Soft rolling building block based on paper folding

Abstract

The invention discloses a soft body rolling building block based on paper folding, and relates to the technical field of deformable structures, the soft body rolling building block comprises a soft body unit, and the soft body unit can generate torsional deformation so that the two ends of the soft body unit can be oppositely close to each other; the two reinforcing units are fixed to the two ends of the soft body unit respectively; the driving units are arranged in a circumferential array mode with the center axis of the soft body unit as the center, one end of each driving unit is connected with one reinforcing unit, the other end of each driving unit is connected with the other reinforcing unit, contraction generated when the driving units are heated can enable the two reinforcing units to be close to each other in the opposite direction, and in the approaching process of the reinforcing units, the driving units are not prone to deformation. And the soft body unit generates torsion and drives the reinforcing unit to rotate. Periodic bending or twisting of the rolling structure is achieved by controlling the states of the different driving units, so that the rolling behavior of the rolling structure is induced, the driving units arranged at equal intervals are used for achieving local controllable driving of the rolling structure, and therefore the deformation path is controllable.

Description

Technical Field

[0001] The present application relates to the technical field of deformable structures, and in particular to an origami-based soft rolling building block. Background Art

[0002] With the rapid development of soft robotics, flexible actuation and non-traditional locomotion have become research hotspots. Compared to rigid structures, soft structures offer superior compliance, safety, and environmental adaptability, particularly in complex, confined, and unknown terrain. Among them, soft building blocks that achieve rolling motion based on deformation actuation represent a novel mobility strategy. They utilize the geometric deformation of the structural body to achieve continuous propulsion without tires or tracks, offering advantages such as simple structure, strong controllability, and robust adaptability.

[0003] Existing soft rolling structures rely on continuous expansion and contraction actuation (e.g., pneumatic, thermal, dielectric, etc.) to shift the center of mass, achieving tumbling or rolling through periodic deformation. However, these structures still face several technical bottlenecks in practical applications: 1. Uncontrollable deformation path: Most structures rely on uniform expansion or full structural deformation, making it difficult to achieve directional control or stabilize the rolling trajectory; 2. Limited structural response: Existing structures are mostly simple spherical, cylindrical, or symmetrical shapes, with poor coupling between deformation and rolling ability, resulting in low rolling efficiency and difficult posture control; 3. Weak modularity and combination capabilities: Traditional rolling units have a single function, making it difficult to expand into reconfigurable, multi-degree-of-freedom, or multi-module linkage systems. Summary of the Invention

[0004] The present application aims to solve one of the above-mentioned technical problems in the prior art. To this end, an embodiment of the present application provides an origami-based soft rolling building block.

[0005] According to an embodiment of the present application, there is provided an origami-based soft rolling building block, comprising a soft unit, wherein the soft unit is capable of undergoing torsional deformation so that two ends of the soft unit are brought closer together;

[0006] Two reinforcing units, the two reinforcing units being fixed to two ends of the soft unit respectively;

[0007] A plurality of driving units are arranged in a circular array with the central axis of the soft unit as the center, one end of the driving unit is connected to one of the reinforcing units, and the other end of the driving unit is connected to another of the reinforcing units. The contraction generated by the driving unit when heated can make the two reinforcing units approach each other. During the process of the reinforcing units approaching each other, the soft unit twists and drives the reinforcing units to rotate.

[0008] The above-mentioned origami-based soft rolling building block has at least the following beneficial effects: the present application constructs a rolling structure through two reinforcing units and a soft unit arranged between the two reinforcing units, and at the same time arranges a driving unit between the two reinforcing units. The soft unit can undergo torsional deformation under the action of external force so that the two ends of the soft body rotate and approach each other at the same time, so that the two reinforcing units can be driven to approach each other by controlling whether the driving unit is in a heated state. By controlling the states of different driving units, the periodic bending or torsion of the rolling structure can be achieved, thereby inducing the rolling behavior of the rolling structure. The driving units arranged at equal intervals are used to achieve local controllable drive of the rolling structure, thereby achieving controllable deformation path.

[0009] According to the origami-based soft rolling building block described in an embodiment of the present application, the reinforcing unit is a circular plate, the center of the circular plate is collinear with the center of the soft unit, and the diameter of the reinforcing unit is larger than the diameter of the soft unit.

[0010] According to the origami-based soft rolling building block described in an embodiment of the present application, the origami-based soft rolling building block also includes an external hanging unit, which is annular and is sleeved on the outside of the soft unit, and the outer side surface of the external hanging unit is provided with a protruding structure.

