Kretzer, M., et al., (2020), 'Robotic Fabrication with Bioplastic Materials', p. 604-612.

Lesna, J. and Nicholas, P. (2020), 'DE GRADUS' - RE: Anthropocene, 2, p. 383–392.

Mogas-Soldevila, L., Duro-Royo, J. and Oxman, N., (2014), 'Water-Based Robotic Fabrication: Large-Scale Additive Manufacturing of Functionally Graded Hydrogel Composites via Multichamber Extrusion' - 3D Printing and Additive Manufacturing, 1(3), p.141-151.

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T hes i s St atem ent

Regenerative ocean farming is the focus of enhancing the production of kelp in order to alleviate the effects of climate change through carbon drawdown, and in turn can be harvested and used to demonstrate alternative nature-based solutions to petroleumbased materials within the built environment through the process of robotic additive manufacturing of water-based composites, in order to reduce waste within the resource cycle.

A i m s & Obj ec t i ves

Aim: To develop a new material derived from kelp with novel properties that can be used as an alternative organic material option, that has the ability to be robotically extruded to create large-scale membranes to be used within the construction industry with a high-value material recovery rate which enables multiple product life cycles. Because of its organic origin, the material will be able to simultaneously act as a carbon sink and as a substrate for future growth and remediation of soils.

Objectives: 1.

To catalogue a material library of small-scale experiments in order to gain a basic understanding of the production process, physical properties, and opportunities and constraints of the material in order to achieve large-scale production.

2. To design a water-based fabrication process best fitted to the material's needs based on extensive prototyping in order to understand the printability of the material and how it can be controlled and adapted to suit the preferred outcome.

3. To develop a strategy of circular design based on the material's behavioral performance and degradability in order to create a natural resource cycle that remediates soils and fuels future growth.

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Met h o d ol o gy

The first section introduces the framework of the global challenges that we face such as global warming, the problem of material waste, and the need to create more sustainable manufacturing processes. The focus is on the context of carbon sequestration and natural technologies within the ocean that can be adapted to tackle climate change. It outlines the scope of research and shows the interest of the researcher to investigate alternative options to what is currently in place today. Additionally, state of the art examples of uses of raw and processed seaweed are studied. This includes traditional Danish construction using eelgrass (a type of seagrass that differs from seaweed in terms of its reproduction, structure and how they transport nutrients and dissolved gases) as well as installation projects done at The Department of Seaweed by Julia Lohmann. State of the art design projects are looked at in order to understand applications of bioplastics and how seaweedbased bioplastics are used as an alternative material for textiles and packaging.

The second section follows on with the material research of seaweed and an extraction of brown seaweed, namely sodium alginate. A set of methodical experiments were conducted and recorded, with the aim of creating a bioplastic material with certain qualities based on strength, translucency and flexibility. Certain material characteristics and behaviors emerged from which the research adapted to. The shrinkage due to water content as well as viscosity of the material steered the progression of the research towards a specific type of manufacturing process.

The third section explores additive manufacturing of the material using digital fabrication methods. This section shows a catalogue of real life experimentation of material prototypes with observations and evaluations of each.The evolution of the research is present in how the material has the ability to adapt and be scaled. Results obtained from developing an applied research of water-based fabrication draws attention to uncontrollable material behaviors that emerge during the curing process and concludes how these characteristics can be used as possibilities for an architectural application to create a material-informed design.

Finally, the conclusions with a general overview and future developments in the field of research are presented as the closing part of the research.

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AIR POLLUTION Photo credit: Ludvig Hedenborg - Pexels Image

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02 CONT E XT

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C a r bo n Cyc l e & Biosequestration

Carbon is an essential element for all life on Earth. This element is in a constant state of movement between phases from place to place, or lifeform to lifeform. Places that retain carbon and keep it from entering the Earth's atmosphere are known as carbon sinks or reservoirs. Carbon moves between reservoirs through processes such as photosynthesis, burning of fossil fuels and respiration. This is known as the carbon cycle.

The Earth and its atmosphere is a closed system, which means that the amount of carbon in this system never changes, however the amount of carbon in certain reservoirs is in a constant flux as it is moving because of these processes. There are a variety of reservoirs, or carbon sinks, with which carbon moves between. On Earth, the majority of carbon is stored in rocks and sediments, with the rest located within the ocean, atmosphere and in living organisms (NOAA, 2021). Carbon is released back into the atmosphere through events such as decomposition of organisms, volcanic eruptions, forest fires or when fossil fuels are burned. Humans have offset the balance between the reservoirs due to anthropogenic activities such as excessive burning of fossil fuels and deforestation. As a result there is an increased amount of carbon dioxide within the Earth's atmosphere which is pushing up the Earth's temperature causing climate change.

- In order to limit global warming to 1.5 degrees Celsius, as called for by the Paris Agreement, greenhouse emissions must fall by 7.6% each year starting in 2020.

Carbon sequestration is the long-term storage of carbon within plants, soils, geologic formations and the ocean. It occurs both naturally and as a result of anthropogenic activities and typically refers to the storage of carbon that has the immediate potential to become carbon dioxide gas (Selin, 2021). For example, large-scale forest regrowth is a form of carbon sequestration as the forests themselves capture carbon through photosynthesis, serving as a carbon sink or reservoir. The ocean absorbs about 30% of annual carbon emissions produced by humans which is buffering the impacts of global warming but has a negative impact on the ocean causing ocean acidification.The challenge is to reduce non-renewable resource consumption by turning to renewable resources that alleviate the effects of climate change in their production instead of contributing to it. Looking to the

NOAA - National Oceanic and Atmospheric Administration (2021), 'What is the carbon cycle?' - US Department of Commerce, N.O. and A.A. Selin, N.E. (2021), 'Carbon Sequestration | Definition, Methods, & Climate Change' - Encyclopedia Britannica

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ocean for renewable resources from Blue Carbon storage, is one solution to tackling these goals. By producing and harvesting seaweed in a sustainable manner, we will be able to alleviate the effects of climate change through carbon sequestration, which in turn will reduce ocean acidification, provide a cleaner environment for marine ecosystems as well as produce a renewable resource that has the potential to be used in a variety of ways.

Figure (page 25) - Carbon Cycle Processes (Author) CO2 released into atmosphere through combustion by burning of fossil fuels

ATMOSPHERE

CO2

CO2 absorbed by ocean through diffusion CO2 Sequestration of CO2

and photosynthesis of aquatic plants Release of oxygen

OCEAN

CO2 released into atmosphere through

3.

respiration and metabolism

through photosynthesis

from atmosphere

LAND

CO2

O2

1.

CO2

2.

CO2 Absorption

O2

C

by plants due to Photosynthesis

CO2

4.

5.

C

C

DECAY BACTERIA

SEDIMENTS

Deposition of inorganic carbon eg. shells as well as organic debris that turn into fossil fuels

Plant floats out to sea and sent to the

over millions of years

deep ocean to act as a carbon sink 1. Photosynthesis in primary consumers 2. Carbon transfer to secondary consumers 3. CO2 release through respiration and metabolism 4. Carbon sedimentation within dead plants and animals 5. Release of carbon in the form of fossil fuels

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B l u e C a r bo n

Figure (page 27, TOP) Seaweed as Blue Carbon Ecosystem

The amount of carbon stored in the oceanic sink exceeds the amount in the atmosphere.

Figure (page 27, BOTTOM) Critical Storage of Carbon in the Ocean and Coastal Habitats (IUCN, 2021)

warming. This is done through biological processes of photosynthesis and the building

Heat and carbon are continuously exchanged between the ocean's surface waters and the atmosphere, or it is stored in reservoirs beneath the ocean's depths for long periods. Oceans absorb about 30% of carbon dioxide produced by humans, buffering the impacts of global of calcium carbonate shells, as well as carbon dioxide dissolving in ocean water. This has a huge effect on the ocean's health, causing the water temperatures and sea levels to rise, as well as marine heat waves. Excessive carbon dioxide is causing ocean acidification, which makes it harder for shellfish and corals to grow their shells and skeletons. Ocean deoxygenation is also happening, affecting the process of photosynthesis by organisms, therefore causing a decline in marine ecosystems.

In response to growing concerns about climate change, considerable interest has been drawn to the possibility of increasing the rate of carbon sequestration through natural technologies within the ocean. The oceans itself accumulates carbon within coastal ecosystems, known as Blue Carbon. Blue Carbon coastal ecosystems occur in shallow waters and account for 50% of long-term carbon sequestration and only make up 2% of the ocean (IUCN, 2021). Blue Carbon ecosystems such as seagrass meadows, mangrove forests and salt marshes are important ecosystems that support the carbon cycle. They provide numerous benefits and services that are essential for climate change adaptation along coasts, which include shoreline protection from storms and rising sea levels, protection from shoreline erosion, regulation of coastal water quality, provision of habitat for marine life and endangered species, as well as food security for many coastal communities (The Blue Carbon Initiative, 2021). Despite their beneficial services, coastal Blue Carbon ecosystems are under threat as some of the most threatened ecosystems on Earth.

Another oceanic biomass that is generally overlooked as an ocean ecosystem capable of large scale carbon sequestration, is seaweed. As seaweed takes up carbon dioxide and releases oxygen through the process of photosynthesis, it can also contribute massively to carbon sequestration in the ocean. Seaweeds can grow at an exceptional rate, making it an excellent agent for absorbing vast amounts of carbon dioxide quickly. Once the carbon

IUCN - International Union for Conservation of Nature (2021), 'Blue carbon' - ICUN The Blue Carbon Initiative (2021), 'What is Blue Carbon?' - US Department of Commerce, N.O. and A.A.

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dioxide is stored within the biomass, it can be harvested for use or left to sink to the depths of the ocean, acting as a carbon reservoir. Seaweed fragments that float out into the open ocean are a mechanism to permanently store blue carbon at depth or on the seafloor.

Seaweed ecosystems such as kelp forests can therefore be added to the list of blue carbon ecosystems that sequester large amounts of carbon. So why are we not investing more into seaweed aquaculture to slow down the effects of climate change?

ATMOSPHERE CO2 released into atmosphere CO2 Absorption

through respiration and

by plants due to

metabolism

Photosynthesis Plant detritus floats

O2

CO2

Onshore transport and decomposition of carbon

C

LAND

OCEAN

out to the ocean

Air bladders burst, causing plant detritus to sink

Exported dissolved carbon travels to the deep ocean C

C

Carbon is sequestered/ buried in the deep ocean

83%

2%

50%

GLOBAL CARBON

COVERAGE

SEDIMENT COVERAGE

of the global carbon cycle is

Coastal habitats cover less than 2%

This 2% counts for approx. 50% of

circulated through the ocean

of the total ocean area

the ocean's sequestered carbon

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Boat in Ocean Photo credit: Eva Elijas - Pexels Images

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"Seaweeds can grow very fast – at rates more than 30 times those of land-based plants."

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Re g e n e r at i ve Ocea n Fa r m i ng

There has been a lot of focus on humanity to dramatically reduce atmospheric carbon within the next decade. The main topics in question are soil health, the health of the ocean and of course climate change. As we see within the carbon cycle, there is a direct relation between agriculture, soil health and the ocean. Recent focus has been given to regenerative agriculture of both land and sea. Regenerative agriculture refers to farming and grazing practices that reduce the effects of climate change by rebuilding soil organic matter and restoring degraded soil biodiversity, which results in both carbon drawdown and water cycle improvement. It incorporates practices like crop rotation, composting, mixed farming as well as smart technologies to improve efficiency. Regenerative farming is a holistic land management practice that focuses on the power of photosynthesis in plants to close the carbon cycle, while enhancing and improving soil health, crop resilience, and nutrient density (Regenerative Agriculture Initiative, 2017). This will largely impact and help the alleviation of climate change, and improvement of water quality and availability. These are done in order to improve the overall ecosystem and can be designed to be context-specific.

