CN110053257B

CN110053257B - Gel bionic artificial muscle 3D printing device and preparation method

Info

Publication number: CN110053257B
Application number: CN201910395796.8A
Authority: CN
Inventors: 孙壮志; 刘思诚; 李文宗
Original assignee: Northeast Forestry University
Current assignee: Northeast Forestry University
Priority date: 2019-05-13
Filing date: 2019-05-13
Publication date: 2021-03-02
Anticipated expiration: 2039-05-13
Also published as: CN110053257A

Abstract

The invention discloses a 3D printing device of gel bionic artificial muscles and a preparation method thereof. The frame is planer-type structure, and printing mechanism installs in frame stand bottom, is equipped with the laser cutting module on the frame crossbeam, and the frame lateral wall is equipped with electrode spraying module, and the frame both sides are equipped with symmetrical guide rail, and simultaneously, be equipped with the drive arrangement who is used for driving print platform to go up and down on the lateral wall, the phase separation module is placed below print platform. The device is suitable for continuously preparing artificial muscles and printing artificial muscle strips with different specifications, and has the advantages of high preparation speed, low cost and batch and standardized production; the artificial muscle electrolyte layer is in close contact with the electrode layer, so that the contact resistance of the electrode layer and the driving layer is reduced, and the deflection displacement and the driving force of the artificial muscle are further enhanced.

Description

Gel bionic artificial muscle 3D printing device and preparation method

Technical Field

The invention relates to the technical field of artificial muscles, in particular to an artificial muscle prepared by a 3D printing method.

Background

The development of the driving technology is through a steam engine, an internal combustion engine and an electric motor, and the flexibility, the use convenience and the energy utilization rate of a mechanical system are greatly improved. However, high performance robots (micro, biomimetic robots) require high flexibility, high redundancy, high efficiency, high load/mass ratio, and motors are difficult to meet. Most of various exercise modes of organisms are realized through muscle stretching and stretching, so that artificial muscles become one of the hot problems in scientific research. The artificial muscle is mainly composed of an ionic polymer film in the middle and metal electrodes on two sides, and is commonly called a sandwich structure, the metal electrodes are well attached to two sides of the film in the preparation process, and the driving force is the movement of cations from the middle of the film.

At present, the artificial muscle is prepared by a precipitation method, a chemical reduction method, a hot pressing and pasting method and a casting method. In the preparation method, a precipitation method is used for precipitating a gelled metal on two sides of the film, but the metal electrodes on two sides of the artificial muscle prepared by the method cannot be well attached to two sides of the film, and the metal electrodes are easy to fall off. In the traditional process method, an actuating film and an electrode film of a driver are independently formed, and then the actuator film and the electrode film are assembled together in a hot-pressing and attaching mode, the method cannot ensure that the electrode film and all parts of the surface of the actuating film can be well attached together, and still many surfaces are in a separated or poor-contact state in a microscopic scale, so that the resistance value of a contact resistor is large, the performance of the driver is limited to the proficiency of an operator, and the performance is unstable. The direct casting method is different from a hot-pressing laminating process, the driving layer film and the electrode film are cast together in a film forming stage, the method has obvious advantages compared with the first three methods, the driving layer and the electrode layer are in close contact and are not prone to cracking, but the casting method is complex in technological process, low in efficiency and high in cost, and batch production cannot be carried out.

Therefore, based on the 3D printing principle, the novel preparation method of the bionic artificial muscle is provided, the artificial muscle electrode layer prepared by the method is tightly attached to the driving layer, the contact resistance is low, and the driving force and the output displacement are obviously improved. In addition, the preparation process is simple, the cost is low, standardized and mass production can be carried out, drivers in various shapes can be printed, and the method is suitable for various working environments.

Disclosure of Invention

The invention aims to provide a 3D printing device of artificial muscles and a preparation method thereof, so as to solve the problems in the background technology.