[0011] According to the origami-based soft rolling building block described in an embodiment of the present application, the interior of the soft unit is hollowed out to make the soft unit cylindrical, wherein the soft unit is a Kresling origami structure, and the outer surface of the soft unit is provided with a plurality of valley fold lines, and the valley fold lines are arranged in a circular array with the central axis of the soft unit as the center.

[0012] According to the origami-based soft rolling building block described in an embodiment of the present application, when the soft unit is in an unfolded state, the angle between the valley fold line and the fold line of the soft unit is set to 45°.

[0013] According to the origami-based soft rolling building block described in an embodiment of the present application, the portion of the soft unit between two adjacent valley fold lines is recessed toward the interior of the soft unit to form a curved surface.

[0014] According to the origami-based soft rolling building block described in an embodiment of the present application, a reinforcement portion is provided on the inner side surface of the soft unit corresponding to the position of the valley fold line, and the ratio of the thickness of the reinforcement portion to the thickness of the soft unit is set to 0.1 to 0.2.

[0015] According to the origami-based soft rolling building block described in the embodiment of the present application, the soft unit and the reinforcement unit are connected into one by casting, wherein the casting material is two-component platinum silicone, and the component A and component B of the two-component platinum silicone are mixed in a mass ratio of 1:1.

[0016] According to the origami-based soft rolling building block described in an embodiment of the present application, the ratio of the length of the soft unit to the thickness of the reinforcing unit is set to 5, and the driving unit is a liquid crystal elastomer.

[0017] According to the origami-based soft rolling building block described in the embodiment of the present application, the origami-based soft rolling building block also includes a docking structure, and the docking structure includes a docking protrusion and a docking groove that can be combined with each other, wherein one of the reinforcing units is provided with a plurality of the docking protrusions, and the docking protrusions are arranged in a circular array with the center of the reinforcing unit as a circle, and the other reinforcing unit is provided with a plurality of the docking grooves, and the docking grooves are arranged in a circular array with the center of the reinforcing unit as a circle, the docking grooves and the reinforcing unit are at the same distance from the center of the reinforcing unit, the number of the docking protrusions and the docking grooves is the same, and the number of the docking protrusions and the docking grooves is not less than two.

[0018] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present application is further described below with reference to the accompanying drawings and embodiments;

[0020] Figure 1 This is a schematic diagram of the structure of the origami-based soft rolling building block of the embodiment of the present application. Figure 1 ;

[0021] Figure 2 This is a structural diagram of the external unit in an embodiment of the present application;

[0022] Figure 3 This is a schematic diagram of the structure of the origami-based soft rolling building block in the embodiment of the present application. Figure 2 ;

[0023] Figure 4 This is a schematic diagram of the structure of the origami-based soft rolling building block in the embodiment of the present application. Figure 3 ;

[0024] Figure 5 This is a schematic diagram of the structure of the origami-based soft rolling building block in the embodiment of the present application. Figure 4 ;

[0025] Figure 6This is a schematic diagram of the structure of the origami-based soft rolling building block in the embodiment of the present application. Figure 5 ;

[0026] Figure 7 This is a schematic diagram of the structure of the origami-based soft rolling building block in the embodiment of the present application. Figure 6 ;

[0027] Figure 8 This is a schematic diagram of the structure of the origami-based soft rolling building block in the embodiment of the present application. Figure 7 .

[0028] Reference numerals: reinforcement unit 110 , casting hole 111 , mounting hole 112 , software unit 120 , valley fold line 121 , reinforcement portion 123 , driving unit 130 , external plug-in unit 140 , protruding structure 141 , docking protrusion 150 . DETAILED DESCRIPTION

[0029] This section will describe the specific embodiments of the present application in detail. The preferred embodiments of the present application are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present application, but it cannot be understood as a limitation on the scope of protection of the present application.

[0030] In the description of this application, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0031] In the description of this application, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly specifying the number or order of the technical features indicated.

[0032] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0033] Reference Figures 1 to 4 An embodiment of the present application provides an origami-based soft rolling building block, comprising a soft unit 120 , two reinforcing units 110 , and a plurality of driving units 130 .

[0034] Among them, the soft unit 120 can undergo torsional deformation under the action of external force so that the two ends of the soft unit 120 approach each other and twist at the same time; the two reinforcement units 110 are respectively fixed at the two ends of the soft unit 120, thereby constructing a rolling structure, and the torsional deformation of the soft unit 120 drives the reinforcement unit 110 to roll.

