Origami Mechanisms Research Articles

Electroadhesion-driven crawling robots based on origami mechanism

Soft crawling robots can operate regularly in complicated situations and are more adapted to their surroundings. This study presents a novel electroadhesion(EA)-driven soft crawling robot utilizing an origami mechanism design. This innovative combination significantly enhances the environmental adaptability and performance of soft crawling robots. The integration of electroadhesion provides strong surface adherence, while origami techniques enable flexible and efficient movement. We detail the design principles and manufacturing process, optimizing key parameters such as leg lengths and folding angles to maximize crawling efficiency. Extensive experimentation confirms the superior performance of this approach. This multidisciplinary strategy, combining electrostatics, origami, and robotics, opens new possibilities in soft robotics design, offering robust solutions for complex environments.

Folding Auxetic Polygonal Kirigami Tubes

Abstract Tubular auxetic structures have wide-ranging applications including medical stents, collapsible energy absorbers, and novel fasteners. To accelerate the development in these areas, and open up new application directions, an expanded range of design and construction methods for auxetic tubes is required. In this study, we propose a new method to construct polygonal cross-sectional auxetic tubes using the principles of origami and kirigami. These tubes exhibit useful global auxetic behavior under axial extension, despite the individual polygon faces not being auxetic themselves. In general, a flat kirigami sheet cannot be simply folded into a polygonal tube since this creates kinematic incompatibilities along the polygon edges. We resolve this issue by replacing the edge folds with an origami mechanism consisting of a pair of triangular facets. This approach eliminates the incompatibilities at the edges while maintaining a connection between faces. The proposed edge connection also introduces additional control parameters for the tube kinematics: for example, introducing a kinematic limit on tube extension and enabling non-uniform behavior along the length of the tube. The rich kinematic behavior possible with polygonal cross-sectional kirigami tubes has potential applications ranging from soft robotics to energy-dissipating devices.

Design and research of deformable wheel-legged robot based on origami mechanisms

This study presents a novel deformable wheeled robot based on an origami mechanism, designed to address the limited environmental adaptability of traditional wheeled robots. The research begins by rigorously establishing the fundamental parameters of the origami unit through an in-depth analysis of the Miura origami motion principle and a comprehensive study of the correlation between geometric parameters. Leveraging the theory of origami thickening, the origami unit is thickened and integrated into the design of the deformable Wheel-Legged mechanism. Controlled by a single motor, four Wheel-Legged structures enable seamless transformation between wheeled and legged forms. The paper provides a comprehensive analysis of the robot’s deformation, obstacle crossing, and other motion processes. Furthermore, it thoroughly investigates the effects of various gaits on the stability of the robot’s movement, followed by rigorous simulation and experimental verification. The experimental results unequivocally demonstrate the robot’s capability in deformation, steering, and obstacle avoidance.

Design of constant-force mechanisms using origami

The origami mechanisms possess numerous unique advantages, including folding, reconfigurability, and multi-stability. The presence of multi-stability introduces a novel concept for the design of constant force mechanisms (CFM). In this study, we present a CFM with multi-segment constant-force regions by leveraging the multi-stable characteristics of the origami mechanism. The design principle behind this CFM involves combining an accordion origami structure with positive stiffness and a Kresling origami structure with multi-segment negative stiffness regions. To achieve zero stiffness, the Kresling origami structure is aligned parallel to the accordion origami. To effectively utilize both the Kresling and accordion origamis, we have established a mechanical model that describes their respective stiffness characteristics to establish design rules for the constant-force mechanism. By carefully designing the parameters of these two origami structures, we evaluate how variations in the structural parameters of Kresling influence the constant force properties of our proposed multi-segment CFM. To illustrate its inherent property of providing constant force across multiple segments, we employ finite element analysis and experiments to obtain force-displacement curves for our mechanism. The results demonstrate the feasibility of our presented design method which paves the way for constructing a simple CFM.

