CN105355776B - Electro-active material and preparation method thereof and the actuator using the electro-active material - Google Patents

Abstract

The invention discloses an electric actuation material, comprising a first material layer, a second material layer and an adhesive layer between the first material layer and the second material layer, the first material layer, the adhesive layer The first material layer is stacked with the second material layer, and the thermal expansion coefficients of the first material layer and the second material layer are different, the first material layer is carbon nanotube paper, and the second material layer is a polymer film. The curling electric actuator based on this electric actuator material has the characteristics of simple preparation process, large-scale preparation in a short time, flexibility, etc., and has the advantages of rapid response, large deformation range, and curling deformation with a bending angle of more than 360°. , outperforming the same type of actuators reported so far.

Description

Electric actuation material and its preparation method and actuator using the same

technical field

The invention relates to the field of electric actuation materials, in particular to an electric actuation material, a preparation method thereof and an actuator using the electric actuation material.

Background technique

The working principle of the actuator is to convert other energy into mechanical energy. There are three ways to achieve this conversion: through electrostatic field into electrostatic force, that is, electrostatic drive; through electromagnetic field into magnetic force, that is, magnetic drive; using materials Thermal expansion or other thermal properties effect the conversion of energy, ie thermal actuation.

Electrostatically driven actuators generally include two electrodes and an electric actuation element arranged between the two electrodes. Quantity and electronegativity to control the relative movement of the electro-actuating element between the electrodes. However, since the electrostatic force is inversely proportional to the square of the distance between the capacitor plates, the electrostatic force is generally significant only when the distance between the electrodes is small, and the requirement for this distance makes the structural design of the actuator more complicated.

Magnetically driven actuators generally include two magnetic poles and an electric actuating element arranged between the two magnetic poles. , but the disadvantage of magnetic drive is the same as that of electrostatic drive, that is, due to the limited range of action of the magnetic field, the upper and lower surfaces of the electric actuator must keep a small distance. The design of this structure requires strict requirements and also limits the actuator. application range.

The thermally driven actuator overcomes the shortcomings of the above-mentioned electrostatically driven and magnetically driven actuators. As long as the actuator structure can ensure a certain amount of heat energy, it can produce corresponding deformation. In addition, compared with the electrostatic force and magnetic field force, The thermal driving force is greater. An electrothermal actuator is disclosed in the prior art, please refer to "Progress of Micro-Electrothermal Actuator Based on Thermal Expansion Effect", Kuang Yining et al., Electronic Devices, vol22, p162 (1999). The electrothermal actuator uses two pieces of metal with different thermal expansion coefficients to form a double-layer structure as an electrostrictive element. When the current is applied and heated, because the thermal expansion of one piece of metal is greater than that of the other, the bimetallic piece will have a smaller thermal expansion. One side is bent. However, since the above-mentioned electric actuator material adopts a metal structure, its flexibility is poor, resulting in a slow thermal response speed of the entire electrothermal actuator.

Carbon-based materials are materials that have attracted much attention in recent years, especially carbon nanotubes. Carbon nanotubes have many excellent properties and can be applied in many fields. Carbon nanotubes are seamless hollow tubes rolled from graphite sheets. Due to the quantum confinement of electrons in carbon nanotubes, electrons can only move along the axial direction of carbon nanotubes in graphite sheets, so carbon nanotubes Exhibits unique electrical and thermal properties. Research and test results show that the average conductivity of carbon nanotubes can reach 100-2000S/m (Siemens/meter). In addition, carbon nanotubes also have excellent mechanical properties, such as high strength and modulus.

Carbon nanotube paper, as the name suggests, is a macroscopic material that prepares carbon nanotubes into thin films and paper through several steps. At present, the preparation method of carbon nanotube paper mainly includes basic steps such as selection of carbon nanotubes, solution dispersion, suction filtration and drying molding. Due to the need to disperse the carbon nanotubes in the solution first, the orientation of the carbon nanotubes in the carbon nanotube paper prepared by this preparation method cannot be determined, and the density of the carbon nanotubes in the carbon nanotube paper is low, which greatly affects the carbon nanotubes. properties of nanotube paper, and are not conducive to mass production. A new method for preparing carbon nanotube paper is to extract carbon nanotube films from carbon nanotube arrays by dry method, and then stack the films layer by layer to form carbon nanotube paper with preferred orientation arrangement.

