Elastic paper folding parallel mechanism and manufacturing method

Abstract

The invention discloses an elastic paper folding parallel mechanism and a manufacturing method. The elastic paper folding parallel mechanism comprises a first platform, a first elastic connecting piece and a second platform. The first elastic connecting piece is provided with two sides oppositely distributed in the vertical direction, and one side is connected with the first platform. The second platform is connected with the other side of the first elastic connecting piece, and the second platform is arranged below the first platform. Wherein the first elastic connecting piece has elasticity, the first platform has a first state and a second state, in the first state, the first platform is close to or away from the second platform, and in the second state, the first elastic connecting piece provides elasticity for the first platform so that the first platform can be located at the initial position. According to the elastic paper folding parallel mechanism and the manufacturing method, the elastic function can be directly integrated into the paper folding body, and the integrated parallel mechanism which is simple in structure, capable of automatically resetting and high in reliability is achieved.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to a flexible origami parallel mechanism and its manufacturing method. Background Technology

[0002] In recent years, as robot applications have expanded from factories to complex environments such as ruins and human cavities, traditional rigid joints are difficult to adapt due to their large weight and high impact brittleness. Flexible robots, with their advantages of being lightweight and compliant, have become a research hotspot.

[0003] However, existing flexible robots generally rely on external springs, steel wires, or shape memory alloys to provide rebound force, resulting in a large number of parts, complex assembly, and susceptibility to fatigue failure. In addition, although many existing flexible origami mechanisms have large deformation capabilities, their unfolding and folding processes often rely on external constraints or active control, lacking autonomous reset functions. This necessitates the additional configuration of drive or locking devices for the system, which not only increases the overall weight and control complexity but also diminishes the inherent advantages of origami structures—lightweight and compact design. Summary of the Invention

[0004] The main objective of this invention is to propose an elastic origami parallel mechanism and manufacturing method, which can directly integrate the elastic function into the origami body to achieve an integrated parallel mechanism that is simple in structure, automatically reset, and highly reliable.

[0005] To achieve the above objectives, some embodiments of the present invention provide a flexible paper-folding parallel mechanism, comprising: First platform; The first elastic connector has two sides that are oppositely distributed in the vertical direction, one side of which is connected to the first platform; The second platform is connected to the other side of the first elastic connector, and the second platform is located below the first platform; The first elastic connector is elastic, and the first platform has a first state and a second state. In the first state, the first platform moves closer to or further away from the second platform. In the second state, the first elastic connector provides elastic force to the first platform so that the first platform is in the initial position.

[0006] In some embodiments, the first resilient connector includes a plurality of first segments arranged circumferentially about a vertical direction and spaced apart.

[0007] In some embodiments, the first platform includes a base structure, a plurality of second elastic connectors and a plurality of intermediate connection structures. The base structure has an edge around a vertical direction, the second elastic connectors are connected to the edge, one side of the intermediate connection structure is connected to the edge through the second elastic connectors, and the other side of the intermediate connection structure is connected to the second platform. The basic structure has a third state and a fourth state. In the third state, the basic structure is close to or far from the intermediate connecting structure. In the fourth state, the second elastic connector provides elastic force to the basic structure so that the basic structure is in the initial position.

[0008] In some embodiments, the intermediate connection structure includes a plurality of first intermediate structures, a plurality of second intermediate structures, and a plurality of third elastic connectors. The first intermediate structure has an edge surrounding itself, the third elastic connectors are connected to a portion of the edge of the first intermediate structure, the second intermediate structure is connected to the side of the third elastic connector away from the first intermediate structure, and the first elastic connectors are connected to the side of the second intermediate structure away from the first intermediate structure.

[0009] In some embodiments, the base structure is sheet-like and configured to be horizontally arranged, and the intermediate connecting structure is sheet-like and inclined to the base structure.

[0010] In some embodiments, the first intermediate structure is sheet-like, the second intermediate structure is sheet-like, the second intermediate structure is inclined to the first intermediate structure, the second intermediate structure is located below the first intermediate structure, and the second intermediate structure is inclined toward the center of the base structure. The first intermediate structure is located below the base structure, and the first intermediate structure is inclined to the base structure, with the inclination direction of the first intermediate structure being opposite to that of the second intermediate structure.

[0011] In some embodiments, the basic structure is configured as an equilateral triangle, the first intermediate structure is configured as an isosceles triangle, and the second intermediate structure is configured as a right triangle. The first platform includes three first intermediate structures, the bottom edges of which are connected to the three sides of the basic structure respectively; The first platform includes six second intermediate structures. The hypotenuse of the second intermediate structure is connected to the waist of the first intermediate structure, and the right-angled side of the second intermediate structure opposite to the hypotenuse is connected to the first elastic connector.

