Soft pneumatic actuator cast mold, soft pneumatic actuator, and method of manufacture
By using soft pneumatic actuator casting molds and manufacturing methods, and utilizing 3D printing technology and water-soluble PVA mold cores, a soft pneumatic actuator capable of driving origami structures under low pressure was prepared. This solved the spatial limitations and insufficient force problems of traditional driving methods, and achieved distributed driving and efficient demolding.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTH CHINA AGRICULTURAL UNIVERSITY
- Filing Date
- 2023-11-21
- Publication Date
- 2026-05-19
AI Technical Summary
Traditional driving methods are difficult to effectively drive multi-layer origami structures within a limited space. Furthermore, traditional motors have insufficient driving force, and smart materials do not provide enough driving force to meet the driving requirements of origami mechanisms.
A soft pneumatic actuator casting mold and manufacturing method is adopted. The mold is manufactured using 3D printing technology. The soft pneumatic actuator is prepared using water-soluble PVA mold core and Ecoflex 0010 material, which drives the rotational movement of the origami structure through air pressure.
It enables the origami structure to be driven with low input pressure within a limited driving space, provides the possibility of distributed driving, and eliminates the need for complex mold processing, making the demolding process simple and efficient.
Smart Images
Figure CN117681356B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of robotics technology, specifically relating to a soft pneumatic actuator casting mold, a soft pneumatic actuator, and a manufacturing method thereof. Background Technology
[0002] Inspired by the origami concept, many research teams have incorporated it into the structural design of robots, resulting in the creation of numerous novel and dexterous origami robots, origami grippers, origami robotic arms, and origami haptic interfaces. While origami mechanisms offer many advantages, they also present challenges in driving them. Furthermore, origami structures suffer from limited actuation space and numerous joints. Limited actuation space restricts the structural size of actuators, limiting their selection and design. The numerous joints, especially in multi-layered origami structures, necessitate distributed actuators to drive the origami mechanism at the joints, placing higher demands on each individual actuator.
[0003] Traditional motor drives are limited by the driving space, making it difficult to directly drive multi-layer origami structures to achieve folding and unfolding movements; while smart material-based driving methods are difficult to provide a large enough output force to drive the origami mechanism. Summary of the Invention
[0004] The main objective of this invention is to overcome the shortcomings and deficiencies of the prior art and to propose a soft pneumatic actuator casting mold, a soft pneumatic actuator, and a manufacturing method. The provided soft pneumatic actuator can drive the rigid plate surface in the origami structure to rotate around the crease with a low input pressure. At the same time, the actuator provides the possibility for distributed drive of origami.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A casting mold for a soft pneumatic actuator includes a mold top cover plate, an air passage mold core, a PVA mold core, fastening bolts, a mold side cover plate, a PLA plate, and a mold bottom support.
[0007] The lower support of the mold is a platform structure, and the PVA mold core is a hollow hexahedron. The PVA mold core is set on the upper bottom surface of the lower support of the mold; the left and right sides of the PVA mold core are connected to the PLA plate respectively; the air channel mold core is inserted into the PVA mold core from the upper bottom surface of the PVA mold core.
[0008] The mold side cover plate is connected to the front and rear sides of the mold lower support by fastening bolts, and the mold upper cover plate is connected to the top of the mold side cover plate by fastening bolts.
[0009] This invention also includes a method for manufacturing a soft pneumatic actuator, based on the casting mold provided by this invention, the method comprising:
[0010] For casting mold manufacturing, a remote-feed 3D printer is used to print the mold top cover plate, air duct core, mold side cover plate, PLA plate, and mold lower support; a near-feed 3D printer is used to print the PVA core.
[0011] Before casting, the mold assembly process involves first bonding and assembling the left and right sealing cover plates and the hollow mold core body of the PVA mold core together to form a complete PVA mold core; then bonding and fixing the rectangular protrusions on the left and right sides of the PVA mold core to the rectangular grooves on the PLA plate; finally, inserting the air passage mold core into the PVA mold core with an interference fit to make it a single unit and fixing it in the center of the lower mold support; then, assembling the mold side cover plates from the front and rear ends of the lower mold support towards the center and fixing them with fastening bolts; and finally, spraying the entire casting mold with release grease.
[0012] Preparation of soft silicone for casting: Ecoflex 0010 material was used for the soft pneumatic actuator; Ecoflex 0010 material was poured into a disposable syringe;
[0013] Casting: Inject the silicone from the syringe through the opening at the top of the mold. After filling, fix the top cover plate of the mold to the side cover plate of the mold with fastening bolts. Inject silicone along the outside of the gas channel mold core to form the boss of the gas channel. Let the cast mold cure naturally at room temperature for four hours.
