(often called agar agar)

Agar is a gelatinous substance made of polysaccharides extracted from the cell walls of red algae (Phylum Rhodophyta). It is often used in laboratory settings as a culture media (commonly called an agar plate) and in cooking settings as a gelling / stabilizing agent.

(often called alginic acid)

Alginate is a polysaccharide obtained from the cell walls of brown algae (Phaeophyceae). When hydrated, it forms a viscous gum. While many recipes will just list ‘alginate’ as an ingredient, the characteristics of the gel will vary widely based on the species of algae from which it was extracted. Not only that but there are various ‘salts’ of alginate that have different properties:

• Sodium alginate is the sodium salt of alginic acid.
• Calcium alginate is created when sodium alginate has the sodium ion removed and replaced with calcium. Calcium alginate can be produced when a sodium alginate solution is combined with a calcium salt.
• Potassium alginate is the potassium salt of alginic acid.

The Anthropocene is an unofficial but widely recognized period of geological time marking the commencement of significant human impact on Earth’s geology and ecosystems. Most notable of these are the effects of anthropogenic climate change, including rising atmospheric greenhouse gas levels, global warming, and other phenomena associated with global climate change.

(also called Microbial Cellulose; associated with SCOBY or the Symbiotic Colony of Bacteria and Yeast)

Bacterial cellulose is a form of cellulose produced by bacteria, principally acetobacter, sarcina ventriculi, and agrobacterium. While bacterial cellulose has the same formula as plant cellulose (C₆H₁₀O₅)_n it has different mechanical properties. It is characterized by high purity, strength, malleability, and increased water retention.

The most common household way of obtaining bacterial cellulose is through the production of kombucha. While the kombucha is fermenting, the bacteria in the SCOBY form a pellicle of bacterial cellulose on the surface. This can be harvested and used as a source of bacterial cellulose.

While there is not yet an official dictionary definition of biodesign, it commonly refers to the incorporation of living organisms as essential components in the design process. It differs from biology-inspired approaches such as biomimicry or biophilia in that it actually incorporates living organisms or their by-products within the design process.

Biodegradable simply means that an object is capable of being broken down into into innocuous (non-toxic) pieces by the action of living things (microorganisms).

While that sounds great, it really means nothing without a timeline. Many types of petroleum-based plastics are technically biodegradable, however it can take up to 1,000 years for them to do so. It’s much preferable to use home compostable materials which can biodegrade within weeks, rather than years.

Biofabrication is the production of complex biologic products from raw materials such as living cells, matrices, biomaterials, and molecules.

A common example of biofabrication is the production of bacterial cellulose by acetobacter.

A material with non-specific biological origins or associations. This definition is intentionally vague as it serves as the umbrella under which many subsets of biologically-related materials can be grouped.

(refer to the chart on the Classroom page for more details)

Biomimicry, or biomimetics, is the emulation of the models, systems, and elements found in nature for the purpose of solving complex problems (often within the fields of design or engineering).

The term Biomimicry was popularized by Janine Benyus who defines it as ‘innovation inspired by nature’.

Biophilia is defined as a hypothetical human tendency to interact with, or be closely associated with, other forms of life in nature. If you want to follow in the steps of the transcendentalists, you might call it the desire to “commune” with nature.

While this sounds like a theory based on “soft” feelings, there are also a host of peer-reviewed scientific studies to determine if there is “hard” evidence to support this idea.

Multiple studies have reported health benefits from contact with nature. There are psychological benefits such as a reduction in stress, improved attention and focus, and physical benefits such as lower risk of heart disease. Scientists have also discovered that patients in hospital recover notably quicker when exposed to nature and biophilic considerations have become common in architecture.

A bioplastic is a polymer derived from renewable biomass sources, such as vegetable fats and oils, corn starch, cellulose, food waste, etc. (unlike conventional plastics made from fossil fuels).

Bioplastics generally rely on a base of biopolymers, which are natural polymers produced by the cells of living organisms, such as gelatin, cellulose, starch, alginate, etc.

(more about this distinction on the Classroom page)

A bioregion is a territory of land and water whose limits are defined by geographical features and ecological systems rather than political boundaries imposed on the landscape.

