Method for manufacturing soft actuator using 4d printing and ink therefor

Abstract

Disclosed are a method for manufacturing a soft actuator using 4D printing, and ink therefor. According to one embodiment of the present disclosure, the method for manufacturing a soft actuator using 4D printing comprises: a printing step of printing 3D architecture using a 3D printer and ink comprising magnetic particles; and a magnetization step of magnetizing the 3D architecture such that the 3D architecture can be transformed into a pre-programmed profile by a magnetic field, wherein at least a part of the ink is an NdFeB-styrene block copolymer (SBS, SIS, SEBS) composite material, and the 3D architecture is composed of a magnetically active soft material.

Description

Manufacturing method of soft actuator using 4D printing and ink therefor

[0001] The present disclosure relates to a method for manufacturing a soft actuator using 4D printing and ink therefor.

[0002] The material described in this section merely provides background information for the present disclosure and does not constitute prior art.

[0003] Elastomer-based soft actuators have potential in a variety of fields, including wearable devices, biomimetics, grippers, artificial muscles, and robotics.

[0004] In particular, magnetoactive soft materials (MSMs), soft elastic composites filled with magnetic particles, are emerging as smart materials in the field of soft actuators. These MSMs exhibit magnetic anisotropy when the magnetic domains of the particles embedded in a non-magnetic soft matrix are aligned. This encoded magnetic anisotropy induces functional behavior (e.g., deformation or translation) through the control of an external magnetic field.

[0005] In addition to research on materials with superior magnetic and elastic properties to improve the applicability of these magnetically active soft materials, research is being conducted on various manufacturing processes, complex 3D shapes, various programming methods, and operating technologies.

[0006] In this regard, 4D printing, which uses 3D printers and smart materials to create 3D architectures that can change shape in response to external stimuli, is attracting significant attention for creating soft actuators based on self-active soft materials.

[0007] In one embodiment, 4D printing can be used to fabricate soft actuators with complex shapes.

[0008] In one embodiment, an ink having excellent elasticity suitable for a soft actuator can be provided.

[0009] In one embodiment, the usability of a pre-programmed 3D architecture can be improved by reconstructing its profile.

[0010] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0011] According to one embodiment of the present disclosure, a method for manufacturing a soft actuator using 4D printing is provided, comprising: a printing process for printing a 3D architecture using ink containing magnetic particles and a 3D printer; and a magnetization process for magnetizing the 3D architecture so that the 3D architecture can be deformed into a pre-programmed profile by a magnetic field, wherein at least a portion of the ink is an NdFeB-Styrene Block Copolymers (SBS, SIS, SEBS) composite, and the 3D architecture is composed of a magnetically active soft material.

[0012] According to another embodiment of the present disclosure, an ink for manufacturing a soft actuator using 4D printing is provided, which is composed of an NdFeB-Styrene Block Copolymers (SBS, SIS, SEBS) composite.

[0013] In one embodiment, it is possible to manufacture soft actuators with complex shapes using 4D printing.

[0014] In one embodiment, there is an effect that can provide an ink with excellent elasticity suitable for a soft actuator.

[0015] In one embodiment, the profile of a pre-programmed 3D architecture can be reconstructed to improve usability.

[0016] FIG. 1 is a flowchart of a method for manufacturing a soft actuator using 4D printing according to one embodiment of the present disclosure.

[0017] FIG. 2 is a diagram schematically illustrating a method for manufacturing a soft actuator using 4D printing according to one embodiment of the present disclosure.

[0018] FIG. 3 is a drawing showing the composition of NdFeB-SIS composite ink according to one embodiment of the present disclosure.

[0019] FIG. 4 is a shear stress-modulus graph and a shear rate-viscosity graph of an ink composed of a NdFeB-SIS composite according to one embodiment of the present disclosure.

[0020] FIG. 5 is a diagram illustrating a micro-surface and configuration of a 3D architecture composed of a magnetically active soft material according to one embodiment of the present disclosure.

[0021] FIG. 6 is a weight percent-moment graph of an ink composed of a NdFeB-SIS composite according to one embodiment of the present disclosure.

[0022] FIG. 7 is a strain-tensile stress graph of a 3D architecture printed with ink including NdFeB magnetic particles according to one embodiment of the present disclosure.

[0023] FIG. 8 is a diagram showing the results of a tensile test of a 3D architecture printed with ink including NdFeB magnetic particles according to one embodiment of the present disclosure.

