Origami spring-inspired shape morphing for flexible robotics

TL;DR

This paper introduces origami spring designs inspired by spring mechanics for flexible robotics, demonstrating their nonlinear behaviors, mechanical improvements through rigidization, and practical robotic applications with enhanced shape morphing capabilities.

Contribution

It presents a new class of origami springs with nonlinear mechanical responses and a rigidization method, enabling advanced shape morphing in flexible robotics.

Findings

Origami springs exhibit nonlinear stretch-twist coupling.

Rigidization improves damage resistance of the springs.

Robots using these springs achieve versatile shape morphing.

Abstract

Flexible robotics are capable of achieving various functionalities by shape morphing, benefiting from their compliant bodies and reconfigurable structures. Here we construct and study a class of origami springs generalized from the known interleaved origami spring, as promising candidates for shape morphing in flexible robotics. These springs are found to exhibit nonlinear stretch-twist coupling and linear/nonlinear mechanical response in the compression/tension region, analyzed by the demonstrated continuum mechanics models, experiments, and finite element simulations. To improve the mechanical performance such as the damage resistance, we establish an origami rigidization method by adding additional creases to the spring system. Guided by the theoretical framework, we experimentally realize three types of flexible robotics -- origami spring ejectors, crawlers, and transformers. These robots show the desired functionality and outstanding mechanical performance. The proposed concept of origami-aided design is expected to pave the way to facilitate the diverse shape morphing of flexible robotics.