Programmable Self-Locking Origami Mechanical Metamaterials.

Area of Science:

• Mechanical Engineering
• Materials Science
• Origami Engineering

Background:

• Mechanical metamaterials often rely on structural multistability for programmable properties.
• Existing methods for programmability in metamaterials are limited.

Purpose of the Study:

• To explore nonflat-foldable origami as a new platform for programmable mechanical metamaterials.
• To demonstrate the self-locking and reconfiguration capabilities of origami for achieving programmability.

Main Methods:

• Investigated a single-collinear degree-4 vertex origami tessellation.
• Combined experimental and numerical analyses to study deformation modes and stiffness.
• Developed a multilayer model to generalize stiffness profiles.

Main Results:

• Each origami unit cell exhibits self-locking and programmable foldability/density.
• A sudden stiffness jump was observed due to a limiting-stopper effect.
• Stiffness is controllable among 2^n values in an n-layer metamaterial.
• Piecewise stiffness triggers bistable responses under harmonic excitations.

Conclusions:

• Self-locking origami provides a novel pathway for creating programmable mechanical metamaterials.
• In situ control over mechanical properties is achievable.
• The findings open new avenues for designing advanced metamaterials with tunable characteristics.