Origami Structures Research Articles

Bilayer Self‐Folding Method with High Folding Force and Angle by Suppressing Delamination of Shrink Layer

Heat‐shrinkable films commonly serve as active materials for self‐folding owing to their capability to fold all hinges upon heating. For origami‐based electronic devices, the self‐folding of the metal layer is necessary. Nevertheless, the self‐folding angle is low owing to the high bending stiffness of metal layers and the low adhesion of heat‐shrinkable films. Here, we introduce a bilayer self‐folding technique that effectively suppresses delamination of the shrink layer, thereby achieving a high folding force and angle. A polyolefin film mechanically fixed on the metal substrate serves to inhibit delamination, regardless of the adhesive properties of the shrink layer. This is achieved by applying adhesives within holes fabricated on the shrink layer. Conventional methods using an adhesive layer to fix the shrink layer lead to delamination at temperatures above 100°C, resulting in a decrease in self‐folding angles. In contrast, our novel fixing method yields a folding angle of 161° at 140°C, with a shrinkage rate of 69%. To demonstrate the versatility of our proposed technique, we self‐fold various origami structures, including Miura‐ori, scissors, cranes, and tessellation with chip LEDs. The introduced method broadens the range of substrate materials suitable for self‐folding and offers new possibilities for the development of origami devices. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Prediction of DNA origami shape using graph neural network.

Unlike proteins, which have a wealth of validated structural data, experimentally or computationally validated DNA origami datasets are limited. Here we present a graph neural network that can predict the three-dimensional conformation of DNA origami assemblies both rapidly and accurately. We develop a hybrid data-driven and physics-informed approach for model training, designed to minimize not only the data-driven loss but also the physics-informed loss. By employing an ensemble strategy, the model can successfully infer the shape of monomeric DNA origami structures almost in real time. Further refinement of the model in an unsupervised manner enables the analysis of supramolecular assemblies consisting of tens to hundreds of DNA blocks. The proposed model enables an automated inverse design of DNA origami structures for given target shapes. Our approach facilitates the real-time virtual prototyping of DNA origami, broadening its design space.

Multi-body dynamical modeling and prediction of flexible origami/kirigami structures by affine transformation

A generalized multi-body dynamical modeling method of Origami/Kirigami structures considering the elastic–flexible coupling of surfaces and nonlinear creases is proposed. For different structures with complex spatial configuration and constraints, an Affine Transformation (AT) technique based on Absolute Nodal Coordinate Formulation (ANCF) is proposed to make the modeling more convenient and efficient. The surfaces are discretized by triangle reduced elements, and the constitutive relations of creases are described by nonlinear state-dependent torque constraints. The proof of the topological invariance of configurations is also given. The simulation of the folding capacity and dynamic behaviors on two Origami structures, Origami solar array mechanism, and enclosed Yoshimura Origami, are given, which verifies the effectiveness of the modeling method. Additionally, the quantitative dynamic behaviors contributes to the design principle of a Kirigami structure for multi-stability. Comparisons between theoretical results from modeling and experiments demonstrate the effectiveness of the modeling method and crease design. The AT-ANCF lays a theoretical foundation for dynamic prediction and design for large deformation Origami/ Kirigami structures, which has significant potential applications in dynamic properties design in the fields of aerospace, robotic etc.

A smashing success: Understanding the compression of origami structures

The buckling behavior of auxetic 3D-printed origami structures showed promising results for applications in impact protection.

