CN110524532B

Movatterモバイル変換

Info

Publication number: CN110524532B
Application number: CN201910819817.4A
Authority: CN
Inventors: 郭东杰; 王付义; 王龙
Original assignee: Santi Ciyuan Information Technology Ningbo Co ltd
Current assignee: Santi Ciyuan Information Technology Ningbo Co ltd
Priority date: 2019-08-31
Filing date: 2019-08-31
Publication date: 2020-12-11
Anticipated expiration: 2039-08-31
Also published as: CN110524532A

Abstract

The invention discloses an electronic artificial muscular electric actuator, a preparation method thereof and application thereof in a finger driving device, wherein the electronic artificial muscular electric actuator consists of a modified graphene oxide/silicon rubber base film, graphite/silicon rubber electrodes fixed on two sides of the base film, a lead and a high-voltage pulse electric signal; the base film is prepared by doping IPDI modified graphene oxide in silicon rubber, and the graphite/silicon rubber electrode is prepared by doping graphite in silicon rubber and is fixed on two sides of the base film. The addition of the modified graphene oxide in the base film improves the dielectric constant, so that the actuation performance is improved. The electronic type artificial muscular electric actuator can generate larger deformation under the same electric field voltage, can be used for a tactile sensor, can change the magnitude of the driving force to the finger and the speed of the frequency by adjusting the voltage and the frequency in the aspect of finger driving, and is suitable for different people.

Description

Electronic artificial muscle electric actuator, preparation method thereof and application thereof in finger driving device

Technical Field

The invention belongs to the technical field of composite materials, and particularly relates to a preparation method of an electronic artificial muscle with large deformation and high performance and application of the electronic artificial muscle in finger driving.

Background

The rehabilitation connection device is based on the diagnosis and treatment of hand surgery, aiming at various factors of hand dysfunction, such as scars, contractures, adhesion, swelling, joint stiffness, muscular atrophy, sensory loss or abnormality and the like, adopts corresponding rehabilitation means such as physical therapy, motor therapy, operation therapy, auxiliary appliances, rehabilitation engineering, psychotherapy and the like, so that the injured hand can recover the maximum function to adapt to daily life activities, work and learning.

The existing rehabilitation training device usually adopts a mechanical method to perform rehabilitation training, and the device comprises a motor, a transmission device and other parts, and has the defects of larger volume, heavier weight and the like.

The inherent material properties and operating principles of dielectric elastomers provide unparalleled features. These may be suitable to provide sufficient functional characteristics to the orthotic system while making it at least lighter, more flexible and comfortable, and therefore easier to wear and carry.

The silicone rubber is an elastomer with a-Si-O-bond as a main chain and an organic group as a side group, has a special semi-organic and semi-inorganic structure, is excellent in high and low temperature resistance, weather resistance, ozone resistance, aging resistance, physiological inertia and high air permeability and is used in the fields of aerospace, automobiles, electronics, medical appliances and the like.

The dielectric elastomer can change shape or volume under the induction of an external electric field, can restore to the original shape or volume when no electric field is applied, and has special mechanical and electrical properties. The device can be used for the interconversion of electric energy and mechanical energy, and has the advantages of low modulus, small density, large deformation, low noise, quick response, high energy density, high electricity/force conversion efficiency and the like. The dielectric elastomer is one of the most potential electroactive polymer materials for manufacturing actuators, sensors, vibrators, energy collectors and other converters, and has wide application potential in the fields of artificial muscles, intelligent bionics, aerospace, machinery, biology and the like.

Dielectric Elastomer (DEP) is an electroactive polymer that is lightweight, low cost, energy efficient, and does not require additional means to convert electrical energy into mechanical energy. After the electrodes are electrified, an electric field is generated, the electrostatic attraction force generated by charges with different polarities between the two electrodes presses the elastic membrane in the membrane thickness direction, and the electrostatic repulsion force generated by charges with same polarity in the horizontal direction expands the membrane on the unit electrode, so that the thickness and the area are changed: the thickness is reduced and the area is enlarged. The elastomeric film returns to its original shape or volume upon removal of the electric field. The intermediate layer is acted by Maxwell force, the material shrinks along the direction of electric field application and expands and extends in the direction perpendicular to the direction of electric field application. As shown in fig. 1, thinning produces deformation, resulting in electro-mechanical energy conversion.