1. The invention provides the following technical scheme: the utility model provides a novel artificial muscle's 3D printing apparatus which characterized in that: as shown in fig. 1, the device comprises a frame (17), a printing mechanism (12), a printing platform mechanism (13), a phase separation module (14), a laser cutting module, an electrode spraying module and a temperature control module. The machine frame (17) comprises a machine body (11), a cross beam and a stand column, wherein the cross beam is transversely arranged on the machine body and can slide along the longitudinal direction of the machine body, and the stand column is arranged on the cross beam and can vertically move and can transversely slide along the cross beam. As shown in fig. 2, the printing mechanism (12) comprises a speed control mechanism (21), a feeding mechanism (22) and a discharging mechanism (23); the discharging mechanism comprises a storage box (24), a conical feeding port (25), a detachable extrusion box (26), a second temperature control device (27) and a spray head (28) which are connected in sequence. As shown in fig. 3, the printing platform mechanism (13) is located below the printing mechanism (12), and is mounted on a side wall guide rail of the frame (17) by a support assembly, which comprises a guide support assembly, a printing platform and a driving assembly; the guide supporting component is installed on a side wall guide rail of the rack (17), the printing platform can slide along the side wall guide rail of the rack (17), the driving component is connected with a driving motor on the rack (17) to drive the printing platform to slide along the guide rail, and the printing platform can be overturned by 360 degrees. As shown in fig. 4, the phase separation module (14) is positioned below the printing platform mechanism (13), and is in a structure similar to a water tank shape and used for carrying out water phase separation on the artificial muscle. The lower bottom plate of the phase separation water tank is provided with a hydraulic driving device which can lift or lower the bottom plate of the phase separation water tank; the bottom plate of the water tank is driven by the hydraulic pump to slide upwards to discharge the sodium chloride liquid out of the separation tank. The laser cutting module is arranged on a beam of the frame (17), slides along the beam under the action of the driving motor, can perform trimming processing on the artificial muscle, avoids short circuit of a positive electrode and a negative electrode, and can cut the artificial muscle into muscle strips with a certain length and width proportion, as shown in a figure 1 (15). The electrode spraying module is arranged on the side wall of the rack (17), after the printing of the artificial muscle driving layer is finished, the turnover mechanism rotates the printing platform by 180 degrees and slides to one side with the electrode nozzle, and the chitosan/MWCNT hydrogel is sprayed on the driving layer, which is shown in figure 1 (16). The temperature control module is divided into two units, namely a first temperature control device and a second temperature control device, the first temperature control device controls the internal temperature of the 3D printer and comprises a first thermocouple, a first heater and a first temperature controller. The second temperature control device controls the temperature of the outer nozzle and comprises a second thermocouple and a second heater which are arranged in the outer nozzle of the spray head and close to the outlet, and a second temperature control instrument electrically connected with the second thermocouple and the second heater.

2. The preparation process of the driver mainly comprises the steps of preparing an electrolyte membrane, preparing an electrode membrane, and assembling the electrolyte membrane and the electrode membrane. The actuator comprises a chitosan/MWCNT flexible conductive hydrogel capable of being sprayed and printed, and an electroactive cellulose polymer material (namely an electrolyte membrane), wherein the chitosan/MWCNT hydrogel electrode layer is directly sprayed and covered on two surfaces of the electrolyte membrane by using a side wall spray head, namely a positive electrode and a negative electrode of the actuator are both directly sprayed with the flexible conductive hydrogel. Or the positive electrode or the negative electrode of the driving membrane is sprayed with hydrogel by 3D printing equipment, the electrode membrane finished by the casting method is adopted as the other layer of the electrode of the driver, then the whole artificial muscle is prepared by the hot-pressing attaching method, the separately prepared chitosan/MWCNT electrode membrane is attached to the other surface of the electrolyte membrane, and then the electrode and the middle layer are tightly compacted by a hot-pressing machine. Moreover, the electrolyte membrane is prepared by the 3D printing device, the two electrode membranes are prepared independently, and then the complete driver is manufactured in a manual assembly mode.

3. The electromechanical characteristics of the whole driver are tested through a self-made experimental platform, and the output displacement and the output force under different conditions are tested. FIG. 5 is a graph of the electrical displacement performance of the actuators (i.e., artificial muscles) prepared by the three methods, and the results of the test of the output displacement performance of the artificial muscles prepared by the three methods are tested by using a laser displacement sensor (model FT5070F, accuracy 0.01 mm); fig. 6 shows the driving force test results of the actuators (i.e., artificial muscles) prepared by the three methods, and the mechanical properties of each actuator were tested by an electronic mechanical universal tester AG-a 10.

