DE102013013402A1 - Bending element arrangement and their use - Google Patents

Abstract

The invention relates to a bending element arrangement and uses of such a bending element arrangement. The bending element arrangement according to the invention is formed with at least one bending element, in which on one surface of an elastically deformable carrier of a bending element next to each other along an axis A at least two differently shaped, formed from a piezoelectric layer or other electromechanically active material layer and electrodes formed deformation element are applied , In this case, at least one deformation element is formed with at least one planar electrode, which covers a piezoelectric layer or a layer formed from another electromechanically active material in the form of a layer at least partially as a closed surface. In addition, the electrodes are formed as interdigitated finger electrodes at least on one of the deformation elements and the carrier is held by means of a fixed clamping.

Description

The invention relates to a bending element arrangement and uses of such a bending element arrangement.

Bending elements by means of a structure in which a piezoelectric layer is used with electrodes on an elastically deformable support to deform the element upon application of an electrical voltage by bending or to detect a deformation effected by the action of forces and moments, are known. The most varied forms and arrangements of electrodes are used. Thus, electrodes are known as planar layers, rod-shaped or fibrous electrodes and as interdigitated finger electrodes (interdigital electrodes short IDE). The polarization in the piezoelectric layer has a preferred direction, so that the direct or indirect piezoelectric effect is available.

With the known structures, however, there is only the possibility of achieving such a bending element (unimorph) deformation in a bending direction, which is determined by the nature of the introduction of the electric field in the piezoelectric material and their achievable bending angle by the value of the applied electrical voltage can be influenced.

For certain applications, however, it is desired that an S-shaped bend is achieved in which one end face of the bending element is clamped and the other makes a movement along an axis which is perpendicular to the surface of the element. Furthermore, the surfaces on the end faces of the bending element remain parallel. It can thereby be achieved that a load arranged in the end face region or an element is moved without an inclination along an axis. In addition, it is desirable to set the course of the bending radius defined along the element and so z. B. adapt to the load to be lifted.

In particular, in these applications, the previously known technical solutions have disadvantages. That's how it is WO 2006/110908 A1 a structure in which a vertical movement can be achieved without an inclination. In this case, a plurality of actuators in the form of so-called "bimorphs" are used to achieve an S-shaped bend. The known structure is complicated to manufacture and it is, if at all possible to realize a limited extent different bending radii in different areas of such an actuator. In addition, actuators must be arranged in any case on two oppositely arranged surfaces of a support member.

It is therefore an object of the invention to provide a bending element arrangement which is inexpensive to produce and can be achieved or exploited with different bending radii and bending directions on bending elements, wherein preferably an S-shaped bend is to be utilized.

According to the invention, this object is achieved with a bending element arrangement having the features of claim 1. The claim 12 indicates uses for it. With features described in the subordinate claims advantageous refinements and embodiments of the invention can be realized.

The bending element arrangement according to the invention is formed with at least one bending element. In the case of the bending element (s), at least two differently shaped deformation elements formed from a layer formed by a piezoelectric layer or another electromechanically active material and / or are formed on a surface of an elastically deformable carrier next to each other along an axis A. On at least one of the deformation elements of a bending element, the electrodes are formed as interlocking finger electrodes and at least one further, the electrodes are flat above and below the active material. The active material can, but does not have to, consistently connect a plurality of deformation elements which are only separated from one another by the different characteristics of the electrodes. Piezoelectric layers have a preferred direction in the polarization in the region of the deformation elements. In the special case of ferroelectric layers, this can also be impressed by applying an electric field. The carrier is held by a fixed clamping.

It is advantageous if deformation elements are arranged at a distance from one another. As a result, the different bending radii that can be achieved with the individual deformation elements and possibly even bending directions can be utilized even better.

In addition to piezoelectric materials, it is also possible to use other suitable electromechanically active materials, for example electrostatically deformable elastomers and dielectrically deformable dielectrics.

On a bending element which can be used in the invention, a deformation element can be formed with at least one planar electrode which a piezoelectric layer or a layer formed from another electromechanically active material in the form of a layer at least partially covered as a closed surface. A piezoelectric layer or a layer of a deformation element formed from another electromechanically active material can be enclosed on two sides by layer-shaped electrodes, wherein an electrode can be formed on the surface of the elastically deformable support. At least one further deformation element on a bending element is then formed with interdigitated finger electrodes (IDE).