[0014] Demolding: Following the demolding sequence from the outside to the inside, remove the left and right mold top cover plates, left and right mold side cover plates, mold lower support, and air channel mold core in sequence; immerse the soft pneumatic actuator with the PVA mold core still attached in the aqueous solution until the PVA mold core is completely dissolved in the aqueous solution; remove the soft actuator and dry it at room temperature to obtain the final soft pneumatic actuator.
[0015] The present invention also includes a soft pneumatic actuator, comprising a silicone cavity and two PLA plates;
[0016] The silicone cavity is manufactured according to the manufacturing method provided by the present invention. It is hexahedral in shape, with one bottom surface being an arc surface and an air inlet provided on the other bottom surface opposite the arc surface.
[0017] The two sides of the silicone cavity are connected to the PLA plate, and the two sides are provided with rectangular protrusions. The PLA plate is provided with rectangular grooves of the same size at the corresponding rectangular protrusions.
[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0019] 1. The driver of the present invention can drive the origami structure with a low input pressure within a limited driving space, and at the same time, it can easily realize the distributed driving of the origami mechanism.
[0020] 2. Regarding the casting method, the molds used in this invention are all rapidly formed using 3D printing technology, eliminating the need for complex mold processing.
[0021] 3. Unlike traditional investment casting methods, this invention uses a water-soluble mold core, and the mold core is rapidly formed by using water-soluble PVA as the raw material for 3D printing. This technical solution can not only achieve the production of complex mold cores very efficiently, but also demolding can be performed in an aqueous solution. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the structure of the casting mold of the present invention;
[0023] Figure 2 This is a schematic diagram of the assembled casting mold of the present invention;
[0024] Figure 3 This is a schematic diagram of the PVA mold core structure;
[0025] Figure 4 This is a side view of the mold side cover plate;
[0026] Figure 5 This is a schematic diagram of the top of the mold side cover plate;
[0027] Figure 6 This is a schematic diagram of the structure of the soft pneumatic actuator of the present invention;
[0028] Figure 7 This is a schematic diagram of the back of the soft pneumatic actuator of the present invention;
[0029] Figure 8 This is a deformation contour map of a soft pneumatic actuator when the input air pressure is 5 kPa;
[0030] Explanation of the reference numerals: 1-Mold top cover plate; 2-Air passage mold core; 3-PVA mold core; 4-Fastening bolt; 5-Mold side cover plate; 6-PLA plate; 7-Mold lower support. Detailed Implementation
[0031] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.
[0032] Example
[0033] like Figure 1 As shown, the present invention provides a casting mold for a soft pneumatic actuator, comprising two mold upper cover plates 1, an air passage mold core 2, a PVA mold core 3, fastening bolts 4, two mold side cover plates 5, two PLA plates 6, and a mold lower support 7.
[0034] The lower support of the mold is a platform structure, and the PVA mold core is a hollow hexahedron. The PVA mold core is set on the upper bottom surface of the lower support of the mold; the left and right sides of the PVA mold core are connected to the PLA plate respectively; the air channel mold core is inserted into the PVA mold core from the upper bottom surface of the PVA mold core.
[0035] The mold side cover plate is connected to the front and rear sides of the mold lower support by fastening bolts, and the mold upper cover plate is connected to the top of the mold side cover plate by fastening bolts.
[0036] In this embodiment, the lower support of the mold is specifically an isosceles trapezoidal platform structure, and the upper bottom surface is provided with an arc groove, on which the PVA mold core is set; the lower support of the mold is provided with two bolt holes on both the front and rear sides for fixing with fastening bolts.
[0037] In this embodiment, the PVA mold core includes a front sealing cover plate, a rear sealing cover plate, and a hollow mold core body; the front sealing cover plate and the rear sealing cover plate are connected to the front and rear sides of the hollow mold core body by adhesive.
[0038] The hollow mold core body has rectangular protrusions on both its left and right sides; the hollow mold core body has round holes for inserting the air passage mold core; the cross-section of the hollow mold core body is fan-shaped. For example... Figure 3 The diagram shown is a schematic of the structure of a PVA mold core.
[0039] In this embodiment, as Figure 4 As shown, the front side of the mold side cover plate has two bolt holes; by tightening bolts, passing through the bolt holes of the mold side cover plate and the bolt holes of the mold lower support, the two mold side cover plates are respectively connected and fixed to the front and rear sides of the mold lower support.