The cellulose bionic artificial muscle 3D printing preparation method comprises the following steps:

(1) preparing artificial muscle materials: first, it is necessary to dissolve cellulose powder in ionic liquid BMIC to a certain concentration and viscosity suitable for printing, and apply it to the intermediate layer of artificial muscle. Then, it is necessary to dissolve chitosan powder into acetic acid solution, dope MWCNT to achieve a certain concentration and viscosity suitable for printing, as a driver electrode layer.

(2)3D modeling and programming: the printing model and control unit was designed using the graphics software SolidWorks using Ardino mega 2560r3 and processed for its upload program.

(3) The 3D printer basically sets up: setting the thickness of a printing driving layer of the 3D printer to be between 0.5mm and 0.8mm and the thickness of the printing driving layer to be between 2mm and 5 mm. The drying temperature was set at 75 ℃ for 30 minutes each. The water phase separation and soaking time of the artificial muscle driving layer is set to be 10 minutes.

(4) Printing of the artificial muscle driving layer: the spray head 1 works, and a prepared cellulose hydrogel solution is printed on a printing platform through the spray head 1; and then the first temperature control device works, the first heater starts heating, and the internal temperature of the printer is raised to 75 ℃ and stabilized for 30 minutes.

(5) Artificial muscle driving layer phase separation: the printing platform rotates 360 ° and the electrolyte layer of the artificial muscle is attached to the printing platform (due to the greater viscosity of the cellulose hydrogel). And then, the printing platform moves downwards along the side wall guide rail under the driving of the driving assembly, and the artificial muscle driving layer is soaked in ionic liquid (1mol/L sodium chloride solution). The lower bottom plate of the phase separation water tank is provided with a hydraulic driver which can lift or lower the bottom plate (5) of the phase separation water tank, and the bottom plate of the water tank can lift and slide under the work of the hydraulic pump to discharge the ionic liquid out of the phase separation water tank.

(6) Printing an electrode: the printing platform rotates 180 degrees, and the cellulose driving layer can be attached to the rotating assembly and cannot fall off due to the fact that a bayonet exists at the bottom of the printing platform, the viscosity of the cellulose membrane is high, and the attachment performance is good. Then, the printing platform moves towards the side of the 3D printer side wall where the electrode spray head is installed along the side wall guide rail. And (3) working an electrode sprayer, and spraying the chitosan/MWCNT conductive hydrogel on the surface of the artificial muscle electrolyte membrane to serve as a positive electrode. The printing platform rotates 360 degrees again, and the negative electrode gel is sprayed on the other surface of the electrolyte membrane.

(7) Laser cutting: and starting the laser cutting module to work. The laser cutter carries out edge cutting treatment on the artificial muscle, and the short circuit of the positive electrode and the negative electrode is avoided.

(8) Final treatment: the laser cutting module is restarted to cut the artificial muscle to obtain artificial muscles with different shapes. Compared with the existing artificial muscle preparation technology, the artificial muscle prepared based on the gel 3D printing has the following advantages.

Compared with the existing casting method for preparing the artificial muscle, the method simplifies the process steps, has higher production efficiency and can be used for batch production.

Compared with a hot-pressing laminating method for forming artificial muscle tissues, the scheme provided by the method ensures that all parts of the surfaces of the electrode film and the driving film can be well laminated together, and poor contact is avoided.

Compared with the chemical deposition method for preparing the artificial muscle, the method for preparing the driver has the advantages that the performance of the driver is not limited to the familiarity of an operator, the performance is stable, and the standardized production can be realized; meanwhile, the driver electrode layer does not use precious metal, the environmental influence is small, and the driver is degradable and environment-friendly. The method is widely applied to the fields of bionic robots, medical equipment, industrial product manufacturing and the like.

Drawings

Fig. 1 is a cross-sectional view of a cellulose bionic artificial muscle 3D printing device.

Fig. 2 is a schematic structural diagram of a printing mechanism of the artificial muscle 3D printer.

Figure 3 printing platform structure diagram of artificial muscle 3D printer.

Fig. 4 shows a structure of a phase separation device for 3D printing of artificial muscles.