[0035] The soft rod driving unit 130 is arranged in a circular array with the central axis of the soft unit 120 as the center, wherein one end of the driving unit 130 is connected to a reinforcing unit 110, and the other end of the driving unit 130 is connected to another reinforcing unit 110. It should be noted that the contraction generated by the driving unit 130 of the present application when heated can make the two reinforcing units 110 approach each other. The force applied during the process of the reinforcing units 110 approaching each other acts on the soft unit 120, causing the soft unit 120 to produce torsional deformation and drive the reinforcing unit 110 to rotate.

[0036] The soft unit 120 is the key to the rolling behavior of the rolling structure. The local deformation of the rolling structure is achieved by controlling whether the driving units 130 at different positions are in a heated state. That is, by heating the driving units 130, the periodic bending or twisting of the rolling structure can be achieved, thereby inducing the rolling behavior of the rolling structure. The driving units 130 arranged at equal intervals are used to achieve local controllable driving of the rolling structure, thereby achieving controllable deformation path.

[0037] like Figure 3 As shown, the reinforcing unit 110 is a circular plate, the center of the circular plate is collinear with the center of the soft unit 120, and the diameter of the reinforcing unit 110 is larger than the diameter of the soft unit 120, so that the rolling structure formed by the reinforcing unit 110 and the soft unit 120 is an axially symmetrical figure, and the deformation process is more controllable.

[0038] In some embodiments, the origami-based soft rolling building block also includes an external hanging unit 140, which is annular and is mounted on the outside of the soft unit 120. The outer side of the external hanging unit 140 is provided with a protruding structure 141, and the rolling friction is increased by the protruding structure 141. The setting of the external hanging unit 140 is used to enhance the stability and rolling efficiency of the rolling direction.

[0039] In the embodiment of the present application, the protruding structure 141 is a unidirectional helical tooth.

[0040] The interior of the soft unit 120 is hollowed out to make the soft unit 120 cylindrical, wherein the soft unit 120 is a Kresling origami structure, and the outer surface of the soft unit 120 is provided with a plurality of valley fold lines 121, which are arranged in a circular array with the central axis of the soft unit 120 as the center.

[0041] The Kresling origami structure is a typical axisymmetric origami unit composed of periodic valley fold lines121. It exhibits excellent axial compressibility, controllable deformation paths, and mechanical programmability. In recent years, Kresling structures have attracted increasing attention in origami mechanics, flexible actuation, and deformable modular systems due to their highly coupled geometric deformation behavior. In particular, in the context of soft-body construction, Kresling structures can induce global geometric asymmetry through local deformation, thereby achieving directional motion or rolling behavior. They offer advantages such as compact configuration, clear response, and modular integration.

[0042] Therefore, this application proposes a new Kresling software building unit that can achieve stable rolling behavior to expand the design boundaries and application capabilities of software motion systems.

[0043] like Figure 3 and Figure 4 As shown, the soft unit 120 is in an unfolded state, and the angle between the valley fold line 121 and the fold line of the soft unit 120 is set to 45°.

[0044] In some embodiments, a portion of the soft unit 120 between two adjacent valley fold lines 121 is recessed toward the inside of the soft unit 120 to form a curved surface.

[0045] like Figure 6 As shown, a reinforcement portion 123 is provided on the inner side of the soft unit 120 at the location corresponding to the valley fold line 121. The ratio of the thickness of the reinforcement portion 123 to the thickness of the soft unit 120 is set to 0.1-0.2. That is, when the thickness of the soft unit 120 is 1 mm, the thickness of the reinforcement portion 123 is set to 0.15, making the overall structure more stable.

[0046] In the embodiment of this application, Figures 3 to 6 As shown, the soft unit 120 and the reinforcement unit 110 are connected into one by casting, wherein the casting material is two-component platinum silicone, and the A component and the B component of the two-component platinum silicone are mixed in a mass ratio of 1:1.

[0047] In some embodiments, a casting hole 111 is provided in the middle of the reinforcement unit 110 to facilitate the molding of the hollow soft unit 120 . The reinforcement unit 110 is also provided with a mounting hole 112 for fixing the driving unit 130 .

[0048] In some embodiments, the ratio of the length of the soft unit 120 to the thickness of the reinforcing unit 110 is set to 5. Under this ratio, the entire rolling structure has good axial compressibility and torsional coupling characteristics.

[0049] The driving unit 130 is a liquid crystal elastomer.

