AT525092A4 - Dielectric soft actuator - Google Patents

Abstract

A method for producing and operating a dielectric soft actuator, and a dielectric soft actuator comprising two intermediate layers (1, 2) acting as dielectrics, the intermediate layers (1, 2) being elastically deformable to actuate the actuator, the intermediate layers (1 , 2) are each provided with an electrode layer (3, 4, 5) on both sides, the two intermediate layers (1, 2) being coupled to one another, in particular shear-resistant, in such a way that a different change in length of the intermediate layers (1, 2) causes a curvature of the Actuator causes along a curved contour (6), wherein the intermediate layers (1, 2) and the electrode layers (3, 4, 5) are each made of a material applied by additive manufacturing, in particular 3D-printed material.

Description

Dielectric soft actuator

The invention relates to a dielectric soft actuator, a method for producing a dielectric soft actuator and a method for operating a dielectric soft actuator.

The basic principle of dielectric soft actuators, which are usually referred to as elastomer actuators, has been known for a long time. According to the state of the art, an elastomer film is provided on both sides with flat or foil-like electrodes. If an actuator voltage is now applied to the two electrodes, the elastomer film is compressed transversely to its main direction of extension and expands by transverse contraction along its main direction of extension. If the tension is interrupted, the elastomer film automatically returns to its original position

original shape back.

According to the prior art, a stack of a large number of such actuators can be used in order to bring about a sufficient change in length transversely to the main direction of extent of the layers in the event of a current-induced contraction. However, this construction is very complex, since a large number of actuators are required for a relatively small movement.

Alternatively, it is also known to attach a single actuator to one side of a flexible plate, but which does not undergo any change in length as the actuator contracts. Due to the different expansion along the main direction of extent of the two components, the arrangement is curved. The effect that causes the curvature can be compared to the kinematic functioning of a bimetallic strip. With these constructions, however, in practice it is not possible to ensure sufficient accuracy of movement. Creeping or permanent bending of the actuator can occur during prolonged operation, making it difficult to return to the zero position. In addition, elastomer actuators with a plate-like structure are soft components that can only absorb very small forces.

Another disadvantage of conventional dielectric elastomer actuators is that they are expensive to manufacture. In a first step, an elastomer film has to be produced and cut to size. In a next step, the elastomer film has to be provided with two flat electrodes. This is done either by coating or by applying previously manufactured electrodes.

The object of the invention is now to provide a dielectric elastomer actuator which has improved efficiency. This includes in particular that the function of the elastomer actuator is improved. However, this preferably also includes that the production of the dielectric elastomer actuator can be made more efficient.

The object according to the invention is achieved in particular by the features of the independent patent claims.

The invention relates to a dielectric actuator, in particular a soft actuator, comprising two intermediate layers acting as dielectrics, the intermediate layers being elastically deformable to actuate the actuator, the intermediate layers each being provided with an electrode layer on both sides, the two intermediate layers being particularly shear-resistant , are coupled to each other that a different change in length of the intermediate layers

Causes curvature of the actuator along a curvature contour.

It is preferably provided that the intermediate layers and the electrode layers are each produced from a material that is applied, in particular 3D-printed, by additive manufacturing.

Provision is preferably made for the intermediate layers to be designed in such a way that they can be elastically deformed in order to actuate the actuator. In particular, when an actuator voltage is applied to the two electrode layers of the respective intermediate layer, they are pressed together by the electrode layers and thereby change their length.

If necessary, it is provided that the intermediate layers and the electrode layers are layers formed consecutively one on top of the other by additive manufacturing, in particular 3D-printed layers.

If necessary, it is provided that at least one electrode layer, preferably all electrode layers, each consist of at least one 3D-printed, electrically conductive

Conductor strip is formed or are.

If necessary, it is provided that the conductor strip is in particular a strip applied by a 3D print head.

If necessary, it is provided that the at least one conductor strip has several

Has main conductor and several connecting conductors.

If necessary, it is provided that the main conductors transverse to the curvature contour and

next to each other, in particular spaced apart, run.

If necessary, provision is made for the connecting conductors to electrically connect the main conductors

connect conductively.

If necessary, it is provided that the conductor strip runs in a meandering or serpentine manner.

Optionally, it is provided that the at least one conductor strip

kinematic structure forms.

If necessary, it is provided that the kinematic structure has different flexural rigidities along different directions.

If necessary, it is provided that the kinematic structure of the course

Curvature contour and the curvature properties of the actuator determined.

If necessary, it is provided that the intermediate layers each consist of at least

a 3D-printed, dielectrically acting intermediate layer strips are formed.

If necessary, it is provided that the intermediate layer strip or strips form an electrical insulating layer.

If necessary, it is provided that the intermediate layers each comprise a plurality of layers of intermediate layer strips that are 3D printed one on top of the other, in particular that the intermediate layers each have a thickness of more than 0.1 mm, in particular of more than 0.15 mm. It is preferably provided that the intermediate layers each have a thickness of less than 0.5 mm, in particular of

less than 0.2 mm.