[0012] In some embodiments, the material of the base structure includes rigid thermoplastic polyester; and / or, The materials for the intermediate connecting structures include rigid thermoplastic polyester; and / or, The material of the first elastic connector includes thermoplastic polyurethane elastomer; and / or, The material of the second elastic connector includes thermoplastic polyurethane elastomer.

[0013] In some embodiments, the rigid thermoplastic polyester is PETG, the thermoplastic polyurethane elastomer is TPU 85A, and the two are integrally fused together in the same printing job through an additive manufacturing process.

[0014] An embodiment of the second aspect of this application provides a manufacturing method for manufacturing the elastic origami parallel mechanism described above, the manufacturing method comprising: A three-dimensional digital model including the first platform, the second platform, and all elastic connectors is established, and the model is divided into rigid and elastic regions. Specify the rigid region as PETG material and the elastic region as TPU 85A material, and configure interlocking beam slice paths at the junction of the two regions; Using a fused deposition modeling equipment with multiple nozzles or an AMS feeding system, PETG and TPU 85A are deposited alternately in the same printing job, so that the two materials are coupled within and between layers. Remove the support structure to obtain a flexible origami parallel mechanism.

[0015] According to the above embodiments, the beneficial effects of this application are: The elastic origami parallel mechanism of this application includes a first platform, a second platform, and a first elastic connector connecting the two. The first platform and the second platform are arranged opposite each other in a vertical direction, and the first elastic connector is located between them, forming a longitudinal elastic support structure. The first platform has a first state and a second state. In the first state, the first platform moves closer to or away from the second platform under the action of an external force; in the second state, that is, after the external force is released, the first elastic connector releases its stored elastic potential energy, driving the first platform to reset to its initial position.

[0016] In summary, this application integrates elasticity directly into the structural body by using elastic components as connectors. This allows the mechanism to generate controllable elastic deformation in the vertical direction under compression or tension, and automatically reset itself after unloading using its stored elastic potential energy. This design eliminates the need for external springs, slide rails, or additional reset parts, reducing the number of parts and assembly layers. This fundamentally reduces the risk of failure due to loose connections, frictional wear, or fatigue fracture, improving system reliability and service life. Simultaneously, the elastic connectors create a continuous force transmission path between platforms, resulting in more uniform load distribution, shorter kinematic chains, and a more compact overall structure. It retains the advantages of large deformation and lightweight design of origami mechanisms while providing a clear elastic recovery function, offering a simple and robust foundation for building highly integrated, maintenance-free flexible robot modules.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a front view schematic diagram of the elastic origami parallel mechanism in one embodiment of this application; Figure 2 This is a top view of the flexible origami parallel mechanism in one embodiment of this application; Figure 3 This is a right-side structural schematic diagram of the elastic origami parallel mechanism in one embodiment of this application; Figure 4 This is a three-dimensional structural diagram of the elastic origami parallel mechanism in one embodiment of this application, viewed from another perspective. Figure 5 This is a flowchart of a manufacturing method in one embodiment of this application; Figure 6 This is a Bambu Studio slice diagram of a flexible origami parallel mechanism in one embodiment of this application. The left side is the model and the right side is the wiping tower (which will appear in dual-material printing). Figure 7 This application presents an example of the effect of using an interlocking beam in the manufacture of an elastic origami parallel mechanism.

[0020] Explanation of icon numbers: 10. Flexible origami parallel mechanism; First platform 100; basic structure 110; second elastic connector 120; intermediate connection structure 130; first intermediate structure 131; second intermediate structure 132; third elastic connector 133; First elastic connector 200; First segment 210; Second platform 300.

[0021] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or," "and / or," or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where A and B are simultaneously satisfied. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0025] The following is for reference. Figures 1 to 7 This application describes the flexible origami parallel mechanism 10 and its manufacturing method according to embodiments thereof. (Refer to...) Figures 1 to 4 The first aspect of this application proposes an elastic origami parallel mechanism 10, which achieves flexibility, self-recovery, and assembly-free characteristics not possessed by traditional rigid parallel mechanisms through the combination of integrated structural design and multi-material additive manufacturing technology. Specifically, the elastic origami parallel mechanism 10 of this application includes a first platform 100, a second platform 300, and a first elastic connector 200 connecting the two. The first platform 100 and the second platform 300 are arranged opposite each other in a vertical direction, and the first elastic connector 200 is located between them, forming a longitudinal elastic support structure. The first platform 100 has a first state and a second state. In the first state, the first platform 100 moves closer to or further away from the second platform 300 under the action of an external force; in the second state, that is, after the external force is released, the first elastic connector 200 releases its stored elastic potential energy, driving the first platform 100 to reset to its initial position.