There are many types of farming and land-use practices that are used to create regenerative food systems and healthy natural ecosystems. With land agriculture taking up space and causing degradation of soils, why not look to the ocean for farming?

Aquaculture or regenerative ocean farming is one of these farming practices that is found in the ocean and incorporates blue carbon ecosystems such as seaweed. Ocean afforestation is a proposal for farming seaweed for carbon drawdown from the atmosphere and ocean.

Seaweed farming is the practice of cultivating and harvesting seaweed, and is becoming an increasingly competitive biomass production candidate for food and related uses. In simplest form, it consists of the management of naturally found batches. In the most advanced form, it consists of fully controlling the life cycle of algae. After harvesting this renewable resource, the seaweed is able to be used for a variety of uses, including food, fertilizer and biofuel. There are many organizations looking to incorporate seaweed and shellfish farming to create regenerative marine permaculture (von Herzen, 2021).

Ocean farming does not require land, fresh water or pesticides and fertilizers. Beyond seaweed's huge potential to counteract ocean acidification and provide habitat for marine

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ecosystems in at least 77 countries, seaweed can be processed into a biofuel. There has also been research done proving that adding seaweed to livestock feed can reduce the methane emissions from cattle and other livestock - which accounts for 70% of all greenhouse gases.

Seaweed can also be added to agricultural soil as a supplement, replacing petroleum-based fertilizers (Woody, 2019). There have been numerous organizations such as AtSeaNova and Greenwave that are developing systems that focus on regenerative seaweed farming.

Green Wave, a non-profit organization established by former fisherman Bren Smith, has come up with a 3D vertical ocean farming system which consists of underwater vertical gardens that grow seaweeds and shellfish on suspended floating ropes. Green Wave's vision is to create clusters of kelp-and-shellfish farms utilizing the entire water column, which can be strategically placed near seafood transporting or consumption hubs. The overall concept of 3D ocean farming is not new, it has been practiced in Asia for decades, where over 500 square kilometers of seaweed farms exist in the Yellow Sea. The seaweed farms are able to buffer the ocean's growing acidity and provide enough nutrients in the ocean water for ideal conditions for the cultivation of shellfish such as oysters, mussels and scallops. Despite the amount of growing attraction in aquaculture within coastal areas in North America and China of integrating kelp into sustainable marine farms, this farming practice is still in early stages of development (Flannery, 2017). Another concern is that there isn't enough knowledge to know whether this type of farming methodology will, when scaled up, have a negative effect on the marine ecosystem and environment around it. A rapid expansion in any industry without tight regulations can cause drawbacks. Unregulated seaweed farming could lead to deleterious impacts on the environment such as a reduction of genetic diversity of native seaweed species due to mono-cropping as well as a potential loss of species and habitat diversity. There could also be potential conflicts created between local residents and other water users such as boaters, fisherman and tourists (Boyd, McNevin, Clay & Johnson, 2005).Therefore, the seaweed industry should develop in a sustainable way instead of just to maximize profits. If we were to farm seaweed in a sustainable way, it could mitigate climate change, promote marine biodiversity and promote jobs in local communities.

Boyd, C., McNevin, A., Clay, J., Johnson, H., (2005), 'Positive and Negative Impacts of Seaweed Farming' ResearchGate, Flannery, T., (2017), 'Sunlight and Seaweed : an argument for how to feed, power and clean up the world' Regenerative Agriculture Initiative (2017), 'What is Regenerative Agriculture?' von Herzen, B. (2021), 'Climate Foundation: Marine Permaculture' - Climate Foundation Woody, T. (2019), 'Forests of seaweed can help climate change without risk of fire, Environment' - National Geographic

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INDONESIAN SEAWEED FARMING Local communities in Indonesia with square seaweed seabeds marked out by bamboo pegs with horizontal line running between the pegs.

ATSEANOVA A biotechnology company that supplies turnkey seaweed farms and the corresponding consumables for small or large scale algae farm businesses.

GREEN WAVE The 3D vertical ocean farming system which consist of underwater vertical gardens that grow seaweeds and shellfish on suspended floating ropes.

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SEAWEED GIRL CLOTHING LINE Jasmine Linington - Edinburgh College of Art MFA Student, Scotland

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03 S EAWEED S TAT E OF T HE A RT

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A rc h ite c tu r a l St ate of t he A rt

There are relatively few architectural projects that include the use of seaweed as a primary material. There has, however, been recent developments and research going into it as seaweed becomes a more sought-after alternative material. The projects that were studied are seen as a starting point in understanding the opportunities and limitations that this uncommon building material could do or become. Seaweed may seem like a relatively new and experimental material, however, there are places where seaweed grows naturally and in abundance, especially in cold coastal regions in the Northern hemisphere, where seaweed has been used as a construction material for centuries.

On the Danish island of Læsø, eelgrass (a type of seagrass) has been used to insulate the roofs and walls of traditional houses, creating a unique vernacular architecture. These large, cloak-like roofs that hang over the sides of the buildings date back to the time the island had a flourishing salt industry. This material was once in large abundance and would wash up regularly on the shores, where it was collected, dried and woven into bundles and piled onto the buildings. Seaweed displays properties that can be highly useful. As well as being an exceptional insulating material (comparable to mineral wool), it is non-toxic, fire-resistant, has high acoustic absorbing qualities and has the ability to absorb and give off moisture - which could be used to help regulate indoor temperatures (MaterialDistrict, 2016). Because of its high salt content, it is also mold resistant and does not decay easily.

Additionally, the material invites plant growth, giving the effect of a green roof or façade.

The combination of these efficient properties allows for this material to be extremely durable, having a life-span of up to 150 years. Unfortunately, during the 1920s, a fungal disease wiped out most of the eelgrass species around the island, causing a decline in using the material as thatching. Today there are less than 20 houses that are still originally thatched with eelgrass. Compared to normal thatched roofs which are still being built today, which have lifespans of between 30 and 40 years, an eelgrass roof can last for up to 200 to 400 years. This proves that traditional building techniques used locally-sourced, organic materials that were environmentally friendly have been lost due to industrialization and the growing demand for newer materials. With a larger sustainable focus in today's world, why are we not incorporating these types of materials in modern day building techniques?

Image (page 36, TOP) Traditional house in Læsø Image (page 36, BOTTOM) Traditional house in Læsø

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The Modern Seaweed House, designed by Vandkunsten and Realdania Byg pays tribute to the island of Læsø and it's traditional method of using locally sourced eelgrass as a building material. This house combines the traditional material with twenty-first century construction techniques. Instead of piling the eelgrass onto the roof, as previously done, the designers stuffed the material into netted bags they called 'pillows' and attached them in length across the timber-framed walls and roof of the house. The eelgrass was also used as an insulation layer within the walls and beneath the floors. The Modern Seaweed House is carefully assimilated into the landscape and shows a delicately balanced connection between nature, the historic surrounding buildings and Læsø's unique cultural history (Frearson, 2013). This project demonstrates a modern construction technique and the potential of eelgrass as a sustainable, locally sourced material that has extremely low energy consumption.

Kathryn Larsen, an architectural technologist and designer, was inspired by the vernacular Danish roofing system of the island of Læsø as well as The Modern Seaweed House by Vandkunsten and Realdania Byg. Her individual thesis research done in 2018 at the Copenhagen School of Design and Technology (KEA), focuses on eelgrass as an alternative sustainable material in architecture, once again extrapolating the highly efficient properties of this material. Seaweed Thatch Reimagined demonstrates a modern technique using this durable material to create prefabricated panels. These prefabrication timber panels are woven with eelgrass and natural resins and provide a new concept of a facade cladding system which can double as insulation and acoustic panels too. Once again, this project demonstrates how a modern construction technique combined with traditional vernacular architecture can create a beautiful and durable component, which, because of its origin, is carbon negative.

Image (page 39, TOP LEFT) The Modern Seaweed House, view of roof Image (page 39, TOP RIGHT) The Modern Seaweed House, eelgrass pillows Image (page 39, BOTTOM) The Modern Seaweed House, view of eelgrass cladding over timber structure

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Similar works done by designers Kirsten Lynge and Tobias Gumstrup Lund Øhrstrøm also use eelgrass in new products that are designed and available on the market as insulation batt (Læsø Zostera) and acoustic panels (Søuld). Tobias Gumstrup Lund Øhrstrøm's IAAC 2015 thesis project, Bio-concretion, also focused on combining eelgrass thatch roofing with modern day concrete construction, but aimed to reimagine the traditional design language of these roofs. The project investigates the combination of this ancient thatching technique with modern digital fabrication tools in order to integrate this traditional building technique into a more contemporary context, with particular focus on fiber direction, solar radiation and optimization of drainage paths (Øhrstrøm, 2015).

Within all of these projects, a lifespan analysis has indicated that buildings with eelgrass can be carbon-neutral if the material is sourced locally and harvested correctly. Building with seaweed is not a new venture, but now that this generation has been forced to reevaluate the way we as humans consume the Earth's resources, there have been advances into carbon-neutral and sustainable materials. Even though eelgrass differs from seaweed in terms of its reproduction, structure and how it transports nutrients and dissolved gases, it still acts in a similar manner once it is dried and used as a construction material. Seaweed has often been referred to as 'the ultimate sustainable material, so why are we not seeing it being used more often? (MaterialDistrict, 2016). These projects demonstrate our current need to advance architecture towards more sustainable alternatives and start constructing this narrative that others can adapt and take further.

Image (page 41, TOP RIGHT) Bio-Concretion IAAC thesis project by Tobias Gumstrup Lund Øhrstrøm Image (page 41, TOP LEFT) Seaweed Thatch Reimagined, construction detail Image (page 41, BOTTOM) Seaweed Thatch Reimagined, prefabricated panels

MaterialDistrict (2016), 'Little Seaweed House' - MaterialDistrict Frearson, A. (2013), 'The Modern Seaweed House' by Vandkunsten and Realdania, Dezeen Øhrstrøm, T. (2015), 'Bio-Concretion' – Materiability

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D es i gner St ate of the Art

Another approach of using seaweed in design is combining it with other materials. Danish designers, Jonas Edvard and Nikolaj Steenfatt have created a new material combining locally harvested fucus seaweed and recycled paper to create a chair and a collection of pendant lamps, called the Terroir Project Collection. They harvest seaweed from their local Danish coastline, dry it and grind it into a powder, after which they cook it into a thick glue which exploits the viscous and adhesive effect of alginate - a natural polymer found in brown seaweeds. The seaweed glue is then combined with recycled paper, molded into the desired shape and fired to create a tough and durable material similar to cork. The idea behind the Terroir Project Collection is to create sustainable furniture using a material which is usually regarded as 'useless and smelly'. The bio-based material can be broken down and reused or recycled as a natural fertilizer as seaweed contains large amounts of nitrogen, iodine, magnesium and calcium (Treggiden, 2015).

Images (page 42, ALL) Terroir Project Collection

by Jonas Edvard and Nikolaj Steenfatt

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Julia Lohmann's Department of Seaweed, established in Finland in 2013, is a transdisciplinary community exploring the marine organisms' potential as a design material.

Designers that are part of the department explore the potentials of algae as a material - as a possible replacement for leather, textile, wood, paper and plastic. Oki Naganode, a largescale installation created by Lohmann in 2013, showcases the potential use of seaweed in its raw form. Lohmann treated the Japanese Kombu seaweed (kelp) with a natural varnish to remain flexible like translucent leather and stretched it over a modular rattan frame. The translucent artistic installation was created to bring awareness to issues we are facing with the natural world, focusing on challenges of climate change (Pownall,2020). Other works

by Lohmann have looked at transforming and manipulating the material using techniques such as laser cutting, molding and stretching in order to create artworks, sculptures and lampshades.