[0050] The working process of this application's origami-based soft scrolling building block is as follows:

[0051] The above-mentioned soft rolling building block is placed on a constant temperature controllable heating platform. Figure 4 and Figure 5 As shown, when two of the drive units 130 come into contact with the heating platform, they undergo anisotropic thermally induced phase transitions and longitudinal contraction. Meanwhile, the remaining drive units 130, not in contact with the heating platform, maintain their original lengths due to insufficient temperature. Consequently, the uneven stretching of the drive wires causes overall asymmetric deformation and localized bending of the soft unit 120.

[0052] Because the soft unit 120 exhibits a degree of spontaneous torsional behavior during bending, the structure's center of mass shifts, causing the soft rolling building block to roll. Simultaneously, as the structure rolls and its posture changes, the drive unit 130 previously in contact with the heating platform gradually lifts away from the heat source, while the adjacent drive unit 130 engages the heating platform and begins to retract. This alternating drive sequence allows the building block to continuously roll in the set direction, achieving a closed-loop response of cyclical drive-deformation-rolling.

[0053] In this study, the Kresling origami-based soft rolling building block exhibits a non-strictly linear trajectory during rolling, instead exhibiting a rolling path that is opposite to its chirality. This is because the Kresling origami structure has a typical axisymmetric configuration, but under external nonuniform actuation, its deformation is not limited to pure bending but is accompanied by significant spontaneous torsion. This coupling is determined by the spatially staggered distribution of internal mountain and valley folds. This results in a rotational eccentricity across the entire unit when axial compression (such as thermal contraction) occurs in a specific area, causing the rolling trajectory to shift.

[0054] In some embodiments, the origami-based soft rolling building block also includes a docking structure, which includes a docking protrusion 150 and a docking groove that can be combined with each other, wherein one reinforcement unit 110 is provided with a plurality of docking protrusions 150, and the docking protrusions 150 are arranged in a circular array with the center of the reinforcement unit 110 as a circle, and the other reinforcement unit 110 is provided with a plurality of docking grooves, and the docking grooves are arranged in a circular array with the center of the reinforcement unit 110 as a circle, the docking grooves and the reinforcement unit 110 are at the same distance from the center of the reinforcement unit 110, the number of docking protrusions 150 and the number of docking grooves are the same, and the number of docking protrusions 150 and the number of docking grooves is not less than two.

[0055] The software rolling building blocks of this application are not only applicable to single module rolling, but can also realize the construction and linkage of multi-module systems through the structural connection mechanism between modules. The specific connection method is as follows:

[0056] The external hanging unit 140 of the reinforcement unit 110 is provided with three docking protrusions 150 on the upper part and three docking grooves on the lower part. Figure 1 and Figure 6 By inserting the docking protrusion 150 of a soft rolling building block into the docking groove of an adjacent soft rolling building block, multiple soft rolling building blocks can be arranged in sequence and firmly connected to form a modular and expandable rolling system.

[0057] According to the chirality difference of Kresling modules (such as left-handedness and right-handedness), system combinations with different motion characteristics can be constructed: Figure 7 and Figure 8 As shown, Figure 7 The researchers demonstrated the connection of two right-handed soft rolling building blocks in series. In this configuration, the two modules generate bending and twisting responses in the same direction during rolling, creating a synergistic superposition of actuation effects, thereby achieving continuous rolling behavior with larger bending angles and stronger center of mass shift.

[0058] In contrast, Figure 8 The figure shows a series combination of one left-handed and one right-handed heterochiral module. Because the two building blocks twist in opposite directions, they produce a degree of complementary and cancelling deformation upon activation, structurally suppressing overall deflection and lateral displacement. This configuration helps achieve a more linear rolling path, making it suitable for applications with high requirements for rolling direction.

[0059] The design of the soft rolling building block in this application is based on the geometric deformation capabilities of the Kresling origami structure, creating a compact flexible skeleton unit. The Kresling structure has natural axisymmetry and geometric coupling properties. Under external force or driving, it can achieve multiple deformation modes such as axial compression, radial expansion, and torsion, providing an ideal geometric scaffold for constructing rolling soft modules.

[0060] Building on this, by attaching liquid crystal elastomer (LCE) actuator filaments to key locations within the Kresling structure, they contract under localized thermal activation, disrupting structural symmetry and inducing coupled bending-torsion deformation of the entire module. The response of the LCE actuator unit 130 is determined by its contact position with the thermal platform, enabling programmable adjustment of the module's deformation path and rolling direction through spatial control of the thermal field distribution.