[0026] In summary, this application integrates elasticity directly into the structural body by using elastic components as connectors. This allows the mechanism to generate controllable elastic deformation in the vertical direction under compression or tension, and automatically reset itself after unloading using its stored elastic potential energy. This design eliminates the need for external springs, slide rails, or additional reset parts, reducing the number of parts and assembly layers. This fundamentally reduces the risk of failure due to loose connections, frictional wear, or fatigue fracture, improving system reliability and service life. Simultaneously, the elastic connectors create a continuous force transmission path between platforms, resulting in more uniform load distribution, shorter kinematic chains, and a more compact overall structure. It retains the advantages of large deformation and lightweight design of origami mechanisms while providing a clear elastic recovery function, offering a simple and robust foundation for building highly integrated, maintenance-free flexible robot modules.

[0027] Reference Figures 1 to 4 In some embodiments, the first elastic connector 200 includes a plurality of first segments 210 arranged circumferentially around the vertical direction and spaced apart.

[0028] The first elastic connector 200 is divided into multiple first segments 210 arranged circumferentially, so that elastic deformation is no longer concentrated on a single continuous body, but is distributed on several independent elastic arms. This multi-segment layout reduces the lateral coupling stress during bending, and each segment can complete its own deformation in a smaller space, avoiding early fatigue or permanent deformation caused by stress concentration in traditional integral elastic components.

[0029] Furthermore, the circumferentially spaced segments form a multi-path force closed loop, allowing external loads from different directions to be preferentially absorbed and rapidly transmitted by the nearest segment, achieving isotropic reset and enhancing the mechanism's adaptability to eccentric loads and instantaneous impacts. The gaps between segments also provide natural avoidance space for in-plane interference during the folding process, eliminating the need for additional material removal or complex gaps. This maintains a high folding ratio while ensuring the uniformity and repeatability of the elastic restoring force, laying the foundation for achieving large-stroke, highly reliable, and compliant spatial motion.

[0030] Reference Figures 1 to 4In some embodiments, the first platform 100 includes a base structure 110, a plurality of second elastic connectors 120, and a plurality of intermediate connecting structures 130. The base structure 110 has an edge around a vertical direction, the second elastic connectors 120 are connected to the edge, one side of the intermediate connecting structure 130 is connected to the edge via the second elastic connectors 120, and the other side of the intermediate connecting structure 130 is connected to the second platform 300. The base structure 110 has a third state and a fourth state. In the third state, the base structure 110 is close to or away from the intermediate connecting structure 130. In the fourth state, the second elastic connectors 120 provide elastic force to the base structure 110 to keep it in its initial position. This design introduces a secondary elastic chain of base structure 110, second elastic connectors 120, and intermediate connecting structures 130 within a single platform, making the first platform 100 itself an elastic subsystem with local degrees of freedom.

[0031] This design decomposes the overall displacement into two stages of sequential deformation: when external force is applied, the base structure 110 first generates a primary displacement relative to the intermediate connecting structure 130 through the second elastic connector 120, followed by the secondary displacement between platforms completed by the first elastic connector 200; during unloading, the second elastic connector 120 provides the restoring force first, quickly pulling the base structure 110 back to its initial position, forming a gradient reset mechanism of "local first, then overall". This graded elastic strategy effectively reduces the strain accumulation of a single elastic element under large stroke, avoids the impact and vibration caused by instantaneous rebound, and improves motion stability and repeatability accuracy.

[0032] Meanwhile, the local elastic element allows the base structure 110 to make minute adaptive adjustments within the plane, actively compensating for geometric shifts caused by manufacturing errors, thermal deformation, or external disturbances, thus enhancing the system's tolerance to environmental uncertainties. Since the second elastic connector 120 is integrated into the platform edge without occupying additional external volume, it maintains the slim profile of the origami mechanism while providing controllable flexibility within the platform, offering a scalable elastic foundation for subsequent high-resolution force control and multi-mode deformation.