To qualify as a bioregion an area must be large enough to be self-reliant and sustain its biological communities, habitats, and ecosystems.

When considering what materials are available to you “locally,” it might be worth thinking of your bioregion rather than your state limits.

(sometimes spelled carrageenins)

Carrageenans are a family of polysaccharides extracted from red seaweeds. They are commonly used in the food industry for their gelling, thickening, and stabilizing properties.

There are three main commercial varieties of carrageenan, which differ in their degree of sulfation (addition of a sulfur trioxide group):

• Kappa-carrageenan has one sulfate group per disaccharide. It forms strong, rigid gels in the presence of potassium ions and reacts with dairy proteins.
• Iota-carrageenan has two sulfate groups per disaccharide. It forms soft gels in the presence of calcium ions.
• Lambda-carrageenan has three sulfate groups per disaccharide. It does not gel and is often used to thicken dairy products.

Most material recipes will use either kappa or iota carrageenan (since lambda doesn’t gel).

Casein is a family of phosphoproteins commonly found in mammalian milk, usually obtained from cow’s milk.

There are two main ways to obtain casein:

• “acid” casein: casein precipitated from milk by heating it with an acid or by the action of lactic acid in souring the milk. This type is often used in making paints and adhesives.
• “rennet” casein: casein produced when milk is curdled by rennet. This type is the chief constituent of cheese and is used in making plastics.

Caseins obtained by the acidification of the milk are insoluble at neutral pH. In order to make them available as an ingredient, it is necessary to conduct a chemical “neutralization” with a base.

Depending on the base used, different types of caseinates with slightly different properties are obtained:

• Sodium Caseinate
• Calcium Caseinate
• Potassium Caseinate

The most common form of these is sodium caseinate and most bioplastics are made using either sodium caseinate or calcium caseinate. Sodium caseinate also tends to form more flexible biofilms than casein caseinate.

A circular system is a closed-loop system that aims to look beyond the current take-make-waste extractive industrial model.

It’s three main goals are:

1. Design out waste and pollution
2. Keep products and materials in use
3. Regenerate natural systems

The aim is to create a closed material loop via reuse, sharing, repair, refurbishment, remanufacturing and recycling. Designing products and services for circularity requires end-of-life consideration from the very beginning.

(often mistakenly called chitin)

While chitosan and chitin are commonly mistaken for one another, they are notably different.

Chitin is an abundant natural polysaccharide commonly found in crustacean shells, insect exoskeletons, and fungi. It is the second most abundant biological macromolecule following cellulose.

Chitosan is a common sub-product of chitin, obtained by its partial deacetylation (removal of an acetyl group). If chitin reaches 50% deacetylation, it becomes soluble in acidic solutions and is called chitosan.

Most material recipes call for the use of chitosan since that is the chemically available variation of chitin.

A mixture in which one substance of insoluble and microscopically dispersed particles is suspended throughout another substance.

For example, milk is a colloid of water with fat and protein globules dispersed throughout. While these globules do not settle out of the mixture with time, they can also be removed without breaking any chemical bonds.

A composite is a solid material composed of two or more substances which have different physical characteristics but which retain their identity within the whole.

example: fiberglass is a composite of plastic and glass fiber

Sometimes mistakenly used interchangeably with biodegradable, compostable materials can be decomposed in an accelerated form of biodegradation under specific conditions that will provide nutrients back to the earth. Items can be at-home compostable (tossed in your home compost) or industrially / commercially compostable (which requires a very high level of heat, not to mention the infrastructure). Home compostable materials and products are really the goal for circular design.

(similar in motive and method to circular design)

Cradle-to-cradle design is a biomimetic approach to the design of products and systems that attempts to model human industry and manufacturing on nature’s processes, where materials are viewed as nutrients that can circle safely within nutrient flows.

Degradable simply means an item is able to be broken down into smaller parts. It doesn’t necessary mean biodegradable — objects can also be photodegradable, or broken down by sunlight. For instance, microplastics are simply degraded pieces of larger plastics.

A DIY material is any material created through individual or collective processes of research and development. The origins of DIY materials are often waste streams within the creator’s community and the techniques of production are often invented or repurposed by the creator.