Design and mechanical properties analysis of a cellular Waterbomb origami structure

Cellular structures are commonly used to design energy-absorbing structures, and origami structures are becoming a prevalent method of cellular structure design. This paper proposes a foldable cellular structure based on the Waterbomb origami pattern. The geometrical configuration of this structure is described. Quasi-static compression tests of the origami tube cell of this cellular structure are conducted, and load-displacement relationship curves are obtained. Numerical simulations are carried out to analyze the effects of aspect ratio, folding angle, thickness and number of layers of origami tubes on initial peak force and specific energy absorption (SEA). Calculation formulas for initial peak force and SEA are obtained by the multiple linear regression method. The degree of influence of each parameter on the mechanical properties of the single-layer tube cell is compared. The results show that the cellular structure exhibits negative stiffness and periodic load-bearing capacity, as well as folding angle has the most significant effect on the load-bearing and energy-absorbing capacity. By adjusting the design parameters, the stiffness, load-bearing capacity and energy absorption capacity of this cellular structure can be adjusted, which shows the programmable mechanical properties of this cellular structure. The foldability and the smooth periodic load-bearing capacity give the structure potential for application as an energy-absorbing structure.

Experimental study of solid-liquid origami composite structures with improved impact resistance

In this paper, a liquid-solid origami composite design is proposed for the improvement of impact resistance. Employing this design strategy, Kresling origami composite structures with different fillings were designed and fabricated, namely air, water, and shear thickening fluid (STF). Quasi-static compression and drop-weight impact experiments were carried out to compare and reveal the static and dynamic mechanical behavior of these structures. The results from drop-weight impact experiments demonstrated that the solid-liquid Kresling origami composite structures exhibited superior yield strength and reduced peak force when compared to their empty counterparts. Notably, the Kresling origami structures filled with STF exhibited significantly heightened yield strength and reduced peak force. For example, at an impact velocity of 3 m/s, the yield strength of single-layer STF-filled Kresling origami structures increased by 772.7% and the peak force decreased by 68.6%. This liquid-solid origami composite design holds the potential to advance the application of origami structures in critical areas such as aerospace, intelligent protection and other important fields. The demonstrated improvements in impact resistance underscore the practical viability of this approach in enhancing structural performance for a range of applications.

Miura origami based reconfigurable polarization converter for multifunctional control of electromagnetic waves

Polarization is one of the basic characteristics of electromagnetic (EM) waves, and its flexible control is very important in many practical applications. At present, most of the multifunction polarization metasurfaces are electrically tunable based on PIN and varactor diodes, which are easy to operate and have strong real-time performance. However, there are still some problems in them, such as few degrees of freedom of planar structure control, complex circuit, bulky sample, and high cost. In view of these shortcomings, this paper proposes a Miura origami based reconfigurable polarization conversion metasurface for multifunctional control of EM waves. The interaction between the electric dipoles is changed by adjusting the folding angle θ, thereby tuning the operating frequency of the polarization conversion and the polarization state of the reflected wave. This mechanical control method brings more degrees of freedom to manipulate EM waves. And the processed sample is with lightweight and low cost. To verify the performance of the proposed origami polarization converter, a Miura origami structure loaded with metal split rings is designed and fabricated. The operating frequency of the structure can be tuned in different folding states. In addition, by controlling the folding angle θ, linear-to-linear and linear-to-circular polarization converters can be realized at different folding states. The proposed Miura origami polarization conversion metasurface provides a new idea for reconfigurable linear polarization conversion and multifunctional devices.

Kresling origami-inspired electromagnetic energy harvester with reversible nonlinearity

This paper presents an electromagnetic energy harvester based on a unique nonlinear Kresling origami-inspired structure. By introducing the equilibrium shift phenomenon, reversible nonlinearity (i.e. mixed softening-hardening behavior) empowers the proposed harvester to work in a broad frequency band, confirmed by both simulation using a dynamic model and experimentation. The prototyped device can produce the open-circuit root mean square (RMS) voltage from 0.09 V to 0.20 V in the reversibly nonlinear response region in (6.19 Hz, 9.63 Hz) and a maximum output power of 0.4956 mW at an optimum load of 18.1 Ω under the excitation of 1.1 g. Moreover, detailed research further reveals that the design parameters of Kresling origami-inspired structure and electrical and mechanical loads influence reversible nonlinearity. Increasing the tip mass and γ 0 in the M2 region of the design map strengthens the softening behavior, and enlarging the electrical load enhances the hardening behavior. The findings from this work deepen the understanding of the nonlinear behavior of Kresling origami, unveils the great potential of origami structure in energy harvesting and offers a new method to realize broadband vibration energy harvesters.