When the structure of DEP is ideal, the relationship between the electric deformation generated by the electrode acting on the elastomer and the electric field intensity is as follows:

in the formula: e is the strength of the applied electric field,₀＝8.854×10^-12f/m is the dielectric constant in vacuum,_ris the relative dielectric constant, S, of the elastomeric film_ZIs the deformation of the elastomer in the thickness direction, and Y is its Young's modulus. From the working principle formula, the electromechanical response capability of the dielectric elastomer is directly proportional to the relative dielectric constant of the material and the square of the electric field intensity, and inversely proportional to the Young modulus. It can thus be seen that increasing the dielectric constant of the material and decreasing the modulus of the material can improve the strain response of the dielectric elastomer actuator at lower electric field strengths.

The driving principle of the dielectric elastomer is similar to that of a parallel electromechanical conversion double-plate capacitor as shown in the following figure, and the principle can be explained by the following equation:

σ＝₀(E/d)²

where σ is referred to as maxwell stress, is the compressive pressure from charging on the surface,₀is the dielectric constant of free space: (₀8.85 × 10-12F/m), and E and d represent the supplied voltage and the thickness between the electrodes, as a relative dielectric constant.

The maximum deformation quantity can be improved from three aspects of dielectric constant, voltage and elastic modulus by an electrostriction formula. Much research in the past has focused on how to increase the dielectric constant of elastomers. Conventionally, the dielectric constant of elastomers has been increased by adding high amounts of ceramic dielectric fillers, such as widely used lead magnesium niobate (PMN), lanthanum lead zirconate titanate (PLZT), and lead zinc niobate (PZN), which cause defects in the formed micron-sized thin film material and are prone to electrical breakdown. For example, Yanju Liu et al use silicone rubber as a base material and barium yohimate with a dielectric constant exceeding that of the base material as a filler to prepare the dielectric elastomer composite material. However, as the hardness of the ceramic filler is higher, the dielectric constant of the obtained composite material is increased along with the increase of the using amount of the filler, and the modulus is also greatly increased, so that the composite material can be deformed only under a very high voltage, and a large amount of barium helioate has poor compatibility with a silicon rubber matrix, is difficult to uniformly disperse, easily causes an overhigh local electric field, and reduces the breakdown voltage of the material.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an electronic artificial muscle, a preparation method thereof and application thereof in finger driving. According to the invention, the basement membrane is prepared by doping the silicon rubber with the KH590 modified graphene oxide, so that the dielectric constant is improved compared with that of the silicon rubber basement membrane. The method for improving the dielectric constant is adopted to improve the deformation capability of the dielectric elastomer, so that the electronic artificial muscular electric actuator with large deformation height performance is manufactured.

In order to solve the technical problems, the invention adopts the following technical scheme:

an electronic artificial muscular electric actuator consists of a modified graphene oxide/silicon rubber base film, graphite/silicon rubber electrodes fixed on two sides of the base film, a lead and a high-voltage pulse electric signal; the base film is prepared by doping graphene oxide modified by 3-isocyanatomethylene-3, 5, 5-trimethylcyclohexyl isocyanate (IPDI) in silicon rubber, and the graphite/silicon rubber electrode is prepared by doping graphite in the silicon rubber and is fixed on two sides of the base film.

Further, the thickness of the basement membrane is 0.2-0.5mm, and the thickness of the graphite/silicon rubber electrodes on the two sides of the basement membrane is 0.03-0.08 mm.

Further, the elastic modulus of the base film is 0.5-5MPa, and the dielectric constant of the base film is 2.2-4.5.

The preparation method of the electronic artificial muscular electric actuator comprises the following steps:

(1) preparing modified graphene oxide;

(2) preparing a modified graphene oxide/silicon rubber substrate membrane solution;

(3) preparing a modified graphene oxide/silicon rubber base film;

(4) prestretching the modified graphene oxide/silicon rubber substrate film;

(5) preparing a graphite/silicon rubber electrode solution;

(6) electronic artificial muscular electric actuator: and (3) coating the graphite/silicon rubber electrode solution uniformly stirred in the step (5) on the modified graphene oxide/silicon rubber base film pre-stretched in the step (4), placing the base film in a vacuum oven at 45 ℃ for drying for 240min, connecting a lead to the graphite/silicon rubber electrode by using an adhesive tape, and winding the base film connected with the lead and coated with the electrode on a compressed spring to manufacture the electronic artificial muscular electric actuator.