The existing carbon nanotube-based electric actuators still have the following disadvantages:

1. The required driving voltage is relatively high, and tens of volts are still required for driving;

2. The response time is long, requiring tens of seconds or even minutes;

3. It is usually prepared by in-situ polymerization or requires solution assistance, which takes a long time and is not conducive to industrial production;

4. The amount of deformation of the actuator still needs to be further improved.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, provide a flexible electric actuator material and a rapid preparation method, and an electric actuator driven by low voltage, extremely fast in thermal response, and large in deformation.

The technical scheme adopted in the present invention is:

An electrically actuated material comprising a first material layer, a second material layer, and an adhesive layer between the first material layer and the second material layer, the first material layer, the adhesive layer, and the second The material layers are stacked, and the thermal expansion coefficients of the first material layer and the second material layer are different, the first material layer is carbon nanotube paper, and the second material layer is a polymer film.

The first material layer and the second material layer are stacked and arranged by bonding and pressing through the adhesive layer.

The thickness of the first material layer is 0.1 μm˜1 mm, the thickness of the second material layer is 1 μm˜5 mm, and the thickness of the adhesive layer 14 is 1 μm˜0.5 mm.

The carbon nanotube paper includes at least one layer of carbon nanotube film. The carbon nanotube film includes a plurality of carbon nanotubes, the plurality of carbon nanotubes are connected end-to-end through van der Waals force, and the axial directions of the plurality of carbon nanotubes are basically aligned along the same direction.

The adhesive of the adhesive layer is one or a combination of photocurable adhesives, heat curable adhesives, and non-conductive curable adhesives.

The binder of the binder layer is one or a combination of polyvinyl alcohol, ethyl α-cyanoacrylate, acrylic glue, light-curable glue and heat-curable glue.

The second material layer is biaxially stretched polypropylene, polypropylene, polyethylene, silicone rubber, fluorosilicone rubber, polymethyl methacrylate, polyethylene terephthalate, polyurethane, epoxy resin , Polyethylacrylate, polybutylacrylate, polystyrene, polybutadiene and polyacrylonitrile or a combination of several.

The thermal expansion coefficient of the carbon nanotube paper is smaller than the thermal expansion coefficient of the polymer film

The invention discloses a preparation method of an electric actuation material, which comprises the following steps:

Step 1: forming a first material layer made of carbon nanotube paper;

Step 2: forming a second material layer composed of a polymerized polymer film;

Step 3: uniformly cover the adhesive used as the adhesive layer on the second material layer formed by the polymer film;

Step 4: Laminating and combining the first material layer made of carbon nanotube paper and the second material layer made of polymer film by bonding and pressing through the adhesive layer.

The method for forming the polymer film includes polycondensation reaction, polyaddition reaction, free radical polymerization reaction, anionic polymerization reaction and cationic polymerization reaction, and the corresponding method is selected according to the different types of polymer monomers in the second material layer to form the polymer film. film.

Methods for uniformly distributing the adhesive layer on the second material layer include spin coating, pulling and smearing.

The present invention also discloses a roll-type electric actuator, which includes a device using the above-mentioned electric actuation material, at least one first electrode and at least one second electrode, and the at least one first electrode and at least one second electrode spaced apart on the electrical actuation material and electrically connected to the electrical actuation material;

When the first electrode and the second electrode are energized, the curl-type electric actuator bends toward the surface of the carbon nanotube paper.

The curling electric actuator realizes curling deformation with a bending angle larger than 360°.

The present invention adopts the above technical solutions, and the beneficial effect of the present application is that compared with the prior art, the electric actuation material has the following advantages: first, the preparation process is simple, the production time is short, and it can be prepared on a large scale in a short time; Second, flexible polymer and carbon nanotube paper are used as the main materials, so that the electric actuator is flexible and has good electrical and mechanical properties of carbon nanotubes; third, the electric actuator responds quickly , the deformation range is large, and the curling deformation with a bending angle greater than 360° can be realized, and the performance is far superior to that of the same type of actuator reported so far.

