A 4D printing device and method for bionic functional structures

Abstract

The present invention discloses a 4D printing method, apparatus, and application thereof, including processes such as proportioning of multi-viscosity liquid components, flow mixing, degassing, temperature-controlled curing, filling, and final curing. Based on an integrated molding design concept, the method enables the preparation of pneumatically driven, self-propelled, deformable bionic structures (referred to as "bionic deformable actuators"). The apparatus and method of the present invention can produce functional components made of elastic, flexible materials with a viscosity range of 2,000 to 38,000 cps. This greatly simplifies the preparation process of bionic deformable actuators, enabling direct printing and single-stage molding without the need for secondary processing.

Description

Technical Field

[0001] The present invention belongs to the field of printing technology, and in particular relates to a 4D printing device and method for bionic functional structures. Background Art

[0002] In recent years, bionic drive structures based on flexible materials have been applied in many fields. Compared with traditional rigid structural devices, bionic drive structures have advantages such as large deformation, multiple degrees of freedom, low cost, high flexibility, safe interaction, and good adaptability to unstructured environments. According to different driving methods, they can be divided into pneumatic flow drive, electric drive, electromagnetic drive, chemical reaction actuation, etc. Among them, the bionic self-driven deformable structure based on pneumatic flow drive (hereinafter referred to as "bionic variant drive body") has the advantages of large load output, reliable movement, and repeatable operation over a long period of time. It has high practical value and can be used in bionic autonomous structures such as bionic aircraft, bionic robots and humanoid hands and limbs.

[0003] Bionic deformable actuators are made of highly elastic, flexible materials with reversible deformation properties, primarily polymers like silicone rubber, and are primarily formed by solidifying multiple liquid components. Currently, the production of bionic deformable actuators is mostly based on 3D printing technology, which involves preparing a mold for the actuator. This is then accomplished through a series of steps, including mixing the adhesive, vacuum degassing, injection into the mold, high-temperature curing, and demolding.

[0004] There are many problems with the current preparation method of using 3D printing molds and then solidifying them. For example, a sufficiently large opening must be reserved to facilitate the ejection of the mold, resulting in some additional openings in the driver after molding. In addition, the existing method cannot achieve one-time molding and needs to be manufactured in parts and then bonded together. This makes the preparation of bionic variant drivers have great limitations, especially the inability to prepare bionic variant driver structures with delicate internal structures or small sizes. In addition, bubbles are prone to appear in the driver during the manufacturing process, especially for elastic and flexible materials with high viscosity of the original liquid component, the success rate of the preparation is low. Therefore, it is necessary to achieve rapid prototyping of bionic variant drivers based on elastic and flexible materials through new technical means.

[0005] Currently, 3D printers based on the fused deposition modeling method on the market mostly use rigid filaments such as ABS and PLA. Although recent efforts have enabled the printing of somewhat flexible materials through shortening the printer's feed stroke and temperature-controlled printing, these raw materials, such as TPU and TPE, are essentially solid linear materials, making it impossible to rapidly and comprehensively fabricate biomimetic actuators based on the solidification of multiple liquid components. Summary of the Invention

[0006] To improve the above-mentioned defects, the present invention proposes a new 4D printing device for functional elastic-flexible material structures and a 4D printing device and method based on the Fluid swirling-mixing gentle temp-dosing principle (FSM-GTD). Based on the proportioning and solidification of liquid base materials of elastic-flexible materials with various viscosities, the one-time molding of bionic variant driving bodies is achieved.

[0007] Specifically, the present invention provides a 4D printing device, comprising: a parallel arm printing mechanism, a material storage unit, a material feeding unit, a material mixing unit, a printing unit, and a curing unit; the material storage unit, the material feeding unit, the material mixing unit, the printing unit, and the curing unit are all arranged on the parallel arm printing mechanism;

[0008] The material storage unit includes a material storage box, and the material storage box includes N areas for independently storing different components;

[0009] The feeding unit includes a liquid inlet tube and a peristaltic pump, wherein the liquid inlet tube includes a liquid inlet end and a liquid inlet pipeline; wherein the heads of the liquid inlet ends are respectively placed in different component areas and connected to the liquid inlet of the peristaltic pump through pipelines to realize the extraction of the original liquid components;

[0010] The liquid outlet of the peristaltic pump is connected to the liquid mixing unit through a pipeline.

