Mycelium as Foam Replacement in Fab Lab
Researcher: Annie Henly, Fabrication Technician, experimenter
Program: College of Design Fabrication Workshop
Can we use mycelium grown in a substrate as a biodegradable replacement for Extruded Polystyrene (XPS) and/or High Density Urethane (HDU) foam in the Fab Lab?
Students use various foams in the Fab Lab to sculpt, route topography, and to create quick prototypes. When their project is over, it is usually thrown out.
Could mycelium be a good biodegradable replacement? Mycelium is the vegetative part of fungi (mushrooms are the fruit), it is a white web of strands between a material (the substrate). To start, we used pre-made kits (wood chip/mycelium mixture).
The Process:
- Add flour and water to the kit bag. Let grow for 5-7 days.
- Break a part the resulting chunk into small pieces, add more flour, and put it into a mold. Let grow for 5-7 days.
- At this point, you can inoculate sterilized substrates with this material, like sawdust, coffee grounds, etc. We experimented with 9 different combinations.
- Remove from mold and let dry (oven or air).
- Carve, CNC route, or laser cut.
The resulting material was comparable to foam for carving and creating quick prototypes (especially with cornstarch/sawdust filler). Routing did not have the fine detail of XPS. Some difficulties arose in sterilization of substrates and how to produce at scale. We have made connections with UMN’s Bioproducts and Biosystems Engineering and could use their equipment to scale up in the future.
