Print a Home for your Fungus

Robotic 3D-printing of self-made biodegradable starch-based materials

For the US author and mycologist Paul Stamets, the answer is simple: “Mushrooms will save the World”. In his book Mycelium Running, he not only vividly describes the many health-promoting properties of fungi, but also explains how they purify air and soil, filter and break down pollutants, provide nutrients for insects and microorganisms, and sustainably promote the growth and development of plants and the environment. The project, split into four phases, aimed to create a balance between the need for innovative, sustainable products and the environmental impact of unnecessary material objects. It revolved around three intertwined topics:

Production of biodegradable starch-based material.
Design of containers intended for fungal growth.
Robotic 3D printing of the envisioned forms using the self-made material.

The central theme was not strictly about the fungi, but more about the design and manufacture of appropriate materials and their further processing. Emphasis was placed on the belief, as posited by American designer Neri Oxman, that material always comes first in nature. The properties of the material determine the structure of the organism, which in turn, shapes its form and appearance.

In Phase 1, the focus was on material production. Students used a printer that processed pellets, leading to the creation of specific printable materials. A range of bioplastic mixtures were created, based on starch and various additives, subsequently processed into strands, dried, and converted into pellets.
Phase 2 encompassed the design process, combining a variety of requirements. These included visual aesthetics and the context-dependent form and structure of the “mushroom vessels”, as well as their technical feasibility. With robotic 3D printing technology, understanding its potential and limitations was crucial for the successful implementation of the design.

Institute
Dessau Department of Design

Students
Michelle Dreßler, Muriel Fischer, Helena Luise Kluge, Jessyca Molina, Johanna Plank, Joan Leonie Prange, Carl Rittel, Francis Sabien, Jan Stackfleth, Benedict von Berlin

Supervision
Benjamin Kemper
Prof. Dr. Manuel Kretzer

Project Date

2022

Category

Biomaterials · Digital Fabrication

In Phase 3, production took place using a collaborative KUKA robot arm equipped with a pellet extruder. Given the novelty of this technology, a particular emphasis of the course was on exploring and utilizing its possibilities.
Finally, in Phase 4, the printed vessels were inoculated with mushroom substrate. A range of fungal species and growth media were available for this step. Owing to the prolonged duration required for fungal cultivation, this phase was executed after the course’s conclusion.

Handmade
“Hanfmade” is a mushroom pot fabricated from a biodegradable, starch-based material via robotic 3D printing. The design strategy sought to ensure that the pot serves not just as a “home” for the mushroom, but also provides a substrate conducive to life. To attain this, the decision was made to incorporate fibers into the base substance, aimed at enhancing the stability of the pot and preventing rapid decay. This addition was intended to facilitate the pot’s repeated use and also support higher weight loads, leading to the concept of a wall-hanging pot design. The aim was to ensure that each pot could be customized and parameterized. This not only generates variety in simple forms but also allows the pots to be adapted to the fungus’s growth conditions. Through parametric changes, the simplicity of the pots does not appear monotonous but allows for each one to be distinct, creating related groups and novel shapes.

Inspiration was primarily drawn from nature, with tree hollows and beehives serving as creative resources. This is because mushrooms have a natural affinity for darker caves and tree crevices, and the layered structure of beehives also inspired the design. The decision was thus made to incorporate these characteristics into the pot’s design. Fabrication of the material followed, which included cutting the fibers, weighing the ingredients, mixing them into a mass, converting them into pellets, and drying them in an oven. Functionality tests were conducted on the finished pellets using a small 3D printer before moving on to a trial run with the KUKA robot arm. In addition to this, tensile strength tests and microscopic examinations were performed to scientifically comprehend how the fibers modified and affected the material. Based on these tests, hemp fiber was chosen due to its superior properties and sustainability.

“Hanfmade” is more than just a mushroom pot—it is a testament to sustainable, innovative design. Made from hemp, this biodegradable pot employs the beneficial properties of the fiber. Beyond its practical function, the 30 cm long model serves as a decorative wall feature, attachable via simple wall hooks. Whether used individually or as a parametrically modified unit, “Hanfmade” offers a promising home for any fungus.