Twisted DNA Origami-Based Chiral Monolayers for Spin Filtering.

DNA monolayers with inherent chirality play a pivotal role across various domains including biosensors, DNA chips, and bioelectronics. Nonetheless, conventional DNA chiral monolayers, typically constructed from single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA), often lack structural orderliness and design flexibility at the interface. Structural DNA nanotechnology has emerged as a promising solution to tackle these challenges. In this study, we present a strategy for crafting highly adaptable twisted DNA origami-based chiral monolayers. These structures exhibit distinct interfacial assembly characteristics and effectively mitigate the structural disorder of dsDNA monolayers, which is constrained by a limited persistence length of ∼50 nm of dsDNA. We highlight the spin-filtering capabilities of seven representative DNA origami-based chiral monolayers, demonstrating a maximal one-order-of-magnitude increase in spin-filtering efficiency per unit area compared with conventional dsDNA chiral monolayers. Intriguingly, our findings reveal that the higher-order tertiary chiral structure of twisted DNA origami further enhances the spin-filtering efficiency. This work paves the way for the rational design of DNA chiral monolayers.

A computational tool for the design of rigid origami structures based on a lumped damage model

As it is well known, origami structures have broad application prospects in aerospace, medical, architectural, robotics, material science, and other engineering fields. However, the comprehension and modeling of the collapse process of this kind of structure are still in the process of development. This paper investigates one specific failure mode: ultra-low cycle fatigue under large displacements. Origami structures are represented as sets of elastic panels with small strains connected by inelastic (plastic-damaged) hinge lines with large rotations. A novel experimental study of the behavior of the Waterbomb origami structure subjected to cyclic loadings with constant amplitudes is first presented. Then, a new model of damage evolution for origami structures is proposed. Finally, parametric studies are described on the influence of several design parameters (initial folding height, number of sides of regular polygons, and length ratio) on structural collapse. The computational tools proposed in this paper can then be used for the optimum design of origami structures and the structural assessment during the two phases of loading: first, the deployment stage, and then service loads on the unfolded solid.

A composite prismatic structure with thermal-torsion coupling effect

This article presents a composite prismatic structure that incorporates inclined rods composed of high-expansion material within a low-expansion material column, thereby enabling the attainment of a thermal-torsion effect. This effect, exhibited by metamaterials, can serve as a driving force for the reconstruction of reconfigurable structures, including origami structures, when subjected to thermal stimulation. The analytical formula for the torsional angle of the combined structure under thermal stimulation is obtained through geometric relationships. The accuracy of this analytical formula is demonstrated by both finite element simulations and experimental findings. To investigate the impact of the structural aspect ratio and inclination angle of the inclined rods on the thermal-torsion effect, a parametric analysis is conducted using the analytical solution and finite element results. The outcomes reveal that the structure is capable of achieving substantial torsional angles in response to temperature variations.

Deep-LASI, single-molecule data analysis software

By avoiding ensemble averaging, single-molecule methods provide novel means of extracting mechanistic insights into function of material and molecules at the nanoscale. However, one of the big limitations is the vast amount of data required for analyzing and extracting the desired information, which is time-consuming and user dependent. Here, we introduce Deep-LASI, a software suite for the manual and automatic analysis of single-molecule traces, interactions, and the underlying kinetics. The software can handle data from one-, two- and three-color fluorescence data, and was particularly designed for the analysis of two- and three-color single-molecule fluorescence resonance energy transfer experiments. The functionalities of the software include: the registration of multiple-channels, trace sorting and categorization, determination of the photobleaching steps, calculation of fluorescence resonance energy transfer correction factors, and kinetic analyses based on hidden Markov modeling or deep neural networks. After a kinetic analysis, the ensuing transition density plots are generated, which can be used for further quantification of the kinetic parameters of the system. Each step in the workflow can be performed manually or with the support of machine learning algorithms. Upon reading in the initial data set, it is also possible to perform the remaining analysis steps automatically without additional supervision. Hence, the time dedicated to the analysis of single-molecule experiments can be reduced from days/weeks to minutes. After a thorough description of the functionalities of the software, we also demonstrate the capabilities of the software via the analysis of a previously published dynamic three-color DNA origami structure fluctuating between three states. With the drastic time reduction in data analysis, new types of experiments become realistically possible that complement our currently available palette of methodologies for investigating the nanoworld.