The actuator can include the following components:

- a first intermediate layer provided on one side with a first electrode layer and on its other side with a second electrode layer,

- a second intermediate layer provided on one side with the second electrode layer and on its other side with a third electrode layer,

- Wherein the actuator preferably has only these or no further intermediate layers or electrode layers.

If necessary, it is provided that the first electrode layer is a 3D-printed layer, that the first intermediate layer has a 3D-

printed layer is that the second electrode layer is a layer 3D printed on the first intermediate layer, the second intermediate layer is a layer 3D printed on the second electrode layer, and the third electrode layer is a layer 3D printed on the second intermediate layer.

If necessary, it is provided that the second electrode layer acts as an electrode layer for the first intermediate layer and for the second intermediate layer

works.

If necessary, it is provided that the electrode layers and the intermediate layers together form a flat body.

If necessary, it is provided that the flat body is designed in the form of small plates, strips, plane or corrugated.

If necessary, it is provided that the effective direction of the actuator runs essentially transversely to the main direction of extent of the electrode layers, the intermediate layers and the flat body.

If necessary, it is provided that the electrode layers are formed from an electrically conductive material suitable for Filament3D printing, in particular from electrically conductive thermoplastic, for example from conductive TPU, from conductive PLA or from a filament provided with metal particles. Products available on the market include Eel 3D Printer Filament (90A) NinjaTek or Proto-Pasta — Composite PLA Filament —- ESD/Conductive — Black — 1.75 mm

to be named.

If necessary, it is provided that at least one intermediate layer or all intermediate layers are made of a dielectric material suitable for filament 3D printing, in particular of TPU, of a shape memory polymer (SMP), or of a polymer that is between two different operating temperatures

has its glass transition temperature, is formed or are. than those available on the market

Products can be named here, for example, TPU - NinjaFlex 3D Printer Filament (85A) or SMP - CONVENA polymers SMP 55 series filament.

If appropriate, provision is made for the electrode layers to be set up to attract one another by applying an electrical actuator voltage.

If necessary, it is provided that a heating device is provided, which is set up to heat the material of the intermediate layer(s) (via its

to heat the glass transition temperature.

If necessary, it is provided that at least one electrode layer, in particular the second electrode layer, is designed to heat the material of the intermediate layer(s) above its glass transition temperature by applying a heating voltage, whereby the electrode layer is part of the heating device and in particular forms the heating element of the heating device .

If necessary, provision is made for an electrical connection to be provided for each electrode layer, with the electrical connection preferably being made or manufactured from a material that is applied, in particular 3D-printed, by additive manufacturing.

is printed with the respective electrode layer in one operation.

If necessary, it is provided that a control device is provided, that the control device is electrically connected to the electrode layers in such a way that an actuator voltage is optionally applied between two electrode layers

can be used to selectively effect a change in length of an intermediate layer.

If necessary, it is provided that the control device is electrically connected to the electrode layers in such a way that at least one of the electrode layers heats the intermediate layers above their glass transition temperature.

In particular, the invention relates to a method for producing a dielectric

Soft actuator, with two intermediate layers acting as dielectrics are formed, which are each provided on both sides with an electrode layer, the two

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Intermediate layers are coupled to one another in such a way, in particular in a shear-resistant manner, that a different change in length of the intermediate layers causes a curvature

of the actuator causes along a curvature contour.

If necessary, provision is made for the intermediate layers and the electrode layers to be formed by additive manufacturing, in particular by 3D printing

will.

If necessary, provision is made for the intermediate layers and the electrode layers to be formed successively in layers on top of one another by additive manufacturing, in particular by 3D printing.

If necessary, it is provided that at least one electrode layer, preferably all electrode layers, are each formed from at least one 3D-printed, electrically conductive conductor strip, the conductor strip being in particular formed by a 3D

print head is applied.

If necessary, it is provided that a kinematic structure is formed by forming the at least one conductor strip, and that the course of the curved contour and the curved properties of the actuator are determined by the selection of the kinematic structure.

If necessary, it is provided that the intermediate layers each consist of at least

a 3D-printed, dielectrically acting interlayer strip.

If necessary, it is provided that the intermediate layer strip or strips form an electrical insulating layer.

If necessary, it is provided that the intermediate layers are each formed by several layers of intermediate layer strips that are 3D printed one on top of the other.

If necessary, it is provided that a first electrode layer is 3D printed, that a first intermediate layer is 3D printed on the first electrode layer, that

3D printing a second electrode layer onto the first interface layer, 3D printing a second interface layer onto the second electrode layer, and

that a third electrode layer is 3D printed on the second intermediate layer.

If necessary, it is provided that an electrical connection is provided for each electrode layer, with the electrical connection preferably being made from a material that is applied, in particular 3D-printed, by additive manufacturing

or is printed with the respective electrode layer in one operation.

In particular, the invention relates to a method for operating an actuator, in which it is provided that an electrical actuator voltage is applied between a first electrode layer formed by additive manufacturing and a second electrode layer formed by additive manufacturing, with application of the actuator voltage: the first electrode layer and attracting the second electrode layer, thereby compressing a first additively manufactured intermediate layer disposed between the two electrode layers, thereby increasing the length of the first intermediate layer relative to another second additively manufactured intermediate layer, and

the actuator curves along a curvature contour.

