EmbroForm: Digital Fabrication of Soft Freeform Objects with Machine Embroidered Pull-up Strings

Paper Title

EmbroForm: Digital Fabrication of Soft Freeform Objects with Machine Embroidered Pull-up Strings

Publication Info

• Topic area: Digital fabrication of soft, freeform 3D objects using machine embroidery.
• Keywords: Digital fabrication, pull-up objects, machine embroidery, soft materials, 2D-to-3D transformation, lacing mechanisms, interactive design, shape-changing objects.

Background and Problem

• Problem / challenge: Existing pull-up object techniques rely on origamic folding, which results in faceted, rigid surfaces and requires manual, labor-intensive string routing. These approaches lack the ability to create soft, organic, and higher-fidelity shapes.
• Significance: Soft, deformable 3D objects are essential for applications like wearables, interactive toys, and home furnishings, where aesthetics, comfort, and ease of prototyping are critical.
• Motivation and related work: Prior work on 2D-to-3D transformations (e.g., origami-inspired folding, sewing, and layering) has limitations in shape fidelity, material stiffness, and manual fabrication effort. Machine embroidery has been used for planar patterns and basic 3D shapes but has not been extended to create soft, organic pull-up objects.

Solution

• Proposed approach: EmbroForm, a digital fabrication pipeline that automates the creation of soft pull-up objects by embedding sliding strings and zig-zag lacings into flexible sheet materials using machine embroidery.
• Novelty:
  1. Automated fabrication technique for routing sliding strings and lacings on flexible materials using machine embroidery.
  2. End-to-end pipeline for generating optimized 2D unwrapped patterns and pull-up string routing paths from a 3D mesh.
  3. Design tool for customizing pull-up objects and exporting machine-ready files.
  4. Validation through technical evaluations and application demonstrations.
• Procedure and key techniques:
  1. Segment a 3D mesh into developable 2D patches using an existing algorithm.
  2. Optimize the layout of 2D patches for embroidery and identify boundary points for merging.
  3. Generate zig-zag lacing paths to join boundaries and convert designs into embroidery machine files.
  4. Fabricate the object by laser cutting, embroidering sliding strings and tunnels, and pulling the lacing to form the 3D shape.

Results

• Concrete findings:
  • Shape accuracy: Prototypes achieved a shape error as low as 5.9% compared to the input mesh.
  • Pull-up forces: Optimized tunnels reduced pulling forces to 0.3(±0.05)N for regular boundaries.
  • Material compatibility: Tested with five materials (cotton, TPU vinyl, faux leather, polyester felt) with varying bending rigidity.
• Advantage over baselines:
  • Higher shape fidelity compared to folding-based methods.
  • Fully soft, deformable, and reversible transformations.
  • Automated fabrication reduces manual effort and errors.
• Experiments / evaluation:
  • Characterized tunnel parameters (dout = 2mm, din = 2mm) for low friction and tear resistance.
  • Evaluated the effect of merging points on shape accuracy, size, and pull-up effort.
  • Demonstrated scalability and versatility with seven 3D meshes and three application prototypes.
• Limitations and future work:
  • Limited by segmentation algorithms for certain geometries.
  • Challenges with slender shapes and entangled string routing.
  • Scaling up constrained by embroidery hoop size; scaling down limited by fabrication precision.
  • Future work includes improving pull-up/resetting mechanisms, extending aesthetics, and integrating actuators.

Summary

EmbroForm introduces a novel pipeline for fabricating soft, organic pull-up objects by embedding sliding strings and lacings into flexible sheet materials using machine embroidery. The approach automates the design and fabrication process, enabling higher shape fidelity, customization, and compatibility with various materials. Validated through technical studies and applications, EmbroForm demonstrates potential for use in shape-changing furniture, interactive toys, and custom animated characters. Future work aims to address scalability, interactive pull-up mechanisms, and expanded functionality.