[0033] Reference Figures 1 to 4In some embodiments, the intermediate connection structure 130 includes a plurality of first intermediate structures 131, a plurality of second intermediate structures 132, and a plurality of third elastic connectors 133. The first intermediate structures 131 have an edge surrounding themselves; the third elastic connectors 133 connect to a portion of the edge of the first intermediate structure 131; the second intermediate structures 132 connect to the side of the third elastic connectors 133 opposite to the first intermediate structure 131; and the first elastic connectors 200 connect to the side of the second intermediate structure 132 away from the first intermediate structure 131. Specifically, the intermediate connection structure 130 is further refined into a first intermediate structure 131, a second intermediate structure 132, and a third elastic connector 133. These three are connected sequentially to form an elastic progressive chain of the first intermediate structure 131, the third elastic connector 133, and the second intermediate structure 132. This layout distributes the bending angle increment, originally concentrated on a single hinge, across two intermediate structures and elastic connectors, reducing the maximum strain per unit length and avoiding material fatigue or permanent deformation caused by excessive local bending, thereby extending the overall cycle life.

[0034] The third elastic connector 133 forms a reversible elastic buffer zone between the two intermediate structures. When the external load changes abruptly, this buffer zone can absorb the impact energy first and delay the transmission of the peak force, effectively suppressing vibration rebound and improving motion stability and positioning accuracy. Since the first intermediate structure 131 and the second intermediate structure 132 are connected by a local edge, the entire elastic chain is embedded in the origami surface without adding extra thickness. This maintains the advantages of the origami structure being lightweight and foldable, while also giving the intermediate connecting structure 130 controllable microscopic compliance, enabling the mechanism to achieve stable and repeatable self-resetting under complex stress environments.

[0035] Reference Figures 1 to 4 In some embodiments, the base structure 110 is sheet-like and configured horizontally, while the intermediate connecting structure 130 is sheet-like and inclined relative to the base structure 110. This design allows the elastic chain, which could originally only stretch and contract in the vertical direction, to gain out-of-plane tilting freedom. This assembly can produce a slight out-of-plane folding at the moment of stress, spontaneously adjusting the direction of force transmission using the tilt angle, converting a portion of the axial load into in-plane shear, thereby reducing the peak value of pure tensile and compressive strain in the elastic connector and avoiding early fatigue caused by localized stress concentration.

[0036] Meanwhile, the inclined arrangement creates a natural slope to guide the folding process, allowing the paper creases to close smoothly along the predetermined inclined edge without additional cuts or gaps. This maintains a high folding ratio while ensuring that each layer accurately returns to the same spatial posture after each unfolding, achieving consistent repositioning. Because the thickness dimension of the sheet structure is much smaller than its in-plane dimension, the mechanism maintains high flexibility while possessing sufficient in-plane bending stiffness to prevent unintended wrinkling due to elastic deformation. The horizontal base sheet also provides a flat load-bearing interface for external loads, allowing the positional error of the force input point to be elastically averaged by the inclined sheet, further enhancing the system's adaptability to eccentric loads.

[0037] Reference Figures 1 to 4 In some embodiments, the first intermediate structure 131 is sheet-like, and the second intermediate structure 132 is sheet-like. The second intermediate structure 132 is inclined to the first intermediate structure 131 and is located below the first intermediate structure 131, tilting towards the center of the base structure 110. The first intermediate structure 131 is located below the base structure 110 and is inclined to the base structure 110, with the tilt direction of the first intermediate structure 131 opposite to that of the second intermediate structure 132. By making both the first intermediate structure 131 and the second intermediate structure 132 sheet-like and tilted in opposite directions, the elastic force flow forms a Z-shaped broken path between adjacent sheets. This path extends the actual working length of the elastic arm without increasing the thickness, distributing the bending curvature under the same displacement to the two inclined sections, reducing the maximum strain per unit length, and avoiding fatigue or permanent deformation caused by excessive local bending.

[0038] The reverse tilting layout generates a symmetrical closing trend during folding. The tilted surfaces of the first intermediate structure 131 and the second intermediate structure 132 guide each other, automatically offsetting out-of-plane lateral offset, ensuring that the fold lines always close and unfold along the predetermined axis, improving repeatability and motion consistency. Furthermore, the elastic deformation on both sides can compensate for each other, forming a self-balancing couple, effectively suppressing platform torsion or warping caused by uneven loads, maintaining overall motion stability. The sheet-like structure itself possesses high in-plane stiffness, and the reverse tilting introduces out-of-plane compliance, enabling the mechanism to combine bending resistance and elastic recovery function in a slim and lightweight form, providing a stable geometric foundation for subsequent large-stroke, self-correcting, compliant parallel motion.

[0039] Understandably, sheet structures can be configured as sheet bodies with planar surfaces or sheet bodies with curved surfaces.