If necessary, it is provided that the electrical actuator voltage between the first electrode layer and the second electrode layer is then reduced or interrupted, that an electrical actuator voltage is applied between the second electrode layer and a third electrode layer formed by additive manufacturing, with application of the actuator voltage: the second Tighten the electrode layer and the third electrode layer, thereby compressing the second intermediate layer sandwiched between the two electrode layers, thereby increasing the length of the second intermediate layer relative to the first intermediate layer and causing the actuator to curve in the opposite direction.

If necessary, it is provided that, in order to actuate the actuator, at least one intermediate layer is actuated by actuating a heating device, in particular by applying

a heating voltage to at least one electrode layer, via which

Glass transition temperature is heated.

If necessary, it is provided that the actuator is strengthened in a curved state caused by attraction of two electrode layers by cooling the at least one intermediate layer to a temperature below the glass transition temperature of the material of the intermediate layer, in particular

that the cooling takes place by reducing or switching off the heating voltage.

Provision is preferably made for the intermediate layers and the electrode layers to be produced by additive manufacturing, preferably by a 3D printer. In particular, the actuator should preferably be produced by a filament 3D printer using the FFF or the FDM method. The 3D printer preferably processes two different filaments, with one of the filaments forming the electrode layers and the other filament forming the intermediate layers. Provision is preferably made for the actuator to be produced in a single printing operation of the 3D printer. In particular, this is possible if the 3D printer allows the printing of multiple materials.

Provision is preferably made for the print head of the 3D printer to output the print material in strip form. Provision is preferably made for the conductor strip to be a strip of the print head that is output directly from the print head. A conductor strip is preferably printed in one operation as a continuous conductor strip with uninterrupted conveyance of the print material. As a result, the conductivity can be improved along the entire conductor strip. The conductor strip preferably has a contour or a shape that is printed in a continuous process

can. In particular, the shape of the conductor strip can be meandering.

Due to its rigidity, the conductor strip forms a kinematic structure. By choosing the pattern in which the conductor strip is applied or arranged, the kinematic structure can have different stiffnesses in different directions

exhibit.

The main conductors are preferably arranged at a distance from one another and are connected to one another by the connecting conductors. In particular, the main conductors can be arranged in the form of ribs or running parallel to one another. As a result, the kinematic structure has a lower rigidity transversely to the course of the main conductors than along the main conductors, since the rigidity is reduced due to the spacing of the main conductors from one another between the main conductors. However, the course of the main conductor and the connecting conductor can be freely selected, so that the kinematic structure has the desired curvature properties of the actuator

determined or co-determined.

In particular, the conductor strip can be ladder-shaped, meander-shaped, rib-shaped or

be formed in any other shape.

Optionally, the conductor strip can have a width of 0.1 in all embodiments

have up to 1mm.

Optionally, the main conductors in all embodiments a distance of

Have 0.1 to 1mm.

If necessary, the main conductors in all embodiments can have a length of 5 to 100 mm, in particular a length of 5 to 50 mm.

As an example size, for example, an actuator with a size of about

70x40 mm can be mentioned.

The intermediate layers are preferably applied using a 3D print head. The intermediate layers can also be formed from strips, with the sections of the intermediate layer strips preferably overlapping one another or directly adjoining one another in order to form a continuous intermediate layer. In particular, the intermediate layer can comprise a plurality of intermediate layer strips lying one on top of the other. For example, the intermediate layer can be formed by two, three or more intermediate layer strips printed one on top of the other. The interlayer strips of

different layers can cross each other so that an im

Substantially continuous uninterrupted intermediate layer is formed. The intermediate layer has the necessary insulator properties due to a continuous, uninterrupted structure, so that a voltage breakdown is prevented

will.

According to a preferred embodiment, the actuator has five layers, in particular three electrode layers and two intermediate layers, the

Layers are arranged alternately.

The actuator is preferably designed in the form of small plates, strips, flat or corrugated. In all of the embodiments, the actuator preferably has an extent that is many times greater along the main direction of extent than transversely to the main direction of extent. In this configuration, it is possible to cause the actuator to bend or curve along a curved contour by changing the length of one of the intermediate layers. The Curvature Movement

takes place transversely to the main extension direction of the actuator.

The intermediate layers can be designed as elastomer layers or at least act like elastomer layers in a certain operating range. The respective intermediate layer is elastically deformable for active actuation of the actuator by applying an actuator voltage.

If necessary, it can be provided that at least one intermediate layer is made of a material that has its glass transition temperature in the operating temperature range of the actuator. In particular, a heating device can be provided which heats the intermediate layer or its material above the glass transition temperature when the heating arrangement is actuated. If the heating device is deactivated, the material can cool down again to a temperature which is below the glass transition temperature. This effect can be used to adapt or select the elasticity properties or the rigidity of the intermediate layers. If the temperature of the material of the intermediate layer is above the glass transition temperature, the actuator can act as a dielectric elastomer actuator. If the temperature of the interlayers is below the

Glass transition temperature, the intermediate layer is stiffened and its shape is essentially fixed. The shape of the actuator can be defined in the basic position

but also in a curved shape modified from the basic position.