Hydrophobic Biomaterial
The focus of this short project was research into a biodegradable biomaterial that could later be used as a support base for mycelium. The biomaterial was intended to be shaped into a conceived form through robotic 3D printing and, in addition, possess a unique property. Based on research into the conditions mushrooms require for optimal growth, the decision was made to study a material with as high a degree of hydrophobicity as possible, in order to ensure the required amount of water for the mushroom in the support base.

For the research on the biomaterial, a basic recipe was provided, to which various additives were added and individual components adjusted to achieve the desired hydrophobic property of the biomaterial. In three different experimental series, tests were conducted with the following different substances: crushed hemp seeds, melted beeswax, and chitosan powder. From the basic recipe and the respective additives, the first pellets were produced, which were needed for extruding the material. In a water test, individual pellets were examined for their water resistance, with the chitosan experimental series proving to be the most hydrophobic. Subsequently, the focus was placed on chitosan as an additive and further experiments were carried out.

The exciting and unique shape for the support base was inspired by coral formations and organic shapes from nature. Small indentations and high walls provide shade, which the mushroom additionally needs. The prototype with the planted mycelium finds its use in the kitchen, on the balcony, or in the garden. If the prototype is no longer needed after its application, it can be disposed of on the compost and decompose there without leaving any residues.

Kula
In this short project, the focus was on the coloration of extrudable bio-material. The initial goal was to create a material that becomes bright and transparent when printed, so that the later growing mushroom takes center stage. The vessel was to have a geometric shape that contrasts with the organic, ornamental mushroom.

The project started with a variation of a recipe, where 100g of cornstarch was replaced with rice starch. The resulting mass was brilliantly white and very hard in pellet form. During a test print at 210°C on 2mm, very transparent light extrusions were created. Essentially, this was exactly the desired result. However, it was quickly noticed that these small test prints could not be transferred to the 5mm extrusion. While this was smooth on the surface, it was neither translucent nor bright. Two further recipes were thus developed: one with 10g of white cellulose fibers and one with a lower glycerol content. Both masses resembled the basic recipe; the cellulose sample became matte and slightly darker than when printed. After this test, the last result was taken as the basic recipe for further color experiments with additives. Five samples were made with spirulina, turmeric, beetroot, indigo, and carbon fibers. All samples, except the carbon one, behaved similarly during printing, becoming partially translucent and showing a lighter or darker coloring.

Twist
The design journey from the initial sketch to the final model was extensive and inspired by various organic forms such as different types of fungi, sea anemones, and corals. Acknowledging the propensity of most fungi to appear in large groupings in nature, the design sought to mimic this ‘family’ aspect. The final form evolved from an organic to an inorganic shape, finally settling on a geometric (Low Poly) form. In tandem with the design process, several experimental series were conducted to determine the ideal composition for the bioplastic material. This represented a dynamic procedure where development, design, and production processes intertwined seamlessly.

The base recipe for the bioplastic incorporated 240 g of glycerol (99.5%), 300 g of cornstarch, 300 g of distilled water, and 150 g of white vinegar (5% acid). These components were mixed at an increasing temperature (up to 80°C) for approximately 15 minutes to create a compact mass. After cooling, the mixture was extruded into long filaments using a meat grinder. The filaments were then left to dry overnight on baking paper. The subsequent day, these were cut into 4-5 mm pellets. Prior to the printing process, the pellets were dried at a constant temperature of 105 °C for a minimum of 10 hours in a drying oven.

With the design and material finalized, the printing process commenced. The pellets were transferred into a 3D printer and melted into filaments, facilitating layer-by-layer printing of the object. External factors such as ambient air, temperature, light, and moisture, along with the high content of the plasticizer glycerol, contributed to the elasticity of the final product. The resulting product boasts a large opening conducive to growth and irrigation. It is lightweight and exhibits a wave-like structure, which offers tactile appeal. The “Twist” embodies an adaptable domicile for mushrooms, reflecting an environmentally friendly and sustainable solution.

Institute
Dessau Department of Design

Students
Michelle Dreßler, Muriel Fischer, Helena Luise Kluge, Jessyca Molina, Johanna Plank, Joan Leonie Prange, Carl Rittel, Francis Sabien, Jan Stackfleth, Benedict von Berlin

Supervision
Benjamin Kemper
Prof. Dr. Manuel Kretzer

Project Date

2022

Print a Home for your Fungus

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