3D Printing Soap: Exploring New Biodegrdable Materials and Creative Possibilities

Paper Title

3D Printing Soap: Exploring New Biodegradable Materials and Creative Possibilities

Publication Info

• Topic area: Sustainable materials and interaction design in digital fabrication.
• Keywords: 3D printing, biodegradable materials, soap, interaction design, ephemerality, environmental responsiveness, transient design, DIY fabrication, sustainable making.

Background and Problem

• Problem / challenge: Traditional soap-making methods rely on molds, limiting geometric customizability, and soap has not been explored as a 3D-printable material in HCI and digital fabrication research.
• Significance: Soap’s biodegradability, water solubility, and reusability make it a sustainable medium for creative and interactive fabrication, addressing environmental concerns in digital fabrication.
• Motivation and related work: Prior research in HCI has explored biodegradable materials like gelatin, sodium alginate, and PVA for interaction design, leveraging their transient properties. However, these materials lack the everyday accessibility and design versatility of soap, which combines aesthetic, functional, and environmental qualities.

Solution

• Proposed approach: A workflow for 3D printing soap, including recipes for soap-based materials, a custom extrusion system, and example artifacts demonstrating expressive and functional possibilities.
• Novelty:
  1. Development of 3D-printable soap recipes using additives to enhance printability and functionality.
  2. Exploration of soap’s design space, enabling customization of color, scent, conductivity, and environmental responsiveness.
  3. Creation of a low-cost, DIY 3D printer optimized for soap-based materials.
  4. Demonstration of novel applications leveraging soap’s transient and sustainable properties.
• Procedure and key techniques:
  • Iterative development of soap formulations combining oils, sodium hydroxide, water, calcium carbonate, and sodium alginate.
  • Design of a custom extrusion system with a gravity-fed hopper and plunger-driven nozzle.
  • Integration of functional additives like thermochromic powders, activated carbon, and natural pigments for interactive properties.
  • Evaluation of biodegradability, water solubility, and reusability through controlled experiments.

Results

• Concrete findings:
  • Final soap recipe: 40g calcium carbonate, 3g sodium alginate, 80g water, and 100g soap base.
  • Biodegradability: Soap prints disintegrated in soil within 9–10 days.
  • Water solubility: Complete dissolution in tap water within 10–12 hours.
  • Reusability: Printed soap artifacts were easily rehydrated and reused.
• Advantage over baselines:
  • Soap’s water solubility and biodegradability outperform conventional thermoplastics in sustainability.
  • Soap’s reusability reduces material waste compared to traditional 3D printing workflows.
• Experiments / evaluation:
  • Biodegradability tested in composting environments over 15 days.
  • Water solubility assessed through dissolution trials in tap water.
  • Conductivity and environmental responsiveness validated with lab tests and spectrophotometric analysis.
• Limitations and future work:
  • Current formulations lack mechanical resilience for complex designs.
  • Future research could explore programmable dissolution profiles and multi-material structures for advanced interaction designs.

Summary

This paper introduces soap as a novel, biodegradable material for 3D printing, supported by a custom extrusion system and optimized formulations. By leveraging soap’s transient properties, the authors demonstrate its potential for sustainable and interactive fabrication through four example artifacts: a temporal QR code, an ephemeral timer circuit, a color-changing vase, and a pH-sensing ring. The findings highlight soap’s biodegradability, water solubility, and reusability, positioning it as a versatile medium for creative and environmentally responsible design. Future work aims to expand the design space through advanced formulations and collaborations with DIY maker communities.