[0040] like Figure 5 As shown, the left and right sides of the mold side cover plate are provided with triangular slots for positioning and fixing the PLA plate; the bottom surface of the mold side cover plate is an arc surface, which matches the arc groove of the mold lower support; the bottom surface of the mold side cover plate is provided with two bolt holes.
[0041] The rear side of the mold side cover plate is fan-shaped and fits with the PVA mold core for sealing.
[0042] In this embodiment, the PLA plate is specifically an isosceles trapezoidal structure, with all four vertices of the isosceles trapezoid removed; the PLA plate has a rectangular groove that engages with and adheres to the rectangular protrusion of the hollow mold core body, thereby connecting and fixing the PLA plate to the PVA mold core; the PLA plate is set on the lower support of the mold and is positioned and fixed by the triangular slot of the mold side cover plate.
[0043] like Figure 1 As shown, in this embodiment, the mold top cover plate is provided with two bolt holes; the fastening bolts pass through the bolt holes of the mold top cover plate and the bolt holes of the mold side cover plate to realize the connection and fixation between the mold top cover plate and the mold side cover plate;
[0044] One end of the mold cover plate is provided with a semi-circular groove, and the semi-circular grooves of the two mold cover plates form a circular groove, with the circular opening located above the PVA mold core.
[0045] In this embodiment, the air passage mold core is a cylinder with a diameter of 2mm, which passes through the circular slot formed by the upper cover plate of the mold and is fixed in the hollow mold core of the PVA mold core by interference fit.
[0046] In another embodiment, a method for manufacturing a soft pneumatic actuator is provided, based on the casting mold of the above embodiment, the method comprising:
[0047] For casting mold manufacturing, a remote-feed 3D printer is used to print the mold top cover plate, air duct core, mold side cover plate, PLA plate, and mold lower support; a near-feed 3D printer is used to print the PVA core.
[0048] Before casting, the mold assembly involves first bonding and assembling the left and right sealing plates and the hollow mold core body of the PVA mold core together to form a complete PVA mold core; then bonding and fixing the rectangular protrusions on the left and right sides of the PVA mold core to the rectangular grooves on the PLA plate; finally, inserting the air passage mold core into the PVA mold core to make it a single unit and fixing it in the center of the lower mold support; then, assembling the mold side plates from the front and rear ends of the lower mold support towards the center and securing them with bolts; finally, spraying the entire casting mold with release grease; as shown below. Figure 2 The image shown is a schematic diagram of the assembled casting mold.
[0049] Preparation of soft silicone for casting: Ecoflex 0010 material was used for the soft pneumatic actuator; Ecoflex 0010 material was poured into a disposable syringe;
[0050] Casting: Inject the silicone from the syringe through the opening at the top of the mold. After filling, fix the top cover plate of the mold to the side cover plate of the mold with fastening bolts. Inject silicone along the outside of the gas channel mold core to form the boss of the gas channel. Let the cast mold cure naturally at room temperature for four hours.
[0051] Demolding: Following the demolding sequence from the outside to the inside, remove the left and right mold top cover plates, left and right mold side cover plates, mold lower support, and air channel mold core in sequence; immerse the soft pneumatic actuator with the PVA mold core still attached in the aqueous solution until the PVA mold core is completely dissolved in the aqueous solution; remove the soft actuator and dry it at room temperature to obtain the final soft pneumatic actuator.
[0052] In another embodiment, a soft pneumatic actuator is provided, comprising a silicone cavity and two PLA plates; as shown Figure 6 and Figure 7The diagram shown is a schematic representation of the structure of this soft pneumatic actuator.
[0053] The silicone cavity is manufactured according to the manufacturing method of the above embodiment. It is hexahedral in shape, with one bottom surface being an arc surface and the other bottom surface opposite the arc surface having an air inlet. The two sides of the silicone cavity are respectively connected to the PLA plate, and the two sides have rectangular protrusions. The PLA plate has rectangular grooves of the same size corresponding to the rectangular protrusions. The PLA plate is in the shape of an isosceles trapezoid, and all four vertices are removed.
[0054] like Figure 8 The figure shown is a deformation cloud diagram of the soft pneumatic actuator in this embodiment when the input air pressure is 5 kPa.