Passivating Blunt‐Ended Helices to Control Monodispersity and Multi‐Subunit Assembly of DNA Origami Structures

Deoxyribonucleic acid (DNA) origami enables the synthesis of bespoke nanoscale structures suitable for diverse applications. Effective design requires preventing uncontrolled aggregation, while still facilitating directed multi‐subunit assembly. Uncontrolled aggregation is often caused by base‐stacking interactions between arrays of blunt‐ended helices, a problem which is typically mitigated by incorporating disordered single‐stranded DNA (ssDNA) (like scaffold loops or poly‐thymine brushes) at the end of double‐stranded DNA (dsDNA) helices. Such disordered regions are ubiquitous in DNA origami structures yet their optimal design requirements in various chemical environments remains unclear. This study systematically investigates scaffold loops and poly‐nucleotide brushes for aggregation prevention and control of multi‐subunit assembly, examining length, sequence, and MgCl2 concentration dependencies. Additionally, a novel strategy is introduced using orthogonal double‐stranded DNA helices to create a steric shield against base stacking. The results reveal key considerations. Poly‐thymine brushes excel in achieving monodispersity across diverse conditions whereas scaffold loops aid directed multi‐subunit assembly. Orthogonal DNA helices remove the need for disordered regions altogether, preventing aggregation over a broad range of MgCl2 concentrations and facilitating controlled multi‐subunit assembly. This study expands the toolbox for DNA origami design and enables a more informed approach for achieving control of monodispersity and multi‐subunit assembly in DNA origami structures.

Bioinspired Superhydrophobic Cellular Origami Exhibiting Improved and Multifunctional Floatability

AbstractInterfacial floater possessing an open surface diversifies the functions of current systems in the field of solar evaporation, micro‐detector, multiphase catalysis, etc. However, most of the current floaters still face challenges such as the anti‐submersion, orientation adjusting, and multifunctional capabilities. Drawing inspiration from water striders and diving bell spiders, here a superhydrophobic cellular origami (SCO) is proposed with reliable stability, submerge resistance, switchable floatability, and multifunctional integration. The remarkable floating ability is achieved through the air storage ability of superhydrophobic air cells. SCO floats stably on the water surface and has a maximum load capacity that is 48% higher than the superhydrophobic sheet. Besides, SCO can resurface rapidly after complete submersion, even using titanium metal as substrate. To further enhance the universality of SCO, the Janus SCO with unbalanced structure can float with a specific orientation facing up and the origami structure is optimized to be switchable with hinge structure for adjustable buoyancy. To prove the concept in 3D structure, a cylindrical SCO is presented for cable locating on the water surface. This study presents an achievable strategy to extend superhydrophobic surfaces into anti‐sinking floaters, offering valuable insights into the development of multifunctional interface carriers.

Elastic energy trapping in Kresling origami

In this study, elastic energy trapping strategy is exploited to investigate the energy absorption capability of origami structures. The twofold novelty of this paper can be summarized as (i) comprehensive analysis of a single Kresling module from a geometrical point of view to illustrate its energy trapping capability in the pathway of compression; (ii) introducing translational and torsional ACKS (achiral coupled Kresling structures); demonstrating their potential to be utilized as a platform for designing energy absorption systems that can trap energy applied by compressional and torsional loads. The outcomes pave the way toward utilizing origami structures in reusable energy-absorbing systems.