Further, the preparation method of the modified graphene oxide in the step (1) is as follows:

a. weighing 500mg of GO powder and 30mL of acetone in a clean and dried 100mL round-bottom flask, ultrasonically dispersing for 10 minutes by using an ultrasonic cell crusher, then adding 4g of IPDI, and continuing to ultrasonically disperse for 10 minutes;

b. setting up an experimental device, fixing a round-bottom flask on an iron support, adding two drops of dibutyltin dilaurate serving as a catalyst, adding a rotor, reacting for 10 hours at normal temperature, centrifugally separating by using acetone after the reaction is finished, taking down a lower-layer solid, performing suction filtration, and drying for 24 hours at 60 ℃ in a vacuum drying oven to obtain GO-IPDI;

c. putting 2gGO-IPDI into a centrifuge tube, then taking 20mL of acetone, ultrasonically dispersing for 10 minutes by an ultrasonic cell crusher, and then adding 10g of hydroxyl silicone oil to continue to ultrasonically disperse for 10 minutes; adding two drops of catalyst dibutyltin dilaurate, adding a rotor, carrying out condensation reflux reaction for 10h at 60 ℃, centrifugally separating a product, cleaning the product with ethanol for 3 times, and drying the product for 24h at 60 ℃ to obtain the modified graphene oxide.

The preparation method of the modified graphene oxide/silicon rubber base membrane solution in the step (2) is as follows: dispersing 1.44mg of dried modified graphene oxide into 4g of n-heptane solution by ultrasonic treatment, uniformly mixing 12g of 186 silicon rubber and 18g of n-heptane solution, adding the modified graphene oxide powder mixed in n-heptane into the mixed solution of n-heptane and silicon rubber, adding 1.2g of cross-linking agent (Dow Corning), stirring with a PMMA rod for 30min to uniformly disperse the modified graphene oxide powder, and placing the mixture in a 0.8MPa vacuum container for 5-7min to remove bubbles to obtain the modified graphene oxide/silicon rubber substrate membrane solution.

Further, the preparation method of the modified graphene oxide/silicone rubber base film in the step (3) is as follows: pouring the prepared graphene oxide/silicon rubber solution into an organic glass mold, placing the organic glass mold in a vacuum drying oven, setting the temperature at 60 ℃ for 280min, and curing to form a film to obtain the graphene oxide/silicon rubber base film.

Further, in the step (4), the edge of the graphene oxide/silicon rubber basement membrane is cut, isometric biaxial stretching is carried out, the deformation amount of the basement membrane reaches 70%, and the pre-stretched basement membrane is placed into a vacuum oven at 80 ℃ and heated for 240 min.

Further, the preparation method of the graphite/silicone rubber electrode solution in the step (5) is as follows: adding graphite powder into silicone rubber (Dow Corning, Midland, MI, USA), adding crosslinking agent (Dow Corning) and n-heptane, and stirring; wherein the mass ratio of the graphite powder, 186 silicon rubber, the cross-linking agent and n-heptane is 5:10:1: 8.

The application of the electronic type artificial muscle electric actuator in the finger driving device comprises the following steps: the finger driving device comprises a support, an electronic type artificial muscular electric actuator, a rope, a pulley and a ring, wherein one end of the rope is connected with the electronic type artificial muscular electric actuator, the other end of the rope is connected with the ring through the pulley, the pulley is arranged on the support, a lead of the electronic type artificial muscular electric actuator is connected with an externally-applied high-voltage pulse electric signal, the electronic type artificial muscle can be connected with the externally-applied high-voltage pulse electric signal through the lead to drive, and therefore the finger can be subjected to rehabilitation training by setting parameters suitable for finger movement of a patient; the high-voltage pulse electrical signal is 0.1-10Hz and 0.8-11 kV.