[0011] The mixing unit includes an electric stirrer, a vacuum pump, and a vacuum stirring chamber; preferably, the electric stirrer is placed on the top of the frame of the parallel arm printing mechanism, and the stirring head is located in the vacuum stirring chamber; the vacuum pump is placed outside the vacuum stirring chamber and is connected to the inside of the stirring chamber through a pipeline; the outlet of the vacuum stirring chamber is connected to one end of the glue fluid pipeline via a solenoid valve to control the outflow of the mixed glue; the other end of the glue fluid pipeline is connected to the printing unit.

[0012] According to an embodiment of the present invention, N is selected from an integer greater than 2, for example, 2, 3, 4 or 5.

[0013] According to an embodiment of the present invention, each liquid inlet tube is preferably a tube body formed by combining a liquid inlet end and a pipeline, such as an integrally formed tube body. It should be understood by those skilled in the art that when the pipeline is used to transmit or transport a fluid, the pipeline is a fluid pipeline, such as a glue fluid pipeline.

[0014] According to an embodiment of the present invention, the parallel-arm printing mechanism includes a frame, three pairs of parallel arms, three pulley sets, and three stepping motors.

[0015] According to an embodiment of the present invention, the frame includes three supporting columns, a crossbeam and an angle piece, the three supporting columns are symmetrically distributed at 120 degrees, and the supporting columns are connected to the crossbeam by using the angle piece.

[0016] According to an embodiment of the present invention, the frame is made of alloy, such as aluminum alloy.

[0017] According to an embodiment of the present invention, each parallel arm independently comprises a first link and a second link; preferably, the first link and the second link do not cross and do not contact each other; preferably, the first link and the second link are parallel.

[0018] Preferably, the first connecting rod and the second connecting rod are made of carbon fiber.

[0019] According to an embodiment of the present invention, each stepping motor corresponds to a pulley set, each pulley set corresponds to a pair of parallel arms, and the stepping motor and the pulley set jointly actuate the parallel arms.

[0020] According to an embodiment of the present invention, the pulley block and the stepping motor are both arranged on the frame.

[0021] According to an embodiment of the present invention, the peristaltic pump in the feeding unit is preferably arranged between the material storage box and the material mixing unit, and is used to extract the material liquid from the material storage box to the liquid mixing unit.

[0022] According to an embodiment of the present invention, the material storage box is arranged at the middle position of the top end of the frame. Preferably, a through hole is arranged in the middle of the material storage box to facilitate each liquid inlet end to be placed in the corresponding liquid area.

[0023] According to an exemplary embodiment of the present invention, the feeding unit may include a combination of N liquid inlet pipes and N peristaltic pumps. Preferably, the number of the liquid inlet pipes and peristaltic pumps is the same as the number of components in the storage box, so that each peristaltic pump controls the feeding of one component respectively.

[0024] According to an embodiment of the present invention, the feeding unit further comprises a peristaltic pump fixing seat, which is provided on the frame and is used for placing the peristaltic pump.

[0025] According to an embodiment of the present invention, the mixing unit includes a vacuum stirring chamber, a vacuum pump, and an electric stirrer. The liquid components are mixed in the vacuum stirring chamber, and the electric stirrer stirs the multi-component raw materials at high speed to thoroughly mix them. The vacuum pump then creates a vacuum environment in the vacuum stirring chamber to vacuum degas the mixed liquid.

[0026] According to an embodiment of the present invention, the mixing unit further comprises a vacuum pump fixing seat, which is arranged on one side of the vacuum stirring chamber and is used to place the vacuum pump.

[0027] According to an embodiment of the present invention, the vacuum stirring chamber further comprises a solenoid valve, which is installed at the outlet at the bottom of the vacuum stirring chamber to control the outflow of the mixed glue.

[0028] According to an embodiment of the present invention, the printing unit comprises a hot end, a print head, and a print head mounting base; the print head comprises a glue flow injector and a nozzle. One end of the print head is connected to the outlet of a vacuum stirring chamber via a glue fluid pipeline, and the spiral groove of the glue flow injector further mixes and removes bubbles from the mixed glue. The hot end is located on the outer wall of the print head, at the end of the glue flow injector, to pre-solidify the mixed liquid and reduce the fluidity of the liquid. The print head assembly and hot end are fixed to the nozzle mounting base.