One of the electrode layers preferably acts in a synergetic manner on the one hand as an electrode of the actuator and on the other hand as a heating element of the heating device.

Provision is preferably made for those electrode layers which are used exclusively as an electrode for the dielectric contraction to have only a single electrical connection. A continuous electrode strip preferably runs from this electrical connection along the electrode layer.

Provision is preferably made for that electrode layer which acts as a heating element of the heating device to have two electrical connections. To act as a heating element, the heating voltage is applied between these two terminals of the electrode layer. The heating voltage is, for example, in the range from 10 V to 200 V, preferably up to 150 V, in particular up to 130 V. The actuator voltage, which is only applied to one connection, is in the range from 200 V to 5 kV, for example.

Heating the material of the intermediate layer above the glass transition temperature is one way of changing the properties, in particular the strength properties, of the intermediate layer. Other conventional means of changing the material, such as pressure or magnetic fields, can also be used

come. Preferably, the material of the intermediate layer is a thermoplastic polymer with a glass transition temperature that is above ambient temperature, in particular

is above 20°C.

In particular, suitable materials for forming the intermediate layer should be as follows

have properties:

- a high dielectric constant to allow a good conversion of the electrical voltage to a mechanical force;

- A good electrical voltage breakdown strength or a good insulator effect;

- 3D printability;

- Optionally, a change in stiffness with the glass transition;

- Optionally, a glass transition temperature that is within the operating range of the actuator.

- a low modulus of elasticity in the softened, elastomeric state.

For example, a conventional shape memory polymer, ie a so-called shape memory polymer, can be used.

To actuate the actuator, an actuator voltage is applied between two electrode layers. The electrode layers preferably each comprise a large number of main conductors which are connected to one another by connecting conductors. The main conductors of the two electrode layers acting on an intermediate layer can be arranged essentially congruently one above the other. As an alternative or in addition, main conductors can also be arranged offset from one another. In particular, the main conductors of one electrode layer can be offset and in particular offset parallel to the main conductors of the further electrode layer of an intermediate layer. Due to this offset, the homogeneity of the electric field

be improved.

The invention is further described below with reference to figures.

FIGS. 1a and 1b show schematic views of an actuator in different operating positions.

2 shows a schematic plan view of an intermediate layer.

FIGS. 3 and 4 show two different designs of an electrode layer in a highly simplified, schematic illustration.

Unless otherwise indicated, the reference numbers correspond to the following components: first intermediate layer 1, second intermediate layer 2, first electrode layer 3, second electrode layer 4, third electrode layer 5, curved contour 6, conductor strip 7, main conductor 8, connecting conductor 9, main extension direction 10, heating device 11, electrical connection 12, interlayer strip 13.

1a shows a schematic view of an actuator or soft actuator, which is designed in particular as a dielectric elastomer actuator or at least acts like a dielectric elastomer actuator. This has a first intermediate layer 1 and a second intermediate layer 2 . The intermediate layers 1, 2 are each provided with electrode layers 3, 4, 5 on both sides. In particular, the first intermediate layer 1 has a first electrode layer 3 on one side and a second electrode layer 4 on its other side. The second intermediate layer 2 is also provided with an electrode layer on both sides. In the present embodiment, the second intermediate layer 2 is provided with the second electrode layer 4 on one side and with a third electrode layer 5 on the other side. As a result, the second electrode layer 4 acts as an electrode layer for the first intermediate layer 1 and for the second intermediate layer 2. However, it also corresponds to the idea of the invention that the central electrode layer is formed by two electrode layers, with each intermediate layer being assigned its own electrode layer.

The first intermediate layer 1 and the second intermediate layer 2 are connected or coupled to one another, this connection taking place in particular via an electrode layer.

In all of the embodiments, the layers of the actuator are preferably connected to one another over a large area, with this connection preferably being an integral connection that is formed by printing the layers on top of one another with a 3D printer.

The position shown is, for example, a position in which no actuator voltage is applied to the electrode layers 3, 4, 5. If an actuator voltage is now applied between the second electrode layer 4 and the third electrode layer 5, the actuator is curved along the curved contour 6, as indicated by the dashed contour. The curvature contour 6 can be changed or set in particular by selecting the electrical actuator voltage. By applying the actuator voltage as shown in Fig. 1a, the second intermediate layer 2 is clamped between its two electrode layers, i.e. between the second electrode layer 4 and the third electrode layer 5, whereby the length along the main extension direction 10 increases due to transverse contraction. Since an extension of the first intermediate layer 1 does not occur in this case, the actuator curves. If the actuator voltage is reduced or set to zero, the second intermediate layer 2 returns to its original position and the actuator is again in its starting position.

