CN110142969B - 4D printing material grabbing and releasing mechanism and method - Google Patents
4D printing material grabbing and releasing mechanism and method Download PDFInfo
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- CN110142969B CN110142969B CN201910429317.XA CN201910429317A CN110142969B CN 110142969 B CN110142969 B CN 110142969B CN 201910429317 A CN201910429317 A CN 201910429317A CN 110142969 B CN110142969 B CN 110142969B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
- B29C64/30—Auxiliary operations or equipment
- B29C64/307—Handling of material to be used in additive manufacturing
- B29C64/321—Feeding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
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- Mechanical Engineering (AREA)
- Optics & Photonics (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Abstract
The invention provides a 4D printing material grabbing and releasing mechanism and a method. The grabbing and releasing mechanism comprises a 4D printing material driving control structure and a supporting structure connected with the driving control structure, wherein the driving control structure comprises a plurality of driver sheets, each driver sheet comprises a pre-stretched dielectric elastomer film, a 4D printing shape memory polymer frame, electrodes and electrode leads, the 4D printing shape memory polymer frame is adhered to the pre-stretched dielectric elastomer film, and the electrodes are coated on the surfaces of the two sides of the film at the hollow-out position of the 4D printing shape memory polymer frame and connected with the electrode leads. The 4D printing material grabbing and releasing mechanism provided by the invention is simple in structure, and is convenient for grabbing and controlling irregular and fragile materials.
Description
Technical Field
The invention relates to the technical field of material clamping control, in particular to a 4D printing material grabbing and releasing mechanism and a method.
Background
4D printing refers to the self-transformation of physical properties and functions (structure, form, size, etc.) of a three-dimensional object obtained by 3D printing under specific environment and excitation (such as electricity, light, magnetism, water, heat, sound, etc.) with the change of time. 4D printing is further development and perfection of 3D printing, and intelligent products with functions of self-assembly, self-unfolding, self-repairing and the like can be produced.
At present, a grabbing and releasing mechanism with a shape memory function is mostly one-way irreversible, and multiple grabbing is realized by manual intervention; although the reversible process can be realized by the dielectric elastomer grabbing mechanism, the dielectric elastomer grabbing mechanism needs to be electrified continuously when the grabbing shape of the dielectric elastomer grabbing mechanism is fixed, and the dielectric elastomer grabbing mechanism cannot be well adapted to materials with different sizes and shapes, and is not beneficial to precise control of the materials.
Therefore, there is a need for improvements in the prior art to provide a gripper release mechanism that is suitable for irregularly soft materials, especially 4D printed materials.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a 4D printing material grabbing and releasing mechanism and a method, which can be applied to grabbing and controlling irregular and fragile materials.
According to a first aspect of the invention, a 4D printed material grabbing release mechanism is provided. The mechanism comprises a 4D printing material drive control structure and a supporting structure connected with the drive control structure, wherein the drive control structure comprises a plurality of driver sheets, each driver sheet comprises a pre-stretched dielectric elastomer film, a 4D printed shape memory polymer frame, electrodes and electrode leads, the 4D printed shape memory polymer frame is adhered to the pre-stretched dielectric elastomer film, and the electrodes are coated on the opposite surfaces of the pre-stretched dielectric elastomer film at the hollow-out position of the 4D printed shape memory polymer frame and connected with the electrode leads.
In one embodiment, the driving control structure comprises four driver sheets with the same structure, the 4D printed shape memory polymer frame of each driver sheet is provided with three hollows, and electrodes are respectively coated on the opposite surfaces of the pre-stretched dielectric elastic film at the three hollows and connected with electrode leads.
In one embodiment, the position of the plurality of driver plies on the support structure is set based on one or more of a length of the plurality of driver plies, a desired bend angle, and a shape of the 4D printed material, a 4D printed material size.