Images (page 43, ALL) Work done at The Department of Seaweed

by Julia Lohmann

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Designers are increasingly experimenting with seaweed and other forms of algae. There has been recent interest towards using algae as a base material in yarn for weaving rugs and as a dye for colouring textiles, as well as using algae as an energy source for powering buildings (Treggiden, 2015). Studio Nienke Hoogvliet's SEA ME rug made of sea algae yarn, knotted by hand in an old fishing net, looks at the new material offering a solution for the sustainability issues being faced within the textile industry and tackling issues such as plastic waste within the ocean. Algiknit is a New York based company that focuses on creating kelp-derived, biodegradable fibers and yarns to contribute towards a circular economy and remediate the harmful cycles of fast fashion. They envisage a closed-loop product lifecycle for the future of the textile industry, utilising materials with a significantly lower footprint than conventional textiles (Algiknit, 2021). Jasmine Linington, a textile designer, uses seaweed to make couture clothing in an attempt to address environmental impacts that the fashion and textile industry faces. The designer uses by-products from the seaweed harvesting process combined with eco-resin to create small bead-like sequins that can be layered into garments. Again, another designer looking at a biodegradable and plastic-free alternative to what is currently available in the fashion industry (Hitti, 2019).

With limited resources showcasing the use of seaweed in its raw form or an extraction of it, there is a pressing need to explore this sustainable and renewable biomass. These projects all share one main focus which is turning to seaweed to reduce the effects of climate change. There has also been recent interest in using seaweed as a base material in bioplastics in order to fight both plastic waste and another planetary issue - food waste.

AlgiKnit (2021), 'About Us' - AlgiKnit Hitti, N. (2019), 'Jasmine Linington uses seaweed to make couture clothing' - Dezeen Pownall, A. (2020), 'Julia Lohmann brings seaweed pavilion to Davos as climate change warning' - Dezeen Treggiden, K. (2015), 'Seaweed and paper combine to create furniture' - Dezeen

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Image (page 45, TOP LEFT) SEA ME Rug

by Studio Nienke Hoogvliet

Image (page 45, TOP RIGHT) Colourful dyes for textile printing

by Blonde and Bieber Studio

Image (page 45, BOTTOM LEFT) Seaweed Bioplatics for Packaging Evoware, Indonesia

Image (page 45, BOTTOM RIGHT) Seaweed Girl Clothing Line Jasmine Linington

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SEAWEED CLOSE UP Photo credit: Eva Elijas - Pexels Images

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04 SE AWEED M AT E R IA L R E S E A R C H

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S eaweed Pro per t ies & Characteristics

Seaweed is a term that can be used to describe many different species of macroscopic, multicellular marine-based plants and algae. Seaweed grows in a variety of forms and colours in the ocean as well as in freshwater environments. There are likely to be thousands of species, where sea kelp is known to be the largest subgroup of seaweed. Seaweed can be broken down into three main categories based on pigmentation: Rhodophyta (red), Chlorophyta (green) and Phaeophyta (brown). These categories are a direct result of the amount of sunlight absorbed through photosynthesis, which in turn depicts how close to the water's surface it grows. Seaweed can grow in almost any marine environment, including rivers, oceans, lochs and lakes and are advantageous as they provide many marine ecosystems with food, habitat and nutrients.

Figure (page 49) - Light Absorption Spectra for Seaweed Pigment (Author)

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RHODOPHYTA / RED

PHAEOPHYTA / BROWN

CHLOROPHYTA / GREEN

SEAWEED

SEAWEED

SEAWEED

(Plocamium cartilagineum)

(Bull Kelp)

(Enteromorpha Linza or Doubled

DEPTH OF OCEAN

Ribbon Weed)

absorbs red absorbs green and blue

reflects green

reflects yellow and red (brown)

absorbs green and blue reflects red

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Figures (page 50-51) - Structure of Seaweed Compared to Land Plant (Author)

The structure of seaweed is different to plants that grow on land. Seaweeds have what are called 'holdfasts' instead of roots, that anchor them in place instead of absorbing nutrients.

These holdfasts are attached to a substrate on the ocean floor such as rocks, that keep them from floating away, which is why seaweed is usually found on rocky shorelines rather than on sand or shingle. From the holdfasts, kelp plants grow towards the water's surface. Gas bladders called pneumatocysts or floats, keep the upper portions of the algae afloat.

Flower for pollination or reproduction

Stem supports leaves and flowers

Stem transports water and nutrients

Leaf/blade for photosynthesis

Roots to anchor and support plant

Roots absorbs water and minerals

EXAMPLE OF LAND PLANT (Dandelion)

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Kelp plants have a pneumatocyst at the base of each blade whereas a bull kelp plant has only one that supports several blades. Some seaweeds, such as Sargassum and Gracilaria, do not have holdfasts, only floats which allow them to float along the surface of the water.

The whole marine plant is photosynthetic which makes it ideal for capturing and storing carbon, turning it into biomass which allows it to grow at a significantly faster rate than terrestrial plants.

Blade/Lamina for photosynthesis

Thallus entire kelp structure (characterized by lack of true roots and vascular system)

Pneumatocyst that keeps algae buoyant

Stipe supports the kelp blades

Holdfast attaches to a substrate

PHAEOPHYTA / BROWN SEAWEED (Bull Kelp)

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Kelp, the largest subgroup of seaweed which also includes the largest and fastest growing seaweeds, is placed in the Phaeophyta (brown) category. On average, giant kelp grows at a rate of 28 cm a day but can grow 60 cm a day in ideal conditions, making it one of the fastest growing plants on the planet (NOAA, 2021). Kelp grow in dense groupings that form an ocean forest, similar to forests that are found on land. Kelp forests harbor a greater variety and higher diversity of marine plants and animals than almost any other ocean community making it the most productive and dynamic ecosystems on Earth. Kelp is most often found along rocky coastlines, and requires clear, relatively shallow saltwater (Oceana, 2021). It requires nutrient-rich waters because of its large size, as it needs to be in an environment with at least a small amount of movement in the water in order to supply it with continuous nutrients. These underwater forests do not overlap with other blue carbon coastal ecosystems, such as mangroves, seagrass meadows and salt marshes, as they grow in more tropical climates.

Due to a combination of overfishing of the oceans, marine pollution, poor water quality, fisheries, invasive species and the temperature rise in ocean waters, kelp forests have suffered and become scarce in many vulnerable coastlines, for example, the Tasmanian east coast. Today, more than 95 percent of eastern Tasmania's kelp forests are gone, with little hope of saving the vanishing ecosystem (Bland, 2017). The most pressing threat to kelp forest preservation is in fact overfishing in coastal areas, which removes consumers, such as sea otters which help to manage sea urchin population. This in turn causes an imbalance in the ecosystem allowing for invasive species, such as urchin barrens, to decimate entire kelp forests, creating a subsurface wasteland littered with shells and starved species.

Figure (page 53) Kelp Forest Ecosystem (Author) [ Source: Steneck, Robert S., Graham, Michael H., et al: Kelp Forest Ecosystems - Biodiversity, Stability, Resilience and Future. In: Environmental Conservation 29 (4), pg 436-459 ]

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Macrocystis Nereocystis

Macrocystis Lessonia

Laminaria

Macrocystis Ecklonia

Macrocystis Nereocystis Macrocystis Lessonia Laminaria Laminaria & Macrocystis Ecklonia Macrocystis Ecklonia

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VERSATILE Seaweed can be used in a variety of products including, food, cosmetics, biofuel, bioplastics, fertilizers and livestock feed.

CARBON SINK Seaweed absorbs at least as much CO2 as trees, without taking up valuable land. A dry tonne of kelp will absorb about a tonne of CO2 in its lifetime.

FAST GROWING Kelp is one of the fastest growing plants in nature, so fast that it can be harvested for various uses every 90 days.

BIOFERTILIZER Seaweed contains growth-stimulating hormones (auxins, cytokinins, gibberellins) which stimulate seed germination and nutrient uptake, while protecting plants from infections.

PROMOTES BIODIVERSITY Promotes marine biodiversity and mitigates the effects of ocean acidification by absorbing excess nutrients.

LOW-CARBON CROP Seaweed ocean farms do not require water, land-use or fertilizers. The crops only require sunlight and nitrients provided by the ocean. The industry also promotes local jobs.

CLEANS WATER Seaweed absorbs excess nutrients such as nitrogen and phosphorus therefore cleaning the water in which it grows.

HIGH IN VITAMINS Seaweed as a source of food is high in nutrients, vitamins (a,b & k), fibers, iodine, protein, magnesium and calcium.

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As a natural biomass and resource, seaweed is not only harmless to the environment but also rich in various nutrients that are beneficial to other organisms such as plants and animals.

In addition to organic compounds such as proteins, amino acids, lipids, cellulose, vitamins and phenols, seaweed is rich in alginate, fucoidan, laminarin and other polysaccharides that are not present in terrestrial plants. This is one of the many reasons this versatile macroalgae is used in a variety of products including pharmaceuticals, food, cosmetics, bioplastics, fertilizers and livestock feed.

Seaweed has been a part of diets in many Asian countries and in some European nations for centuries. Today, edible seaweeds are widely consumed, especially in Asian countries, as fresh, dried or as ingredients in prepared foods. It has also traditionally been used

by Western food industries for its polysaccharide extracts such as agar, alginate and carrageenan, which contain compounds with potential nutritional benefits which is opening up many opportunities within the food industry. The food industry exploits their gelling, water-retention, emulsifying and thickening properties. Most commonly seen in products such as ice cream and toothpaste. Seaweeds are not only seen as beneficial for consumption by humans, adding seaweed to livestock feed can also reduce the amount of methane emissions emitted by cattle and other grazing livestock. Many cosmetic and pharmaceutical products also contain extracts of seaweed and are used mainly because of its water retention properties.

As a biofertilizer, seaweed is a sustainable alternative to chemical fertilizers. Due to its rich source of nutrients such as potassium, nitrogen and phosphorus, seaweed extracts used in the agricultural domain can promote seed germination, improve crop yield and increase crop resistance to environmental stresses. Seaweeds also contain growth-stimulating hormones such as auxins, cytokinin and gibberellin which promotes seed germination and nutrient uptake, while protecting plants from infections (Nabti, Jha and Hartmann, 2017). Seaweed as a fertilizer dates back to the nineteenth century where coastal dwellers would collect storm-cast seaweeds. In the early twentieth century small industries started to emerge developing the drying and milling of harvested seaweed, but these industries dwindled due to the emergence of chemical fertilizers. Today, with the rising popularity of

Image (page 54) - Photo Credit: Darina Belonogova - Pexels Images

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Sharks

Sea Otters

Larger Fish & Predators

Large Crabs & Lobsters Star Fish Small Predatory Fish & Invertebrates Sea Urchins Drift Algae & Dead Animals Smaller Herbivorous Fishes & Invertebrates Sessile Invertebrates Planktonic Algae

Kelp & Other Algae

CHANNEL ISLANDS KELP CALIFORNIA Photo credit: Shutterstock Images

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Microscopic Planktonic Algae

organic farming, there is some revival of the industry, however, not on a large scale. This industry needs a push of innovation and investment as it is currently confined to seaweed abundant coastlines in contrast to sunnier climates as wet seaweed is heavy and not usually

Figure (page 56) - Kelp Forest Ecosystem (Author)

transported far inland.

Over the last few years there has been an increasing interest placed on the investigation of seaweed as a possible source for biofuel. The idea is to grow large quantities of seaweed in the ocean and then ferment it to generate methane gas as fuel. There is also the potential to use seaweed in wastewater treatment as some seaweeds are able to absorb heavy metal ions such as zinc and cadmium from polluted waters (Wang, et al., 2020) However, there is still a lot of research and development needed for both these sustainable applications.

Even though most of the uses of seaweed is seen as a sustainable alternative, there is still some speculation as to how sustainable it can be. If seaweed production were to increase, absorbing excess carbon from the atmosphere and ocean, how do we know that this would not cause an imbalance in marine life or coastal ecosystems? If seaweed farms were to develop at a rapid rate, there may be areas that are overlooked and therefore not be as sustainable as wanted.