The invention has the beneficial effects that: 1. the electronic type artificial muscle electric actuator has excellent electric-mechanical conversion performance, can generate large deformation, and is improved by 1.15-1.4 times compared with the electric deformation of a silicon rubber membrane. 2. The electronic type artificial muscular electric actuator of the invention has wider application, for example, the electronic type artificial muscular electric actuator of the invention can generate larger deformation under the same electric field voltage, so the electronic type artificial muscular electric actuator can be used for a tactile sensor and can also be used for preparing an electromechanical conversion driving device such as artificial muscles, microfluidic pump valves, loudspeakers, sensitive tactile display and the like. In the aspect of finger driving, the magnitude and the frequency of the driving force for the finger can be changed by adjusting the voltage and the frequency, so that the finger driving device is suitable for different crowds. 3. The base film has excellent deformation/actuation capability: the addition of the modified graphene oxide in the base film improves the dielectric constant, so that the actuation performance is improved. 4. And grafting IPDI on the surface of GO by using a two-step method and then grafting PDMS to prepare GO-IPDI-PDMS. The compatibility of GO with non-polar solvents and non-polar polymers can be improved, so that the GO can be uniformly dispersed in the polymers, and various properties of the composite material such as mechanics, dielectric, electric conduction, heat conduction and the like can be improved.

Drawings

FIG. 1 shows a structure of an electronic artificial muscle;

FIG. 2 is a schematic view of the driving principle of an electronic type artificial muscle electric actuator;

FIG. 3 is a block diagram of an axial actuator;

FIG. 4 is a schematic view of an axial actuator;

FIG. 5 is an axial actuator travel schematic;

fig. 6 is a schematic view of an electronic type artificial muscle finger driving device.

Detailed Description

The present invention will be further described with reference to the following examples. It is to be understood that the following examples are illustrative only and are not intended to limit the scope of the invention, which is to be given numerous insubstantial modifications and adaptations by those skilled in the art based on the teachings set forth above.

Example 1 (preparation of modified Stone graphene oxide/Silicone rubber base film)

A clean and dried 100mL round bottom flask is taken, 500mg GO powder is weighed, 30mL acetone is weighed, and an ultrasonic cell crusher is used for ultrasonic dispersion for 10 minutes. 4g of IPDI (3-isocyanatomethylene-3, 5, 5-tris) were weighed into a flask and dispersed ultrasonically for 10 minutes by an ultrasonic cell disrupter. An experimental device is set up, the flask is fixed on an iron support, two drops of catalyst (dibutyltin dilaurate) are added, a rotor is added, and the reaction is carried out for 10 hours at normal temperature. After the reaction is finished, performing centrifugal separation by using acetone, taking a lower-layer solid, performing suction filtration, and drying in a vacuum drying oven at 60 ℃ overnight to obtain GO-IPDI; 2gGO-IPDI was placed in a centrifuge tube, and 20mL of acetone was added and dispersed by ultrasonic using an ultrasonic cell disrupter for 10 minutes. 10g of hydroxyl silicone oil is added into a centrifuge tube, and an ultrasonic cell crusher ultrasonically disperses for 10 minutes. Adding two drops of catalyst, adding rotor, and reflux-condensing at 60 deg.C for 10 hr. The product was centrifuged and washed 3 times with ethanol and dried at 60 ℃ for 24 h. Dispersing 1.44mg of dried modified graphene oxide into 4g of n-heptane solution by ultrasonic treatment, uniformly mixing 12g of 186 silicon rubber with 18g of n-heptane solution, adding the modified graphene oxide powder mixed in n-heptane into the mixed solution of n-heptane and silicon rubber, adding 0.8g of cross-linking agent, stirring with a PMMA rod for 30min to uniformly disperse, and placing in a 0.8MPa vacuum container for 5-7min to remove bubbles. And pouring the prepared graphene oxide/silicon rubber solution into a 70 x 10mm organic glass mold, placing the organic glass mold in a vacuum drying oven, setting the temperature at 60 ℃ and the time at 280min, and curing to form a film.