In one embodiment, the support structure includes a cylindrical fixed end, a polygonal platform, and a plurality of slots for connecting the plurality of driver slices, the cylindrical fixed end is connected to a first surface of the polygonal platform, the slots are connected to a second surface of the polygonal platform, and the number of the slots equals the number of the plurality of driver slices.
In one embodiment, the pre-stretched dielectric elastomer film is pre-stretched to a desired pre-stretch ratio based on the degree of bending and recovery of the driver blade required prior to assembly of the mechanism.
In one embodiment, the 4D printing material is a thermoplastic and thermoset shape memory polymer or composite thereof with shape memory effect.
In one embodiment, the pre-stretched dielectric elastomer film is an acrylic, silicone rubber, or an electronic type dielectric elastomer.
In one embodiment, the electrodes are carbon paste, the electrode leads comprise copper adhesive tapes and copper wires, the carbon paste is uniformly coated on the opposite surfaces of the pre-stretched dielectric elastomer films at the hollow parts of the driver sheet layers, the copper adhesive tapes are adhered to the edge positions of the surfaces of the pre-stretched dielectric elastomer films at the hollow parts of the driver sheet layers, and the copper wires are connected on the copper adhesive tapes.
According to a second aspect of the present invention, there is provided a 4D printed material grabbing and releasing method, the method comprising the steps of:
heating the 4D printing material grabbing and releasing mechanism for the first time to enable the 4D printing shape memory polymer frame to reach the glass transition temperature, and bending the driver sheet layer under the pre-stretching action of the pre-stretching dielectric elastomer film to finish grabbing;
at room temperature, cooling the 4D printing material grabbing and releasing mechanism to enable the 4D printing material grabbing and releasing mechanism to be in a 4D printing material locking state;
and heating the 4D printing material grabbing and releasing mechanism for the second time and electrifying to recover the driver sheet layer from the bending state to finish the releasing action.
Compared with the prior art, the invention has the beneficial effects that: at room temperature, the modulus of the grabbing and releasing mechanism is high, so that high grabbing force can be provided, and heavy objects can be grabbed; the driver sheet layer in the grabbing and releasing structure provided by the invention comprises a 4D printing frame and a pre-stretched dielectric elastomer film, the driver sheet layer is bent towards one side under the heating condition to realize the grabbing process, the driver sheet layer is electrified after being heated for a period of time, the driver sheet layer realizes the unfolding process, the whole grabbing and releasing process does not need artificial shaping, the whole control process is realized by controlling the heating temperature and the electrified voltage, and the angle is controllable. The grabbing and releasing structure provided by the invention is simple in structure and convenient to operate, and can be used for grabbing irregularly-shaped and fragile articles.
Drawings
The invention is illustrated and described only by way of example and not by way of limitation in the scope of the invention as set forth in the following drawings, in which:
fig. 1 is an isometric view of a 4D printed material capture release mechanism according to one embodiment of the present invention;
FIG. 2 is an isometric view of a driver blade layer of a 4D printed material capture release mechanism according to one embodiment of the invention;
wherein, 1-4D printing a shape memory polymer frame; 2-pre-stretching the dielectric elastomer film; 3-an electrode; 4-electrode lead; 5-connecting holes; 6-a support structure; 7-drive control structure.
Detailed Description
In order to make the objects, technical solutions, design methods, and advantages of the present invention more apparent, the present invention will be further described in detail by specific embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.
Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.
According to an embodiment of the present invention, there is provided a 4D printing material grabbing and releasing mechanism, as shown in fig. 1, the mechanism integrally includes two parts, namely, a driving control structure 7 and a supporting structure 6, wherein the driving control structure 7 is used for realizing grabbing, controlling, releasing and the like actions on the 4D printing material, and the supporting structure 6 is connected with the driving control structure 7 and is used for fixing the driving control structure.