A first set of experiments were conducted by drying large pieces of kelp in various ways in order to understand the material and its characteristics. The kelp pieces were washed with tap water and cut up into equally sized pieces and exposed to different kinds of heat sources, including natural air drying, hot air from a hair dryer and oven drying. Through the drying process, one can see the salt content of the kelp emerge to the surface in random patterned white flakes. These first material experiments were conducted to get a physical understanding of the raw material. These experiments were interesting but limiting in terms of controlling the material and potentially scaling it to an architectural size. Based on these observations, a further investigation went into other forms of kelp, such as sodium alginate.

Bland, A. (2017), 'As Oceans Warm, the World's Kelp Forests Begin to Disappear' - Yale E360 Nabti, E., Jha, B. & Hartmann, A., (2017), 'Impact of seaweeds on agricultural crop production as biofertilizer' - Int. J. Environ. Sci. Technol. 14, 1119–1134 NOAA - National Oceanic and Atmospheric Administration (2021),'What is the carbon cycle?' - US Department of Commerce, N.O. and A.A. Oceana (2021), 'Giant Kelp' - Oceana Wang, S., et al., (2020), 'A state-of-the-art review on dual purpose seaweeds utilization for wastewater treatment and crude bio-oil production' - Energy Conversion and Management 222, 113253

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1. APPLIED HEAT

20min After Heat Applied

1 Week Later

Soft Flexible More brittle Salt rising to the surface

Flexible More brittle Salt on surface

2. AIR DRY

1 Week of Air Drying Slightly Flexible More brittle Salt rising to the surface

1 Week of Air Drying & Oven Drying More brittle Salt rising to the surface

3. OVEN HEAT

Original Washed Kelp

20min in Oven

Soft Flexible High Water Content

Hard Brittle Salt on Surface

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S e awe e d E xt r a c t i o n: S o di u m Alginate

In order to make a kelp biocomposite membrane, an extraction of kelp was looked into instead of the raw form of kelp. Various red and brown seaweeds are used to produce three hydrocolloids: agar, alginate and carrageenan. Hydrocolloids are defined as a long chain of hydrophilic polymers that are characterized by their capability to form viscous dispersions and/or gels when dissolved in water (Khalil, et al., 2018). Alginate, agar and carrageenan are three commercially valuable hydrocolloids derived from red and brown seaweeds that are used to thicken aqueous solutions to form gels and stabilize many different products.

The food industry exploits their thickening, gelling, water-retention, and emulsifying properties. These biopolymers are also currently being used in the production of bioplastics because of these properties.

The main use of brown seaweeds are as food and as the raw material for the extraction of alginate. The most useful brown seaweeds are seen to grow in cold water conditions in both the Northern and Southern Hemispheres. They are also found in warmer waters, but these are less suitable for alginate production and rarely used as food. Alginate is a compound known as a polysaccharide. It is the term usually used for the salts of alginic acid, and is present in the cell walls of brown algae as the calcium, magnesium and sodium salts of alginic acid. In order to convert seaweed into sodium alginate, an extraction process is used in order to obtain dry, powdered sodium alginate. There are two different ways of recovering the sodium alginate.

Sodium Alginate is a naturally occurring biopolymer which has been extensively investigated and used for many biomedical applications such as tissue engineering and drug delivery, due to its biocompatibility, low-toxicity, relatively low cost and mild gelation by addition of divalent cations such as calcium. The use of alginates is based on two main properties.

The first is their ability to thicken in the presence of water or increase the viscosity of aqueous solutions and the second is their ability to form gels due to cross-linking of ions in the presence of calcium. With these properties, sodium alginate has additionally been used in textile printing, foods and pharmaceuticals.

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Sodium alginate bioplastic is typically made by combining two separate mixtures: one containing sodium alginate, water and glycerine (as a base) and a curing agent, calcium chloride. The calcium chloride solution can be sprayed on top of the bioplastic mixture and has the ability to form a gel layer. Gels formed from alginates have the amazing ability to withstand heat and temperature of up to 150 degrees celsius without melting. Alginate bioplastics, once dipped in calcium chloride, are water resistant with neutral or acidic solutions, and will dissolve within a few hours if submerged within an alkaline solution (Raspanti, 2019).

CRO S S - LI N K I N G O F PO LY MER S (+ C A LC I U M C H LO R I DE) Ability to cross-link polymer chains with calcium ions resulting in an INSOLUBLE, GEL-LIKE SUBSTANCE

Sodium Alginate extruded into Calcium Chloride 2g Sodium Alginate in 100ml H20 2g Calcium Chloride un 100ml H2O

Figure (page 62-63) - Diagram showing uses of Sodium Alginate (Author)

Khalil, A., et al., (2018), 'A review of extractions of seaweed hydrocolloids: Properties and applications' - Express Polymer Letters. 12. 296-317 Raspanti, C., (2019), 'Biofabricating Materials' - Fabricademy

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Bioactive Compounds: Polysaccharides Pigments Proteins Minerals Lipids Vitamins Antioxidants

BR OWN S EA WEEDS 1. Acidification of the seaweeds.

2. Alkaline extraction with sodium carbonate (Na2CO3)

EX TRA CTION PROCES S

3. Solid/liquid separation 4. Precipitation 5. Drying

Properties: Antibacterial Antifungal

S ODIUM A LGINA TE

Powdered State

Antiviral

Antioxidative

Anti-inflammatory Anticancer Biocompostible Non-toxic Biodegradable

B I O C H EM I C A L E N G I N E ERI N G

A G RI C ULT UR E

T EX T ILES + PA CK A G IN G

FOOD IN D US T R Y

Gelling Properties Water-retention Spherification

Tissue

Alginate Dressing

Engineering

Wound

Pharmaceutical Industry

Diet Pills Dental Molds Cosmetics

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KELP BIOPLASTIC INGREDIENTS Photo credit: Ilaena Mariam Napier (Author)

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B i o pl a s t i c Res ea rch

Figure (page 67) - Diagram showing Bioplastic Composition (Author)

Bioplastics form part of a large family of biomaterials which can be derived from a variety of origins. A bioplastic is a biobased polymer that is entirely or partially, or at least 20 percent, derived from renewable biomass, such as plant-based sources, recycled food or animal waste, and may or not be biodegradable. In the case of this research, all ingredients used are plant-based. Therefore because of its biological origin, rather than petroleum origin, it is inherently biodegradable. Meaning it can easily be broken down in carbon dioxide, water, energy and biomass with the aid of microbes, making it carbon neutral. The polylactic acid called PLA is the most commercially available bioplastic. It is a biodegradable bioplastic obtained from the fermentation of cornstarch. PLA is used in various sectors, from food packaging to surgery and most commonly seen in 3D printing.

Bioplastics consist of a biopolymer for strength, plasticizers for flexibility, a solvent such as water, and additives for additional properties such as texture, colour, strength, durability, etc. Typical biopolymers used in creating bioplastics are agar, alginate, gelatine, starch, chitosan and cellulose. Glycerine is typically used as a plasticizer to create flexibility.

Additives such as egg shells, chalk, fibers, oils and even food waste such as ground coffee can be added to reduce the amount of shrinkage that occurs due to the water content.

Fibers can be added for additional structure and reinforcement and soaps and emulsifiers can be added for additional texture and foaming. Bioplastics can typically be reused by being melted back down and cast again.

Biopolymers: Biopolymers are natural polymers produced by the cells of living organisms.

There has been a lot of research into looking at alternative solutions to petroleumbased products which would be renewable as well as biodegradable and therefore pose a lower risk to the environment. Biopolymers are a possible solution because they are biodegradable materials obtained from natural raw materials. However, not all biodegradable polymers are biopolymers (produced from renewable resources). There are also many challenges related to biopolymers such as their limited rate of production, cost of production and suitability of properties.

There are three main classes of biopolymers: polynucleotides (RNA and DNA),

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BIOPLASTIC COMPOSITION

BIOPOLYMER(S)

PLASTICISER(S)

ADDITIVE(S)

(Natural and Synthetic) Polymers give the plastic its

Plasticisers give it its

Additives give it other

strength

bendable and moldable

wualities such as colour,

properties

durability, strength etc.

EXAMPLES

EXAMPLES

(Sorbitol, Glycerine)

(Spirulina, Vinegar, Fibers,

EXAMPLES (Chitin, Gelatin, Algae, Agar Agar, Cellulose, Alginate,

Kelp Powder)

Starch)

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polypeptides and proteins (collagen and fibrin), and polysaccharides (starch, cellulose and alginate). Biopolymers are the base ingredient for the creation of bioplastics with each bringing different results in terms of strength, durability or texture.

1.

Sodium Alginate (Properties previously mentioned )

2. Cellulose Cellulose is the most abundant organic polymer on Earth, making up a third of all plant matter. It is a polysaccharide that makes up an important structural component of the primary cell wall of green plants, including algae. Cellulose is mainly used to produce paper and textiles and is very common due to its abundant supply, biocompatibility, and is environmentally friendly. Cellulose is very structured with stacked chains that result in stability and strength. In this case, cellulose powder was added as a secondary biopolymer in order to improve the characteristics of the material in which sodium alginate is lacking such as poor water vapor barrier and mechanical strength (Khalil, et al., 2017).

3. Cornstarch Cornstarch is composed of amylose and amylopectin polymers which both consist of glucose (sugar) monomers. Starch is a white powdery substance that is tasteless and odorless and is insoluble in cold water as it forms lumpy granules.

Fibers can be added to the polymer matrix to increase mechanical properties of starch, such as elasticity and strength. Without these fibers, starch has poor mechanical properties due to its sensitivity to moisture. Heated water is able to break the intermolecular bonds, which allows the starch to dissolve and become a viscous fluid. The advantages of cornstarch is that it is a low cost, renewable, biodegradable and abundant polymer. The addition of vinegar, a weak acid, helps to break down the amylopectin polymers, which allows for the outcome of the bioplastic to be more flexible (Pistofidou, 2018).

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Plasticizers: Plasticizers are usually added to polymers in order to modify their extensibility, flexibility and mechanical properties. By adding a plasticizer to a biopolymer, it disrupts the hydrogen bonding and results in a stronger, less ductile material with much higher flexibility.

1.

Vegetable Glycerine: Vegetable Glycerine is a sugar alcohol extracted from plant oils, animal products or petroleum. In this case, vegetable glycerine was used. It is a sugar alcohol compound which is derived from vegetable fats such as soy, coconut and palm oils. Glycerine is a colourless, odorless and viscous liquid which is non-toxic.

It fully dissolves in water and is hygroscopic, which is the phenomenon of attracting and holding water molecules through either absorption or adsorption from its surrounding environment.

Additives: 1.

Vinegar (acid): Vinegar is an acetic liquid that is produced through fermentation. It was added in combination with cornstarch in order to help break up the polymer chains to make the bioplastic less brittle.

2. Sunflower Oil: Sunflower oil is the non-volatile oil pressed from the seeds of a sunflower. It is mainly used for frying food as well as in cosmetics. The addition of it in the bioplastic mixture was to reduce the amount of shrinkage (by replacing water content), as well as to make the final product water resistant.

3. Kelp Powder: Kelp powder is extracted from sea kelp and is said to be a good source of vitamins, minerals and elements that include iodine, magnesium, potassium, calcium and

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iron. It is currently used in a range of health food products. The addition of kelp powder in these bioplastic experiments was as an additive to contribute to the overall smell and colour of the outcome. The addition of kelp powder had no chemical effect on the properties of the bioplastic apart from the appearance.

By adding more kelp powder, the bioplastic would become darker in colour.

Throughout the research, the same kelp powder was used.

4. Hemp Fibers: Hemp is used in a variety of products, and was one of the first plants to be spun into a usable fiber. Along with bamboo, it is one of the fastest growing plants on Earth. The addition of hemp fibers in the bioplastic mixture is to increase the tensile strength of the bioplastic while introducing a sustainable combination of materials which would allow for degradation of the overall product.