Example 2 (preparation of Large deformation electronic type Artificial muscular electric actuator)

And taking the cured graphene oxide/silicon rubber basement membrane out of the die, trimming, and then carrying out equiaxial biaxial stretching to ensure that the deformation of the basement membrane reaches 70%. The substrate film was placed in a vacuum oven at 80 ℃ and heated for 240 min. 5.0g of graphite powder is weighed into a solution containing 10.0g of silicone rubber, 1g of cross-linking agent is added, 8g of n-heptane is added and the mixture is stirred uniformly. And brushing the uniformly stirred graphite/silicon rubber electrode solution on a base film, and drying in a vacuum oven at 45 ℃ for 240 min.

The sheet resistance of the electrode obtained by the four-probe apparatus test is shown in table 1.

TABLE 1 area resistance of the electrodes

Example 3 (preparation of Silicone rubber film)

Firstly, weighing 5.0g of 186 silicone rubber and 0.5g of cross-linking agent, then adding 15mL of n-heptane, uniformly mixing, vacuumizing to remove air bubbles in the solution, finally casting in a mold, and placing in an oven at 60 ℃ for 240 min.

EXAMPLE 4 electric actuation Properties

Electric signal of electronic artificial muscle

The experimental device mainly comprises a signal generating unit and a signal amplifying unit. The hardware of the signal generating unit consists of a 6024E multifunctional data acquisition card of NI company; the software is obtained by LabVIEW programming; the signal amplification unit is composed of a power amplification chip OPA548 by the company TI.

And (3) testing the electric actuating performance: the electronic type artificial muscular electric actuator taking graphene oxide/silicon rubber as a base film and the electric actuator taking silicon rubber as the base film are respectively arranged at two electrodes of a power supply, the control voltage is between 1.5 and 10kV, the working frequency is 0.1 to 20Hz, the deformation process of the electronic type artificial muscular electric actuator is recorded by a camera in the whole process, and deformation results under different voltages and different frequencies are obtained through calculation (table 2).

TABLE 2 deformation results at the same voltage and different frequencies

Example 5

Use of an electronic type artificial muscular electric actuator in a finger drive device: the finger driving device comprises a support, an electronic type artificial muscular electric actuator, a rope, a pulley and a ring, wherein one end of the rope is connected with the electronic type artificial muscular electric actuator, the other end of the rope is connected with the ring through the pulley, the pulley is arranged on the support, and a lead of the electronic type artificial muscular electric actuator is connected with an externally-applied high-voltage pulse electric signal.

Preparation of the finger drive device: firstly, performing isometric pre-stretching on a 10 × 0.5mm modified graphene oxide/silicon rubber base film in two directions, then coating a graphite/silicon rubber electrode, drying in an oven at 40 ℃ for 240min for curing, then connecting a lead to the graphite/silicon rubber electrode by using an adhesive tape, and winding the base film connected with a lead and coated with the electrode on a compressed spring to manufacture the electronic type artificial muscle electric actuator (as shown in fig. 4). When the stretched base film is wound around the spring, the tension of the base film interacts with the elastic restoring force of the spring, so that the actuator reaches an equilibrium initial length h. When a voltage load is applied to the actuator, the tension of the membrane is weakened by Maxwell electrostatic force, the spring returns to its original length to produce an elongation H, and when the voltage is unloaded, the tension of the base membrane returns, the spring is compressed again, and the actuator returns to its original state (as shown in fig. 5). This produces a stroke that drives the finger in motion.

The prepared electronic artificial muscle is placed on thebracket 1, therope 3 is connected with the spring inside the electronicartificial muscle 2, and therope 3 is connected with thering 5 by bypassing thepulley 4, so that the finger rehabilitation training is performed (as shown in fig. 6).

The foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A method for preparing an electronic artificial muscular electric actuator, comprising the steps of:

(1) preparing modified graphene oxide;

(3) preparing a modified graphene oxide/silicon rubber base film;

(4) prestretching the modified graphene oxide/silicon rubber substrate film;

(5) preparing a graphite/silicon rubber electrode solution;