[0029] According to an embodiment of the present invention, one end of the first connecting rod and one end of the second connecting rod are respectively arranged on the left and right sides of the pulley of the corresponding pulley group, and the other end of the first connecting rod and the other end of the second connecting rod are adjacent to each other and arranged on the parallel arm mounting point of the nozzle fixing seat.

[0030] According to an embodiment of the present invention, the curing unit includes a heated bed disposed below the printing unit. Preferably, the heated bed includes a loading platform and a heating element, which heats the pre-cured material extruded from the nozzle, thereby curing it in a relatively short time.

[0031] According to an embodiment of the present invention, the 4D printing device further includes a controller and an operation panel connected to the controller. The controller can be selected from controllers of known models and functions in the art. For example, the controller is connected to the stepper motor, peristaltic pump, vacuum pump, electric stirrer, hot end, hot bed, and other related components.

[0032] According to an exemplary embodiment of the present invention, the 4D printing device includes: a parallel arm printing mechanism, a material storage unit, a material feeding unit, a material mixing unit, a printing unit, and a curing unit; the material storage unit, the material feeding unit, the material mixing unit, the printing unit, and the curing unit are all arranged on the parallel arm printing mechanism;

[0033] The storage unit includes a two-component storage box, and the two-component storage box includes a first area for independently storing a first component and a second area for independently storing a second component;

[0034] The feeding unit includes a first liquid inlet pipe, a second liquid inlet pipe, a first peristaltic pump and a second peristaltic pump;

[0035] The first liquid inlet pipe includes a first liquid inlet end and a first fluid pipe, the head of the first liquid inlet end is placed in the first group partition, and the tail is connected to the liquid inlet of the first peristaltic pump via the first fluid pipe;

[0036] The second liquid inlet pipe includes a second liquid inlet end and a second fluid pipe, the head of the second liquid inlet end is placed in the second group partition, and the tail is connected to the liquid inlet of the second peristaltic pump via the second fluid pipe;

[0037] The liquid outlets of the first peristaltic pump and the second peristaltic pump are respectively connected to the vacuum stirring chamber via fluid pipes;

[0038] The first peristaltic pump and the second peristaltic pump are respectively arranged between the material storage unit and the material mixing unit, and are used to extract the material liquid of different component areas from the material storage box through the pipeline into the vacuum stirring chamber;

[0039] The printing unit includes a hot end, a glue flow injector, a nozzle and a print head fixing seat; the hot end is placed on the outer periphery of the end of the glue flow injector; the glue flow injector, the nozzle and the hot end are fixed on the print head fixing seat.

[0040] According to an embodiment of the present invention, the component is a liquid component, preferably a liquid component for preparing an elastic and flexible material.

[0041] Furthermore, the present invention also provides the use of the above-mentioned 4D printing device in the preparation of elastic and flexible materials.

[0042] Preferably, the elastic material is made of a plurality of liquid components, and preferably, the viscosity of the liquid material is 2000-38000 cps.

[0043] Preferably, the elastic-flexible material can be used for preparing a bionic variant driving body.

[0044] Furthermore, the present invention also provides a 4D printing method, which includes a printing process of mixing multiple liquid components of the same or different viscosities according to a proportion, degassing, curing at a suitable temperature, filling, and final curing.

[0045] Preferably, the 4D printing method is performed in the above-mentioned device of the present invention.

[0046] According to an embodiment of the present invention, the elastically flexible material has the meaning as described above.

[0047] According to an embodiment of the present invention, the 4D printing method includes the following steps: at least two components of the liquid are stirred and vacuum degassed in a liquid mixing unit, and then flowed through a glue flow injector for secondary mixing and degassing and the flow rate is regulated, and then pre-cured at the hot end and printed by the nozzle to a hot bed for curing, and finally a printed part is obtained.

[0048] Beneficial effects of the present invention:

[0049] This invention proposes a novel 4D printing method using liquid-vortex mixing and warm injection. Based on a parallel-arm printing mechanism, it integrates a material storage unit, a material feeding unit, a material mixing unit, a printing unit, and a curing unit to form a 4D printing device for biomimetic functional structures. This device and method are suitable for printing liquid components of elastic and flexible materials with viscosities ranging from 2,000 to 38,000 cps, particularly functional flexible materials. This new 4D printing process enables the direct fabrication of biomimetic variant actuators using these materials as raw materials.