Khalil, A., et al., (2017), 'Biodegradable polymer films from seaweed polysaccharides: A review on cellulose as a reinforcement material' - Express Polymer Letters 11, 244–265.

Pistofidou, A., (2018), 'Bioplastic Cook Book' - WWW Document - Issuu.

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I m p a c t of B i o pl a s t i c s

There are three main categories that bioplastics can be divided into when it comes to its biodegradability at the end of its lifecycle, namely: degradable, biodegradable and compostable.

Degradable: Degradable is the capability of being decomposed chemically or biologically. Chemical additives are used in the plastic to make it crumble more quickly than it would normally.

Both plastics and bioplastics are degradable, however this does not mean that the plastic will be broken down and incorporated back into nature. Microplastics are little pieces of plastic that are ingested by organisms and therefore incorporated into the lifecycle of organisms.

Microbeads, a type of microplastic, are extremely tiny pieces of plastic that can pass through water filtration systems and end up in oceans and other water bodies, threatening marine ecosystems. According to the United Nations Environment Programme, plastic microbeads first appeared in products about fifty years ago, when plastics started replacing natural ingredients. An important difference between the degradability of bio-based and petroleum-based materials is the time in which it takes for them to degrade.

Biodegradable: Biodegradable means that it can be broken down in water, carbon dioxide and compost by living microorganisms within a controlled environment such as bacteria and fungi.

Decomposition of something can take up to several months. Bioplastics that do not biodegrade easily are considered non-biodegradable.

Compostable: Compostable plastics are plastics that are able to be broken down by microorganisms in a compost site. The plastic breaks down into water, carbon dioxide, inorganic compounds and biomass leaving no toxic residue.

According to European Bioplastics, a plastic material is defined as a bioplastic if it is either bio-based, biodegradable or features both properties.

- European Bioplastics (2015)

71

Ini t i a l Mater i a l E x periments

Figure (page 73, TOP) - Diagram showing Cooking Process of Bioplastics (Author)

The aim of this step in the process was to firstly, understand how to make a bioplastic using a combination of these materials and secondly to evaluate the outcome of the material in terms of its strength, translucency and flexibility. A set of methodical experiments were conducted where different combinations of materials were mixed, cooked, cast into frames and then oven dried. This was done in order to gain an accurate representation of the characteristics and qualities that each material encompasses. Because these bioplastics

Figure (page 73, BOTTOM) - Diagram showing Shrinking Process of Bioplastics (Author)

are water-based, the time in which they take to cure is an important factor that affects the quality of the outcome. The way in which the material dried and shrunk through evaporation was a key aspect that was taken into account.

A cooking process is used to make bioplastics where measured materials are added to a certain amount of water and heated in a pot on the stove to 90 degrees celsius until everything has dissolved into a homogeneous solution. A whisk or spoon is used to stir the substance evenly in order to avoid lumps. The plasticizer (in this case glycerine) is then added and stirred in. In order to reduce the shrinkage of the bioplastic during the curing process, cook the mixture until it starts to froth and water evaporates from the surface.

Once the mixture reaches 90 degrees celsius it can then be poured into a frame and set to dry at a low temperature (60 degrees celsius) for two hours in an oven or out to air dry which will take longer. Ratio changes in the recipe results in different material properties.

It is best to cast the cooked bioplastic mixture onto a non-porous surface like glass, plastic or acrylic. In the case of this research process, acrylic frames were lasercut and used to cast 100x100mm squares and 100x400mm rectangles. However, many bioplastic research has gone into using molds to create different shapes and surface textures.

Sodium alginate is specifically tricky when dissolving and cooking as poor dispersion in water occurs if it is added too rapidly, producing flour-like lumps wetted only on the outside. A way to avoid this is to heat the water to about 75 degrees celsius before adding the sodium alginate powder slowly while mixing at the same time. Another approach is dissolving the sodium alginate powder in a small amount of water in a jar for 24 hours or until completely dissolved before cooking the solution with the other ingredients.

72

An initial set of experiments was conducted in order to understand a combination of different materials, with a constant base of water, glycerine and sodium alginate. Additional ingredients such as cornstarch, vinegar, sunflower oil, beeswax, kelp powder, chitosan and cellulose powder were added in order to see how they would affect the outcome. Fibers were also added to see how the material would change as it shrunk and deformed. The outcome bioplastics were then evaluated based on the controlled proportions of ingredients according to the needs of flexibility, translucency, strength and appearance.

1.

Measure powders and Water

2.

Heat water at medium temperature and add powders and mix until completely dissolved int a homogeneous solution

3.

Add glycerine to the solution and keep mixing (the more cooking, the more water is evaporated which reduces the shrinkage)

4.

Set mixture into acrylic frame

5.

Choose drying method (oven dry at 65 degrees for 2 hours / air dry or heat dry)

6.

Document material and see how it dries and deforms/shrinks

73

Experiment 01: No Sodium Alginate

100ml Water

100ml Water

5g Kelp Powder

5g Kelp Powder

5g Kelp Powder

2ml Sunflower Oil

2ml Sunflower Oil

2ml Sunflower Oil

2ml Glycerine

3ml Glycerine

4ml Glycerine

3 days later

24 hours later

Immediately

100ml Water

74

Experiment 02: With Sodium Alginate

100ml Water

100ml Water

2g Kelp Powder

2g Kelp Powder

2g Kelp Powder

2ml Sunflower Oil

2ml Sunflower Oil

2ml Sunflower Oil

2ml Glycerine

3ml Glycerine

4ml Glycerine

5g Sodium Alginate Powder

5g Sodium Alginate Powder

5g Sodium Alginate Powder

3 days later

24 hours later

Immediately

100ml Water

Observations: If there is no sodium alginate added to the mixture there is no polymer or base for the materials to bind together with. This experiment showed the importance of the need for sodium alginate and not only kelp powder.

75

Experiment 03: Increasing Glycerine

A001

A002

A003

100ml Water 2g Kelp Powder 5g Sodium Alginate Powder 4ml Glycerine

100ml Water 2g Kelp Powder 5g Sodium Alginate Powder 5ml Glycerine

100ml Water 2g Kelp Powder 5g Sodium Alginate Powder 6ml Glycerine

Observations: [ Shrinkage of 0-5% ] It is seen that the more glycerine that is added, the more flexible the material will be, reducing the risk of tearing away from the frame during shrinkage.

76

Immediately

100mm

100mm

o

2 hours later with 65 C

8 hours later

24 hours later

1 week later

77

MORE FLEXIBLE

MORE RIGID

A003 A002 A001

Experiment 04: Increasing Glycerine + Calcium Chloride

A004

A005

A006

100ml Water 2g Kelp Powder 5g Sodium Alginate Powder 4ml Glycerine

100ml Water 2g Kelp Powder 5g Sodium Alginate Powder 5ml Glycerine

100ml Water 2g Kelp Powder 5g Sodium Alginate Powder 6ml Glycerine

+ 10% concentration calcium chloride

+ 10% concentration calcium chloride

+ 10% concentration calcium chloride

Observations: [ Shrinkage of 80% ] It is seen that the more glycerine that is added, the more flexible the material will be, reducing the risk of tearing away from the frame during shrinkage.

The material combination is the same as the previous experiment, however with the addition of spraying calcium chloride on the wet mixture. The calcium chloride causes the material to start shrinking and breaking away from the frame immediately, making the final result smaller than the prevous experiment.

78

Immediately

o

2 hours later with 65 C

8 hours later

24 hours later

1 week later

79

MORE FLEXIBLE

MORE RIGID

A006 A005 A004

Experiment 05: Increasing Sodium Alginate

B001

B002

B003

100ml Water 2g Kelp Powder 4ml Glycerine 6g Sodium Alginate Powder

100ml Water 2g Kelp Powder 5ml Glycerine 8g Sodium Alginate Powder

100ml Water 2g Kelp Powder 6ml Glycerine 10g Sodium Alginate Powder

Observations: [ Shrinkage of 5-10% ] It is seen that the more sodium alginate that is added to the mixture, the more brittle the end product becomes, making the material tear in multiple places as it dries

80

Immediately

o

2 hours later with 65 C

8 hours later

24 hours later

1 week later

81

MORE RIGID

MORE FLEXIBLE

B003 B002 B001

Experiment 06: Increasing Cornstarch

C001

C002

C003

100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder 2ml Vinegar 2g Cornstarch

100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder 2ml Vinegar 3g Cornstarch

100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder 2ml Vinegar 4g Cornstarch

Observations: [ Shrinkage of 10-20% ] Cornstarch is a a polymer that is best used with the addition of vinegar to allow the mixture to become more flexible. It is seen in the experiment that the more cornstarch that is added, the more brittle the material becomes, allowing it to break and tear as it dries. The addition of cornstarch with sodium alginate, changes the appearance of the material, making it more yellow than orange.

82

Immediately

o

2 hours later with 65 C

8 hours later

24 hours later

1 week later

MORE RIGID

MORE FLEXIBLE

C003 C002 C001

83

D001

Experiment 07: Adding Fibers

D001 100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Jute Fibers

D002 100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder Hemp Fibers

D003 100ml Water 2g Kelp Powder 6ml Glycerine 5g Sodium Alginate Powder Hemp Fibers

D004 100ml Water 2g Kelp Powder 6ml Glycerine 5g Sodium Alginate Powder Hemp Fibers

Observations: [ Shrinkage of 5-10% ] This material used the recipe from the previous experiment using cornstarch, with the addition of fibers. The fibers were added to bring mechanical strength to the experiments. It is seen that the material dried and teared differently with the addition of fibers.

84

D004 D003 D002

Immediately

o

2 hours later with 65 C

8 hours later

24 hours later

1 week later

85

F001

Experiment 08: Adding Fibers

F001 100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Jute Fibers

F002 100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder Hemp Fibers

F003 100ml Water 2g Kelp Powder 6ml Glycerine 5g Sodium Alginate Powder Hemp Fibers

F004 100ml Water 2g Kelp Powder 6ml Glycerine 5g Sodium Alginate Powder Hemp Fibers

Observations: [ Shrinkage of 5-10% ] This material used the recipe from the previous experiment, with the addition of fibers. The fibers were added to bring mechanical strength to the experiments. It is seen that the material dried and teared differently with the addition of fibers.

86

F004 F003 F002

Immediately

o

2 hours later with 65 C

8 hours later

24 hours later

1 week later

87

E001

E002

Immediately

24 hours later

Immediately

24 hours later

Experiment 09: Adding Fibers

E001 200ml Water 2g Kelp Powder 4ml Glycerine 6g Sodium Alginate Hemp Fibers

E002 200ml Water 3g Kelp Powder 5ml Glycerine 6g Sodium Alginate Powder Hemp Fibers

E003 200ml Water 4g Kelp Powder 8ml Glycerine 10g Sodium Alginate Powder Jute Fibers

E003

E004

Immediately E004

400mm

200ml Water 2g Kelp Powder 6ml Glycerine 5g Sodium Alginate Powder Hemp Fibers

88

100mm

24 hours later

Immediately

24 hours later

400mm

o

300mm

G001 1600ml Water 18g Kelp Powder 20ml Glycerine 36g Sodium Alginate Jute Fibers

2 hours later with 65 C

Experiment 10: Large Scale + Adding Fibers

Observations: [ Shrinkage of 5-10% ] This material used the recipe from the previous experiment, with the addition of fibers. The fibers experiments. It is seen that the material dried and teared differently with the addition of fibers. This was the largest of the set of experiments with a rectangle shape of 400mm x 300mm. The material

8 hours later

were added to bring mechanical strength to the

shrunk with the fibers, creating sine waves along the ridges.