[0024] FIG. 9 is a diagram showing the results of a compression experiment of a 3D architecture printed with ink including NdFeB magnetic particles according to one embodiment of the present disclosure.

[0025] FIG. 10 is a diagram illustrating a method for reconstructing a magnetization profile of a 3D architecture according to one embodiment of the present disclosure.

[0026] FIG. 11 is a diagram showing various application examples of a soft actuator based on a magnetically active soft material according to one embodiment of the present disclosure.

[0027] FIG. 12 is a drawing showing an example in which a soft actuator according to one embodiment of the present disclosure is applied to a gripper.

[0028] FIG. 13 is a drawing showing an example in which a soft actuator according to one embodiment of the present disclosure is applied to a 3D electric switch.

[0029] Hereinafter, some embodiments of the present disclosure will be described in detail using exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings. Furthermore, when describing the present disclosure, detailed descriptions of related known components or functions will be omitted if they are deemed to obscure the gist of the present disclosure.

[0030] In describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms.

[0031] When a component is described as being 'connected', 'coupled' or 'connected' to another component, it should be understood that the component may be directly connected or connected to that other component, but that another component may also be 'connected', 'coupled' or 'connected' between the components.

[0032] Throughout the specification, when a part is said to 'include' or 'have' a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0033] Terms such as ‘part’, ‘module’, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

[0034] Unless stated otherwise, the description of any one embodiment is intended to be applicable to other embodiments.

[0035] The following description of the invention, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced.

[0036] FIG. 1 is a flowchart of a method for manufacturing a soft actuator using 4D printing according to one embodiment of the present disclosure.

[0037] FIG. 2 is a diagram schematically illustrating a method for manufacturing a soft actuator using 4D printing according to one embodiment of the present disclosure.

[0038] Referring to FIGS. 1 and 2, a method for manufacturing a soft actuator using 4D printing according to an embodiment of the present disclosure may include a process of printing a 3D architecture using ink (300, see FIG. 3) and a 3D printer (S110, (b) of FIG. 2), a process of magnetizing the 3D architecture so that the 3D architecture can be deformed into a pre-programmed profile by a magnetic field (S120, (c) of FIG. 2), a process of reconstructing the profile of the 3D architecture (S130), and a process of applying a magnetic field so that the 3D architecture is deformed into the pre-programmed profile (S140, (d) of FIG. 2).

[0039] The process of printing a 3D architecture (S110) refers to a process of printing a 3D architecture using ink containing magnetic particles and a 3D printer. This printing process may be a direct ink writing (DIW) process that directly prints a 3D architecture using ink, as illustrated in (b) of Fig. 2.

[0040] The process of magnetizing the 3D architecture so that the 3D architecture can be deformed into a pre-programmed profile by a magnetic field (S120) may be a process of magnetizing the 3D architecture printed with ink containing magnetic particles by placing it in a magnetizer. For example, the process of magnetizing the 3D architecture may be a process of folding the 3D architecture into a pre-programmed profile and placing it in a magnetizer. The 3D architecture may be magnetized using a high pulse magnetic field (Bm) of 2.7 T.

[0041] To facilitate the folding of a 3D architecture for magnetization or the deformation of a magnetized 3D architecture, the 3D architecture may include one or more hinges. By forming hinges along the folded portions of the 3D architecture along the deformation profile, the shape of the 3D architecture can be easily deformed. In other words, a 3D architecture including one or more hinges can be printed using a 3D printer and ink.

[0042] In addition, the method for manufacturing a soft actuator using 4D printing according to the present disclosure may further include a process (S130) of reconstructing the profile of a 3D architecture. In other words, the magnetization profile of a 3D architecture that has already been magnetized and has a programmed profile can be reconstructed. The profile can be reconstructed by adjusting the direction in which the 3D architecture is inserted into the magnetizer. Specific details of reconstructing the magnetization profile of the 3D architecture will be described later with reference to FIG. 10.

[0043] A magnetic field is applied to the magnetized 3D architecture (S140) to transform the 3D architecture into a pre-programmed profile (see Fig. 12, etc.).

[0044] As described above, the method for manufacturing a soft actuator using 4D printing according to the present disclosure prints a 3D architecture using ink containing magnetic particles and a 3D printer (S110), magnetizes the 3D architecture so that the 3D architecture can be deformed into a pre-programmed profile by a magnetic field (S120), and applies an external magnetic field to the magnetized 3D architecture (S130), thereby deforming the 3D architecture into the pre-programmed shape and functioning as a soft actuator. In addition, when magnetizing the 3D architecture, the direction in which the 3D architecture is introduced into the magnetizer can be adjusted to reconfigure the magnetization profile of the 3D architecture.