In one embodiment, the drive control structure 7 comprises a plurality of driver slices, 4 driver slices are illustrated in fig. 1, and as shown in fig. 2, each driver slice comprises a pre-stretched dielectric elastomer film 2, a 4D printed shape memory polymer frame 1, electrodes 3 and electrode leads 4. In this embodiment, a 4D printed shape memory polymer frame 1 is adhered to a pre-stretched dielectric elastomer film 2, electrodes 3 are then coated on both sides of the film 2 at the hollow of the frame 1 (i.e., on the upper and lower opposite surfaces of the film 2 at the hollow), electrode leads 4 are alternately placed on the electrodes to form a driver sheet, and four identical driver sheets are respectively fixed to a support structure 6 to form a grasping and releasing mechanism. It should be noted that, in practical applications, the number of the driver sheets may be set as required, for example, 3 or 6, and the frame 1 may be provided with a plurality of openings, for example, 4 or 5 openings, and the shape, position and size of the openings may be set as appropriate according to the desired degree of bending of the driver sheets and the flexibility of bending.
In this fig. 1 embodiment, support structure 6 includes cylinder stiff end, polygon platform and the draw-in groove that is used for connecting the driver lamella, can adopt modes such as welding to connect between these three, and lamella draw-in groove and polygon platform contained angle can set up between 0 to 90 (upper and lower axial contained angle), are provided with the hole with connecting hole 5 matched with on the lamella draw-in groove, and connecting hole 5 on the driver lamella is fixed with the hole accessible screw on the lamella draw-in groove. It should be understood that other shapes of fixed end or polygonal platforms may be used, such as circular platforms, etc.
The pre-stretched dielectric elastomer film 2 has the characteristic of electrostriction, can change the shape and the volume when being acted by an external electric field, and can return to the original shape or volume after the external electric field is removed. The two opposite surfaces of the dielectric elastomer are coated with flexible electrodes, voltage is applied to the electrodes, opposite charges of the upper layer of electrodes and the lower layer of electrodes attract each other, like charges of each layer of electrodes repel each other, and when the electric field force is large enough, the dielectric elastomer generates obvious area and thickness changes, so that driving is realized.
The pre-stretched dielectric elastomer film 2 may be acrylic, silicone rubber, or an electronic type dielectric elastomer, or the like. For example, the pre-stretched dielectric elastomer film 2 is a VHB4910 or VHB4905 acrylic double-sided tape supplied by 3M company, which is inherently tacky and can be adhered directly to the 4D printed shape memory polymer frame 1. In practical application, attention needs to be paid to keeping the bonding surface of the frame 1 smooth and clean, and air between the frame 1 and the pre-stretched dielectric elastomer film 2 is extruded out as much as possible during bonding, so that the bonding is ensured to be tight.
The pre-stretched dielectric elastomer film 2 needs to be pre-stretched before use, and the stretching ratio directly influences the bending angle and the recovery rate of the driver sheet layer. For example, when the shape memory polymer frame thickness is 1.2mm and the stretch ratio is 1.5 times, the bend angle of the driver sheet is 270 °, and when the stretch ratio is 1.2 times, the bend angle of the driver sheet is 90 °.
The connection between each driver blade and the support structure 6, and the distance between each driver blade and the axial center of the support structure, can be set according to the length of the driver blade, the required bending angle, the shape and size of the object to be grasped, and other factors. For example, the distance of each driver slice to the axial (top-bottom) center of the support structure is set to be greater than 0mm and less than 120 mm.
In one embodiment, the electrode lead 4 is formed by combining a copper tape and a copper wire, the copper tape with a proper length is cut and pasted at a position near one side edge of the dielectric elastomer film 2 at the hollow part of the driver sheet layer, and then the copper wire is connected and pasted together at the edge of the frame 1 for fixing. For the embodiment of fig. 2, 6 electrode wires are required to be adhered, and the grabbing and releasing mechanism is connected with a power supply through a copper wire during working.
In one embodiment, the electrodes 3 are made of carbon paste, and the carbon paste is uniformly applied to both sides of the dielectric elastomer film 2 at the hollow of the driver sheet (i.e., the upper and lower surfaces of the hollow film). The junction of the electrode 3 and the copper tape in the electrode lead 4 is carefully treated to prevent electrical leakage.
