Design and 4D Printing of Cross-Folded Origami Structures: A Preliminary Investigation

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• 4D printing research has explored complex structure folding and unfolding.
• Cross-folding origami structures, defined by overlapping folds, remain under-investigated.

Purpose of the Study:

• To investigate cross-folding origami structures using multi-material components and varying hinge thicknesses.
• To establish design guidelines for complex origami structures with overlapping and non-overlapping folding lines.

Main Methods:

• Tensile tests were conducted to evaluate multi-material components and single-material hinge thicknesses.
• Investigated the impact of hinge thickness on folding cycles and fracture points.
• Demonstrated implementation using a flower petal shape with single and multi-material segments.

Main Results:

• Multi-material composition significantly affects maximum strain and Young's modulus.
• For single materials, shape recovery speed is inversely proportional to hinge thickness.
• Flexural strength is proportional to hinge thickness; 0.5 mm hinges allowed 3 folds, 0.3 mm allowed 1, and 0.1 mm fractured immediately.
• Incorporating holes relieved stress and prevented fracture.

Conclusions:

• Design guidelines for cross-folding structures were established, applicable to single and multi-material designs.
• The study successfully demonstrated complex origami implementation with overlapping and non-overlapping folds.
• Future work includes exploring intermediate hinge thicknesses and hole placement for precise fracture prediction.