[0045] FIG. 3 is a drawing showing the composition of NdFeB-SIS composite ink according to one embodiment of the present disclosure.

[0046] Referring to FIG. 3, a method for manufacturing a soft actuator using 4D printing according to one embodiment of the present disclosure will be described in detail with respect to ink.

[0047] At least a portion of the ink (300) according to one embodiment of the present disclosure may be an NdFeB-SIS composite, an NdFeB-SEBS composite, or an NdFeB-SBS composite. Here, Nd represents neodymium, Fe represents iron, B represents boron, SIS represents styrene-isoprene-styrene, SEBS represents styrene-ethylene / butylene-styrene, and SBS represents styrene-butadiene-styrene. The ink (300) may be composed of NdFeB magnetic particles (310), an SIS, SEBS, or SBS soft matrix (320), and toluene as a solvent (300). The mass percentage range of the NdFeB magnetic particles (310) of the ink (300) may be 45 wt% to 90 wt%. Preferably, the mass percentage of the NdFeB magnetic particles (310) of the ink (300) may be 75 wt%, and the mass percentage of the SIS, SEBS, or SBS soft matrix (320) may be 25 wt%. In one embodiment according to the present disclosure, the 3D architecture may be composed of a magnetoactive soft material (MSM) because it includes magnetic particles, deforms into a pre-programmed profile when a magnetic field is applied, and has excellent elasticity as described below.

[0048] Meanwhile, the ink (300) according to the present disclosure may be partially composed of an NdFeB-SIS composite, an NdFeB-SEBS composite, or an NdFeB-SBS composite, and another portion may be composed of another material, such as a conductive material. For example, by another portion being composed of a conductive material, it may be utilized as a 3D electrical switch, etc.

[0049] Figure 4 shows a shear stress-modulus graph (a) and a shear rate-viscosity graph (b) of an ink composed of a NdFeB (75 wt%)-SIS (25 wt%) composite.

[0050] Referring to FIG. 4, the rheological properties of the ink (300) according to the present disclosure are At the shear yield stress of the solid, Fluid-like in behavior It appears that the viscosity of the ink (300) exhibiting shear thinning behavior is changed to shear rate at This behavior of the ink (300) enables the additive deposition of the self-active soft material by inducing continuous supply of the ink (300) without clogging the nozzle during printing. Accordingly, the printed 3D architecture can effectively maintain its shape without flowing down, making it suitable for 3D printing.

[0051] FIG. 5 shows the results of analyzing the micro surface and composition of a 3D architecture composed of a magnetically active soft material using FE-SEM (Field Emission Scanning Electron Microscopy) and EDX (Energy-Dispersive X-ray spectroscopy) according to one embodiment of the present disclosure.

[0052] Referring to Fig. 5, it can be seen that 75 wt% of NdFeB magnetic particles under high load are uniformly distributed within the pattern. This indicates that no agglomeration occurred between the NdFeB particles during the magnetization process, as the soft matrix composed of SIS fixed the positions of the magnetic particles. The detection of neodymium (Nd), iron (Fe), and carbon (C) in the analysis results indicates that the 3D architecture includes NdFeB and SIS.

[0053] FIG. 6 is a graph showing the weight percent-moment analysis of a 3D architecture printed with ink composed of a NdFeB-SIS composite according to one embodiment of the present disclosure using a VSM (Vibrating Sample Magnetometer).

[0054] Referring to Fig. 6, it can be seen that as the mass percentage of NdFeB in the 3D architecture increases from 45 wt% to 90 wt%, the magnetic moment of the 3D architecture gradually increases. In this way, considering the fact that the magnetic moment increases as the mass percentage of NdFeB increases and the printing conditions (nozzle size, printing speed, etc.), an ink containing an appropriate mass percentage of NdFeB can be used.

[0055] FIG. 7 is a strain-tensile stress graph of a 3D architecture printed with ink including NdFeB magnetic particles according to one embodiment of the present disclosure.

[0056] FIG. 8 is a diagram showing the results of a tensile test of a 3D architecture printed with ink including NdFeB magnetic particles according to one embodiment of the present disclosure.

[0057] FIG. 9 is a diagram showing the results of a compression experiment of a 3D architecture printed with ink including NdFeB magnetic particles according to one embodiment of the present disclosure.