(6) electronic artificial muscular electric actuator: coating the graphite/silicon rubber electrode solution uniformly stirred in the step (5) on the modified graphene oxide/silicon rubber base film pre-stretched in the step (4), placing the modified graphene oxide/silicon rubber base film in a vacuum oven for drying at 45 ℃ for 240min, connecting a lead to the graphite/silicon rubber electrode by using an adhesive tape, and winding the base film connected with the lead and coated with the electrode on a compressed spring to manufacture an electronic artificial muscular electric actuator;

the preparation method of the modified graphene oxide in the step (1) comprises the following steps:

c. putting 2gGO-IPDI into a centrifuge tube, then taking 20mL of acetone, ultrasonically dispersing for 10 minutes by an ultrasonic cell crusher, and then adding 10g of hydroxyl silicone oil to continue to ultrasonically disperse for 10 minutes; adding two drops of catalyst dibutyltin dilaurate, adding a rotor, carrying out condensation reflux reaction for 10h at 60 ℃, centrifugally separating a product, cleaning the product with ethanol for 3 times, and drying the product for 24h at 60 ℃ to obtain modified graphene oxide;

the electronic artificial intramuscular electric actuator consists of a modified graphene oxide/silicon rubber basement membrane, graphite/silicon rubber electrodes fixed on two sides of the basement membrane, a lead and a high-voltage pulse electric signal; the base film is prepared by doping graphene oxide modified by 3-isocyanatomethylene-3, 5, 5-trimethylcyclohexyl isocyanate (IPDI) in silicon rubber, and the graphite/silicon rubber electrode is prepared by doping graphite in the silicon rubber and is fixed on two sides of the base film.

2. The method of preparing an electronic artificial muscular electric actuator as claimed in claim 1, wherein: the thickness of the basement membrane is 0.2-0.5mm, and the thickness of the graphite/silicon rubber electrodes on the two sides of the basement membrane is 0.03-0.08 mm.

3. The method of preparing an electronic artificial muscular electric actuator as claimed in claim 1, wherein: the elastic modulus of the basement membrane is 0.5-5MPa, and the dielectric constant of the basement membrane is 2.2-4.5.

4. The method of preparing an electronic artificial muscular electric actuator as claimed in claim 1, wherein: the preparation method of the modified graphene oxide/silicon rubber base membrane solution in the step (2) is as follows: dispersing 1.44mg of dried modified graphene oxide into 4g of n-heptane solution by ultrasonic treatment, then uniformly mixing 12g of 186 silicon rubber and 18g of n-heptane solution, adding the modified graphene oxide powder mixed in n-heptane into the mixed solution of n-heptane and silicon rubber, adding 1.2g of cross-linking agent, stirring with a PMMA rod for 30min to uniformly disperse, and placing in a 0.8MPa vacuum container for 5-7min to remove bubbles to obtain the modified graphene oxide/silicon rubber base membrane solution.

5. The method of preparing an electronic artificial muscular electric actuator as claimed in claim 1, wherein: the preparation method of the modified graphene oxide/silicon rubber base film in the step (3) is as follows: pouring the prepared graphene oxide/silicon rubber solution into an organic glass mold, placing the organic glass mold in a vacuum drying oven, setting the temperature at 60 ℃ for 280min, and curing to form a film to obtain the graphene oxide/silicon rubber base film.

6. The method of preparing an electronic artificial muscular electric actuator as claimed in claim 1, wherein: and (4) edge cutting treatment is carried out on the graphene oxide/silicon rubber basement membrane, isometric biaxial stretching is carried out, the deformation amount of the basement membrane reaches 70%, and the pre-stretched basement membrane is placed into a vacuum oven at 80 ℃ and heated for 240 min.

7. The method of preparing an electronic artificial muscular electric actuator as claimed in claim 1, wherein: the preparation method of the graphite/silicon rubber electrode solution in the step (5) is as follows: adding graphite powder into silicon rubber, adding a cross-linking agent and n-heptane, and uniformly stirring for later use; wherein the mass ratio of the graphite powder, 186 silicon rubber, the cross-linking agent and n-heptane is 5:10:1: 8.

8. Use of an electronic artificial muscular electric actuator obtained by the production method according to any one of claims 1 to 7 in a finger drive device, characterized in that: the finger driving device comprises a support (1), an electronic type artificial muscle electric actuator (2), a rope (3), a pulley (4) and a ring (5), one end of the rope is connected with the electronic type artificial muscle electric actuator, the other end of the rope is connected with the ring through the pulley, the pulley is arranged on the support, and a lead of the electronic type artificial muscle electric actuator is connected with an external high-voltage pulse electric signal.