[0040] Reference Figures 1 to 4In some embodiments, the base structure 110 is configured as an equilateral triangle, the first intermediate structure 131 is configured as an isosceles triangle, and the second intermediate structure 132 is configured as a right triangle. The first platform 100 includes three first intermediate structures 131, the bases of which are connected to the three sides of the base structure 110. The first platform 100 includes six second intermediate structures 132, the hypotenuses of which are connected to the sides of the first intermediate structures 131, and the right-angled sides of the second intermediate structures 132 opposite to the hypotenuses are connected to the first elastic connector 200. The base structure 110 is an equilateral triangle, the first intermediate structure 131 is an isosceles triangle, and the second intermediate structure 132 is a right triangle; together, they form a paper-folding grid composed of triangular facets. The inherent geometric stability of triangles ensures that each facet rotates relative to the preset creases during folding without generating additional in-plane deformation, fundamentally suppressing unintended wrinkling or twisting, ensuring that it can accurately recover to the same spatial posture after each unfolding, and achieving high repeatability.

[0041] The circumferentially symmetrical layout of the equilateral base ensures that the load is evenly distributed across the three main force transmission paths, avoiding localized stress concentration caused by eccentric loading. The hypotenuses, legs, and right-angled sides of the isosceles and right-angled triangles overlap sequentially, forming continuous origami ridges. During folding, the hypotenuses synchronously contract inwards, and during unfolding, they synchronously expand outwards, ensuring coordinated movement and reducing the risk of jamming or lag. Furthermore, the all-triangular topology endows the mechanism with a certain self-locking characteristic: when subjected to unexpected reverse forces, the mechanical interference between the triangular facets prevents excessive flipping, protecting the elastic connectors from overload damage and thus extending cycle life. The sheet-like triangular facets maintain high in-plane stiffness while having extremely low thickness, allowing the mechanism to achieve excellent bending resistance while retaining the advantages of being lightweight and stackable, providing an ideal geometric framework for constructing a lightweight, long-stroke, and highly reliable compliant parallel platform.

[0042] In some embodiments, to avoid interference between the internal structure of the elastic origami parallel mechanism 10 when the first platform 100 and the second platform 300 are close together, the apex angles of the aforementioned right-angled triangles and isosceles triangles can be arc-shaped to release enough space and make the elastic origami parallel mechanism 10 more free.

[0043] In some embodiments, the second platform 300 is similar to the first platform 100, and both are symmetrical about the horizontal plane.

[0044] It should be noted that the basic structure 110 and the intermediate connecting structure 130, as long as they meet the central symmetry condition and can be manufactured according to the 3rsr configuration, are both within the scope of protection of this application. The descriptions of isosceles triangles, isosceles triangles, and right triangles in the preceding text are intended to illustrate the basic design concept of this application. In specific products, the structure can be other types of triangles or similar shapes, such as curved sides and rounded corners, to improve the compatibility of the flexible origami parallel mechanism 10.

[0045] Reference Figure 6 and Figure 7 In some embodiments, the material of the base structure 110 includes rigid thermoplastic polyester; in some embodiments, the material of the intermediate connecting structure 130 includes rigid thermoplastic polyester; in some embodiments, the material of the first elastic connector 200 includes thermoplastic polyurethane elastomer; and in some embodiments, the material of the second elastic connector 120 includes thermoplastic polyurethane elastomer.

[0046] By selecting rigid thermoplastic polyester as the material for rigid components and thermoplastic polyurethane elastomer as the material for elastic components, a natural partitioning is formed within the same structure, where rigid material areas bear external forces and soft material areas accommodate deformation. Rigid thermoplastic polyester exhibits high flexural modulus and dimensional stability after printing and cooling, ensuring that the base structure 110 and intermediate connecting structure 130 are not prone to creep or relaxation under long-term loads, providing a durable geometric reference for the folded paper sheet. Thermoplastic polyurethane elastomer possesses excellent fatigue resistance and resilience memory, maintaining stable elastic recovery force even under repeated bending, avoiding the drawbacks of traditional rubber materials such as easy aging and permanent deformation. During additive manufacturing, the two materials directly contact and solidify in a molten state, forming a strong bond at the interface that combines mechanical interlocking and molecular diffusion. No adhesives or mechanical fasteners are required, simplifying the process and eliminating potential failure points caused by additional connectors. The material combination also endows the mechanism with excellent environmental resistance. For example, the rigid thermoplastic polyester is inert to moisture and common solvents, protecting the internal elastomer from external corrosion; the thermoplastic polyurethane elastomer remains flexible over a wide temperature range, ensuring smooth folding motion under varying working conditions. By simultaneously molding the rigid and elastic areas in the same printing job, the mechanism achieves high load-bearing capacity while maintaining overall lightweight design, realizing a highly integrated, maintenance-free, compliant parallel module.