FIG. 1b shows the same schematic representation of the actuator as FIG. 1a. However, in FIG. 1 b the actuator voltage is applied to the first intermediate layer 1 , which means that it acts between the first electrode layer 3 and the second electrode layer 4 . In this case, the first intermediate layer 1 is pressed together by the two electrode layers 3, 4 and their length in the direction of main extension 10 is increased. As a result, the actuator can be curved in the opposite direction, as indicated by the dashed contour.

The production of the 5-layer unit described is preferably possible using a conventional FFF 3D printer with two extruders. For production, it may be possible to use conventional 3D printing filaments that are already on the market. Soft TPU can optionally be used for the intermediate layer 1, 2 in all of the embodiments. For the electrode layer 3, 4, 5, electrically conductive TPU filament can optionally be used in all embodiments

be used.

The actuator can preferably be manufactured entirely using 3D printing and in an integral design without any further process steps.

In order to choose the rigidity of the electrode layers 3, 4, 5, they are preferably not designed as a full surface, but as spaced conductor strips 7. This makes it possible to increase the flexibility and thus the deformability of the electrode layers 3, 4, 5 compared to a full-surface design of the same electrode material

improve.

The dielectric intermediate layer 1, 2 is preferably made from several thinner layers in order to achieve better homogeneity in 3D printing. This increases the puncture resistance and subsequently the achievable movement amplitude compared to 3D-printed 1-layer membranes.

2 shows a schematic plan view of an intermediate layer 1, 2. This intermediate layer 1, 2 is preferably produced by additive manufacturing, in particular by 3D printing. 2 shows a possible structure of an intermediate layer 1, 2, which was produced by a filament 3D printer. In this case, an essentially continuous, uninterrupted layer is printed, which is formed by at least one intermediate layer strip 13 . The strands of the interlayer strip 13 are applied substantially face to face to prevent gaps between the interlayer strips 13 . The intermediate layer 1, 2 is preferably constructed in several layers, with several intermediate layer strips 13 or layers of intermediate layer strips 13 being placed one on top of the other. For example, two, three or more layers applied by a 3D printer can form an intermediate layer 1, 2.

3 shows a possible embodiment of an electrode layer 3, 4, 5 in a highly simplified representation. The electrode layer 3, 4, 5 comprises a conductor strip 7 which, in the present embodiment, extends in a meandering or serpentine manner in order to form the electrode layer 3, 4, 5. The conductor strip 7 comprises a plurality of main conductors 8 which are conductively connected to one another by connecting conductors 9 . In the present embodiment, the main conductors 8 run at a distance from one another and next to one another. In order to nevertheless establish an electrically conductive connection, the main conductors 8 are electrically connected by connecting conductors 9

conductively connected. In this embodiment, the main conductors 8 are electrically conductively connected at one point to the respective adjacent main conductor 8 . In the present embodiment, the main conductors 8 run in the form of ribs. As a result of this rib-shaped design, the electrode layer 3, 4, 5 has greater flexural rigidity along the course of the ribs than across the ribs. The configuration of the conductor strips 7 forms a kinematic structure that influences the flexural rigidity or the curvature behavior of the actuator. In addition, the electrode layer 3, 4, 5 has an electrical connection 12 to which the actuator voltage can be applied.

FIG. 4 shows a further embodiment of a possible configuration of an electrode layer in a highly simplified representation. The electrode layer 3, 4, 5 comprises a conductor strip 7 with main conductors 8 and connecting conductors 9. Similar to the embodiment in FIG. 3, the main conductors 8 run essentially at a distance from one another and next to one another. The connecting conductors 9 are provided for the electrical connection. A kinematic structure is formed by the shape of the conductor strips 7, which influences or determines the curvature properties of the actuator. However, the configuration according to FIG. 4 is not in the form of a meander or a snake, but in the form of a ladder. In particular, the conductor strip 7 comprises a plurality of main conductors 8 running parallel and spaced apart from one another and connecting conductors 9 running on both sides of the main conductors 8. In this embodiment, the main conductors 8 are electrically conductively connected to the respectively adjacent main conductor 8 at two points.

The electrode layer according to FIG. 4 comprises two electrical connections 12. To apply the actuator voltage, it is sufficient to apply this to an electrical connection 12, since the actuator voltage acts between two electrode layers. However, the electrode layer according to FIG. 4 is also designed as a heating element of a heating device 11 . By applying a heating voltage between the two electrical connections 12 of the same electrode layer 3, 4, 5, the conductor strip 7 or the electrode layer 3, 4, 5 can act as a heating element.

Alternatively it can be provided that as a heating element of the heating device

formed electrode layer 3, 4, 5 has a conductor strip 7 formed

3, but both ends of the conductor strip 7 have an electrical connection 12.

If necessary, the conductor strip 7 can also meander from a connection 12 to the opposite end of the electrode layer 3, 4, 5 -- and then

back to the other end to form the second connection 12 there.

In the following, exemplary steps for manufacturing the actuator are described:

First, a three-dimensional computer model of the actuator to be built can be created. As shown in the figures, the shape of the actuator can be plate-like or strip-like. In principle, however, such an actuator can have any shape and can also be part of a complex component. For example, the actuator can be used to make part of a device movable, with the device preferably also being a 3D-printed device. As a result, the device and the actuator can essentially be manufactured in one work step on a 3D printer.

