A/D/O by MINI | Materials: Chitin

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Materials

Materials: Chitin

Chitin extracted from seafood shells and insect exoskeletons to form a bioplastic is the next up-and-coming design material explored in our dedicated series.

Following a meal of seafood, crab or shrimp shells are usually treated as waste and disposed. But contained in those shells is a valuable material: chitin. This fibrous substance also forms part of the architecture of fish scales, the cell walls of fungi, the shells of other crustaceans and mollusks, as well as the exoskeletons of insects. When treated with an alkaline substance such as sodium hydroxide, chitin can be transformed into a biopolymer known as chitosan.

Often sourced from waste streams, it is non-toxic, abundant, safely water soluble, can decompose under the right conditions, and has the characteristics that allow it to be processed similarly to plastic. Given the potential and versatility of chitosan, it’s surprising that it is not already a more popular material among designers. But some are quickly catching on, and those using the material are fully aware of its potential.

Mediated Matter Group's Aguahoja pavilion is made from translucent chitin panels.

In an effort to counter the ever mounting plastic waste crisis, the Mediated Matter Group at MIT has been exploring chitosan since 2016 in its Aguahoja project. From fallen leaves and shrimp shells, the team extracted chitosan, cellulose and natural colored dyes, which they combined with pectin and water to create a “biocompatible material” that safely decomposes.

Aguahoja I and II include a five-meter-tall pavilion resembling the wing of an insect, and a material library showcasing a range of flexibilities and translucencies possible through altering the ratios of the biopolymers. 

The group's biocompatible material, seen here close-up, will safely decompose in earth or water.

Through what the Mediated Matter Group describe as a “computationally grown” process “printed by a robot”, alluding to the use of an algorithm and a 3D printer, the team developed intricate organic shapes, textures and structures. Once the piece is put back into water or the ground, it is designed to quickly break down and reintegrate through what the group calls “programmed decomposition”.

While in this project its mission is predicated on plastic reduction, the team is not creating objects that directly replace petroleum-based plastics. Instead, the sculptural objects and striking material samples stand as a hopeful monument to the material and its potential. The process behind Aguahoja is a complex combination of technologies and collaborators, however there are simpler approaches to using chitin and chitosan that are more utilitarian. 

The Shellworks has manipulated chitin from waste shells to create cups.

Also in search of a replacement to plastic, The Shellworks has developed a range of machines that process waste shells into cups and packages. After distilling the chitin from the shells, one machine transforms substance into smooth sheets, while another dips a mold into warm chitin to create cups. 

The machines are engineered in a straight forward and pragmatic style that one could almost imagine trying at home, or conversely on an assembly line. At the end of a short video that shows how The Shellworks functions, discarded cups and waste products are simply dissolved with the addition of a solvent, and the material can be used again.

The stages of development for The Shellworks' chitin bioplastic could be scaled with market demand.

Designer Andrew Edwards sees The Shellworks as a model and resource for the industry. “The future of chitin could be bright if the processes used to produce it are developed and scaled sustainably,” he told The Journal.

By working with both the development of the material as well as the equipment, The Shellworks ensures that both the product and the process are true to their mission to end plastic pollution and food waste. There is certainly enough of the latter to scale its model, and as the team continues to exemplify the benefits of chitin bioplastic, the market may demand it.

Austėja Platūkytė uses chitin as a natural binder to create composite materials.

Having experimented and worked with a range of materials, material researcher and product designer Austėja Platūkytė also sees benefits of using chitin over other materials. Compared to plant-based materials, which will continue to use land and therefore resources to be grown, Platūkytė noted that “chitosan is from the marine environment and does not compete with the earth or other human resources”.

It is a holistic way of understanding the rise of new materials, which calls into question the limits and intentions of many alternatives. A plant-based bioplastic may be more sustainable than a petroleum-based one, but where and how it is grown remains up for debate. 

Platūkytė's chitin-bound materials include boards in various colors.

Platūkytė’s current work uses powdered chitin as a natural binder to create composite materials that perform on two levels. Functionally she sees these materials as a way to provide non-toxic alternatives to conventional furniture or household objects, while philosophically she is interested in the material flows and traces we will leave behind as a species.

Along with material research, she is studying cultural and social relationships to materials, and described her research work “as the main guide for how to live and think in the new Anthropocene period and rethink the relationship between future humans, nature, and materials laying down in geological layers”. Chitin and chitosan are conduits for departing from traditional ideals and incentives for manufacture on both a physical and cultural level.

Platūkytė experimented with chitin as part of her PhD research into eco-friendly materials.

As waste piles up in our oceans and in landfills, re-contextualizing it as a resource is a survival tool. Beyond chitin, designers are resuscitating other marine food waste – from Lucy Hughes, who won this year’s James Dyson Award for her fish-scale bioplastic Marina Tex, to the revival of the century-old practice of using oyster shells to create a concrete composite called tabby. But implementing these on a wide scale might require even more creative and disruptive approaches to processing this waste, and a mentality shift in what we regard as valuable.

This article is part of a series exploring new materials in design, linked to the A/D/O 2019 curatorial theme Future Matter(s).

Text by Lily Saporta Tagiuri.

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