[0047] Reference Figure 6 and Figure 7In some embodiments, the rigid thermoplastic polyester is PETG, and the thermoplastic polyurethane elastomer is TPU 85A, which are integrally fused together in the same printing job through an additive manufacturing process. This design leverages the excellent interlayer bonding and dimensional stability of PETG, making the base structure 110 and the intermediate connecting structure 130 less prone to warping during printing, providing a reliable benchmark for the accuracy of subsequent paper folding creases. Simultaneously, TPU 85A, in its molten state, undergoes microscopic molecular interdiffusion and mechanical interlocking with the PETG interface, forming a high-strength transition zone after solidification, avoiding the delamination or peeling risks common in traditional multi-material splicing. The overlapping melting temperature windows of the two filaments allow for seamless switching on general-purpose multi-nozzle or AMS feeding systems without additional hardware modifications, reducing manufacturing barriers and equipment costs. Integral fusion also eliminates assembly errors caused by secondary connections such as adhesives and screws, allowing the geometric relative positions between the elastic and rigid areas to be directly defined by a digital model, ensuring that each finished product has consistent mechanical properties and motion trajectories, providing repeatable quality assurance for mass production. In addition, the transparency of PETG and the matte texture of TPU 85A create a striking visual contrast, allowing for direct observation of interface quality and crease deformation during the R&D phase, facilitating later optimization and iteration. The shared environmentally friendly and non-toxic properties of both materials also meet the high safety requirements of human-computer interaction in scenarios such as education and healthcare, making them suitable for various applications.

[0048] Reference Figure 5 The second aspect of this application provides a manufacturing method for manufacturing the elastic origami parallel mechanism 10 described above. The manufacturing method includes: S101: Establish a three-dimensional digital model including the first platform 100, the second platform 300 and all elastic connectors, and divide the model into rigid and elastic regions; S103: Specify the rigid region as PETG material, the elastic region as TPU 85A material, and configure an interlocking beam slice path at the junction of the two regions; S105: A fused deposition modeling equipment using a multi-nozzle or AMS feeding system, which alternately deposits PETG and TPU 85A in the same printing job, so that the two materials are coupled within and between layers; S107: Remove the support structure to obtain the flexible origami parallel mechanism 10.

[0049] In S101, a 3D digital model is established and partitioned, incorporating all load-bearing skeletons and elastic hinges of the mechanism into the same drawing space at once. Boolean operations are used to precisely divide rigid and elastic regions, ensuring clear geometric boundaries for subsequent material assignment and path generation, avoiding the baseline offset caused by traditional printing-then-assembly methods. In S103, material specification and interlocking beam slicing utilize slicing software to automatically generate interlocking grid paths at the interface between PETG and TPU 85A, enabling the two melts to form intralayer interlocking and interlayer anchoring during solidification. This solves the problem of easy delamination at elastic and rigid interfaces due to differences in thermal expansion coefficients, while eliminating the need for adhesives or mechanical fasteners, achieving true zero-additional connection. In S105, alternating deposition within the same printing task relies on a multi-nozzle or AMS system, completing material switching in a single, uninterrupted task. During printing, the equipment maintains the same hotbed temperature and environmental parameters, ensuring the two filaments meet and fuse in their optimal melting state, avoiding cumulative errors caused by multiple clamping operations and eliminating the impact of manual splicing on folding accuracy. S107 removes the supports to obtain the finished product. Due to the good drape performance of PETG and the low shrinkage characteristics of TPU 85A, most areas of the mechanism can be self-supported or have very little support. Post-processing only requires peeling off a small number of soluble or fractured supports. Without drilling, tapping or riveting, a flexible origami parallel mechanism 10 that can be tested immediately can be obtained, which shortens the iteration cycle from design to verification, reduces development costs, and provides an automated process paradigm for mass customized production.

[0050] Below, refer to Figures 1 to 7This paper systematically describes the elastic origami parallel mechanism 10 and its manufacturing method according to a specific embodiment. The core of this application is to directly form an origami-style 3-RSR topology with a rigid PETG skeleton and elastic TPU 85A hinges within a single printing task. The whole is composed of a first platform 100, a second platform 300, and a first elastic connector 200 sandwiched between the two. The platform is further subdivided into a basic structure 110, an intermediate connecting structure 130, and multiple levels of elastic connectors. As long as the basic structure 110 and the intermediate connecting structure 130 meet the central symmetry condition and can be manufactured according to the 3RSR configuration, they are all within the protection scope of this application. For example, in some embodiments, all the facets of the basic structure 110 and the intermediate connecting structure 130 are configured as triangular thin sheets, which are overlapped step by step according to equilateral, isosceles, and right-angle relationships to form a self-locking origami grid. The mechanism contains no external springs, positioning discs, or fasteners. The design of this application involves integrally molding an elastic material and another rigid material, for example, by melting the two materials together to simultaneously form mechanical interlocking and molecular diffusion coupling within and between layers. In some embodiments, the elastic material is TPU 85A, and the rigid material is PETG. The restoring force comes from the bending energy stored at the crease of the TPU 85A hinge, achieving an integrated design where the structure is elastic. All triangular facets are coplanar in the unfolded state and synchronously retract inward along predetermined creases during folding. After unfolding, thanks to the high dimensional stability of PETG, they accurately return to the same spatial posture, ensuring high repeatability.