To the best of my knowledge, the definition and research of DIY materials was developed by the Materials Experience Lab.

Gelatin is a blend of peptides and proteins that comes from the partial hydrolysis of collagen. This collagen is sourced from the skin, bones, and connective tissue of animals – often cattle, chicken, pigs, and fish. For that reason, most gelatin-based bioplastics are notably non-vegan.

(often used interchangeably with glycerin)

Glycerol is a simple polyol (organic compound containing multiple hydroxyl groups) compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. It can be obtained from both plant and animal sources and is often sourced from soybeans, palm, and animal-derived tallow.

While they are often used interchangeably, glycerol and glycerin are technically different:

Glycerol refers to the pure substance found directly in the triglycerides of fats and oils. It is a trihydroxy sugar alcohol.

Glycerin refers to the byproduct of producing fatty acid, fatty ester, or soap (from oils or fats) and is a trihydroxy sugar alcohol.

Essentially, the difference between glycerol and glycerin is that glycerol is a pure form and glycerin contains at least 95% glycerol. While the chemical formula is the same, they are not technically interchangeable when purity is required.

(often called Lifecycle Analysis)

A Life Cycle Analysis (LCA) is the detailed study of changes to a product, process, or activity throughout its existence. It often involves an accounting of the inputs and outputs to the system, including the flows of energy, water, materials, and pollution.

An LCA traces the “life” of an object from the initial state as raw materials, through various state changes during processing, to the end of life at disposal. The environmental impacts are recorded and analyzed to create an impact analysis and allow for informed decisions surrounding production.

Newer forms of Life Cycle Analysis will also account for labor practices and the social and sociological impacts to give a holistic Social Life Cycle Analysis (S-LCA).

(not to be confused with the Material Design pioneered by Google)

Material Design is the design, redesign, reform, reuse, or redefinition of materials. It can encompass the creation of an entirely new material, or the repurposing of a material for new or innovative needs. Often material designers will work with a waste stream of an industrial process to convert it into a useful material product.

More than just the association with material science, the new generation of material designers place emphasis on the role materials play in social, economical, political, and environmental spheres.

Material Driven Design (MDD) methodology facilitates designing products/concepts for material experiences. The process starts with a material (or a material proposal), and ends with a product or concept. It suggests four main action steps presented in a sequential manner as:

(1) Understanding The Material: Technical and Experiential Characterization

(2) Creating Materials Experience Vision

(3) Manifesting Materials Experience Patterns

(4) Designing Material/Product Concepts

This method is unique in that it doesn’t start with a design brief in the traditional sense, but rather a material starting point around which constraints must be drawn. The method emphasizes the designer’s journey from tangible material to abstract ideation and then back again to a final product. Material Driven-Design is often used to create meaningful circular products from industrial waste streams.

Material Ecology is a term coined by Neri Oxman that aims to establish a deeper, more scientific and precise relationship between the design object and an environment. It takes the known field of ecology and applies it to the material world to break down materials to their basic elements. It consists of the study and design of products and processes integrating environmentally aware computational
form-generation and digital fabrication.

Material flows are essentially the life cycle of materials from “cradle” (extraction) to “grave” (end-of-life). They trace the life of materials including the various state changes during processing into finished objects. Material flows are a subset of a larger Life Cycle Assessment.

A monomaterial is a product which is only composed of a single type of material. While this sounds obvious, it can be surprisingly rare to find in modern manufactured objects.

Monomaterials are ideally suited for recycling since there is no separation or disassembly required. For example, since milk cartons are made from paperboard coated with a plastic film, they are not a monomaterial. Since paper and plastic are usually recycled separately, this makes milk cartons difficult to recycle.

A monomer is a molecule that can react with other monomer molecules to form a larger chain or three-dimensional network called a polymer. A monomer is essentially the building block of longer polymer molecules.

Mycelium consists of the mass of interwoven filamentous hyphae that forms the vegetative part of a fungus.

In nature, this part is often submerged in soil but in biofabrication it is often cultured within a specific mold or laboratory medium.

Technically a pellicle is a biofilm that forms at the air-water interface of a mixture, indicating that a particular culture is aerobic. On this site it almost always refers to a layer of SCOBY that forms on the surface of a kombucha culture.