Figure 5 compares the output displacement (cm) versus time(s) curves for three implemented artificial muscles.

Figure 6 compares the output force (mN) versus time(s) for three artificial muscles performed.

Detailed Description

The technical solutions of the three embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

Example one

The invention provides a technical scheme that: A3D printing preparation method of gel bionic artificial muscle comprises the following steps:

(1)3D modeling and programming: and designing a model by using drawing software SolidWorks and uploading and processing a simple program of the single chip microcomputer.

(2) The 3D printer basically sets up: the thickness precision of the 3D printing driving layer is set to be 0.5-0.8 mm, and the printing thickness is set to be 2-5 mm. The drying temperature was set at 75 ℃ and the run was 30 minutes each. Setting the water phase separation soaking time of the artificial muscle electrolyte layer as 10 minutes.

(3) Printing of the artificial muscle driving layer: spraying the cellulose hydrogel prepared in advance on a printing platform through the spray head; and then the first temperature control device works, the first heater starts heating, and the internal temperature of the printer is raised to 75 ℃ and stabilized for 30 minutes.

(4) Artificial muscle electrolyte layer phase separation: the printing platform is driven by the driving assembly to move downwards along the side wall track, and the artificial muscle electrolyte layer is soaked in ionic liquid (1mol/L sodium chloride solution). The chloride ions of the ionic liquid enter the driving layer, and the ion permeability of the electrolyte membrane can be enhanced. A hydraulic pump is installed on the lower bottom plate of the phase separation water tank, the bottom plate (5) of the phase separation water tank can ascend or descend, and the bottom plate of the water tank ascends and slides under the operation of the hydraulic pump to discharge the ionic liquid out of the phase separation water tank.

(5) Printing chitosan/MWCNT flexible electrode: and the side wall electrode spray head works, and a layer of electrode is sprayed on the surface of the cellulose electrolyte layer. Then, the printing platform rotates 180 degrees, because there is the bayonet socket in the printing platform bottom and the cellulose membrane adhesion performance is very good, consequently the cellulose drive layer can be attached to and can not drop on the rotating assembly. The electrode nozzle works to print the positive electrode of the driver on the surface of the driving film. And then, the printing platform rotates by 360 degrees again, the other face of the electrolyte membrane faces to the electrode spray head, and chitosan/MWCNT hydrogel is sprayed on the other surface of the artificial muscle electrolyte layer to serve as a negative electrode.

(6) Laser cutting: the laser cutting module 5 is started to work, and the laser cutter is arranged on a cross beam of the frame and can move along the cross beam. The laser cutter carries out edge cutting treatment on the driver (namely the artificial muscle), and the short circuit of the positive electrode and the negative electrode is avoided.

(7) Untreated: the laser cutting module is restarted to cut the artificial muscle to obtain the artificial muscle with different length and width ratios, such as an artificial muscle strip with the length multiplied by the width of 8cm multiplied by 1 cm.

Carry out two

In the second implementation, the anode or the cathode of the artificial muscle electrode layer is sprayed by 3D printing. The other electrode layer is used for preparing a complete driver by a hot-pressing laminating method; firstly, a separately prepared chitosan/MWCNT flexible hydrogel electrode is attached to the other surface of the artificial muscle driving layer in a hot pressing mode, then a hot pressing machine is used for slightly compacting, the electrode layer and the driving layer are enabled to be tightly attached, no crack is generated in the bending process, and the detailed preparation process is as follows.

(1)3D modeling and programming: and designing a model by using drawing software SolidWorks and uploading a program to the single chip microcomputer.

(2) The 3D printer basically sets up: setting the printing precision of a 3D printer to be between 0.5mm and 0.8mm, and setting the printing thickness of the artificial muscle electrolyte layer to be between 3mm and 5 mm. The drying temperature is set to be 75 ℃, and the operation is carried out for 30 minutes each time. Setting the water phase separation soaking time of the artificial muscle electrolyte layer as 10 minutes.

(3) Printing of the artificial muscle driving layer: the spray head works, and the prepared cellulose solution is printed on the printing platform through the spray head; and then the first temperature control device works, the first heater starts heating, and the internal temperature of the printer is raised to 75 ℃ and stabilized for 30 minutes.