Kresling origami mechanics explained: Experiments and theory

From a kinematics perspective, a Kresling origami cell couples axial displacement (contraction/expansion) with twist, leading to non-rigid origami behavior. From an energy landscape perspective, the selection of the Kresling origami geometry, together with its fabrication process and material, lead to energy envelopes allowing single or multiple stable states. In this context, this paper explores the Kresling origami mechanics through mathematical modeling integrated with experimental testing. On the theoretical mechanics front, we present a comprehensive model incorporating the representative geometrical parameters of the Kresling origami cell into the corresponding energy function in order to capture its essential mechanical behavior. On the experimental mechanics front, we create two fixtures that demonstrate the ability to control axial displacement (contraction/expansion) and twist independently, without imposing any constraints on the chiral arrangement of individual cells within the Kresling origami array (composed of multiple cells). Finally, we show the coexistence of multiple mechanical and morphological configurations within the same Kresling array by programming its loading modes, i.e., compression or twist. The fundamental nature of this work makes it applicable to several fields of engineering, including soft robotics and mechanical computing.

Origami‐Patterned Rigidification for Soft Robotic Bifurcation

The fluid‐transportation functions based on the volume‐regulating behavior of the chamber‐like organs inspire the development of artificial organs. Due to the intrinsic compliance of soft robotics for biomimicking purposes and the volume‐regulation capability of the 3D origami patterns, the soft robots with origami patterns show promising potential in such research. However, the folding deformation of the origami facets cannot be straightforwardly implemented as the actuation or the body movement, and the predetermined movements of the pattern limit the appropriate functions for specific applications. In this work, an origami‐patterned rigidification (OPR) method is proposed for applying rigid origami mechanisms (herein, the cuboctahedron origami ball) to the chamber‐like structure of soft robots. The motion of the soft robot is programmed by purposefully rigidified the soft chamber following the pattern. The resultant OPR structures are granted with functions corresponding to the predetermined motion of the pattern, and the expanded movements through the bifurcation brought by the soft–rigid characteristics. The concept, design, and fabrication of the OPR robot are presented. By analyzing the deformation of the soft creases, the kinematic models of the predetermined and expanded degrees of freedom are presented and verified by experiments. The extended functions of two OPR robots are demonstrated.

Design, optimization and verification of a conical guiding origami mechanism for underwater docking station

Underwater docking station requires a conical guiding device with a large tolerance capacity and smaller volume to recover unmanned underwater vehicles (UUVs). Here, this paper innovatively introduces a conical guiding origami mechanism designed by an array and rotation approach based on a rigid origami mechanism. The Jacobian matrix method systematically calculates the degree of freedom (DOF) of the device. The variation function of dihedral angle in the folding process of the origami mechanism is derived, and the kinematics model is established within the Cartesian coordinate system. Based on this model, we established a mathematical model for optimizing the origami mechanism by considering number of units and unit volume as the design variables, subject to minimizing the underwater flow area and length. The sequential quadratic programming algorithm is employed to identify the optimum design variables. Subsequently, based on optimized results, collision simulation is carried out, and a conical guiding device tailored for an underwater docking station is successfully designed. The proposed device can be used as an underwater docking station to recover UUVs for ocean exploration. The proposed device has a large tolerance capacity, minimal shrinkage state cross-sectional area and length, excellent hydrodynamic performance, and a high spatial utilization rate.

Assembly law of multi-ring hybrid origami mechanism and calculation method of the degree of freedom

This paper proposes a method for calculating the degrees of freedom of multi-loop hybrid folding mechanisms, which is used to calculate the degrees of freedom of multi-loop hybrid folding mechanisms, redefines the problem of not being able to determine whether the folding units are in series and parallel during the assembly process, summaries the two cases of redundant constraints, gives the calculation principle of multi-loop hybrid folding mechanisms, calculates the degrees of freedom for The calculation of degrees of freedom for the assembly of a variety of different crease folding units is carried out to verify the accuracy and feasibility of the degree of freedom calculation rule proposed in this paper. The control of the hand claw is improved and the number of drives added to the envelope type paper folding hand claw to capture space debris is reduced, greatly improving the reliability and stability of the paper-folding hand claw in space capture work, which is of great significance to the problem of calculating degrees of freedom after the assembly of paper folding units and the analysis of degrees of freedom of complex paper folding mechanisms and their design.