Description of drawings

The present invention will be described in further detail below in conjunction with accompanying drawing and specific embodiment;

Fig. 1 is a schematic structural view of the electro-actuating material of the present invention;

Fig. 2 is the structural representation of the coiled electric actuator of the present invention;

Fig. 3 is a schematic diagram of the actuation effect of the coiled electric actuator of the present invention after being energized.

Detailed ways

Example 1:

As shown in one of FIG. 1 to FIG. 3 , the present invention provides an electro-actuation material 10 comprising a first material layer 13 , an adhesive layer 14 and a second material layer 15 . The first material layer 13 , the adhesive layer 14 , and the second material layer 15 have the same length and width, and they are stacked. The thermal expansion coefficients of the first material layer and the second material layer are different.

The first material layer 13 is carbon nanotube paper. The carbon nanotube paper includes at least one layer of carbon nanotube film. When the carbon nanotube paper 13 includes a multilayer carbon nanotube film, the number of layers of the carbon nanotube film is not limited, and the plurality of carbon nanotube films can be Arranged side by side or stacked, and the film contains a plurality of carbon nanotubes, the plurality of carbon nanotubes are basically parallel to each other and parallel to the surface of the carbon nanotube paper. Specifically, a plurality of carbon nanotubes in the carbon nanotube paper are connected end to end by van der Waals force, and the axial directions of the plurality of carbon nanotubes are basically aligned along the same direction.

In this embodiment, the thickness of the first material layer 13 may be 0.1 μm˜1 mm.

Preferably, the carbon nanotube paper has a thickness of 7 μm and contains 400 carbon nanotube film layers.

The adhesive of the adhesive layer 14 can be one or more of polyvinyl alcohol, ethyl α-cyanoacrylate, acrylic adhesive, light curing adhesive, heat curing adhesive, non-conductive curing adhesive, etc. Combinations of, but not limited to, these materials.

In this embodiment, the thickness of the adhesive layer 14 may be 1 μm˜0.5 mm.

Preferably, the adhesive is acrylic glue with a thickness of 5 μm.

The second material layer 15 is a polymer, which can be biaxially stretched polypropylene, polypropylene, polyethylene, silicone rubber, fluorosilicone rubber, polymethyl methacrylate, polyethylene terephthalate, polyethylene One or a combination of polyurethane, epoxy resin, polyethylacrylate, polybutylacrylate, polystyrene, polybutadiene, polyacrylonitrile, etc., but not limited to these materials.

In this embodiment, the thickness of the second material layer may be 1 μm˜5 mm.

Preferably, the polymer is biaxially oriented polypropylene with a thickness of 35 μm.

The thickness ratio of the carbon nanotube paper in the first material layer 13 to the polymer film in the second material layer 15 may be 1:2-1:200, preferably, the thickness ratio is 1:5-1:10.

The preparation method of the electric actuation material 10 of the present invention comprises the following steps:

Step 1: forming a first material layer made of carbon nanotube paper;

The carbon nanotube paper as described in step 1, the method for preparing the carbon nanotube paper is to grow carbon nanotube arrays by chemical vapor deposition, and then use the method of direct film drawing to extract carbon nanotubes from the carbon nanotube arrays Finally, the carbon nanotube film is stacked layer by layer to obtain carbon nanotube paper.

Step 2: forming a second material layer composed of a polymerized polymer film;

For the polymer film described in step 2, the method for forming the polymer film is divided into polycondensation reaction, polyaddition reaction, free radical polymerization reaction, anionic polymerization reaction or cationic reaction according to the type of polymer monomer in the second material layer. Polymerization. In this embodiment, a polycondensation reaction is used to form a polypropylene film, and then the polypropylene film is biaxially stretched to form a biaxially oriented polypropylene film.

Step 3: uniformly cover the adhesive used as the adhesive layer on the second material layer formed by the polymer film;

For the adhesive layer described in step 3, methods for evenly distributing the adhesive layer on the second material layer include spin coating, pulling, and smearing, but are not limited to the above methods. In this embodiment, the acrylic glue is evenly covered on the biaxially oriented polypropylene film by a pulling method to form an adhesive layer.