[0050] Specifically, the feeding unit is improved: (1) The feeding method is improved: Unlike traditional fused deposition model 3D printers, the base material of the elastic flexible material is a liquid component with a wide viscosity range. The existing method of gear meshing solid filaments cannot achieve feeding. The present invention uses a peristaltic pump group to extract the liquid component. According to different viscosities, the extraction pressure and speed of the pump group can be adjusted, thereby controlling the feeding speed.

[0051] (2) Improved component mixing method: The elastic and flexible material mainly based on silicone rubber is used in a multi-component ratio. For example, the A:B component is fully mixed in a volume ratio of 1:1 before it can be cured. The present invention sets a vacuum stirring chamber at the front end of the printing unit feed port, where the A / B component liquid extracted by the peristaltic pump group is mixed. First, the two components are fully mixed by an electric stirrer, and then the vacuum pump is turned on to vacuum degas the mixed liquid. The printing unit contains a glue flow injector with a spiral inner channel to further degas and mix the mixed liquid flowing through. The flow rate of the mixed liquid is controlled by the variable diameter structure of the channel inside the injector.

[0052] Improved printing methods for functional materials: Liquid components are difficult to shape after being extruded onto a hot bed in a fluid state, especially low-viscosity liquid components, which cure at room temperature in approximately 10 to 30 minutes. High temperatures, however, can catalyze their curing, quickly becoming viscous and showing a tendency to solidify at temperatures of several tens of degrees Celsius. Based on this property, the present invention adds a hot end to the nozzle, catalyzing the curing of the mixed liquid raw materials through controlled heating, rendering them essentially non-fluid after extrusion through the nozzle, and achieving final curing through secondary heating on the hot bed.

[0053] The device and method of the present invention greatly simplify the preparation process of the bionic variant driver, realize direct printing and one-time molding, and do not require secondary processing; the printing success rate is high, and delicate and tiny structures can be prepared, with a wide range of applications, shortening the preparation and production cycle and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Schematic diagram of the three-dimensional structure of the 4D printing device in Example 1;

[0055] Figure 2 This is a front view of the 4D printing device in Example 1;

[0056] Figure 3 This is a cross-sectional view of a unit component of the 4D printing device in Example 1.

[0057] Figure markings: 1: aluminum alloy frame, 2: stepper motor, 3: pulley set, 4: carbon fiber rod, 5: two-component storage box, 6: electric stirrer, 7-1: first peristaltic pump, 7-2: second peristaltic pump, 8: vacuum pump, 9: vacuum stirring chamber, 10: glue fluid pipeline, 11: glue flow injector, 12: hot end, 13: nozzle fixing seat, 14: nozzle, 15: hot bed, 16: control panel, 17: first liquid inlet end, 18: second liquid inlet end. DETAILED DESCRIPTION

[0058] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0059] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0060] Example 1

[0061] like Figure 1-3 The 4D printing device shown includes: a parallel arm printing mechanism, a material storage unit, a material feeding unit, a material mixing unit, a printing unit, and a curing unit; the material storage unit, the material feeding unit, the material mixing unit, the printing unit, and the curing unit are all arranged on the parallel arm printing mechanism;

[0062] The storage unit includes a two-component storage box 5, which includes two areas for independently storing a first component and a second component;

[0063] The feeding unit includes a first liquid inlet pipe, a second liquid inlet pipe, a first peristaltic pump 7-1 and a second peristaltic pump 7-2;

[0064] The first liquid inlet pipe includes a first liquid inlet end 17 and a first fluid pipe (not shown in the figure). The head of the first liquid inlet end 17 is placed in the first group partition, and the tail is connected to the liquid inlet of the first peristaltic pump 7-1 via the first fluid pipe.

[0065] The second liquid inlet pipe includes a second liquid inlet end 18 and a second fluid pipe (not shown in the figure), the head of the second liquid inlet end 18 is placed in the second group partition, and the tail is connected to the liquid inlet of the second peristaltic pump 7-2 via the second fluid pipe;

[0066] According to a preferred embodiment, each liquid inlet pipe is a pipe body integrally formed by each liquid inlet end and the fluid pipe connected thereto.