Waterbomb Origami Mechanism Pneumatic Manipulator Design Based on DH Parameter Method and Symmetric Folding Hypothesis

Waterbomb Origami Mechanism Pneumatic Manipulator Design Based on DH Parameter Method and Symmetric Folding Hypothesis

Origamic metal-organic framework toward mechanical metamaterial

Origami, known as paper folding has become a fascinating research topic recently. Origami-inspired materials often establish mechanical properties that are difficult to achieve in conventional materials. However, the materials based on origami tessellation at the molecular level have been significantly underexplored. Herein, we report a two-dimensional (2D) porphyrinic metal-organic framework (MOF), self-assembled from Zn nodes and flexible porphyrin linkers, displaying folding motions based on origami tessellation. A combined experimental and theoretical investigation demonstrated the origami mechanism of the 2D porphyrinic MOF, whereby the flexible linker acts as a pivoting point. The discovery of the 2D tessellation hidden in the 2D MOF unveils origami mechanics at the molecular level.

The novel synthesis of origami-inspired mechanisms based on graph theory

In this paper, a novel synthesis approach based on graph theory is proposed. This approach can be used to design the creases of origami mechanisms. All possible contracted graphs of the 1-DOF origami mechanism are provided based on the number and graph synthesis methods. Then, a new method named loop synthesis is presented and this method is used to obtain different loop situations of the contracted graphs considering the structural characteristics of the origami mechanism. Two theorems are proposed and proven to determine the availability of loop situations. Furthermore, a modified thick panel design method for the origami mechanism is presented, and both single units and multiple units of the origami mechanism are modelled. At the same time, a rotary actuator based on this mechanism is introduced to verify the validity of the above synthesis approach. Finally, rotation, repeatability, and static torque tests are conducted to measure the inherent stiffness constant of the actuator. This approach, which was proven to be effective for designing the origami mechanism, can be readily applied to generate the desired mechanism.

Low-frequency vibration isolation via an elastic origami-inspired structure

This paper presents a new elastic origami-inspired structure with quasi-zero-stiffness (QZS) characteristics to provide effective low-frequency vibration isolation performance. The geometric structure of the origami mechanism is first introduced, followed by the establishment of its mechanical model through the integration of elastic joints with compression springs. The derived strong nonlinear stiffness characteristics of the elastic origami mechanism are conducive to exploring a QZS isolator with high performance. Then by using the multiscale method, the dynamic behavior of the origami-inspired isolator is obtained, and the parameter influencing investigations validate that the proposed vibration isolation system has strong design flexibility and superior vibration suppression capability. An experimental prototype was fabricated and a series of vibration testing experiments under different working conditions were carried out. The experimental results demonstrated the effectiveness of the established theoretical model. Furthermore, the comparison with typical nonlinear passive isolators verified the advantages of the developed origami-inspired vibration isolation system. This work has the potential to advance the practical applications of origami-based mechanisms and also provides a new technical candidate for high-performance vibration isolation systems.

Tuning of Multi-stability Profile and Transition Sequence of Stacked Miura-Origami Metamaterials