As is usual with additive manufacturing, a printing material is applied in layers to obtain a desired shape. Basically, different additives

Manufacturing processes are applied.

However, a filament 3D printer is preferably used. To produce the configurations of the actuator shown in the figures, a first electrode layer 3 can be printed onto the printing bed or a support structure in a first step, and the first electrode layer 3 can be configured, for example, as shown in FIG. A continuous conductor strip 7 is preferably printed, which is designed to be electrically conductive in order to be able to form an electrode. The form in which the conductor strip 7 is applied defines a kinematic structure which subsequently influences or at least influences the bending properties of the actuator. For example, the conductor strips 7 or the main conductors 8 can be printed in the form of ribs, ie in particular parallel next to one another. The exact

The shape of the conductor strip 7 can be defined, for example, in the software that generates the control instructions for the 3D printer. When creating the first electrode layer 3, a connection 12 is preferably also printed at the same time. Once the first electrode layer 3 has been created, a first intermediate layer 1 can be printed on this first electrode layer 3 . For this purpose, however, a different material is generally used than for the electrode layer 3. The material for the intermediate layer 1 requires a low modulus of elasticity and dielectric properties for the actuator to be able to be actuated. The low modulus of elasticity does not have to be present over the entire temperature range, but only for the area in which the actuator is to be operated. To produce the first intermediate layer 1, an intermediate layer strip 13 is applied, which can also be created in a meandering or serpentine manner. In particular, a continuous uninterrupted layer should be formed to prevent voltage breakdown between the electrodes. Multiple layers of an intermediate layer strip 13 are preferably printed one on top of the other in order to create a continuous and

to obtain a sufficiently thick layer.

Once the first intermediate layer 1 has been created, a second electrode layer 4 can be printed on the first intermediate layer 1 . The second electrode layer 4 is preferably formed as shown in FIG. 4 . In particular, this electrode layer

two connections 12, which make it possible to apply a heating voltage in addition to the actuator voltage. If the heating voltage is applied, the conductor strip 7 of the second electrode layer 4 heats up.

Once the second electrode layer 4 has been created, the second intermediate layer 2 can be applied to this layer in a manner analogous to the first intermediate layer 1 . The third electrode layer 5 can subsequently be applied to the second intermediate layer 2, this being preferred, as in Fig. 3

shown, is formed. A preferred structure of the actuator is formed by this five-layer structure.

The connections of the electrode layers 3, 4, 5 are preferably also printed in one operation with the creation of these respective layers.

The material change of the filament of the 3D printer can either be done manually, or a 3D printer is used that allows an automatic material change.

If the actuator is part of another component or a device, the component can be built up beforehand or afterwards or at the same time using the 3D printer

will.

In the following, an exemplary method for operating an actuator

shown:

The actuator, as shown for example in FIGS. 1a and 1b, is in its zero position when no voltage is applied to the electrode layers 3,4,5. If the actuator is now to perform an actuator movement, an actuator voltage is applied between two layers, in particular between two electrode layers 3 , 4 , 5 lying on the same intermediate layer 1 , 2 . This actuator voltage pulls the two electrode layers 3, 4, 5 towards one another and the intermediate layer 1, 2 lying between them is pressed together.

The length of the intermediate layer 1, 2 changes along the main extension direction 10 as a result of transverse contraction. This change in length can also be carried out by the electrode layers 3, 4, 5, since these, as shown for example in Fig.

3 are shown in meandering or serpentine form.

During this movement, however, one of the electrode layers 3, 4, 5 remains without actuator voltage, with the result that the other intermediate layer is not squeezed and its length is also essentially not changed. The difference in length of the two intermediate layers causes the actuator to curve, with this effect being comparable to the effect of a bimetallic strip. If the actuator voltage is reduced or switched off, the actuator returns to its zero position. To then move the actuator in the opposite direction, the electrode layers 3, 4, 5 of the other intermediate layer with a

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Actuator voltage are supplied, so that the actuator curves in an analogous manner in the other direction.

A prerequisite for the actuator being able to be actuated is that at least one of the intermediate layers 1, 2 allows a low modulus of elasticity or elastic deformability under the pressure of the electrode layers 3, 4, 5. If a material is used for the intermediate layer 1, 2, which is either stiff or elastic in the operating range of the actuator, the intermediate layer 1, 2 must first be brought into its soft state for the actuator to move. If, for example, a material is used for the intermediate layer 1, 2 that has its glass transition temperature in the operating temperature range, a heating device 11 can be actuated in a first step, which brings the intermediate layers 1, 2 to a temperature above the glass transition temperature. The actuator can then be actuated as previously described. If the intermediate layer 1, 2 is subsequently cooled again, the position of the actuator can be fixed again. This fixation can be, for example, in the curved or in the zero

location.