Step 4: Laminating and combining the first material layer made of carbon nanotube paper and the second material layer made of polymer film by bonding and pressing through the adhesive layer.

The present invention provides a roll-type electric actuator 100 , which includes a first electrode 11 , a second electrode 12 and the electric actuation material 10 .

The first electrode 11 and the second electrode 12 are spaced apart and fixed on the surface of the first material layer 13 . In this embodiment, the first electrode 11 and the second electrode 12 are electrically connected to the first material layer 13 for inputting external current into the first material layer 13 .

In this embodiment, the first electrode 11 and the second electrode 12 can be rod-shaped, strip-shaped, block-shaped or other two-dimensional and three-dimensional shapes, and the cross-sectional shape can be circular, square, trapezoidal, triangular, polygonal or other irregular shapes. The materials of the first electrode 11 and the second electrode 12 can be selected from gold, silver, copper, copper alloy, platinum, platinum alloy, tellurium, steel, iron, zinc, tungsten, molybdenum, aluminum oxide, indium tin oxide, zinc oxide , conductive polymers, graphite or other conductive carbon materials, other conductive materials that can be used in solids, etc.

Preferably, the shape is strip, and the material is copper.

In this embodiment, the material of the first electrode 11 and the second electrode 12 is copper, the shape is strip shape, the width is 1mm, the length is 18mm, and the spacing is 70mm; the first material layer 13 is carbon nanometer Tube paper with a length of 70 mm, a width of 18 mm, and a thickness of 7 μm; the adhesive layer 14 is acrylic glue, a length of 70 mm, a width of 18 mm, and a thickness of 5 μm; the polymer of the second material layer 15 is bidirectional Stretched polypropylene with a length of 70 mm, a width of 18 mm and a thickness of 35 μm.

When the roll-type electric actuator 100 is applied, a voltage is applied to both ends of the first material layer 13 of the roll-type electric actuator 100 through the first electrode 11 and the second electrode 12, and the current can pass through the first electrode 11 and the second electrode 12. A material layer 13 is transported. Due to the high thermal conductivity of the first material layer 13 and the Joule heating effect, the temperature of the second material layer 15 rises rapidly, and the heat spreads from the surrounding of the first material layer 13 to the entire electric actuator rapidly. The thermal expansion coefficients between the first material layer 13 and the second material layer 15 are different, so that the elongated lengths of the two layers of materials are not consistent, and the first material layer 13 and the second material layer 15 are tightly bonded together through the adhesive layer, Therefore, relative sliding will not occur when heated and elongated, and because the thermal expansion coefficient of the first material layer 13 is small, the crimp-type electric actuator 100 is bent toward the side of the first material layer 13 .

In addition, in this embodiment, a power supply voltage is applied to both ends of the coiled electric actuator 100 through wires, and the degree of deformation of the coiled electric actuator 100 is measured.

In this embodiment, when no power is applied, the initial bending angle of the coiled electric actuator 100 is 21° (the radius of curvature is 0.06cm ^-1 ); After 10 s, the bending angle is 389° (the radius of curvature is 1.03cm ^-1 ); the bending angle difference before and after electrification is greater than 360°, realizing curl deformation. Compared with the current electric actuator of the same type, its deformation performance is particularly excellent, the response speed is fast, and it has the advantages of flexibility, lightness, and large-scale preparation in a short time.

The preparation method of the coiled electric actuator 100 of the present invention comprises the following steps:

Step 1: forming a first material layer made of carbon nanotube paper;

The carbon nanotube paper as described in step 1, the method for preparing the carbon nanotube paper is to grow carbon nanotube arrays by chemical vapor deposition, and then use the method of direct film drawing to extract carbon nanotubes from the carbon nanotube arrays Finally, the carbon nanotube film is stacked layer by layer to obtain carbon nanotube paper.

Step 2: forming a second material layer composed of a polymerized polymer film;

For the polymer film described in step 2, the method for forming the polymer film is divided into polycondensation reaction, polyaddition reaction, free radical polymerization reaction, anionic polymerization reaction or cationic reaction according to the type of polymer monomer in the second material layer. Polymerization. In this embodiment, a polycondensation reaction is used to form a polypropylene film, and then the polypropylene film is biaxially stretched to form a biaxially oriented polypropylene film.