24 hours later 1 week later 89

90

91

HYDROPHILIC Water absorption / retention

TRANSPARENT

Translucency of material allows for lightweight membrane application

92

SHRINKAGE / DEFORMATION

PRINTABLE

As the material dries, the

The material thickens and has a

evaporation of water causes the

self-sticking ability and allows for

edges to shrink / deform

a printable material

HEAT-RESISTANT

SELF-SUPPORTIVE

Very heat resistant and can withstand temperatures of up to 150 degrees

The material is not self supportive so would need a substructure

Re c ip e Devel o pm ent & B ehavioral Attributes

Once these material experiments were successfully conducted, one could evaluate and compare each prototype based on strength, translucency and flexibility. During this first phase, a better understanding of the differences and similarities between each recipe was noted. A similar approach in methodology of the experiments was carried out as the same base material of sodium alginate was used. The outcomes then varied in texture, colour, strength, flexibility, deformation and water resistance.

As this bioplastic is water based, a large amount of shrinkage occurs during the drying process which causes huge deformations, mostly visible along the edge of the material. The addition of fibers and oils were used in order to reduce the amount of shrinkage. Increasing the amount of glycerine also reduces the amount of shrinkage and increases flexibility.

Mold is another issue that appears along the top surface of the material due to its water content which can be reduced by decreasing the drying time and allowing both sides of the material surface to be exposed to air. If the bioplastic is thick, this could also causes mold. A solution to prevent mold would be to cover it with a textile during the drying process. Bioplastics are not naturally water resistant, the addition of wax into the mixture can create a water resistant material or in the case of alginate, the spraying of calcium chloride will form a water resistant layer.

Figure (page 92) - Diagram showing behavioral attributes of kelp bioplastic material (Author)

93

Based on the material experiments carried out, one base recipe was then chosen, which was used and altered slightly throughout the rest of the research. Later on in the research, there was an addition of another biopolymer, cellulose powder, which is the most abundant biopolymer in the world, was added in order to improve the characteristics of the material in which sodium alginate is lacking such as poor water vapour barrier and mechanical strength. Casting of bioplastics is a common way of exploring base properties of different ingredients and is largely done in bioplastic research, however it is limited in size and control of the material. The viscosity of the wet material was also taken into consideration as alginate can be robotically extruded. The fact that sodium alginate is the base ingredient is advantageous as it is a natural thickener and is of a suitable consistency for extruding. Because of this quality, additive manufacturing strategies were explored in order to produce larger products with precision and control.

Figure (page 95) - Diagram showing chosen recipe of bioplastic composition (Author)

94

THICKNESS

BIOPLASTIC Strong

COMPOSITION

BIOPOLYMER(S)

WATER

BIOPOLYMER(S)

PLASTICISER(S)

Flexible

ADDITIVE(S)

1. SODIUM ALGINATE

VEGETABLE GLYCERINE

KELP POWDER

4,39%

3,51%

1.76%

87,7%

2. CELLULOSE POWDER

2.64% - Added for colour

- Polysaccharide

- Polyol compound

- Structural component of cell

- Odorless / colourless /

walls of green plants

viscous

- Most abundant polymer on

- Non-toxic

Earth

- Antimicrobial + Antiviral

pigmentation

- Sweetener

STRENGTH Watery

TRANSLUCENCY / COLOUR

Thick

Light / Smell

WATER CONTENT Shrinks / Cracks

Small Shrinkage

Dark / Smell

FLEXIBILTY Flexible

Brittle

95

ROBOTIC FABRICATION OF AMBER LAMINARIA Photo Credit: Ilaena Mariam Napier (Author)

96

05 K E LP B IOCOMPOS IT E A D D I T I V E MA NUFACT UR ING

97

98

CASTING

3D PRINTING

ROBOTIC EXTRUSION

99

Experiment 11: Hand Extrusions

Observations: [ Shrinkage of 0-5% ] This material used the recipe from the previous experiments with the addition of either Chitosan Powder or Cellulose Powder in order to utilize their natural mechanical properties. The hand extrusions

H004 100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder 5g Chitosan Powder

were carried out using syringes. Different material combinations were experimented to see the ease of extrusion, viscosity of material, spreading of material and drying time. In the case of the catenary threads, the parameter measured was if the material would fall and break due to gravity or hold.

H005 100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder 10g Cellulose Powder

100

Immediately 3 hours later - air dry

Immediately

3 hours later - air dry

101

Air Pressure

300cc Catridge for material

Thumb Crank on top of stepper motor

Stepper Motor

Metal Screw

3D printed part

Mount to attach to 3D printer

3D printed nozzle for extrusion

102

Ext r us io n Pr i nt i ng St r ategi es & Parameters

Casting, as seen in the initial experiments, was limited in size and wasteful in terms of using molds. The next step was to move to a controlled form of additive manufacturing such as small-scale 3D printing. The methodology chosen was to start on a small scale and determine the possibilities and limitations of the material and then move gradually to a larger scale. Before moving to the 3D printer, hand extrusion tests were conducted to test multiple variations of the base recipe. This was to measure the extrudability, curing time and overall outcome of the material.

A Creality Ender-3 Pro 3D printer with printing dimensions of 220x220x250mm was bought and manually changed to be able to extrude a paste-based solution. This included attaching a 3D printed piece which allows for the attachment of a cartridge containing the material which is then extruded by the help of air pressure. In addition, there is a metal screw attached to a stepper motor placed at the top of the 3D printed piece to assist with the extrusion of the material. This extrusion setup was initially designed in IAAC for 3D printing of clay, however it worked with the seaweed biocomposite due to its viscosity. As this bioplastic paste has a gel-like consistency, it is able to be extruded using less than 1 pascal of air pressure. Naturally, the first experiments looked at printing three-dimensionally.

The alginate biocomposite paste was able to extrude and stick together horizontally and vertically, allowing for different opportunities to emerge, however the outcome of the material after curing (because of shrinkage due to water content) was not desirable. The printed prototypes shrunk by more than 50%, resulting in brittle elements. An alternative solution was to print two-dimensionally, in order to get more promising results. Flat sheet printing was explored, bringing resemblance to casting but instead of the material being poured or deposited in an uncontrolled manner, the material was deposited evenly across the desired region, giving adaptability and flexibility to the printing process.

Figure (page 100) - Diagram showing 3D Printer parts used for printing the kelp biocomposite material (Author)

103

100ml Water 2g Kelp Powder 4ml Glycerine 10g Sodium Alginate Powder

104

Nozzle Size: Pressure: Height above surface: Slicing Distance: Print Speed: Jog Speed:

4mm 3Pa 0.1 3.0 1000mm/s 2100mm/s

Nozzle Size: Pressure: Height above surface: Slicing Distance: Print Speed: Jog Speed:

4mm 3Pa 0.1 3.0 500mm/s 2500mm/s

Nozzle Size: Pressure: Height above surface: Slicing Distance: Print Speed: Jog Speed:

4mm 3Pa 0.1 3.0 1000mm/s 2100mm/s

Nozzle Size: Pressure: Height above surface: Slicing Distance: Print Speed: Jog Speed:

4mm 3Pa 0.1 3.0 500mm/s 2500mm/s

100ml Water 2g Kelp Powder 4ml Glycerine 5g Sodium Alginate Powder

Nozzle Size: 4mm Pressure: 1Pa Height above surface: 0.1 Slicing Distance: 1.5 Print Speed: 500mm/s Jog Speed: 2500mm/s

100mm x 100mm

Nozzle Size: 4mm Pressure: 1Pa Height above surface: 0.1 Slicing Distance: 1.5 Print Speed: 500mm/s Jog Speed: 2500mm/s

Nozzle Size: 4mm Pressure: 1Pa Height above surface: 0.1 Slicing Distance: 1.5 Print Speed: 500mm/s Jog Speed: 2500mm/s

Nozzle Size: 4mm Pressure: 1Pa Height above surface: 0.1 Slicing Distance: 1.5 Print Speed: 500mm/s Jog Speed: 2500mm/s

105

3D printing is affected by different parameters which directly relate to the outcome of the prints. These include but are not limited to: the extrusion height above the surface bed, the toolpath direction, the nozzle size and shape, and the flowrate of the material which is determined by the speed of the machine and amount of air pressure applied. After testing small experiments changing certain parameters, one could determine how this material was affected by each parameter. Unlike most other materials in 3D printing, this kelp biocomposite is strongly affected by the directionality of the machine's toolpath. In order to understand and explore this further, small tests were done using different sizes and shapes of nozzles.

4mm Round Nozzle

Immediately

48 Hours Later

1C)

Nozzle Size = 4mm Height = 4mm Flowrate = 100% Pressure = 1Pa Shrinkage = 20%

1B)

Nozzle Size = 4mm Height = 3mm Flowrate = 100% Pressure = 1Pa Shrinkage = 20%

1A)

Nozzle Size = 4mm Height = 2mm Flowrate = 100% Pressure = 1Pa Shrinkage = 20%

15mmx4mm Flat Chamfered Nozzle

Toolpath along Length

106

2C)

Nozzle Size = Flat Height = 0,25mm Flowrate = 100% Pressure = 1Pa

2B)

Nozzle Size = Flat Height = 0,5mm Flowrate = 100% Pressure = 1Pa

2A)

Nozzle Size = Flat Height = 1,0mm Flowrate = 100% Pressure = 1Pa

One Direction

The idea of the flat, long vacuum-cleaner-like nozzle was to try and spread the material in a more efficient manner, as sheet printing was chosen to be the desired outcome. By exploring the directionality of the machine's toolpath in either length or width across the sheets, outcomes were visibly seen. The material shrinks and pulls in the direction in which it was printed. Even though the 3D printed nozzles of different diameters and shapes were explored and gave interesting results, it limited the control and deposition of the print. The thinner the material is, the less it shrinks and deforms, however it is not as strong as when it is thicker. Once these tests were conducted and the material was seen to be printable, scaling up was possible.

Immediately

48 Hours Later

4C)

Nozzle Size = 4mm Height = 1mm Flowrate = 60% Pressure = 1Pa Line Distance = 7.0mm Shrinkage = 20%

4B)

Nozzle Size = 4mm Height = 1mm Flowrate = 80% Pressure = 1Pa Line Distance = 6.5mm Shrinkage = 20%

4A)

Nozzle Size = 4mm Height = 1mm Flowrate = 100% Pressure = 1Pa Line Distance = 6.0mm Shrinkage = 20% Toolpath along Width

3A)

Nozzle Size = Flat Height = 0,25mm Flowrate = 100% Pressure = 1Pa Line Distance = 15mm

3B)

Nozzle Size = Flat Height = 0,25mm Flowrate = 100% Pressure = 1Pa Line Distance = 20mm

3C)

Nozzle Size = Flat Height = 0,25mm Flowrate = 100% Pressure = 1Pa Line Distance = 17,5mm

One Direction

107

These tests were translated onto a bigger scale using the ABB140 robot where sheets of up to 1 meter in length could be printed. The setup of the ABB140 robot is similar to that of the 3D printer, with the option of having six axes of control. A Luthum extruder canister with a capacity of 1.4 litres is the end effector that is attached to the flange of the robot.. The aluminium cylinder allows for a plastic tube filled with the material to be inserted, allowing for ease of changing material during the printing process. The canister is then attached to an air pressure pump on one end and changeable nozzles on the other. As flat sheets are being printed, the canister is always positioned at 90 degree to the surface bed and there is control of the machine's X, Y and Z axes when manipulating the machine. Rhinoceros and Grasshopper were used to construct and program the G-codes needed for the robotic process.