[0058] Meanwhile, while magnetic properties are essential for implementing soft actuators based on magnetically active soft materials, mechanical properties must also be considered. Therefore, the mechanical properties of 3D architectures printed with NdFeB-SIS composite ink according to the present disclosure will be described with reference to FIGS. 7 to 9 .

[0059] A 3D architecture based on a magneto-active soft material in the shape of a dog bone, as illustrated in Fig. 7, was used for the tensile test. The tensile modulus of the linear elastic region is ~160 kPa, and the 3D architecture can be elongated by more than 1000% without defects, as shown in Fig. 8(c). Thus, the 3D architecture of the magneto-active soft material based on NdFeB-SIS according to the present disclosure demonstrates excellent elasticity.

[0060] A cylindrical 3D architecture based on a magnetically active soft material was used in the compression experiments. The 3D architecture was compressed to a strain of 70% at 11 MPa. Despite being compressed by a 900 kg vehicle, the 3D architecture fully withstood the load and gradually recovered without damage.

[0061] Therefore, the magnetically active soft material based on the NdFeB-SIS composite according to the present disclosure has a high degree of deformation freedom and also excellent mechanical properties, making it very suitable for implementing a robust soft actuator.

[0062] FIG. 10 is a diagram for explaining a method for reconstructing a magnetization profile of a 3D architecture according to one embodiment of the present disclosure. Based on the states illustrated in the drawings, (a) and (b) of FIG. 10 represent a front view and a side view when a magnetic field is formed in a direction from bottom to top, (c) and (d) of FIG. 10 represent a front view and a side view when a magnetic field is formed in a direction from right to left, and (e) and (f) of FIG. 10 represent a front view and a side view when a magnetic field is formed in a direction perpendicular to both the up-down direction and the left-right direction, that is, in a direction from left to right based on the side view.

[0063] As shown in Fig. 10, it can be seen that the magnetization profile of the 3D architecture varies depending on the direction of the magnetic field (Bm) that magnetizes the 3D architecture based on the NdFeB-SIS composite, NdFeB-SEBS composite, or NdFeB-SBS composite, i.e., the direction in which the 3D architecture is introduced into the magnetizer. Therefore, the magnetization profile of the 3D architecture can be reconfigured by controlling the direction of the magnetic field (Bm) that magnetizes the 3D architecture and / or the direction in which the 3D architecture is introduced into the magnetizer. In this way, even when the magnetization profile has already been programmed, the soft actuator can be freely implemented by reconfiguring the magnetization profile of the 3D architecture, thereby improving usability.

[0064] FIG. 11 is a diagram illustrating various application examples of a soft actuator based on a magnetically active soft material according to one embodiment of the present disclosure. As illustrated in FIG. 11, the soft actuator based on a magnetically active soft material according to the present disclosure can be configured in various profiles, such as an accordion, a cube, and a pyramid.

[0065] FIG. 12 is a drawing showing an example in which a soft actuator according to one embodiment of the present disclosure is applied to a gripper.

[0066] As illustrated in FIG. 12, as an example, the soft actuator according to the present disclosure may be applied to a gripper such as a finger-shaped gripper. In this case, the soft actuator may be configured such that when a magnetic field of 35.77 mT is applied, the finger-shaped components contract toward the center to grip an object, and conversely, when a magnetic field of -35.77 mT is applied, the contracted finger-shaped components expand again to put down the object.

[0067] FIG. 13 is a drawing showing an example in which a soft actuator according to one embodiment of the present disclosure is applied to a 3D electric switch.

[0068] As illustrated in FIG. 13, the soft actuator according to the present disclosure can be stretched when a magnetic field is applied, and the stretched soft actuator can be deformed to tilt in various directions depending on the direction or strength of the magnetic field. As described above, the soft actuator (3D architecture) according to the present disclosure may be partially composed of a magnetically active soft material and partially composed of a conductive material. In other words, a portion of the soft actuator may be composed of a magnetically active soft material and deformed to unfold and tilt in various directions depending on a magnetic field, and a portion of the soft actuator may be composed of a conductive material, so that the portion of the soft actuator composed of the conductive material may come into contact with terminals arranged in various directions to function as a 3D electrical switch.