If the fixation takes place by stiffening the intermediate layer 1, 2 in the curved position, the actuator can automatically return to the zero position when the intermediate layer 1, 2 is softened again. If necessary, this movement can be supported by applying an actuator voltage

Claims (1)

patent claims 1. Dielectric soft actuator, comprising two intermediate layers (1, 2) acting as dielectrics, - the intermediate layers (1, 2) being elastically deformable to actuate the actuator, - the intermediate layers (1, 2) each having an electrode layer on both sides (3, 4, 5), - the two intermediate layers (1, 2) being coupled to one another in such a way, in particular shear-resistant, that a different change in length of the intermediate layers (1, 2) causes a curvature of the actuator along a curvature contour (6) effected, characterized in that the intermediate layers (1, 2) and the electrode layers (3, 4, 5) are each made of a material applied by additive manufacturing, in particular 3D-printed material. 2. Actuator according to claim 1, characterized in that the intermediate layers (1, 2) and the electrode layers (3, 4, 5) are layers formed consecutively one on top of the other by additive manufacturing, in particular 3D-printed layers. 3. Actuator according to Claim 1 or 2, characterized in that at least one electrode layer (3, 4, 5), preferably all electrode layers (3, 4, 5), each consists of at least one 3D-printed, electrically conductive conductor strip (7) is or are formed, - wherein the conductor strip (7) is in particular a strip applied by a 3D print head. 4. Actuator according to Claim 3, characterized in that - the at least one conductor strip (7) has main conductors (8) and connecting conductors (9), - the main conductors (8) being transverse to the curved contour (6) and next to one another, in particular at a distance from one another, get lost, - And wherein the connecting conductors (9) electrically conductive the main conductors (8). connect, - In particular that the conductor strip (7) runs in a meandering shape. Actuator according to Claim 3 or 4, characterized in that - that the at least one conductor strip (7) forms a kinematic structure, - that the kinematic structure has different bending stiffnesses along different directions, - In particular, that the kinematic structure determines the course of the curvature contour (6) and the curvature properties of the actuator. Actuator according to one of Claims 1 to 5, characterized in that - that the intermediate layers (1, 2) are each formed from at least one 3D-printed, dielectrically acting intermediate layer strip (13), - and that the or each strip of interlayer (13) form an electrical insulating layer. Actuator according to Claim 6, characterized in that - that the intermediate layers (1, 2) each comprise a plurality of layers of intermediate layer strips (13) that are 3D printed one on top of the other, - in particular that the intermediate layers (1, 2) each have a thickness of more than 0.1 mm or more than 0.15 mm, - and optionally that the intermediate layers each have a thickness of less than 0.5 mm, in particular less than 0.2 mm. An actuator according to any one of claims 1 to 7, comprising: - a first intermediate layer (1) which is provided on one side with a first electrode layer (3) and on its other side with a second electrode layer (4), - a second intermediate layer (2) which is provided on one side with the second (4) electrode layer and on its other side with a third electrode layer (5), - Wherein the actuator preferably has only these or no further intermediate layers (1, 2) or electrode layers (3, 4, 5). 24/38 11. 12. 13. 24 — 61249 — Actuator according to Claim 8, characterized in that - that the first electrode layer (3) is a 3D printed layer, - that the first intermediate layer (1) is a layer 3D printed on the first electrode layer (3), - that the second electrode layer (4) is a layer 3D printed on the first intermediate layer (1), - that the second intermediate layer (2) is a 3D-printed layer on the second electrode layer (4), - and that the third electrode layer (5) is a 3D-printed layer on the second intermediate layer (2). Actuator according to Claim 8 or 9, characterized in that the second electrode layer (4) acts as an electrode layer for the first intermediate layer (1) and for the second intermediate layer (2). Actuator according to one of Claims 1 to 10, characterized in that - that the electrode layers (3, 4, 5) and the intermediate layers (1, 2) together form a flat body, - where the flat body can be plate-shaped, strip-shaped, flat or corrugated, - And that the direction of action of the actuator is essentially transverse to the main extension direction (10) of the electrode layers (3, 4, 5), the intermediate layers (1, 2) and the flat body. Actuator according to one of Claims 1 to 11, characterized in that the electrode layers (3, 4, 5) are made of an electrically conductive material suitable for filament 3D printing, in particular of electrically conductive thermoplastic, for example of conductive TPU, of conductive PLA or formed from a filament provided with metal particles. Actuator according to one of claims 1 to 12, characterized in that at least one intermediate layer or all intermediate layers (1, 2) made of a dielectric material suitable for filament 3D printing, in particular: 15 16 17 18 25 — 61249 — - made of TPU - made of a shape memory polymer, - or is or are formed from a polymer which has its glass transition temperature between two different operating temperatures. Actuator according to one of Claims 1 to 13, characterized in that - the electrode layers (3, 4, 5) are set up to attract one another by applying an electrical actuator voltage. Actuator according to one of Claims 1 to 14, characterized in that a heating device (11) is provided which is set up to heat the material of the intermediate layer(s) (1, 2) above its glass transition temperature. Actuator according to one of Claims 1 to 15, characterized in that at least one electrode layer (3, 4, 5), in particular the second electrode layer (4), is designed to remove the material of the intermediate layer(s) (1, 2) by applying a heating voltage above its glass