[0067] The first peristaltic pump 7-1 and the second peristaltic pump 7-2 are both arranged between the material storage unit and the material mixing unit. The liquid outlets of the first peristaltic pump 7-1 and the second peristaltic pump 7-2 are respectively connected to the vacuum stirring chamber 9 via fluid pipes, so as to pump the material liquid from the material storage box into the vacuum stirring chamber 9 of the material mixing unit.

[0068] The mixing unit includes a vacuum pump 8, a vacuum mixing chamber 9, and an electric stirrer 6. The electric stirrer is placed on top of the frame, with the stirring head located inside the vacuum mixing chamber. The vacuum pump is located outside the vacuum mixing chamber and connected to the interior of the mixing chamber via a fluid pipe. The outlet of the vacuum mixing chamber 9 is connected to one end of a glue fluid pipeline 10 via a solenoid valve to control the outflow of the mixed glue. The other end of the glue fluid pipeline 10 is connected to the printing unit.

[0069] The printing unit includes a hot end 12, a printing nozzle consisting of a glue flow injector 11 and a nozzle 14, and a nozzle fixing base 13; one end of the nozzle is connected to the outlet of the vacuum stirring chamber 9 via a glue fluid pipeline 10, and the mixed glue is further mixed and defoamed through the spiral groove of the glue flow injector 11; the hot end 12 is placed on the outer wall of the printing nozzle, at the end of the glue flow injector 11, so as to pre-solidify the mixed liquid and reduce the fluidity of the liquid; the end outlet of the glue flow injector 11 is connected to the nozzle feed port, and a reducing structure is provided in the connecting section; the printing nozzle assembly consisting of the nozzle 14 and the glue flow injector 11, and the hot end 12 are all fixed on the nozzle fixing base 13.

[0070] The parallel arm printing mechanism includes an aluminum alloy frame 1, three pairs of parallel arms, three pulley sets and three stepper motors. The aluminum alloy frame 1 includes three supporting columns, crossbeams and angle pieces. The three supporting columns are symmetrically distributed at 120 degrees, and the supporting columns are connected to the crossbeams by angle pieces. Each parallel arm includes two carbon fiber rods 4. The two carbon fiber rods 4 do not cross and do not contact each other, and are preferably parallel. Each stepper motor 2 corresponds to a pulley set 3, and each pulley set corresponds to a pair of parallel arms. The parallel arms are actuated jointly by the stepper motor and the pulley set. The pulley set 3 and the stepper motor 2 are both arranged on the frame. One end of the two carbon fiber rods is respectively arranged on the left and right sides of the pulley of the corresponding pulley set, and the other ends of the two carbon fiber rods are adjacently arranged on the parallel arm mounting point of the nozzle fixing seat.

[0071] The two-component storage box is arranged at the middle position of the top end of the frame. The two-component storage box is provided with through holes respectively, so that each liquid inlet end can be placed in the corresponding component area.

[0072] The curing unit includes a hot bed 15, which is arranged below the nozzle 14. The hot bed includes a stage and a heating element, which heats the pre-cured material extruded from the nozzle so as to cure it in a relatively short time.

[0073] The 4D printing device also includes a controller (not shown) and a control panel 16 connected to the controller. The controller can be selected from any controller known in the art with a suitable model and functionality. The controller is connected to the stepper motor, peristaltic pump, hot end, and heating elements in the heated bed.

[0074] The transmission components are composed of a stepper motor 2, a pulley set 3, a nozzle fixing seat 13, and a carbon fiber rod 4, which realize movement in three directions of X\Y\Z; the two-component storage box 5 is used to store the liquid components of the original base material. Each component is extracted by a peristaltic pump 7, mixed in a vacuum stirring chamber 9 through a fluid tube, and the various liquid components are fully mixed by an electric stirrer 6, and vacuum degassing is performed by a vacuum pump 8. The outlet of the vacuum stirring chamber 9 is connected to the glue fluid pipeline 10, and the end of the glue fluid pipeline 10 is connected to the glue flow injector 11. The internal spiral groove can further mix and degas the mixed liquid. The temperature of the hot end 12 is set according to the viscosity of the liquid component to pre-cure it and reduce its fluidity; then the pre-cured mixture is extruded onto the hot bed 15 through the nozzle 14. The high temperature environment of the hot bed 15 allows the pre-cured silicone rubber to cure in a relatively short time.