Catenary hanging "threads" were briefly looked into as a potential design component, with the material being extruded over openings allowing catenary shapes to appear. The recipe was altered slightly, adding more sodium alginate to the mix in order to have a thicker viscosity. This proves the adaptability of the seaweed biocomposite material is able to have in printing whatever is desired of it. The catenary threads printed well, however, twodimensional printing was still preferred. Flat, one layered sheets with different toolpaths were printed successfully creating flexible and translucent membranes that work well in tension but not well in compression. An interesting observation was that if a shape outline or border is printed first and then filled in, the material is contained and pulled within this frame. By combining a shape outline with a regular toolpath pattern, an evenly distributed sheet could be printed. This was to prevent the material from spreading outside of the desired shape. During the drying and curing, the sheet would shrink in height and length as it lost water content and curl upwards away from the flat acrylic surface. These surface deformations were natural and difficult to predict or control at this stage, however it was noted that the deformations were more prominent when the material deposition was thicker, and when a heat source was applied to speed up the drying stage.

Figure (page 109, TOP) - Diagram showing ABB140 Robotic Setup for printing the kelp biocomposite material (Author) Figure (page 109, BOTTOM) - Diagram showing toolpath patterns and size for printing the kelp biocomposite material (Author)

108

Air pressure

ABB140 Robotic Setup:

Luthum Extruder Maximum capacity: 1.4 litres

Changeable Nozzle 4mm / 6mm / 8mm

Space for Acrylic Sheet (1200 x 500mm) Robotic Table

1. Sheet Printing

2. Catenary Extrusions

Toolpath Patterns:

450mm

150mm

109

First Large-Scale done using the ABB140 Robotic Arm: 150x450mm sheets with borders

1.

110

2.

3.

4.

5.

6.

111

Image (page 112, TOP) - Printing Kelp Biocomposite on ABB140 at IAAC (Author)

112

Image (page 112, BOTTOM) Dried 1 layer kelp biocomposite sheet (Author)

Image (page 113, TOP) Dried 1 layer kelp biocomposite sheets (Author)

Image (page 113, BOTTOM) - Dried 1 layer kelp biocomposite sheet with shadow (Author)

113

Two layer printing was a notable turning point in the research as this gave the sheets certain unique characteristics that had not been seen before. The layered sheet would take between seven and ten days to dry (depending on the size of the sheet). Over the drying period, the surrounding conditions were crucial in the outcome of the prints such as relative temperature, humidity and air flow. Maintaining the same controlled environment for each print was necessary but at the same time difficult to achieve. Nonetheless, the printing of these multi-layered sheets gave way for interesting shrinkage patterns and deformations. The first of the two layers was printed as seen previously, with a border and infill running along the width of the shape. The top layers, however, were designed to act as a substructure made from the same material. Due to the placement of these ribs vertically and horizontally, an equal distribution of shrinkage occurred throughout the sheet. This was designed in order to get an equal distribution across the sheet in order for easier collection of results. Now that the material was thicker in height, more deformations were imminent. The most interesting outcome was the sine wave created on the edge of these sheets due to these ribs, pulling away from the material.

Figure (page 115, TOP) - Diagram showing 1 Layer Extrusion Analysis (Author) Figure (page 1115, BOTTOM) - Diagram showing 2 Layer Extrusion Analysis (Author)

114

1 Layer Sheet Analysis

1.

2.

3.

4.

Front View

Top View

Printing of one layer: •

Border

•

Internal infill polyline

•

Toolpath along width

•

Drying and shrinkage towards centre point along length

•

Drying and bending of edges away

Edges start to curve upwards in

from surface

wave form

Drying and shrinkage in height

2 Layer Sheet Analysis 1.

2.

3.

4.

Front View

Top View

Printing of one layer: •

Border

•

Internal infill polyline

•

Toolpath along width

•

Top layers in grid

•

Drying and shrinkage towards

•

centre point along length • •

Shrinkage broken along

•

Drying and bending of edges

Edges start to curve upwards in

away from surface

sine wave form

Ribs start melting into

length by ribs

bottom layer and petrude on

Drying and shrinkage in

underside

height

115

Image (page 117, TOP) - Images showing the Dryng Process of sheet with layers printed at same time (Author) Image (page 117, BOTTOM) - Close up texture of printed sheet (Author)

116

DAY 01

DAY 02

DAY 03

DAY 04

DAY 07

DAY 10

117

C at a l o gu e of E xp lorations

A catalogue of shapes and strategies were tested all with two to four layers and using a combination of 4, 6 and 8 millimeter round nozzles. All sheets were recorded and analyzed on their size, percentage of shrinkage, as well as effects of translucency, strength and flexibility. It can be seen on average that the sheets shrink 10 to 20 percent in length and 5 to 10 percent in width.

The catalogue of experiments can be divided into categories based on the families of prints.

Different parameters were experimented within each category. The amount of material deposited through the nozzle size, print volume, print time, layer thickness and surface area of the sheets were documented once printed. The drying time and method were also recorded. Once the sheets were dried, the shrinkage percentage was calculated by measuring the surface area of the dried print. Other parameters such as distance from surface bed, speed of the robot, as well as pressure were all recorded and adapted between each print in order to get to the desired outcome. Within each family category, one parameter was changed in order to understand the importance of each. The general shape and size of the prints remained constant. From this catalogue of experiments certain material behaviors started to emerge, showing that as much as one tries to control the material, it has a mind of its own. Top layer 'ribs' that were designed for structure, emerged on the underside of the sheets, giving a sense of multi materiality. Uniform sine waves appeared along the edges, due to shrinkage and pulling of material between the strategically placed ribs.

Aesthetically translucent patterns were seen with the presence of light, giving these flat sheets more dimensionality to them. Uniform gaps and openings started to emerge during the shrinking process where there was not enough overlapping material or weak points in the print. This shows that certain material behaviors remained the same from prototype to prototype where the material seemed to behave the way it was supposed to.

Image (page 119) Self-holding membrane (Author)

118

119

SHEET 1 / 2 / 3

120

SHEET 4 / 5 / 6 / 7

SHEET 11 / 12

SHEET 13 / 14

121

SHEET 1 / 2 / 3

SHEET 4 / 5 / 6 / 7

Dimensions Surface Area (wet) Surface Area (dry) Shrinkage

150x450mm 70114.28mm2 51287.97mm2 26.85%

Dimensions Surface Area (wet) Surface Area (dry) Shrinkage

150x450mm 75572.1mm2 67263.41mm2 10.99%

Composition: Water Sodium Alginate Glycerine Cellulose Powder Kelp Powder

87.72% 4.39% 3.51% 2.63% 1.75%

Composition: Water Sodium Alginate Glycerine Cellulose Powder Kelp Powder

87.72% 4.39% 3.51% 2.63% 1.75%

Effect: Translucency 0.6 Strength 1.0 Flexibility 0.3

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Effect: Translucency 0.8 Strength 0.7 Flexibility 0.7

SHEET 11 / 12

SHEET 13 / 14

Dimensions Surface Area (wet) Surface Area (dry) Shrinkage

150x450mm 56163.31mm2 47017.23mm2 16.28%

Dimensions Surface Area (wet) Surface Area (dry) Shrinkage

150x450mm 70709.69mm2 63638.72mm2 10%

Composition: Water Sodium Alginate Glycerine Cellulose Powder Kelp Powder

87.72% 4.39% 3.51% 2.63% 1.75%

Composition: Water Sodium Alginate Glycerine Cellulose Powder Kelp Powder

87.72% 4.39% 3.51% 2.63% 1.75%

Effect: Translucency 0.7 Strength 0.9 Flexibility 0.3

Effect: Translucency 0.8 Strength 0.7 Flexibility 0.9

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Unfo res een Ou tcomes & Solutions

From these prints, there were many outcomes that were predicted to a certain point but unavoidable. Molding was occurring due the time it takes for the prints to dry. The thicker the prints, the longer they take to dry and therefore are most susceptible to molding. There are a few methods that could be incorporated into the methodology in order to avoid this. Molding could be eliminated or reduced by adding certain essential oils that have antibacterial properties to the bioplastic recipe. Essential oils such as lemongrass, eucalyptus and cinnamon all have antibacterial properties that could be added. These oils were not added to the mixture, in order to keep the experimental process constant, however it could be in future developments of the project. Another solution to prevent molding would be to cover the print in a breathable textile while it is drying, or by adding constant airflow to the room. In this case a fan was used to keep a constant airflow. When this method of drying was added, the resulting prints dried too quickly and became dehydrated and as a result the sheets became brittle and began to crack in certain weak points.

Another aspect to consider is the spreading of the material when printing more than one layer. This occurs when the cooked bioplastic material was not refrigerated and therefore warm when extruded. This resulted in the material spreading out beyond its self-made borders. This also occurs when multiple layers are printed on top of each other during the same print. To prevent this from happening, the layers were separated and printed on separate days. In order to make the material durable and able to be exposed to elements, calcium chloride was sprayed over it once it was almost dry, in order to create a gel film on the surface as previously mentioned. If the calcium chloride solution is sprayed onto a still wet prototype, the crosslinking immediately starts to occur, speeding up the shrinkage process.

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RIBS

EDGE WAVES

TRANSLUCENCY

GRID OPENINGS

SHRINKAGE

125

Layer Progression of Prints:

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SMALLER VERTICAL RIBS Top layer Kelp Biocomposite

VERTICAL RIBS Top layer

2

Kelp Biocomposite

PRINT AFTER 1 - 3 DAYS & DRY FOR MIN. 7 DAYS

HORIZONTAL RIBS Top layer Kelp Biocomposite

SHAPE INFILL Bottom layer Kelp Biocomposite

1

PRINT & DRY FOR 1 - 3 DAYS

SHAPE OUTLINE Bottom layer Kelp Biocomposite

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DRIED PROTOTYPE WITH DEFORMATIONS Photo Credit: Ilaena Mariam Napier (Author)

128

06 M AT ER I A L INFOR ME D D E S IGN

129

130

D e s ig n for S hr i nk a ge

Generally, water-based bioplastics will shrink due to evaporation of water content as they cure. The loss of water causes the prototypes to shrink evenly towards the geometric centrepoint, causing spatial deformations. In addition to shrinkage in size, the loss of water can place stress on the bioplastic which may lead to cracking. When cooking the bioplastic, it is advised to cook the mixture for a longer period of time to ensure more evaporation occurs early, instead of later on during the drying process. The addition of glycerine relieves this stress on the material, the more glycerine that is added, the less it will shrink and deform. During the process of casting, if bioplastics are left in a frame during the drying process they will undergo shrinkage warping, either bending the frame in which it is in or breaking away from it, causing tearing.

During the additive manufacturing of the seaweed biocomposite, it was noticed that thinner layers of composite were less likely to shrink and deform. Using a thinner nozzle size to deposit the material was also a contributing factor in creating a material that was thinner, and therefore not as prone to shrinkage. The thickness of the material has a direct relation to the amount of shrinkage that will occur, due to the fact that there is more material and subsequently more water content. However, if the material thickness is too great, depending on the environmental drying conditions, the material is prone to molding. This was a factor that had to be considered during this set of experiments. In order to prevent this from occurring, the layers were separated and printed on separate days. This was so that the bottom material was allowed to set and dry, before the top layer or layers of vertical and horizontal ribs were printed between one and three days later. The time allowed for the bottom layer to dry was not enough to allow for it to start shrinking and deforming. The bottom layer was still wet enough for the top layer or layers to stick to it and merge into one form, and together drying, shrinking and deforming. There were successful outcomes that emerged using this strategy, firstly less molding would occur, and secondly strong ribs were created with a flexible and translucent membrane beneath.

Importantly, due to the biological makeup of the composites used, most specifically the sodium alginate which is a natural thickening agent and has water-retaining properties, the components made can harness natural shrinkage to create spatial shape formation. The wet

Image (page 130) Dried Prototype with Deformations (Author)

131

material is deposited in flat layers, however during the curing process where evaporation occurs, the material dries and breaks away from the surface, forming three-dimensional shapes. These are due to the internal directional evaporation stresses which can be defined by geometrically designed heterogeneous patterns (Mogas-Soldevila, Duro-Royo and Oxman, 2014). These patterns were briefly explored to understand the shrinkage of simple shapes. More complex geometries were explored computationally and could be applied to the research during future developments of it.