Step 3: uniformly cover the adhesive used as the adhesive layer on the second material layer formed by the polymer film;

For the adhesive layer described in step 3, methods for evenly distributing the adhesive layer on the second material layer include spin coating, pulling, and smearing, but are not limited to the above methods. In this embodiment, the acrylic glue is evenly covered on the biaxially oriented polypropylene film by a pulling method to form an adhesive layer.

Step 4: Laminating and combining the first material layer made of carbon nanotube paper and the second material layer made of polymer film by bonding and pressing through the adhesive layer.

Step five: use conductive glue to combine the two electrodes with the carbon nanotube paper respectively to form a coiled electric actuator.

In addition, those skilled in the art can also make other changes within the spirit of the present invention. Of course, these changes made according to the spirit of the present invention should be included within the scope of protection claimed by the present invention.

Claims (10)

1. An electrically actuated material, characterized in that it comprises a first material layer, a second material layer and an adhesive layer between the first material layer and the second material layer, the first material layer, The adhesive layer and the second material layer are stacked, and the thermal expansion coefficients of the first material layer and the second material layer are different, the first material layer is carbon nanotube paper, and the second material layer is a polymer film. 2. The electric actuation material according to claim 1, characterized in that: the first material layer and the second material layer are stacked in a manner of bonding and pressing through an adhesive layer; the first material layer The thickness of the layer is 0.1 μm-1 mm, the thickness of the second material layer is 1 μm-5 mm, and the thickness of the adhesive layer 14 is 1 μm-0.5 mm. 3. The electric actuation material according to claim 1, characterized in that: the carbon nanotube paper comprises at least one layer of carbon nanotube film, the carbon nanotube film comprises a plurality of carbon nanotubes, the plurality of carbon nanotubes The carbon nanotubes are connected end to end by van der Waals force, and the axial directions of the plurality of carbon nanotubes are arranged along the same direction; One or more combinations of cured glue; the second material layer is biaxially stretched polypropylene, polypropylene, polyethylene, silicone rubber, fluorosilicone rubber, polymethyl methacrylate, polyethylene terephthalate One or a combination of ethylene glycol formate, polyurethane, epoxy resin, polyethylacrylate, polybutylacrylate, polystyrene, polybutadiene and polyacrylonitrile. 4. The electro-actuating material according to claim 1, wherein the thermal expansion coefficient of the carbon nanotube paper is smaller than the thermal expansion coefficient of the polymer film. 5. A method for preparing an electrically actuated material, comprising the steps of: Step 1: forming a first material layer made of carbon nanotube paper; Step 2: forming a second material layer composed of a polymerized polymer film; Step 3: uniformly cover the adhesive used as the adhesive layer on the second material layer formed by the polymer film; Step 4: Laminating and combining the first material layer made of carbon nanotube paper and the second material layer made of polymer film by bonding and pressing through the adhesive layer. 6. The preparation method of a kind of electric actuation material according to claim 5, is characterized in that: the method for forming described polymer thin film comprises polycondensation reaction, polyaddition reaction, radical polymerization reaction, anionic polymerization reaction and cationic polymerization Reaction, according to the different types of polymer monomers in the second material layer, select a corresponding method to form the polymer film. 7 . The method for preparing an electric actuation material according to claim 5 , wherein the method for uniformly distributing the adhesive layer on the second material layer includes a spin coating method, a pulling method and a smearing method. 8. A coiled electric actuator, characterized in that it comprises an electric actuating material according to any one of claims 1 to 7, at least one first electrode and at least one second electrode, the at least one The first electrode and at least one second electrode are arranged on the electric actuation material at intervals, and are electrically connected with the electric actuation material. 9. A kind of rolling type electric actuator according to claim 8, it is characterized in that: when described first electrode and second electrode are energized, described rolling type electric actuator is to carbon nanotube paper The surface direction is curved. 10. A coiled electric actuator according to claim 8, characterized in that: said coiled electric actuator realizes coiled deformation with a bending angle greater than 360°.