[0061] Unlike traditional drive methods, the LCE drive component used in this application requires no external power supply or embedded circuitry, relying solely on an external, unified heat source (such as a constant temperature platform) to achieve actuation response, demonstrating typical passive drive characteristics. This drive method not only simplifies system construction but also enables the soft rolling building block to possess excellent energy integration capabilities and sustainable operation characteristics.

[0062] The external attachment units 140 at each end of the soft rolling building block further convert bending deformation into directional rolling motion. When the drive causes the module to bend and shift its center of mass, the friction wheels effectively limit the direction of movement, preventing slippage and rollback, thereby achieving continuous propulsion of the soft rolling building block.

[0063] The design of this soft rolling building block utilizes a unified configuration standard, with all units sharing the same geometric interfaces and connection mechanisms. This allows for the assembly of any number of modules with any chirality combination through mechanical plug-in. Whether arranged in series with homochirality or in staggered arrangements with heterochirality, the modules can achieve coordinated motion. Driven uniformly through thermal field excitation, the design demonstrates excellent structural scalability, assembly flexibility, and motion coordination, making it suitable for building flexible mobility systems in complex environments.

[0064] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. A soft rolling building block based on origami, characterized by: include a soft unit, wherein the soft unit is capable of torsion deformation so that two ends of the soft unit are brought closer together; Two reinforcing units, the two reinforcing units being fixed to two ends of the soft unit respectively; A plurality of driving units are arranged in a circular array with the central axis of the soft unit as the center, one end of the driving unit is connected to one of the reinforcing units, and the other end of the driving unit is connected to another of the reinforcing units. The contraction generated by the driving unit when heated can make the two reinforcing units approach each other. During the process of the reinforcing units approaching each other, the soft unit twists and drives the reinforcing units to rotate.

2. The origami-based soft rolling building block according to claim 1, characterized in that: The reinforcing unit is a circular plate, the center of the circular plate is collinear with the center of the soft unit, and the diameter of the reinforcing unit is greater than the diameter of the soft unit.

3. The origami-based soft rolling building block according to claim 1, characterized in that: The origami-based soft rolling building block further comprises an external hanging unit, which is annular and sleeved on the outside of the soft unit, and a protruding structure is provided on the outer side of the external hanging unit.

4. The origami-based soft rolling building block according to claim 1, characterized in that: The interior of the soft unit is hollowed out to make the soft unit cylindrical, wherein the soft unit is a Kresling origami structure, and the outer surface of the soft unit is provided with a plurality of valley fold lines, and the valley fold lines are arranged in a circular array with the central axis of the soft unit as the center.

5. The origami-based soft rolling building block according to claim 4, characterized in that: When the software unit is in an unfolded state, the angle between the valley fold line and the fold line of the software unit is set to 45°.

6. The origami-based soft rolling building block according to claim 4 or 5, characterized in that: The portion of the soft unit located between two adjacent valley fold lines is recessed toward the inside of the soft unit to form a curved surface.

7. The origami-based soft rolling building block according to claim 4 or 5, characterized in that: A reinforcement portion is provided on the inner side surface of the soft unit at a position corresponding to the valley fold line, and a ratio of a thickness of the reinforcement portion to a thickness of the soft unit is set to 0.1 to 0.

15.

8. The origami-based soft rolling building block according to claim 1, characterized in that: The soft unit and the reinforcement unit are connected into one by casting, wherein the casting material is two-component platinum silicone, and the component A and the component B of the two-component platinum silicone are mixed in a mass ratio of 1:

1.

9. The origami-based soft rolling building block according to claim 1, characterized in that: The ratio of the length of the soft unit to the thickness of the reinforcing unit is set to 5, and the driving unit is a liquid crystal elastomer.

10. The origami-based soft rolling building block according to claim 1, characterized in that: The origami-based soft rolling building block also includes a docking structure, which includes docking protrusions and docking grooves that can be combined with each other, wherein one of the reinforcing units is provided with a plurality of the docking protrusions, and the docking protrusions are arranged in a circular array with the center of the reinforcing unit as a circle, and the other reinforcing unit is provided with a plurality of the docking grooves, and the docking grooves are arranged in a circular array with the center of the reinforcing unit as a circle, the docking grooves and the reinforcing unit are at the same distance from the center of the reinforcing unit, the number of the docking protrusions and the docking grooves is the same, and the number of the docking protrusions and the docking grooves is not less than two.

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