[0075] This device is suitable for printing functional elastic materials with various viscosity base materials, particularly for 4D printing of functional elastic materials. It enables the direct preparation of biomimetic variant actuators using these materials as raw materials. The device and printing method of the present invention greatly simplify the preparation process of biomimetic variant actuators, enabling direct printing and single-step molding without the need for secondary processing. It has a high printing success rate, can produce delicate and tiny structures, and has a wide range of applications.

[0076] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A 4D printing device, characterized in that: The device comprises: a parallel arm printing mechanism, a material storage unit, a material feeding unit, a material mixing unit, a printing unit and a curing unit; the material storage unit, the material feeding unit, the material mixing unit, the printing unit and the curing unit are all arranged on the parallel arm printing mechanism; The material storage unit includes a material storage box, which includes N areas for independently storing different liquid components, wherein the liquid component is a liquid raw material of an elastic and flexible material with a viscosity of 2000-38000 cps; The feeding unit includes a liquid inlet tube and a peristaltic pump, wherein the liquid inlet tube includes a liquid inlet end and a liquid inlet pipeline; wherein the heads of the liquid inlet ends are respectively placed in different component areas and connected to the liquid inlet of the peristaltic pump through pipelines to realize the extraction of the original liquid components; The liquid outlet of the peristaltic pump is connected to the liquid mixing unit through a pipeline; N is selected from an integer greater than 2; The mixing unit includes an electric stirrer, a vacuum pump, and a vacuum stirring chamber; the electric stirrer is placed on the top of the frame, and the stirring head is located in the vacuum stirring chamber; the vacuum pump is placed outside the vacuum stirring chamber and connected to the inside of the vacuum stirring chamber through a pipeline; the outlet of the vacuum stirring chamber is connected to one end of the glue fluid pipeline via a solenoid valve to control the outflow of the mixed glue; the other end of the glue fluid pipeline is connected to the printing unit; The printing unit includes a hot end, a printing nozzle and a printing nozzle fixing seat; the printing nozzle includes a glue flow injector and a nozzle; one end of the printing nozzle is connected to the outlet of the vacuum stirring chamber via a glue fluid pipeline, and a spiral groove is provided in the glue flow injector to further remove bubbles and mix the mixed liquid flowing through, and the flow rate of the mixed liquid is controlled by the variable diameter structure of the channel in the glue flow injector; the hot end is provided on the outer wall of the nozzle, located at the end of the glue flow injector, so as to pre-solidify the mixed liquid and reduce the fluidity of the liquid; the end outlet of the glue flow injector is connected to the nozzle feed port, and a variable diameter structure is provided in the connecting section; the printing nozzle assembly consisting of the nozzle and the glue flow injector and the hot end are fixed on the nozzle fixing seat.

2. The 4D printing device according to claim 1, characterized in that: The parallel arm printing mechanism comprises a frame, three pairs of parallel arms, three pulley sets and three stepping motors.

3. The 4D printing device according to claim 2, characterized in that: The frame includes three supporting columns, a crossbeam and an angle piece, wherein the three supporting columns are symmetrically distributed at 120 degrees, and the supporting columns are connected to the crossbeam by an angle piece; And / or, each parallel arm independently includes a first connecting rod and a second connecting rod, and the first connecting rod and the second connecting rod do not cross and do not contact each other; And / or, each stepper motor corresponds to a pulley set, each pulley set corresponds to a pair of parallel arms, and the stepper motor and the pulley set jointly actuate the parallel arms; And / or, the pulley assembly and the stepper motor are both arranged on the frame.

4. The 4D printing device according to claim 3, characterized in that: The first connecting rod and the second connecting rod are parallel; And / or, the first connecting rod and the second connecting rod are made of carbon fiber.

5. The 4D printing device according to claim 1, characterized in that: The peristaltic pump in the feeding unit is arranged between the material storage box and the mixing unit, and is used to extract the material liquid from the material storage box to the mixing unit; And / or, the material storage box is arranged at a middle position of the top end of the frame.