[0051] The manufacturing method described in this application is achieved through 3D printing technology, for example, on a Bambu printer. For instance, a complete 3D digital model is first created in SolidWorks. Boolean cutting is used to designate the areas requiring future bending as elastic regions, and the remaining load-bearing surfaces as rigid regions. This model is then imported into Bambu Studio, assigning TPU 85A to the elastic regions and PETG to the rigid regions. An interlocking beam slicing option is enabled at the interface, automatically generating an interlaced grid path that allows the two melts to simultaneously form mechanical interlocking and molecular diffusion coupling within and between layers. During printing, the AMS feeding system automatically switches nozzles according to the slicing instructions, continuously depositing the two materials at the same hotbed temperature, resulting in a single part that requires no post-assembly. Thanks to the excellent drape performance of PETG and the low shrinkage rate of TPU 85A, the entire structure is supported by TPU 85A, which can be directly peeled off for processing.

[0052] Since all elasticity is provided by the material itself, the mechanism will not experience fatigue-induced wire breakage of metal springs or aging failure of adhesive interfaces during long-term use. The reverse-tilted triangular facets and circumferentially symmetrical layout work together to automatically counteract platform torsion caused by eccentric loads, resulting in smooth movement and rapid reset. The high-precision filament feeding and closed-loop temperature control of the Tuozhu printer ensure uniform thickness of each crease. The bending stiffness of the elastic zone can be adjusted in situ during the slicing stage by modifying the fill rate, crease curvature, or layer thickness, providing programmable stiffness and elasticity matching schemes for flexible robot modules with different loads and stroke requirements. In summary, this solution, with the elastic origami parallel mechanism 10 as its core, achieves lightweight, maintenance-free, high cycle life, and low-cost rapid iteration—achievements that traditional 3-RSR mechanisms cannot simultaneously provide—through Tuozhu's multi-material integrated molding process. This provides a new, ready-to-use solution for compliant actuators in education, healthcare, and service robots.

[0053] The following describes the elastic origami parallel mechanism 10 of this application using a specific application scenario. For example, the elastic origami parallel mechanism 10 of this application can serve as a flexible joint module for a snake robot, enabling high-degree-of-freedom and highly compliant meandering motion. Traditional snake robots often rely on motors, gears, or linkage mechanisms to drive each segment, resulting in complex structures, heavy weight, and susceptibility to mechanical failure due to impact loads. The 3-RSR topology elastic origami parallel mechanism 10 provided in this application, with its integrated molding, assembly-free, and self-resetting characteristics, can be directly embedded between adjacent segments of a snake robot, serving as a passively compliant or actively driven elastic hinge unit.

[0054] Specifically, multiple elastic origami parallel mechanisms 10 of this application are arranged in series along the axial direction of the snake robot. Each module can generate controllable large-stroke elastic deformation in the vertical and tilt directions when subjected to external thrust, lateral collision, or active drive, and automatically return to its initial posture after the disturbance is removed, thereby giving the robot excellent environmental adaptability and impact resistance. For example, when crawling in a narrow pipe, the mechanism can adapt to the curvature of the pipe wall and undergo local deformation to avoid rigid collisions; when crossing obstacles, the elastic reset characteristic can assist the body segments to quickly return to the correct position and maintain the continuity of movement. In addition, since the mechanism is printed in one piece using PETG / TPU dual materials, it is lightweight, low-noise, and requires no lubrication, making it particularly suitable for long-term operation in scenarios with high requirements for safety, quietness, and reliability, such as medical endoscopy, disaster search and rescue, and industrial inspection.

[0055] Furthermore, by adjusting the thickness, crease angle, or filler density of the TPU elastic connectors, the stiffness of each joint module can be programmed during the digital model stage to achieve a gradient compliant distribution along the robot's torso, thereby simulating the spatial regulation mechanism of muscle tension in biological snakes and improving motion efficiency and terrain traversal capabilities.