A physics-informed neural network for Kresling origami structures

Origami structures have the advantages of foldability and adjustability, with applications spanning numerous engineering fields. However, there remains a dearth of intelligent and convenient methods that can effectively tackle both potential energy prediction and design problems on origami structures. This study proposes a novel physics-informed neural network (PINN) to predict and design potential energy curves of Kresling origami structures without labelled data. A sorting operation is coupled into the PINN, ensuring the prediction correctness. The accuracy of the potential energy curves predicted by the PINN is demonstrated through comparison with a reference and the exhaustive method. A prediction only takes less than one second and the precision of the PINN significantly surpasses that of the exhaustive method, proving the extremely high efficiency and credibility of the PINN. Furthermore, two design cases for Kresling origami structures, matching a target potential energy curve and a set of target potential energy points, are performed. The designed structures meet the expectations and each design takes a few seconds, showing the efficiency and applicability of the PINN in inverse design. The presented physics-driven approach without labelled data offers an innovative tool with learning ability to predict and design. It also provides a valuable reference for the force and stiffness design of Kresling origami structures. In addition, the code of the PINN is shared online.

Design of origami structures with curved tiles between the creases

An efficient way to introduce elastic energy that can bias an origami structure toward desired shapes is to allow curved tiles between the creases. The bending of the tiles supplies the energy and the tiles themselves may have additional functionality. In this paper, we present a basic theorem and systematic design methods for quite general curved origami structures that can be folded from a flat sheet, and we present methods to accurately find the stored elastic energy. Here the tiles are allowed to undergo curved isometric mappings, and the associated creases necessarily undergo isometric mappings as curves. These assumptions are consistent with a variety of practical methods for crease design. The h3 scaling of the energy of thin sheets (h= thickness) spans a broad energy range. Different tiles in an origami design can have different values of h, and individual tiles can also have varying h. Following developments for piecewise rigid origami Fan Feng et al. (2020), we develop further the Lagrangian approach and the group orbit procedure in this context. We notice that some of the simplest designs that arise from the group orbit procedure for certain circle groups provide better matches to the buckling patterns observed in compressed cylinders and cones than known patterns.

Quantitative Analysis of Resistance to Deformation of the DNA Origami Framework Supported by Struts.

Nanostructures with controlled shapes are of particular interest due to their consistent physical and chemical properties and their potential for assembly into complex superstructures. The use of supporting struts has proven to be effective in the construction of precise DNA polyhedra. However, the influence of struts on the structure of DNA origami frameworks on the nanoscale remains unclear. In this study, we developed a flexible square DNA origami (SDO) framework and enhanced its structural stability by incorporating interarm supporting struts (SDO-s). Comparing the framework with and without such struts, we found that SDO-s demonstrated a significantly improved resistance to deformation. We assessed the deformability of these two DNA origami structures through the statistical analysis of interior angles of polygons based on atomic force microscopy and transmission electron microscopy data. Our results showed that SDO-s exhibited more centralized interior angle distributions compared to SDO, reducing from 30-150° to 60-120°. Furthermore, molecular dynamics simulations indicated that supporting struts significantly decreased the thermodynamic fluctuations of the SDO-s, as described by the root-mean-square fluctuation parameter. Finally, we experimentally demonstrated that the 2D arrays assembled from SDO-s exhibited significantly higher quality than those assembled from SDO. These quantitative analyses provide an understanding of how supporting struts can enhance the structural integrity of DNA origami frameworks.

Deep-learning-assisted single-molecule FRET analyses established using DNA origami structures

Deep-learning-assisted single-molecule FRET analyses established using DNA origami structures

Design and Analysis of Adaptive Flipper With Origami Structure for Frog-Inspired Swimming Robot

Design and Analysis of Adaptive Flipper With Origami Structure for Frog-Inspired Swimming Robot