Design, Mould, Grow!: A Fabrication Pipeline for Growing 3D Designs Using Myco-Materials

Title of the Paper

Design, Mould, Grow!: A Fabrication Pipeline for Growing 3D Designs Using Myco-Materials

Paper Information

• Subject Area: Human-Computer Interaction (HCI) and Sustainable Design
• Keywords: Biodesign, Biomanufacturing, Design Tools, 3D Printing, Sustainable HCI, Bio-HCI, Myco-Materials, Innovative Interaction Systems, Multi-Material Sustainable Design

Research Background and Issues

• Problems and Challenges:

  • Systematic exploration of myco-materials used in 3D printing is still in its infancy.
  • Many existing studies lack a deep understanding of fungal growth characteristics and reproducible design and fabrication workflows suitable for sterile experimental environments.
  • Current design tools and methodologies cannot easily convert a 3D design into molds suitable for fungal material growth.
  • There is a need to develop simpler myco-material fabrication processes to address the complex sterile conditions required in typical HCI labs.

• Significance:

  • Sustainability has become a critical focus in HCI research. Myco-materials, as a type of biomaterial, offer advantages such as rapid degradation, reusability, and the potential to use organic waste as raw material.
  • Creating 3D objects using organic waste and myco-materials has profound implications for reducing environmental pollution, promoting a circular economy, and developing bio-interactive systems.

• Research Motivation and Related Work:

  • Myco-materials can naturally bind organic substances like wood waste into rigid structures, offering an eco-friendlier alternative to traditional plastics.
  • Existing HCI research on myco-materials primarily focuses on small, simple shapes or low-fidelity prototypes, without exploring their application in complex 3D manufacturing and interaction systems.
  • This study aims to systematically explore the potential of 3D shaping with myco-materials, develop a reproducible pipeline for designing and fabricating organic 3D objects, and evaluate their practical application potential in HCI.

Solution

• Proposed Methods or Solutions:

  1. Developed a parametric design tool as a Grasshopper plugin for Rhino 3D, enabling easy conversion of 3D designs into molds suitable for myco-material shaping.
  2. Demonstrated a fabrication process reproducible in HCI labs, using pre-cultivated fungal substrates to avoid the need for expensive biological lab facilities.
  3. Conducted multiple case studies to comprehensively evaluate the geometric fidelity, mechanical properties, and interaction design adaptability of myco-materials.

• Innovations:

  • Designed a complete fabrication pipeline centered on myco-materials, covering design, self-repairing growth objects, and final product production.
  • Provided software support to simplify the complex mold design process and compensate for volume shrinkage during the drying process of myco-materials through parametric modeling.
  • Validated the integration of electronic components into myco-materials to develop interactive devices while exploring remanufacturing pathways for organic waste.

• Implementation Steps and Key Techniques:

  • Fungal Cultivation Research:
    • Selected Ganoderma steyaertanum fungi suitable for HCI applications, mixing its substrate with organic materials (e.g., sawdust, coffee grounds).
    • Optimized fungal cultivation processes using commercial spawn kits in non-research environments.
  • Mold Design:
    • Used parametric modeling tools to adjust mold angles and create ventilation holes to support fungal growth.
    • Software automatically compensated for size reductions due to myco-material drying shrinkage.
  • Growth Process and Post-Processing:
    • Designed a DIY incubator with humidity and dark environment controls, eliminating the need for costly lab-grade equipment.
    • Implemented a staged cultivation process, including bulk growth, mold shaping, and open growth phases.
    • Finalized applications after drying the myco-materials.

Research Outcomes

• Specific Achievements:

  • Fabrication Achievements: Developed a successful fabrication technique using widely available tools and materials (e.g., 3D printing, commercial spawn kits) to create functional myco-material objects in standard labs.
  • Software Tool: Provided a CAD tool plugin enabling designers to quickly convert any 3D design into negative molds.
  • Experimental Results:
    • Experiments showed that coffee grounds as an additive improved material shape retention and geometric fidelity (over 94%).
    • Mechanical properties of designed objects could be optimized by adjusting inclusions (e.g., adding glycerin).
    • Proposed the feasibility of assembling multiple sub-molds to address the growth of complex shapes.

• Advantages:

  • Cost-Effectiveness: Demonstrated that while myco-materials are slightly more expensive than 3D printing, their added sustainability features (e.g., biodegradability) compensate for the cost difference.
  • Usability: Developed a more flexible and simple fabrication method for small-scale or non-specialized labs.
  • Scalability: Showcased the potential for complex interaction designs, such as smart flowerpots, heat-sensitive coasters, and smart pressure mats.

• Experimental or Evaluation Results:

  • Successfully fabricated complex and vivid 3D models, such as the Stanford Bunny.
  • Shrinkage evaluation revealed that designs must be scaled up to 1.09 times the original model to achieve target geometric dimensions.
  • Mechanical tests indicated that materials mixed with coffee waste exhibited better elasticity.

• Limitations and Future Directions:

  • Time and Control: The fungal growth duration (approximately 2-3 weeks) limits efficiency; overcoming dependencies on humidity, light, and other conditions is necessary.
  • Additive Manufacturing Potential: The applicability of direct 3D printing with myco-materials remains limited and requires further exploration.
  • Process Improvement: Further optimization of software is needed to automate the design process for embedding electronic components.
  • Environmental Opportunities: Investigate the potential for collaboration between fungi and existing biomaterials (e.g., PLA) for decomposition.

This study highlights the innovative potential at the intersection of HCI and sustainable design. By demonstrating the feasibility of full-process fabrication with myco-materials, it provides a valuable starting point for further exploration of circular manufacturing and the integration of interaction technologies.