Piel Vivo

Biodegradable Plastic Material Design

Is programming material intelligence using food waste deposition to trigger automatic three-dimensional formation of material that is printed using six-axis robotic extrusion the future of food waste?

 

In this system, gelatin-based bio-plastic is supplemented with granular organic matter from food waste in conjunction with a split frame system that enables the self-formation of three-dimensional geometries by directing the force of the material’s uniform contraction as it dries.

 

By adjusting the food waste added to the bio-plastic, its properties can be tuned according to formal and performative needs; here, dehydrated granulated orange peel and dehydrated spent espresso-ground coffee are used both to impart their inherent characteristics and also to influence the degree of curvature of the resulting surfaces and columnar structures.

2016

Category: Material Science, bioplastics

Location: IAAC, Barcelona

Duration: 6 months

Researchers: Noor El-Gewely, Lili Tayefi, Christopher Wong

 

Advisor: Areti Markopoulou, 

Assisted by: Alexandre Dubor, Angelos Chronis

Space Dynamics Workshop: Manuel Kretzer

Material Science Support:  Athanassia Athanassiou, Ilker Bayer, from IIT Istituto Italiano Di Technologia

Robotic Fabrication Support:  Djordje Stanojevic

Additive Manufacturing Support:  Sofoklis Giannakopoulous

Computational Support:  Rodrigo Aguirre

Physical Computing Support:  Angel Muñoz

Film Production: Lili Tayefi

Music: Glass Animals, Gooey

Material Science

Our aim was to incorporate local food waste from our urban environment, and local context, in order to divert this matter from ending up in landfill. Some of the local produce that initially came to mind was: Orange Peel and Shrimp Peel. Spain is famous 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.

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.

We performed a series of material experiments on our 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.

Fabrication & Shrinkage Over Time

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 an output of a self-assembly behaviour of the form. This was most dramatic in the coffee based bio-plastic.

Moving forward, we wanted 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.

 

How could we begin to control the resultant behaviour of the material based on the geometry and location of the various food-wastes in the composite?

In addition to the system of composite panels we were creating, another challenge of our material investigation was to demonstrate that we could develop a material that was able to be 3D printed vertically.


Due to the unique self-forming properties of the bio-plastic, we wanted to work with this quality in mind when creating the vertical tool-paths. Therefore we intentionally designed weaknesses into the structure, that would act as a point of flexion. The geometry of the 3D printed object would transform over time as
a result of the curing process.

3D Printability

Our objective for this research is to create an ephemeral architecture with an embedded material intelligence, using low-cost, local materials, which responds to its environment and its users based on their changing needs in contemporary society.

An important factor that we addressed at this stage of the project was the material uniformity. The less uniform a material is, the more difficult it is to print. In order to improve the material uniformity we needed to reduce the granular size of the orange peel. This was done by two steps: a better food processor, and dehydrating the OP in the oven before processing it.

There are several parameters to control when it comes to additive manufacturing such as – viscosity, nozzle diameter, temperature, air pressure, height above printing surface. All the factors mentioned such as – viscosity, nozzle diameter, temperature, air pressure, height above printing surface, are directly linked to the scale used.

 

Consequently for each item that we had resolved, it had to be re-calibrated as we moved up in scale. A lesson for future reference is to fi rst decide what is the scale of the object to be 3D printed – food, art or construction, then tailor the fabrication method to suit.

 

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