Meta-Ori: monolithic meta-origami for nonlinear inflatable soft actuators

2025-03-30

AI Summary

Conventional soft pneumatic actuators suffer from limited design parameter spaces and complex fabrication processes, hindering multifunctional integration and programmable nonlinear mechanical responses. To address this, we propose a monolithic meta-origami (Meta-Ori) architecture that tightly integrates a mechanical metamaterial shell with Kresling origami-based pneumatic units via geometry–material co-design, enabling programmable nonlinear volumetric actuation. Leveraging fully 3D-printed fabrication (FDM with TPU) and Grasshopper-based parametric modeling, we achieve—for the first time—the monolithic integration of cylindrical-topology metamaterials and origami units. Experimental validation demonstrates sequential two-stage motion, highly repeatable pressure–volume nonlinear response, and millisecond-scale energy release. This approach substantially expands design freedom and overcomes the longstanding trade-off between functional programmability and manufacturing simplicity in traditional pneumatic actuators.

Technology Category

• Search and Optimization: Metareasoning and Metaheuristics
• Machine Learning: Active Learning
• Computer Vision: Multi-modal Vision

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications
• Economics, Online Markets and Human Computation: Architectures and workflows that use LLMs for crowd work

Abstract

The nonlinear mechanical response of soft materials and slender structures is purposefully harnessed to program functions by design in soft robotic actuators, such as sequencing, amplified response, fast energy release, etc. However, typical designs of nonlinear actuators - e.g. balloons, inverted membranes, springs - have limited design parameters space and complex fabrication processes, hindering the achievement of more elaborated functions. Mechanical metamaterials, on the other hand, have very large design parameter spaces, which allow fine-tuning of nonlinear behaviours. In this work, we present a novel approach to fabricate nonlinear inflatables based on metamaterials and origami (Meta-Ori) as monolithic parts that can be fully 3D printed via Fused Deposition Modeling (FDM) using thermoplastic polyurethane (TPU) commercial filaments. Our design consists of a metamaterial shell with cylindrical topology and nonlinear mechanical response combined with a Kresling origami inflatable acting as a pneumatic transmitter. We develop and release a design tool in the visual programming language Grasshopper to interactively design our Meta-Ori. We characterize the mechanical response of the metashell and the origami, and the nonlinear pressure-volume curve of the Meta-Ori inflatable and, lastly, we demonstrate the actuation sequencing of a bi-segment monolithic Meta-Ori soft actuator.

Problem

• Develops monolithic meta-origami inflatables for nonlinear soft actuators
• Addresses limited design parameters in traditional nonlinear actuators
• Enables 3D printing of tunable metamaterial-based pneumatic actuators

Innovation

• Monolithic 3D printed metamaterial-origami inflatables
• FDM with TPU for nonlinear soft actuators
• Grasshopper tool for interactive Meta-Ori design