[0055] It should also be noted that, in this specification, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0056] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A casting mold for a soft pneumatic actuator, characterized in that, Includes mold top cover plate, air passage mold core, PVA mold core, fastening bolts, mold side cover plate, PLA plate and mold lower support; The lower support of the mold is a platform structure, and the PVA mold core is a hollow hexahedron. The PVA mold core is set on the upper bottom surface of the lower support of the mold; the left and right sides of the PVA mold core are connected to the PLA plate respectively; the air channel mold core is inserted into the PVA mold core from the upper bottom surface of the PVA mold core. The mold side cover plate is connected to the front and rear sides of the mold lower support by fastening bolts, and the mold upper cover plate is connected to the top of the mold side cover plate by fastening bolts. The lower support of the mold is specifically an isosceles trapezoidal platform structure, and the upper bottom surface is provided with an arc groove, on which the PVA mold core is set; the lower support of the mold is provided with two bolt holes on both the front and rear sides for use with fastening bolts for fixing. The PVA mold core includes a front sealing cover, a rear sealing cover, and a hollow mold core body; The front and rear sealing covers are connected to the front and rear sides of the hollow mold core body by adhesive. The hollow mold core body has rectangular protrusions on both the left and right sides; the hollow mold core body has round holes for inserting the air passage mold core; The main body of the hollow mold core has a fan-shaped cross-section; There are two mold side cover plates, and the front side of the mold side cover plates has two bolt holes; By tightening bolts through the bolt holes of the mold side cover plate and the bolt holes of the mold lower support, the two mold side cover plates are respectively connected and fixed to the front and rear sides of the mold lower support. The mold side cover plate has triangular slots on both the left and right sides for positioning and fixing PLA plates; The bottom surface of the mold side cover plate is an arc surface, which matches the arc groove of the mold lower support; Two bolt holes are provided on the bottom surface of the mold side cover plate; The rear side of the mold side cover plate is fan-shaped, which fits and seals with the PVA mold core; There are two PLA boards, which are isosceles trapezoidal structures, with all four vertices of the isosceles trapezoids removed. The PLA plate has a rectangular groove that matches and adheres to the rectangular protrusion of the hollow mold core body, thereby achieving the connection and fixation between the PLA plate and the PVA mold core. The PLA plate is set on the lower support of the mold and is positioned and fixed by the triangular slot of the mold side cover plate; There are two mold top cover plates, each with two bolt holes; fastening bolts pass through the bolt holes in the mold top cover plate and the bolt holes in the mold side cover plate to connect and fix the mold top cover plate and the mold side cover plate. One end of the mold cover plate is provided with a semi-circular groove, and the semi-circular grooves of the two mold cover plates form a circular groove, with the circular opening located above the PVA mold core.
2. The casting mold for a soft pneumatic actuator according to claim 1, characterized in that, The air passage mold core is a cylinder with a diameter of 2mm, which passes through the circular slot formed by the mold cover plate and is fixed in the hollow mold core of the PVA mold core by interference fit.
3. A method for manufacturing a soft pneumatic actuator, characterized in that, Based on the casting mold according to any one of claims 1-2, the method includes: For casting mold manufacturing, a remote-feed 3D printer is used to print the mold top cover plate, air duct core, mold side cover plate, PLA plate, and mold lower support; a near-feed 3D printer is used to print the PVA core. Before casting, the mold assembly process involves first bonding and assembling the left and right sealing cover plates and the hollow mold core body of the PVA mold core together to form a complete PVA mold core; then bonding and fixing the rectangular protrusions on the left and right sides of the PVA mold core to the rectangular grooves on the PLA plate; finally, inserting the air passage mold core into the PVA mold core with an interference fit to make it a single unit and fixing it in the center of the lower mold support; then, assembling the mold side cover plates from the front and rear ends of the lower mold support towards the center and fixing them with fastening bolts; and finally, spraying the entire casting mold with release grease. Preparation of soft silicone for casting: Ecoflex 0010 material was used for the soft pneumatic actuator; Ecoflex 0010 material was poured into a disposable syringe; Casting: Inject the silicone from the syringe through the opening at the top of the mold. After filling, fix the top cover plate of the mold to the side cover plate of the mold with fastening bolts. Inject silicone along the outside of the gas channel mold core to form the boss of the gas channel. Let the cast mold cure naturally at room temperature for four hours. Demolding: Following the demolding sequence from the outside to the inside, remove the left and right mold top cover plates, left and right mold side cover plates, mold lower support, and air channel mold core in sequence; immerse the soft pneumatic actuator with the PVA mold core still attached in the aqueous solution until the PVA mold core is completely dissolved in the aqueous solution; remove the soft actuator and dry it at room temperature to obtain the final soft pneumatic actuator.