Heterogeneous origami-architected materials with variable stiffness

Yasuhiro Miyazawa,Jinkyu Yang,James H Lynch,Hiromi Yasuda,Jordan R Raney,Takahiro Kunimine,Hyungkyu Kim,Kosei Tsujikawa

doi:10.1038/s43246-021-00212-4

Abstract

Origami, the ancient art of paper folding, has shown its potential as a versatile platform to design various reconfigurable structures. The designs of most origami-inspired architected materials rely on a periodic arrangement of identical unit cells repeated throughout the whole system. It is challenging to alter the arrangement once the design is fixed, which may limit the reconfigurable nature of origami-based structures. Inspired by phase transformations in natural materials, here we study origami tessellations that can transform between homogeneous configurations and highly heterogeneous configurations composed of different phases of origami unit cells. We find that extremely localized and reprogrammable heterogeneity can be achieved in our origami tessellation, which enables the control of mechanical stiffness and in-situ tunable locking behavior. To analyze this high reconfigurability and variable stiffness systematically, we employ Shannon information entropy. Our design and analysis strategy can pave the way for designing new types of transformable mechanical devices.

Highlights

Origami, the ancient art of paper folding, has shown its potential as a versatile platform to design various reconfigurable structures
We find that the origami tessellation can support homogeneous configurations, and highly heterogeneous configurations by virtue of phase transformation
Our origami unit cell consists of two flat sheets folded, whose crease patterns are defined by the length parameters (l, m, d) and angle (α)

Summary

Introduction

The ancient art of paper folding, has shown its potential as a versatile platform to design various reconfigurable structures. High stiffness has been achieved either by the collision of vertices in the waterbomb origami[21] or by employing Miura-ori to induce self-locking[3,20,22] Such stiffening response can be achieved without modifying predefined design parameters, once this stiffening response is implemented in the design, it is extremely difficult to remove this feature after fabrication. We find that the origami tessellation can support homogeneous configurations (i.e., all unit cells are in the identical phase, which exhibits the same folding motion within the tessellation), and highly heterogeneous configurations (i.e., different phases of origami unit cell coexist in the same tessellation while maintaining its reconfigurability) by virtue of phase transformation This extrinsic heterogeneity proffers rich morphology changes as well as finely controllable stiffness in the self-contact regime, which has been extremely challenging, especially after assembly, as mentioned earlier. The versatile conversion between homogeneous and heterogeneous states in origami is phenomenologically analogous to the structural phase transformation of the crystal structure

Methods

Results

Conclusion