The grabbing and releasing mechanism provided by the invention is connected with a power supply during working, the power supply can be composed of a direct current power supply and a high-voltage amplifier, the using voltage value is between 3kv and 10kv, and the power supply is connected through an electrode lead (copper wire) on a driver sheet layer.
In one embodiment, the working process of the 4D printed material grabbing and releasing mechanism provided by the invention comprises the following steps:
step S110, the grasping and releasing mechanism is heated to make the driver sheet in a bent state.
The grasping release mechanism is placed in an incubator for heating, the temperature of the incubator can be set to the glass transition temperature of the 4D printed shape memory polymer frame 1, the heating time can be set to about 60s to 90s, the driver sheet is bent to one side (e.g., to the inside) under the pre-stretching action of the pre-stretched dielectric elastomer film 2 during the heating process, and the driver sheet can be considered to reach an equilibrium state when it is no longer bent.
And step S120, cooling the position of the grabbing and releasing mechanism to enable the grabbing and releasing mechanism to be in a locking state.
And at room temperature, cooling the grabbing release mechanism to fix the shape of the printing material and enable the printing material to be in a locked state.
In step S130, the grasping and releasing mechanism is heated for the second time and is powered on to be in the released state.
And heating the grabbing and releasing mechanism for 60 seconds again, electrifying, releasing the prestress part in the dielectric elastomer film 2, gradually unfolding the grabbing and releasing mechanism under the action of the shape memory effect of the shape memory polymer until the driver sheet layer is observed not to be obviously restored, cooling, and powering off after cooling and fixing the shape.
In summary, the driver sheet layer of the gripping and releasing mechanism for the soft material for 4D printing provided by the invention is composed of a 4D printing frame and a pre-stretched dielectric elastomer film, and under a heating condition, the driver sheet layer is bent towards one side to realize a gripping process; the driver sheet layer is electrified after being heated for a period of time, the expansion process is realized by the driver sheet layer, the whole grabbing and releasing process does not need artificial shaping, the whole printing process can be realized by controlling the heating temperature and the electrified voltage, and the placing angle of the printing material can be controlled. In this document, the printing material is a shape memory polymer, and the printed member may change with time, so that a time dimension is increased, which is referred to as 4D printing, and the whole process may achieve a plurality of stable states such as a clamping state (or a grasping state), a locking state, and a releasing state of the material.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (9)
1. A4D printing material grabbing and releasing mechanism comprises a 4D printing material driving control structure and a supporting structure connected with the driving control structure, and is characterized in that the driving control structure comprises a plurality of driver sheets, each driver sheet comprises a pre-stretched dielectric elastomer film, a 4D printing shape memory polymer frame, electrodes and electrode leads, wherein the 4D printing shape memory polymer frame is adhered to the pre-stretched dielectric elastomer film, and the electrodes are coated on the opposite surfaces of the pre-stretched dielectric elastomer film at the hollow-out position of the 4D printing shape memory polymer frame and connected with the electrode leads.
2. The mechanism of claim 1, wherein the drive control structure comprises four driver slices of identical construction, the 4D printed shape memory polymer frame of each driver slice having three openings, the opposing surfaces of the pre-stretched dielectric elastic film at the three openings being coated with electrodes and connected to electrode leads, respectively.
3. The mechanism of claim 1, wherein the position of the plurality of driver plies on the support structure is set based on one or more of a length of the plurality of driver plies, a desired bend angle, and a shape of 4D printed material, a 4D printed material size.
4. The mechanism of claim 1, wherein the support structure includes a cylindrical fixed end, a polygonal platform, and a plurality of slots for connecting the plurality of driver slices, wherein a first surface of the polygonal platform connects to the cylindrical fixed end and a second surface of the polygonal platform connects to the slots, and wherein the number of slots is equal to the number of driver slices.
