In order to fully take advantage of working with a biodegradable material, and the ethos of reducing, reusing and recycling, a team from Barcelona’s Iaac investigated how to incorporate food-waste, including orange peels, shrimp peels and used ground coffee into, bio-plastic. Food-waste is generally perceived as unwanted matter unless used for compost.
The team, made up of senior faculty member Areti Markopolou, fabrication expert Alexandre Dubor, computational expert Anfgelos Chronis, and students Christopher Wong, Lili Tayefi and Noor Elgewely (with external support from bioplastic expert Atanassia Atanassiou) has the aim was to incorporate local food waste from urban environment, and local context, in order to divert this matter from ending up in a landfill. Some of the local produce initially considered were orange peel and shrimp peel, since Spain is known for its oranges, and Barcelona for its seafood. In addition to merely up-cycling food-waste, the organic matter would actually provide added beneficial properties to the bio-plastic.
From food waste to functional bioplastic
Orange peel contains cellulose, which is an important structural component of the primary cell walls of green plants. It also happens to be the most abundant organic polymer on Earth. Cellulose has a high molecular chain length, or degree of polymerization. This high chain length relates to high tensile strength.
Compared to starch, cellulose is more crystalline, meaning it can take higher temperatures before becoming amorphous in water. The team performed a series of material experiments on the bio-plastic to understand how and to what degree the material would transform when subjected to various strains and stresses.
“Some of the lessons learned from our material experiments we learned the Orange peel bio-plastic had improved strength, and higher heat-resistance. While the coffee powder bio-plastic was more hydrophobic,” said Lily Tayefi, one of the authors of Iaac offical project page. “Another observation that applied to both types of the bio-plastic was, their shrinkage and bend over time. The higher percentage of food-waste we used in the material, the more the material would bend on its own. The input of dehydrating the material would trigger output of a self-assembly behavior of the form. This was most dramatic in the coffee-based bio-plastic.”
Moving forward, they set out to develop a material system that combines the different characteristics of both the Orange and Coffee based bio-plastic in order to create a composite material.
From a design perspective, there are different properties that the various types of bio-plastic offer us, based on what type of food-waste we incorporate into it. Due to the ease of production and accessibility of this material, it can be tailored with the desired parameters to suit, based on specific requirements for each project, but also to fine-tune the material performance within any given structure or object.
3D printing local food waste
Although coffee and orange were the materials experimented with thus far, the Iaac team anticipates that this bio-plastic can be locally re-appropriated to incorporate the specific food-waste which is most abundant at a given geographical location. At this stage in the project, the researchers are investigating how to incorporate the material system of Piel Vivo into an urban cityscape, and participate in the food production and energy cycle of the city.
“We envision – they state – a strategy for the city of the future, where each neighborhood could have a hub (Shown in Red) to collect food-waste from its surrounding, Food-sources (Yellow) and Residents (Blue). At the food-waste hub, the matter is collected and sorted, and the bio-plastic is processed here. The bio-plastic can be made on-demand based on the user requirements, and go directly back for distribution to its local community, reducing the need for transportation.” The final objective for this research is to create an ephemeral architecture with an embedded material intelligence, using low-cost, local materials, which respond to the local environment and its users based on their changing needs in contemporary society.