Over time, because of the evaporation of water from the bioplastic, the pieces will transition from flexible elements to a rigid, more structural piece that will respond to the surrounding environment, especially heat, humidity and rain. The inverse of shrinkage happens when you expose bioplastic to water. The presence of water or humidity can alter the overall shape of the element because of swelling due to sodium alginate related properties of water-retention. Unless the bioplastic has been made water resistant by the addition of wax during the cooking process or by spraying calcium chloride to the alginate bioplastic after curing, this process can happen as soon as the bioplastic is exposed to water or humidity. However, the fact that this research focuses on the recyclability of the elements, being able to dissolve within water is a key aspect that water-based composites have. The role of water in design and production of water-based composites is extremely important. It is a key aspect for initiation, activation, shape formation and biodegradation, ultimately being the most important ingredient of the project.

Images (page 133) Drying Process of Sheet with Layers printed on Different Days (Author) Image (page 33) Edge wave detail of dried print (Author)

Mogas-Soldevila, L., Duro-Royo, J. and Oxman, N., (2014), 'Water-Based Robotic Fabrication: Large-Scale Additive Manufacturing of Functionally Graded Hydrogel Composites via Multichamber Extrusion' - 3D Printing and Additive Manufacturing, 1(3), p.141-151.

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DAY 0 // 17th May

DAY 3 // 20th May

DAY 4 // 21st May

DAY 8 // 25th May

133

Images (page 135) Kelp Surface Pattern Image (page 135) Dragonfly Wing Images (page 135) Leaf Venation Patterns

134

G e o metr i c St u di es

An exploration into natural self-supporting structures was carried out for the purpose of the research. There are many studies that show the correlation between nature based design and architectural design, mostly because humans are inspired by what they find in nature. Biomimicry within architecture and engineering is not new. The study looked at lightweight structures within nature that are also strong and stiff. The veins seen within insect wings, specifically dragonfly wings, as well as leaf venation geometry were a source of inspiration as they are lightweight but strong and flexible. The veins of leaves are intricate structures that function both to distribute resources and reinforce strength.

Though it appears all vein patterns have the same overall organization and hierarchy, no two leaves are the same. Rather, each leaf has its own peculiarities emerging from its unique circumstances. Across species, the patterns differ drastically; they can be radial like a lilypad, or parallel like a blade of grass.

These were driving factors into the development of the shape and structure of the printed sheets. As they dried they would form three-dimensional, self-holding, monolithic structures. Natural patterns were also explored using vector fields in order to complexify the structural lines that could be printed as secondary layers or ribs on the biocomposite membranes. Many different geometric patterns were explored computationally, however not all were implemented into the fabrication process.This was due to the limited amount of fabrication time available as the goal was to first understand the simplified patterns and how they affect the material outcomes. By negotiating the geometrical pattern density on the surface of the prints, a certain amount of control of the shrinkage, pulling, stiffness, pressure and structural support of the sheets is gained. More complex geometric patterns could be explored in future developments of this research.

135

GEOMETRY STUDIES

136

137

138

Negative 38.5° starting point

X and Y noise at 15°

Positive 15° starting point

X 25° and Y noise at 45°

Negative -90° starting point

X 60° and Y noise at 45°

Negative -125° starting point

X 60° and Y noise at 90°

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D es i gn Devel o pment

Once there was an understanding about the material and how it was affected by certain parameters which would determine the outcome, there was a push to scale it up using the KUKA robot. Although the use of additive manufacturing has opened up opportunities to print highly complex geometries, the envelope is generally confined by the reach of the machine. In this case, the surface bed in which the robot can reach is 2x1.5 meters, creating a limitation to the scalability of the print. This did, however, allow for the possibility of printing a 2 meter long sheet. There were many factors that affected this large print.

Firstly, the 1.4 liter Luthum end effector was attached to the Kuka which therefore limited the amount of material that could be deposited in one tube. The G-code therefore had to be calculated and separated based on this factor. This limiting factor affected the overall print time as the tube within the canister needed to be replaced often. Another limitation that affected the end result was the time available with the KUKA robot. This affected the desirable drying time between bottom and top layers of the print, which had an effect on how the material dried and cured. Due to the fact that the prints were separated by a week between them, the top and bottom layered did not stick together. They went on to dry in a way that was not predetermined as seen in previously smaller prints. The bottom, membrane infill began separating across the width of the print as they were not constrained by the secondary ribs. These openings, although unexpected, created aesthetically pleasing natural three-dimensional spatial formations that were true to what the material wanted to do. Again it is seen that the material remains true to its behaviour.

Image (page 141, TOP) Large Prototype of Amber Laminaria (Author) Image (page 141, BOTTOM) Large Prototype with KUKA Robot (Author)

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141

Image (page 142, TOP) - Wet Kelp Biocomposite Print on KUKA (Author)

Image (page 142, BOTTOM) 1 Day Kelp Biocomposite Print on KUKA (Author)

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Image (page 143, TOP) Dried Kelp Biocomposite KUKA Print (Author)

Image (page 143, BOTTOM) - Dried Kelp Biocomposite KUKA Print (Author)

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LARGE SCALE PROTOTYPE: Layer 01 Printed: Monday 31st May Layer 02 Printed: Friday 4th June

DAY 09: Tuesday June 8th • • •

Air Dried for 2 days Fan added for increased drying time Prototype turned over to allow for distributed drying

DAY 10: Wednesday June 9th • • • •

Air Dried for 2 days Fan added for increased drying time Prototype turned over to allow for distributed drying Ribs starting to show

DAY 11: Thursday June 10th • • • •

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Air Dried for 2 days Fan added for increased drying time Prototype turned over to allow for distributed drying Ribs starting to show

145

Experiment: Printing Membrane with Openings 1 Layer Print with Openings

1 Layer Print without Openings

Experiment: Printing Membrane with Openings and Ribs 2 Layer Print with Openings

146

2 Layer Print without Openings

Results of Prints with Openings

1000mm long print, 1 layer

1000mm long print, 1 layer + ribs

Results of Print with Openings and Ribs (Detail)

147

LARGE DRIED PROTOTYPE Photo Credit: Ilaena Mariam Napier (Author)

148

07 KE LP B IOCOMPOS IT E A PPLICAT ION

149

Combining Multiple Materials

Images (page 150) 1 Layer Membrane sticked to create an opening for ratten frame (Author)

Figure (page 151) - Self-holding membrane idea with mono-materiality (Author)

150

Mate r ia l D r i ven Des i gn

By layering this material and creating three dimensional membranes, many application possibilities emerge. The initial idea was to create self-supporting membranes that could be combined in order to create a shell-like pavilion. The idea is that the structure can be created close to kelp rich coastlines and so, once it starts to degrade and return to the earth, it completes the natural resource cycle and contributes back to the ecosystem from where it originates.

The material could also be printed into components that could form part of a facade system.

The presence of salt within the material allows for the material to be resistant to rusting.

This is a huge benefit when applying this material to external structures, especially those located close to the coast. A facade system would promote opportunities for this unique material to thrive. With the use of robotic additive manufacturing comes the ability to Over time, with the evaporation of water as well as the other external environmental conditions, the design would transition from a flexible system to a more rigid one. With humidity the system would swell due to the water-retention properties of sodium alginate.

With small amounts of rain, the system would resist and become flexible and then harden and deform once exposed to heat. When exposed to longer durations of water, the system would degrade and eventually return to the earth.

CURVED BASE // Kelp Membrane

CENTRAL RIB // Kelp Biocomposite OUTER RIBS // Kelp Biocomposite

EDGE WAVE // Kelp Membrane

151

B i o degr a da bi l i t y

Within today's world, manufacturing of products is generally done wastefully with the outcomes that are often highly difficult to recycle. Synthetically made plastics are one of the worst examples of this as they are the most energy intensive materials to degrade posing huge health problems for the environment. Water-based material structures are naturally degradable while displaying exceptional and diverse mechanical properties (Fernandez and Ingber). By creating, fabricating and designing using renewable and biocompatible polymers, one is able to design an architectural strategy that would not contribute to carbon emissions but rather sequester them and have the ability to create a natural resource cycle.

Therefore, the material can decay and return to the earth, for the purpose of remediating soils and fueling new growth. This water-based biocomposite material additionally has the potential to be fully recovered and reused in its original form, relieving the strain on nonrenewable resources. The project aims to devise a system that encourages the protection and nourishment of the ecosystems, while at the same time providing humans with a new material system.

Figure (page 153) - Kelp Biocomposite Membranes with Timber Structure Resource Cycle(Author)

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KELP BIOCOMPOSITE STRUCTURE Circular Design

CO2

Structure helps promote plant life

O2

Sequestration of atmospheric CO2

CO2

O2 Release of oxygen through

CO2 absorption through

photosynthesis

photosynthesis

OCEAN

LOCAL

DEGRADATION

WATER

HARVESTING

OF KELP BIOCOMPOSITE REMEDIATION OF SOILS Kelp becomes fertilizer for soils. As a biofertilizer, seaweed is a sustainable alternative to chemical fertilizers.

Contains suitable nitrogen, potassium and phosphorus.

KELP FARM Small-scale kelp farm close to the water's edge.

Promotes biodiversity, cleans ocean water, promotes economy and creates local jobs.

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CO N C LU S IO N S Regenerative ocean farming is the focus of enhancing the production of kelp in order to alleviate the effects of climate change through carbon drawdown, and in turn can be harvested and used to demonstrate alternative nature-based solutions to petroleumbased materials within the built environment through the process of robotic additive manufacturing of water-based composites, in order to reduce waste within the resource cycle.

The research is driven by current issues of global warming, the problem of material waste, as well as the need to create more sustainable manufacturing processes. The use of seaweed brings attention to underutilized resources that are found naturally in abundance and can be used and produced in a sustainable manner to create alternative renewable materials.

Seaweed does not require land, fresh water or any additive fertilizers to grow naturally or farm, therefore, it does not compete with conventional agriculture practices for land space.

As a natural polymer, sodium alginate is shown to have many environmental uses and benefits due to its high nutrient and salt content and remarkable mechanical and hydrophilic properties making it biocompatible and biodegradable. Due to its ability to thicken in the presence of water and form gels in the presence of calcium, it can easily be robotically extruded, dried and cured to create a water-resistant, self-supporting membrane which can biodegrade or be broken down and reprinted. By combining the use of this adaptable material with additive manufacturing methods, the research opens up new possibilities for sustainable additive manufacturing to create large-scale biodegradable materials within the built environment.

The research is a starting point for further research in this field. The general problem seen today is trying to find a solution to manufacturing these natural materials at a large scale. The use of additive manufacturing of water-based materials, specifically in engineering, design and architecture, is still in its early stages and needs to be explored further. This research demonstrates a robotic additive manufacturing strategy to create flat sheets, however, water-based robotic fabrication holds potential applications for completely recyclable materials within the architectural realm with potential applications such as water storage, water-induced shape formation or degradation over time. Potential further research can be

155

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done to improve the extrusion process of multi-material extrusions, material distribution, or other geometric shapes and patterns to suit specific applications. In terms of further material exploration, the addition of chopped fibers or sand particles could be added to the bioplastic recipe and tested to provide enhanced mechanical properties of the printed sheets. Additionally, combining seaweed bioplastic membranes with a substructure of alternate materials can also be noticed and explored further.

By tackling topics as large as climate change, one needs to find solutions on a small scale that can have a large impact. Seaweed farming has the potential to sequester large amounts of carbon and act as a carbon sink. It can then be harvested and used to create new material systems that encourage the protection and nourishment of the ecosystems from which they come. Replacing non-renewable resources with their bio-polymer alternatives will enable the ability to customize materials to be created, used, recycled and replenished to reduce the effects of climate change while nourishing the planet.

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A M BE R LAM INAR IA Additive Manufacturing of Seaweed as a Biocomposite Material