A polymer is a substance consisting of very large molecules (or macromolecules) composed of smaller repeating subunits (called monomers).

Polymers can come from either fossil fuels (often called synthetic polymers) or biological sources (biopolymers).

All polymers are created via polymerization of smaller monomer molecules. As a result, polymers have large molecular mass which produces unique physical properties such as toughness, high elasticity, and a tendency to form amorphous and semi-crystalline structures rather than crystals.

For a substance to be recyclable, it must be capable of being made fit for use again through a particular process (either physically or chemically).

It is worth mentioning that in the United States, the classic recycling symbol listed on packaging simply means that a material is capable of being recycled. Whether it actually is depends on your location, your local recycling capabilities, and the design of the object.

Planet Money did a great series of podcasts on the recycling industry in the United States which can be found here.

The term “regenerative” describes processes that restore, renew or revitalize their own sources of energy and materials. Regenerative is often used to describe restorative methods of agriculture, as well as increasingly within the design sphere.

Regenerative design is a holistic systems approach to design that seeks to create resilient, equitable human and ecological systems.

Regenerative design practices have been informed by the disciplines of biomimicry, biophilia, ecological economics, circular design, as well as inclusive social movements.

Renewable simply means something (a material or resource) is capable of being replaced by natural ecological cycles or sound management practices.

Often bioplastics will state that they are sourced from “renewable resources” which generally means biomass sources such as corn starch, cellulose, etc. It should be noted that this doesn’t necessarily mean that these bioplastics are biodegradable. It is also possible that they have been blended with petroleum-based plastics but still are labelled as “from renewable sources.”

(also called amylum)

Starch is a complex carbohydrate consisting of glucose monomers held together by glycosidic bonds. Starch is produced by most photosynthetic plants as a form of energy storage.

Pure starch is a white, tasteless and odorless powder that is insoluble in cold water or alcohol. Globally, it is the most common carbohydrate in human diets and is found in many staple foods such as wheat, potatoes, corn, rice, and cassava.

Sustainability is often defined as “the ability to meet the needs of the present generation without compromising the ability of future generations to meet their own needs”.

However, while the origins of the sustainability movement are rooted in a desire to see human civilization exist not at the expense of Earth’s biosphere, it has become a somewhat outdated term within the environmental movement.

Current global economic and production systems often rely on constant consumption and a belief in infinite economic growth. Obviously since there are limited resources on Earth, this belief is inherently unsustainable.

Increasingly, young activists are using terms such as regeneration and regenerative design to convey the need to not sustain the existing flawed systems, but to create new models that will allow civilization to restore the Earth’s biosphere.

Systems thinking is a holistic approach to understanding systems and the emergent behavior that is created from component interactions. In nature, systems thinking examples include ecosystems in which various elements such as air, water, nutrients, plants, and animals interact to influence their evolution.

Polymers that form permanent cross-links during the curing process. These have higher stress tolerance than thermoplastics and are immune to re-melting under elevated temperatures.

In the diagram below you can see the monomer strands that have a few permanent cross-linked nodes. Unlike thermoplastics which are held together through “weak” intermolecular forces, thermosets are held together through cross-linking (links which may be “strong” covalent or ionic bonds).

Polymers that do not form permanent cross-links when curing or cooling. These can be remolded under the right conditions but have lower stress tolerance than thermosets.

In the diagram below you can see the monomer strands loosely held together like strands of spaghetti through “weak” intermolecular forces. These forces weaken when heated until they break, allowing thermoplastics to return to a viscous liquid state for reshaping. The intermolecular forces reform upon cooling.

A virgin material is one that is in its raw state before any modification or processing. It is matter that is being used as a material for the first time.

For some context, recycled plastics often need a certain amount of virgin material to be mixed in to increase material strength and ensure high quality results.

Waste is often defined as something that is produced in excess of what is required. This include offcuts from the production of fabrics and textiles, pollution and effluent from manufacturing processes, and post-consumer trash that is sent to landfill.

Waste is undergoing a reckoning where it is now being viewed as a problem that can be designed out. If one designs while considering the full life cycle of an object, the end-of-life phase can be designed to minimize or eliminate waste altogether.