(4) Artificial muscle electrolyte layer phase separation: the printing platform moves downwards along the side wall guide rail under the driving of the driving assembly, and the artificial muscle electrolyte layer is soaked in ionic liquid (1mol/L sodium chloride solution). The chloride ions of the ionic liquid enter the driving layer, and the chloride ion permeability of the electrolyte membrane can be enhanced. The bottom plate of the phase separation water tank is provided with a hydraulic pump which can ascend or descend the bottom plate of the phase separation water tank, and the bottom plate of the water tank ascends and slides under the work of a hydraulic pump driver to discharge the ionic liquid out of the phase separation water tank.

(5) Printing chitosan/MWCNT flexible electrode: the side wall electrode spray head works to spray a layer of electrode on the surface of the cellulose electrolyte. Firstly, the printing platform rotates 180 degrees, and the cellulose driving layer can be attached to the rotating component and cannot fall off due to the fact that the bayonet at the bottom of the printing platform is provided with the cellulose film, and the attachment performance is very good. Then, the side wall electrode spray head works, and conductive hydrogel is sprayed on the surface of the electrolyte membrane to serve as the positive electrode of the driver.

(6) Laser cutting: the laser cutting module 5 is started to work, and the laser cutter is arranged on a cross beam of the frame and can slide along the cross beam under the drive of the stepping motor. The laser cutter carries out edge cutting processing on the driving film. The cellulose driver was simultaneously segmented into 8cm x 1 cm-sized small muscle strips.

(7) Hot-pressing and laminating: assembling the semi-finished artificial muscle prepared by the 3D printer and the separately prepared flexible electrode together; then, a certain force was applied slightly with the tablet press. And finally, spraying an electrode on one side of the prepared complete electrolyte membrane by using 3D printing equipment, and independently preparing the hot-pressed artificial muscle on the other side of the prepared complete electrolyte membrane.

Implementation III

In the third implementation, the middle electrolyte layer of the artificial muscle is prepared by 3D printing, and the positive electrode film and the negative electrode film are both prepared independently by adopting a casting film method; then, manually laminating the separately prepared flexible electrode films on two sides of the cellulose electrolyte membrane artificial muscle by a hot-pressing laminating method to form a positive electrode and a negative electrode; and then, compacting the electrolyte layer and the electrode layer of the driver tightly by a hot press.

(2) The 3D printer basically sets up: the printing precision of the 3D printer is set to be between 0.5mm and 0.8mm, and the printing thickness of the artificial muscle driving layer is set to be between 3mm and 5 mm. The drying temperature was set at 75 ℃ and the run was 30 minutes each. The soaking time of the artificial muscle electrolyte layer is set to be 10 minutes.

(3) Printing of the artificial muscle driving layer: the spray head works, and the cellulose solution prepared in advance is printed on the rotating component through the spray head; and then the first temperature control device works, the first heater starts heating, and the internal temperature of the printer is raised to 75 ℃ and stabilized for 30 minutes.

(4) Artificial muscle driving layer phase separation: first, the artificial muscle electrolyte layer is adhered to the printing platform, which is rotated 360 °. Then, the printing platform moves downwards along the side wall guide rail under the driving of the driving assembly, the artificial muscle electrolyte layer is soaked in ionic liquid (1mol/L sodium chloride solution), and chloride ions of the ionic liquid enter the electrolyte layer, so that the ion permeability of the electrolyte membrane can be enhanced. The bottom plate of the phase separation water tank is provided with a hydraulic pump which can lift or lower the bottom plate of the phase separation water tank, and the bottom plate of the water tank can lift and slide under the work of the hydraulic pump to discharge the ionic liquid out of the phase separation water tank.

(5) Laser cutting: the laser cutting module 5 is started to work, and the laser cutter is arranged on a cross beam of the frame and can slide along the cross beam under the drive of the stepping motor. The laser cutter performs trimming processing on the driver. Artificial muscles of different shapes can also be cut according to specific requirements, such as dividing a cellulose driving layer into small muscle strips of 8cm multiplied by 1 cm.

(6) Assembling: and assembling the artificial muscle electrolyte layer prepared by 3D printing and the separately prepared electrode into a sandwich structure, and slightly compacting on a tablet press. And (5) mounting an electrode clamp, and testing the output force and the output displacement of the electrode clamp.