[0056] In summary, this application not only provides a novel flexible joint solution for snake robots with a simple structure and reliable performance, but also provides a generalized design paradigm for the development of other biomimetic soft robots, deployable space mechanisms, and micro parallel platforms.

[0057] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural transformations made based on the content of the specification and drawings of this application under the concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A flexible paper-folding parallel mechanism, characterized in that, include: First platform; The first elastic connector has two sides that are oppositely distributed in the vertical direction, one side of which is connected to the first platform; The second platform is connected to the other side of the first elastic connector, and the second platform is located below the first platform; The first elastic connector is elastic, and the first platform has a first state and a second state. In the first state, the first platform moves closer to or further away from the second platform. In the second state, the first elastic connector provides elastic force to the first platform so that the first platform is in an initial position.

2. The elastic origami parallel mechanism according to claim 1, characterized in that, The first elastic connector includes a plurality of first segments, which are arranged circumferentially around the vertical direction and are spaced apart.

3. The elastic origami parallel mechanism according to claim 1, characterized in that, The first platform includes a basic structure, a plurality of second elastic connectors and a plurality of intermediate connecting structures. The basic structure has an edge around the vertical direction. The second elastic connectors are connected to the edge. One side of the intermediate connecting structure is connected to the edge through the second elastic connectors, and the other side of the intermediate connecting structure is connected to the second platform. The base structure has a third state and a fourth state. In the third state, the base structure is close to or far from the intermediate connecting structure. In the fourth state, the second elastic connector provides elastic force to the base structure so that the base structure is in the initial position.

4. The elastic paper-folding parallel mechanism according to claim 3, characterized in that, The intermediate connection structure includes multiple first intermediate structures, multiple second intermediate structures, and multiple third elastic connectors. The first intermediate structure has an edge surrounding itself. The third elastic connectors connect to a portion of the edge of the first intermediate structure. The second intermediate structure connects to the side of the third elastic connector away from the first intermediate structure. The first elastic connector connects to the side of the second intermediate structure away from the first intermediate structure.

5. The elastic paper-folding parallel mechanism according to claim 4, characterized in that, The base structure is sheet-like and is arranged horizontally. The intermediate connecting structure is sheet-like and is inclined to the base structure.

6. The elastic origami parallel mechanism according to claim 5, characterized in that, The first intermediate structure is sheet-like, the second intermediate structure is sheet-like, the second intermediate structure is inclined to the first intermediate structure, the second intermediate structure is located below the first intermediate structure, and the second intermediate structure is inclined towards the center of the base structure; The first intermediate structure is located below the base structure, the first intermediate structure is inclined to the base structure, and the inclination direction of the first intermediate structure is opposite to the inclination direction of the second intermediate structure.

7. The elastic origami parallel mechanism according to claim 6, characterized in that, The basic structure is configured as an equilateral triangle, the first intermediate structure is configured as an isosceles triangle, and the second intermediate structure is configured as a right triangle; The first platform includes three first intermediate structures, and the bottom edge of each first intermediate structure is connected to the three sides of the basic structure respectively; The first platform includes six second intermediate structures. The hypotenuse of the second intermediate structure is connected to the waist of the first intermediate structure, and the right-angled side of the second intermediate structure opposite to the hypotenuse is connected to the first elastic connector.

8. The elastic origami parallel mechanism according to any one of claims 3 to 7, characterized in that, The material of the basic structure includes rigid thermoplastic polyester; and / or, The material of the intermediate connecting structure includes rigid thermoplastic polyester; and / or, The material of the first elastic connector includes thermoplastic polyurethane elastomer; and / or, The material of the second elastic connector includes thermoplastic polyurethane elastomer.

9. The elastic origami parallel mechanism according to claim 8, characterized in that, The rigid thermoplastic polyester is PETG, and the thermoplastic polyurethane elastomer is TPU 85A. The two are integrally fused together in the same printing task through an additive manufacturing process.

10. A manufacturing method for manufacturing the elastic origami parallel mechanism according to any one of claims 1 to 9, characterized in that, The manufacturing method includes: A three-dimensional digital model including the first platform, the second platform, and all elastic connectors is established, and the model is divided into rigid and elastic regions. The rigid region is designated as PETG material, the elastic region is designated as TPU 85A material, and an interlocking beam slice path is configured at the junction of the two regions. Using a fused deposition modeling equipment with multiple nozzles or an AMS feeding system, PETG and TPU 85A are deposited alternately in the same printing job, so that the two materials are coupled within and between layers. Remove the support structure to obtain the elastic origami parallel mechanism.

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