5. The mechanism of claim 1, wherein the pre-stretched dielectric elastomer film is pre-stretched to a desired pre-stretch ratio based on a desired degree of bending and recovery of the driver blade before assembly of the mechanism.
6. The mechanism of claim 1, wherein said pre-stretched dielectric elastomer film is silicone rubber, silicone, polyurethane, nitrile rubber, acrylic, natural rubber, vinylidene fluoride trifluoroethylene, and composites thereof.
7. The mechanism of claim 1, wherein the electrodes are carbon paste, the electrode leads comprise copper tape and copper wire, the carbon paste is uniformly applied to the opposing surfaces of the pre-stretched dielectric elastomer film at the openings in the actuator sheets, the copper tape is adhered to the edges of the surfaces of the pre-stretched dielectric elastomer film at the openings in the actuator sheets, and the copper wire is connected to the copper tape.
8. Mechanism according to any of claims 1 to 7, wherein the 4D printed material is a thermoplastic and thermosetting shape memory polymer with shape memory effect or a composite thereof.
9. A 4D printed material grabbing and releasing method based on the mechanism of any one of claims 1 to 8, comprising the following steps:
heating the 4D printing material grabbing and releasing mechanism for the first time to enable the 4D printing shape memory polymer frame to reach the glass transition temperature, and bending the driver sheet layer under the pre-stretching action of the pre-stretching dielectric elastomer film to finish grabbing;
at room temperature, cooling the 4D printing material grabbing and releasing mechanism to enable the 4D printing material grabbing and releasing mechanism to be in a 4D printing material locking state;
and heating the 4D printing material grabbing and releasing mechanism for the second time and electrifying to recover the driver sheet layer from the bending state to finish the releasing action.
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| CN201910429317.XA CN110142969B (en) | 2019-05-22 | 2019-05-22 | 4D printing material grabbing and releasing mechanism and method |
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| CN201910429317.XA CN110142969B (en) | 2019-05-22 | 2019-05-22 | 4D printing material grabbing and releasing mechanism and method |
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| CN111230911B (en) | 2020-03-20 | 2021-05-04 | 燕山大学 | Flexible finger joint paw based on 4D printing and trajectory tracking control method thereof |
| CN111469517B (en) * | 2020-04-22 | 2021-10-15 | 浙江大学 | Laminated driving structure and manufacturing method thereof |
| CN112477140B (en) * | 2020-10-15 | 2023-02-17 | 中国科学院微电子研究所 | Electrical heating 4D printing assembly and printing method |
| CN114274162A (en) * | 2022-01-10 | 2022-04-05 | 华中科技大学 | Dielectric elastomer driver, flexible foot and starfish-like soft robot |
| CN115055916B (en) * | 2022-06-10 | 2024-06-07 | 清华大学 | Shape memory alloy soft driver with temperature self-sensing function |
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| JPH02274526A (en) * | 1989-04-18 | 1990-11-08 | Nippon Zeon Co Ltd | Molding shape memory resin article |
| KR100991863B1 (en) * | 2008-01-23 | 2010-11-04 | 포항공과대학교 산학협력단 | Method of forming memory shape of high k material, high k material having imprint effect and memory shape device using the high k material |
| CN105416613A (en) * | 2015-11-23 | 2016-03-23 | 哈尔滨工业大学 | Repeatable and flexible capture structure based on dielectric elastomer and shape memory polymer and method for capturing space debris |
| CN107814940A (en) * | 2017-11-03 | 2018-03-20 | 哈尔滨工业大学 | A kind of preparation method of shape-memory polymer and its application in 4D printings |
| CN108516029A (en) * | 2018-04-02 | 2018-09-11 | 上海交通大学 | Autonomous rolling soft robot based on dielectric elastomer |
| CN108858265A (en) * | 2018-08-10 | 2018-11-23 | 上海交通大学 | Flexible grips based on artificial-muscle |
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