[0069] Although the flowchart of the present disclosure describes each process as being executed sequentially, this is merely an illustrative description of the technical idea of ​​some embodiments of the present invention. In other words, those skilled in the art to which some embodiments of the present invention pertain may modify and apply various modifications and variations, such as changing and executing the processes described in the flowchart without departing from the essential characteristics of some embodiments of the present invention, or executing one or more of the processes in parallel. Therefore, the flowchart is not limited to a chronological order.

[0070] Various implementations of the systems and techniques described herein may be implemented as digital electronic circuits, integrated circuits, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include implementations of one or more computer programs executable on a programmable system. The programmable system includes at least one programmable processor (which may be a special purpose processor or a general purpose processor) coupled to receive data and instructions from and transmit data and instructions to a storage system, at least one input device, and at least one output device. Computer programs (also known as programs, software, software applications, or code) include instructions for the programmable processor and are stored on a "computer-readable recording medium."

[0071] A computer-readable recording medium includes any type of recording device that stores data that can be read by a computer system. Such a computer-readable recording medium may be a non-volatile or non-transitory medium such as a ROM, CD-ROM, magnetic tape, floppy disk, memory card, hard disk, magneto-optical disk, storage device, and may further include a transitory medium such as a data transmission medium. Furthermore, the computer-readable recording medium may be distributed across network-connected computer systems, so that computer-readable code can be stored and executed in a distributed manner.

[0072] Various implementations of the systems and techniques described herein can be implemented by a programmable computer. The computer includes a programmable processor, a data storage system (including volatile memory, non-volatile memory, or other types of storage systems, or a combination thereof), and at least one communication interface. For example, the programmable computer can be one of a server, a network appliance, a set-top box, an embedded device, a computer expansion module, a personal computer, a laptop, a personal data assistant (PDA), a cloud computing system, or a mobile device.

[0073] The above description is merely an example of the technical idea of ​​the present embodiment, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of ​​the present embodiment, but rather to explain it, and the scope of the technical idea of ​​the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment should be interpreted by the claims below, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of rights of the present embodiment.

[0074]

[0075] [Explanation of symbols]

[0076] 300: Ink

[0077] 310: NdFeB magnetic particles

[0078] 320: The Matrix

[0079] 330: Solvent

[0080]

[0081] [CROSS-REFERENCE TO RELATED APPLICATION]

[0082] This patent application claims priority to Korean Patent Application No. 10-2023-0144525, filed on October 26, 2023, which is incorporated herein by reference in its entirety.

Claims

In a method for manufacturing a soft actuator using 1.4D printing, A printing process for printing 3D architecture using ink containing magnetic particles and a 3D printer; and Including a magnetization process for magnetizing the 3D architecture so that the 3D architecture can be deformed into a pre-programmed profile by a magnetic field, A method for manufacturing a soft actuator, wherein at least some of the ink is a NdFeB-Styrene Block Copolymers (SBS, SIS, SEBS) composite, and the 3D architecture is composed of a magnetoactive soft material (MSM).

2. In paragraph 1, The above printing process is a method for manufacturing a soft actuator that is a direct ink writing (DIW) process.

3. In paragraph 1, A method for manufacturing a soft actuator, wherein the mass percentage of NdFeB in the ink ranges from 45 wt% to 90 wt%.

4. In paragraph 1, A method for manufacturing a soft actuator, wherein another part of the above ink is composed of a conductive material.

5. In paragraph 1, The above magnetization process is, A method for manufacturing a soft actuator, which is a process of folding the 3D architecture according to the profile using the origami method and inserting it into a magnetizer.

6. In paragraph 5, The above 3D architecture is a method for manufacturing a soft actuator including one or more hinges.

7. In paragraph 1, A method for manufacturing a soft actuator further comprising a reconstructing process for reconstructing the above profile.

8. In paragraph 7, The above reconstruction process is, A method for manufacturing a soft actuator, which is a process of reconstructing the above profile by controlling the direction in which the above 3D architecture is inserted into a magnetizer. 9.4 Ink for manufacturing a soft actuator using 4D printing, the ink comprising an NdFeB-SIS composite or an NdFeB-SBS composite.

10. In paragraph 9, NdFeB magnetic particles; A matrix consisting of SIS, SEBS or SBS; and A solvent composed of toluene Ink made of .

11. In paragraph 10, An ink in which the mass percentage of the above NdFeB magnetic particles ranges from 45 wt% to 90 wt%.

12. In paragraph 11, An ink wherein the mass percentage of the NdFeB magnetic particles is 75 wt% and the mass percentage of the matrix is ​​25 wt%.

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