6. The 4D printing device according to claim 1, characterized in that: The feeding unit includes a combination of N liquid inlet pipes and N peristaltic pumps.

7. The 4D printing device according to claim 3, characterized in that: One end of the first connecting rod and one end of the second connecting rod are respectively arranged on the left and right sides of the pulley of the corresponding pulley group, and the other end of the first connecting rod and the other end of the second connecting rod are adjacent to the parallel arm installation point of the nozzle fixing seat.

8. The 4D printing device according to any one of claims 1 to 7, characterized in that: The 4D printing device further includes a controller and a control panel connected to the controller.

9. A 4D printing device, characterized in that: The 4D printing device includes: a parallel arm printing mechanism, a material storage unit, a material feeding unit, a material mixing unit, a printing unit and a curing unit; the material storage unit, the material feeding unit, the material mixing unit, the printing unit and the curing unit are all arranged on the parallel arm printing mechanism; The storage unit includes a dual-liquid component storage box, which includes a first area for independently storing a first component and a second area for independently storing a second component; the liquid component is a liquid base material of an elastic and flexible material with a viscosity of 2000-38000 cps; The feeding unit includes a first liquid inlet pipe, a second liquid inlet pipe, a first peristaltic pump and a second peristaltic pump; The first liquid inlet pipe includes a first liquid inlet end and a first fluid pipe, the head of the first liquid inlet end is placed in the first group partition, and the tail is connected to the liquid inlet of the first peristaltic pump via the first fluid pipe; The second liquid inlet pipe includes a second liquid inlet end and a second fluid pipe, the head of the second liquid inlet end is placed in the second group partition, and the tail is connected to the liquid inlet of the second peristaltic pump via the second fluid pipe; The liquid outlets of the first peristaltic pump and the second peristaltic pump are respectively connected to the vacuum stirring chamber via fluid pipes; The first peristaltic pump and the second peristaltic pump are respectively arranged between the material storage unit and the material mixing unit, and are used to extract the material liquid of different component areas from the material storage box through the glue fluid pipeline into the vacuum stirring chamber; The mixing unit includes an electric stirrer, a vacuum pump, and a vacuum stirring chamber; the electric stirrer is placed on the top of the frame, and the stirring head is located in the vacuum stirring chamber; the vacuum pump is placed outside the vacuum stirring chamber and connected to the inside of the vacuum stirring chamber through a pipeline; the outlet of the vacuum stirring chamber is connected to one end of the glue fluid pipeline via a solenoid valve to control the outflow of the mixed glue; the other end of the glue fluid pipeline is connected to the printing unit; The printing unit includes a hot end, a printing nozzle and a printing nozzle fixing seat; the printing nozzle includes a glue flow injector and a nozzle; one end of the nozzle is connected to the outlet of the vacuum stirring chamber via a glue fluid pipeline, and a spiral groove is provided in the glue flow injector to further remove bubbles and mix the mixed liquid flowing through, and the flow rate of the mixed liquid is controlled by the variable diameter structure of the channel in the glue flow injector; the hot end is provided on the outer wall of the nozzle, located at the end of the glue flow injector, so as to pre-solidify the mixed liquid and reduce the fluidity of the liquid; the end outlet of the glue flow injector is connected to the nozzle feed port, and a variable diameter structure is provided in the connecting section; the printing nozzle assembly and the hot end composed of the nozzle and the glue flow injector are fixed on the nozzle fixing seat.

10. Use of the device according to any one of claims 1 to 9 in preparing elastic and flexible materials, characterized in that: The original base material of the elastic and flexible material is a plurality of liquid components, and the viscosity of the liquid material is 2000-38000 cps.

11. A 4D printing method, comprising the steps of mixing at least two liquid components according to a ratio, degassing, curing at an appropriate temperature, filling, and finally curing, wherein the 4D printing method is performed in the apparatus according to any one of claims 1 to 9; The 4D printing method includes the following steps: at least two components of the liquid are stirred and vacuum degassed in a liquid mixing unit, then flowed through a glue flow injector for secondary mixing and degassed while regulating the flow rate, and then pre-cured at a hot end, printed by a nozzle, and cured on a hot bed to finally obtain a printed part.

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