The electromechanical test results (fig. 5 and 6) of the three embodiments show that the artificial muscle (cellulose-based ion driver) prepared by 3D printing has great advantages over the traditional manual preparation. Output and output displacement are improved because the artificial muscle electrode layer prepared by 3D printing is in close contact with the middle layer, contact resistance is greatly reduced, and electron transfer is facilitated. According to the driving principle of the artificial muscle, the smaller the contact resistance between the electrode layer and the middle layer is, the better the driving effect of the artificial muscle is. In addition, the preparation of the gel-type artificial muscle by the 3D method has the following advantages.

Firstly, the preparation process is simple, and the preparation flow is simplified;

secondly, the preparation efficiency is high, and standardized mass production can be realized;

thirdly, compared with manual manufacturing, the labor cost is reduced, and meanwhile, the influence of human factors on the performance of the driver is reduced.

Claims

1. A method for preparing gel bionic artificial muscle by using a 3D printing device comprises a frame, a printing mechanism, a printing platform, a phase separation module, a laser cutting module, an electrode spraying module and a temperature control module; the printing machine comprises a rack, a printing mechanism and a printing platform mechanism, wherein the rack comprises a machine body, a cross beam and a stand column, the cross beam is transversely arranged on the machine body and can longitudinally slide along the machine body, the stand column is vertically arranged on the cross beam and can vertically move and can transversely slide along the cross beam, the printing mechanism is arranged at the bottom end of the stand column and comprises a speed control mechanism, a discharging mechanism and a nozzle, the discharging mechanism is connected with a feeding mechanism through a guide pipe, the feeding mechanism is positioned on the side wall of the printing device, and the; the printing platform mechanism comprises a guide supporting assembly, a printing platform and a driving assembly; the guide support assembly is arranged on a side wall guide rail of the frame, and the printing platform can slide along the side wall guide rail; the phase separation module is positioned below the printing platform, comprises a motion plate, a driver, a spring and a shell and is used for carrying out water phase separation on the artificial muscle; the laser cutting module is arranged on the beam and can slide along the beam under the action of the driving unit to perform trimming processing on the artificial muscle driving layer so as to avoid the short circuit of positive and negative electrodes of the artificial muscle; the electrode spraying module is installed on the side wall of the rack, the temperature control module is provided with two units, namely a first temperature control device and a second temperature control device, the first temperature control device controls the internal temperature of the 3D printer, the second temperature control device comprises a second thermocouple and a second heater which are arranged in the upper portion of the outer nozzle of the spray head and close to the outlet, the second thermocouple and the second heater are used for preheating chitosan gel, and the method for preparing gel type bionic artificial muscle by adopting the 3D printing device is characterized in that: the artificial muscle driving electrode comprises a chitosan/MWCNT electrode material and an artificial muscle driving layer, wherein the chitosan/MWCNT flexible electrode is directly sprayed on two surfaces of the artificial muscle driving layer, namely only a positive electrode and a negative electrode adopt the chitosan/MWCNT flexible electrode; the chitosan/MWCNT flexible electrode adopts carbon nano tube dispersion liquid with different ratios; the cellulose artificial muscle driving layer adopts ionic liquid 1-butyl-3-methylimidazolium chloride to dissolve cellulose powder; after the artificial muscle driving layer is printed, the printing platform slides downwards, the cellulose membrane is soaked in 1mol/L sodium chloride solution, sodium chloride liquid is discharged out of the water phase separation tank after water phase separation is finished, the temperature in the printer is raised by the first temperature control device, the artificial muscle driving layer is dried, and after drying is finished, the flexible chitosan/MWCNT flexible electrode can be sprayed on the surface of the artificial muscle driving layer; the chitosan/MWCNT electrode material is prepared from 75% of chitosan by mass and 25% of carbon nano tubes by mass; after the chitosan/MWCNT flexible electrode is sprayed, the laser cutting module carries out edge cutting treatment, so that short circuit of a positive electrode and a negative electrode is avoided; the gel artificial muscle is characterized in that before the chitosan/MWCNT flexible electrode material is sprayed, enough ionic hydrate is distributed in the driving layer of the artificial muscle through soaking or wetting so as to improve the driving performance of the artificial muscle.