Multi-stable origami structures and metamaterials possess unique advantages and could exhibit multiple stable three-dimensional configurations, which have attracted widespread research interest and held promise for applications in many fields. Although a great deal of attention has been paid to the design and application of multi-stable origami structures, less knowledge is available about the transition sequence among different stable configurations, especially in terms of the fundamental mechanism and the tuning method. To fill this gap, with the multi-stable dual-cell stacked Miura-ori chain as a platform, this paper explores the rules that govern the configuration transition and proposes effective methods for tuning the transition sequence. Specifically, by correlating the energy evolution, the transition paths, and the associated force–displacement profiles, we find that the critical extension/compression forces of the component cells play a critical role in governing the transition sequence. Accordingly, we summarize the rules for predicting the transition sequence: the component cell that first reaches the critical force during quasi-static extension or compression will be the first to undergo a configuration switch. Based on these findings, two methods, i.e., a design method based on crease-stiffness assignment and an online method based on internal pressure regulation, are proposed to tune the stability profile and the transition sequence of the multi-stable origami structure. The crease-stiffness design approach, although effective, cannot be employed for online tuning once the prototype has been fabricated. The pressure-based approach, on the other hand, has been shown experimentally to be effective in adjusting the constitutive force–displacement profiles of the component cells and, in turn, tuning the transition sequence according to the summarized rules. The results of this study will advance the state of the art of origami mechanics and promote the engineering applications of multi-stable origami metamaterials.

A novel analysis method for magnetically actuated soft origami mechanisms

The magnetically actuated soft origami mechanisms (MASOMs), which integrates the advantages of magnetic actuation and origami mechanisms, possesses promising prospective applications on soft untethered machines such as soft robots and compliant actuators. Generally, the deformation behavior of these mechanisms are analyzed through finite element analysis (FEA) considering elusive nonlinear constitutive equations of magnetically actuated elastomer that captures magnetic body torque and force induced by a magnetic field. However, it is time-consuming and troublesome to model and analyze the case with heterogeneous magnetization distribution. We propose an equivalent magnetic bar and hinge model to investigate the folding behavior of planar MASOMs under a uniform magnetic field. Both FEA and experiments are conducted to demonstrate the effectiveness of the proposed model in analyzing MASOMs with different system geometries and magnetization profiles. Two case studies with parallel and serial origami creases and different magnetization profiles are provided to show the practicability. The proposed model provides an effective method to investigate and design MASOMs.

Design and analysis of reconfigurable and deployable thin-walled architectural equipment inspired by Mirror-Miura origami patterns

In this paper, three reconfigurable Mirror-Miura origami (MMO) patterns are designed by the Miura origami units. The kinematics of three reconfigurable Mirror-Miura origami patterns are analyzed through an equivalent spherical 4R mechanism. On this base, different reconfigurable origami mechanisms are realized by using three different MMO patterns, which are developed in the form of an open-stacked array and a closed-stacked array. The physical properties (Equivalent volume and relative density) and mechanical properties (In-plane and out-plane Poisson's ratios) of the reconfigurable origami mechanisms are analyzed in this paper. Besides, the origami model of thick panels with three different MMO patterns is proposed to establish the deployable and reconfigurable architecture prototype with various shapes, which have been validated by experiments. Based on the MMO pattern, a reconfigurable square architecture filled with polyurethane foam caulk is selected to develop a closed-loop castle prototype. The load capacity of the closed-loop castle prototype with MMO patterns is tested, which indicates that the 1.7Kg filled square closed-loop architecture can suffer from the 94Kg weights in the longitudinal direction of the single closed-loop architecture, and the 8.5Kg weights in the side direction at least. Therefore, the proposed reconfigurable thin-walled architectural equipment designs with the MMO origami pattern have the characteristic of light-weight and high-bearing, which is promising for building engineering to improve the construction speed to some extent.

High-fidelity modeling of dynamic origami folding using Absolute Nodal Coordinate Formulation (ANCF)

Origami has evolved into a framework for creating engineering systems at vastly different scales: from large deployable airframes to architected materials to small DNA machines. These emerging applications require us to develop high-fidelity models that can simulate and examine folding-induced mechanical responses, especially those involving significant facet rotation, non-uniform deformation, and complex dynamics. To this end, this study formulates and experimentally validates a new origami mechanics model based on Absolute Nodal Coordinate Formulation (ANCF), which has unique advantages for predicting the nonlinear dynamics of multibody systems with large rotation and deformation. This new model treats origami facets as ANCF thin plate elements rotating around compliant creases. Moreover, Torsional Spring Damper Actuator (TSDA) connectors are developed to represent crease folding. After careful calibration with experimentally measured constitutive material properties, this study provides the first reported quantitative agreement between simulation predictions and experiment results involving complex and non-uniform facet deformation and transient dynamic responses. Therefore, this model can help deepen our knowledge of folding-induced mechanics and dynamics, fostering future applications for origami.