transition temperature, as a result of which the electrode layers (3, 4, 5) are part of the heating device (11). Actuator according to one of Claims 1 to 16, characterized in that an electrical connection (12) is provided for each electrode layer (3, 4, 5), the electrical connection (12) preferably consisting of a, in particular 3D, material applied by additive manufacturing Printed, material is manufactured or co-printed with the respective electrode layer (3, 4, 5) in one operation. Actuator according to one of Claims 1 to 17, characterized in that - that a control device is provided, - that the control device is electrically connected to the electrode layers (3, 4, 5) in such a way that an actuator voltage can be applied between two electrode layers (3, 4, 5) in order to selectively bring about a change in length of an intermediate layer (1, 2). , - In particular that the control device is so electrically connected to the electrode layers (3, 4, 5) that at least one of 20 21 22 26 — 61249 — Electrode layers (3, 4, 5) the intermediate layers (1, 2) over which Glass transition temperature heated. Method for producing a dielectric soft actuator, which is designed in particular according to one of claims 1 to 18, - wherein two intermediate layers (1, 2) acting as dielectrics are formed, which are each provided with an electrode layer (3, 4, 5) on both sides, - the two intermediate layers (1, 2) being coupled to one another, in particular shear-resistant, in such a way that a different change in length of the intermediate layers (1, 2) causes the actuator to curve along a curved contour (6), characterized, - that the intermediate layers (1, 2) and the electrode layers (3, 4, 5) are formed by additive manufacturing, in particular by 3D printing. Method according to claim 19, characterized in that - That the intermediate layers (1, 2) and the electrode layers (3, 4, 5) are formed consecutively in layers on top of each other by additive manufacturing, in particular by 3D printing. Method according to one of claims 19 or 20, characterized in that - that at least one electrode layer (3, 4, 5), preferably all electrode layers (3, 4, 5), are each formed from at least one 3D-printed, electrically conductive conductor strip (7), - Wherein the conductor strip (7) applied in particular by a 3D print head will. Method according to one of Claims 19 to 21, characterized in that - that by forming the at least one conductor strip (7), a kinematic structure is formed which has different bending stiffnesses along different directions, - And that the course of the curvature contour (6) and the curvature properties of the actuator are determined by the choice of the kinematic structure. 27738 24 25 26 27 — 61249 — Method according to one of Claims 19 to 22, characterized in that - that the intermediate layers (1, 2) are each formed from at least one 3D-printed, dielectrically acting intermediate layer strip (13), - that the intermediate layer strip or strips (13) form an electrical insulating layer, - and in particular that the intermediate layers (1, 2) are each formed by several layers of intermediate layer strips (13) that are 3D printed one on top of the other. Method according to one of Claims 19 to 23, characterized in that - that a first electrode layer (3) is 3D printed, - that a first intermediate layer (1) is 3D printed on the first electrode layer (3), - that a second electrode layer (4) is 3D printed on the first intermediate layer (1), - that a second intermediate layer (2) is 3D printed on the second electrode layer (4), - and that a third electrode layer (5) is 3D printed on the second intermediate layer (2). Method according to one of Claims 19 to 24, characterized in that - that an electrical connection (12) is provided for each electrode layer (3, 4, 5), the electrical connection (12) preferably being made from a material applied by additive manufacturing, in particular 3D-printed, or with the respective electrode layer ( 3, 4, 5) is printed in one operation. Method for operating an actuator, which is designed in particular according to one of claims 1 to 18, characterized in that an electrical actuator voltage is applied between a first electrode layer (3) formed by additive manufacturing and a second electrode layer (4) formed by additive manufacturing, where by applying the actuator voltage: - tighten the first electrode layer (3) and the second electrode layer (4), - Characterized by a between the two electrode layers (3, 4) arranged 28 29 28 — 61249 — compress the first intermediate layer (1) formed by additive manufacturing, - thereby increasing the length of the first intermediate layer (1) compared to a further second intermediate layer (2) formed by additive manufacturing, - and the actuator curves along a curved contour (6). Method according to Claim 26, characterized in that the electrical actuator voltage between the first electrode layer (3) and the second electrode layer (4) is then reduced, - that an electrical actuator voltage is applied between the second electrode layer (4) and a third electrode layer (5) formed by additive manufacturing, with application of the actuator voltage: - tighten the second electrode layer (4) and the third electrode layer (5), - thereby compressing the second intermediate layer (2) arranged between the two electrode layers (4, 5), - thereby increasing the length of the second intermediate layer (2) compared to the first intermediate layer (1), - and the actuator curves in the opposite direction. Method according to Claim 26 or 27, characterized in that at least one intermediate layer (1, 2) is heated above its glass transition temperature by actuating a heating device (11), in particular by applying a heating voltage to at least one electrode layer (3, 4, 5). Method according to one of Claims 26 to 28, characterized in that - that the actuator is strengthened in a curved state caused by the attraction of two electrode layers (3, 4, 5) by cooling the at least one intermediate layer (1, 2) to a temperature below the glass transition temperature of the material of the intermediate layer (1, 2) he follows, - in particular that the cooling takes place by reducing or switching off the heating voltage.