Design and parameter optimization of a biomimetic jellyfish origami mechanism (BJOM) based on waterbomb tessellations

In this paper, a biomimetic jellyfish origami mechanism (BJOM) based on waterbomb tessellations is designed. Its geometric model is established, and its kinematic equation is derived. Its volume ratio and fineness ratio that characterize the morphological characteristics are analyzed. The maximum volume ratio and the maximum fineness ratio range were taken as the two optimization objectives, respectively. And two independent single-objective optimization models were established to optimize the structural parameters of the BJOM. Compared with the example before optimization, the results of the two optimization models have greatly improved the range of fineness ratio and the volume ratio. Finally, three factors about fineness ratio, volume ratio and material consumption were comprehensively considered to establish a three-objective optimization model. The results of these three optimization models compared is shown: the BJOM after three-objective comprehensive optimization has better comprehensive performance than the former two optimization schemes. It shows the feasibility of the optimization method and the superiority of the optimization design.

Nonlinear stiffness analysis and programming of a composite origami metamaterial with embedded joint-type metastructures

Origami metamaterials have tremendous application potential in the fields of advanced deployable mechanisms, intelligent robots, and energy absorption devices. In this paper, we embed the flexible joints with metamaterial properties into the origami metamaterial structure, making the origami mechanism have simultaneous geometric nonlinearity and joint stiffness nonlinearity, and investigate the nonlinear stiffness characteristics of this composite metamaterial in detail. To enhance the bearing capacity of the overall structure, the tension spring is mounted to simulate the elastic effect of the crease, and the mechanical metamaterial property of this flexible joint is also revealed theoretically. Based on the kinematics of Miura-ori pattern, the static nonlinear mechanical properties of the composite metastructure are obtained. Besides, the detailed parameter analysis gives an effective validation of the strong design flexibility of the proposed origami mechanism, and the stiffness property programming is realized by tuning structural parameters. Finally, an experimental system is established to test the static mechanical properties of the flexible joint and the origami mechanism, and the high agreement between experimental curves and theoretical results confirms the effectiveness and practicality of the composite metamaterial. This work is helpful for the design of origami metamaterials exploiting their stiffness nonlinearity.

Origami With Rotational Symmetry: A Review on Their Mechanics and Design

Abstract Origami has emerged as a powerful mechanism for designing functional foldable and deployable structures. Among various origami patterns, a large class of origami exhibits rotational symmetry, which possesses the advantages of elegant geometric shapes, axisymmetric contraction/expansion, and omnidirectional deployability, etc. Due to these merits, origami with rotational symmetry has found widespread applications in various engineering fields such as foldable emergency shelters, deformable wheels, deployable medical stents, and deployable solar panels. To guide the rational design of origami-based deployable structures and functional devices, numerous works in recent years have been devoted to understanding the geometric designs and mechanical behaviors of rotationally symmetric origami. In this review, we classify origami structures with rotational symmetry into three categories according to the dimensional transitions between their deployed and folded states as three-dimensional to three-dimensional, three-dimensional to two-dimensional, and two-dimensional to two-dimensional. Based on these three categories, we systematically review the geometric designs of their origami patterns and the mechanical behaviors during their folding motions. We summarize the existing theories and numerical methods for analyzing and designing these origami structures. Also, potential directions and future challenges of rotationally symmetric origami mechanics and applications are discussed. This review can provide guidelines for origami with rotational symmetry to achieve more functional applications across a wide range of length scales.

Design, Assembly, and Function of DNA Origami Mechanisms.

This chapter provides an overview of the common procedures used in making functional DNA origami devices. These procedures include the design, assembly, purification, and characterization of the DNA origami structures, with a focus on dynamic devices.