The finger electrodes can be made on the surface of the elastically deformable carrier or its surface coating, in the interior of the active layer or on its surface, as well as in combinations of these variants. For improved formation of electric fields that cause deformation, the electrodes should preferably be formed on and under the active material.

If a carrier made of an electrically conductive material is used, it can be used as an electrode for at least one of the deformation elements.

When driving a deformation element with a piezoelectric layer, in which electrodes are arranged on both surfaces of the layer and the electric field is formed across the thickness of the layer, a lateral compression can be achieved, which bends the carrier in one direction. In a deformation element with finger electrodes on the same surface of a piezoelectric layer, a lateral formation of an electric field with applied electrical voltage is achieved, which leads to an expansion of the carrier materially connected to the layer in this area and thus to a bend in the opposite direction, if the two differently shaped deformation elements are formed on the same surface of the carrier and attached thereto. The preferred direction of polarization in the piezoelectric layer is in each case in the direction of the applied electric field, or is stamped in this case in the special case of a ferroelectric material. Since the two deformation elements according to the invention are to be arranged side by side according to the invention, so an S-shaped bending of the bending element can be achieved.

Since two or more deformation elements can be arranged on the same surface of a carrier, it is also possible to provide the contacting of the electrodes on this side of the surface, so that no vias (VIA's) are required.

In the invention, it is advantageously possible to form the deformation elements on the same surface of the carrier. As a result, the production can be simplified and made cheaper. This has an advantageous effect even if the individual components of the deformation elements (layer and electrodes) are formed in thick-film technology on the support, which can be achieved by the various printing methods (screen printing, stencil printing, aerosol printing, ink-jet printing). In this case, a suspension with paste-like or low-viscosity consistency in which particles of piezoelectrics or of another electromechanical material and, for example, metallic particles for the formation of electrodes are contained can be used. After the order, a heat treatment can be performed. This can be carried out in two stages with drying and subsequent heating to higher temperatures. In this case, contained organic components and the liquid can be expelled and carried out sintering at higher temperatures while cohesive connections of the components of the respective deformation element with each other and with the carrier can be achieved. An embodiment of the electrodes in thin-film technology (evaporation, sputtering, PVD, CVD, PECVD, laser deposition) is also possible.

The formation of the layers and / or electrodes can also take place in depressions which are formed in a surface of the respective carrier. As a result, in addition to the cohesive and a positive connection between components of the deformation elements and the carrier can be achieved, which can be exploited in the bending.

Surprisingly, it has also been found that when using a deformation element with finger electrodes and a further deformation element with one or two planar electrodes formed as a layer, upon application of an electrical voltage, an S-shaped deformation can be achieved, if the deformation elements on the same surface of the support are arranged.

If a plurality of deformation elements are formed on a common carrier, which are each formed with interdigitated finger electrodes, different bending radii can be achieved even with the same applied electrical voltage, if the arrangement, geoemtrische design, dimensioning and / or the distances of individual finger electrodes to each other and / or the Electromechanically active materials in the trained deformation elements are each different.

In the case of the deformation elements formed on a carrier, interdigitated finger electrodes of at least one deformation element can have different distances from one another and / or fingers of a finger electrode can have a different length and / or width. There is also the possibility that with two deformation elements, in each case a different number of fingers of their finger electrodes can be selected. As a result, different bending radii can be achieved with the differently designed finger electrodes.

The effect of varying degrees of bending radii can also be achieved by the choice of the size and in particular the geometric design of electrodes and / or piezoelectric layers or layers of another electromechanically active material layers, if they over their length with respect to the axis A of the carrier a have varying width. This width can change continuously or continuously. Triangular shapes or other shapes can be chosen. Here, possible forms in the description of examples will be discussed below.

Different bending radii can be achieved by deformation elements, if the deformation elements, which are formed on a surface of a carrier, different high voltages are applied to the respective electrodes or in that at constant voltage by varying the distance between the electrodes locally different high electrical Field strengths can be formed or achieved.

A carrier usable in a bending element may be formed of a material selected from Al ₂ O ₃ , LTCC, ZrO ₂ , silicon, a metal, preferably a steel, a fiber composite material or a polymer. The selection of the material can take place under the aspect of the force or moment to be applied or to be detected or of a path to be achieved by the bend.

Carriers should have a correspondingly smaller width and an even smaller thickness in relation to their length, so that as a result of the respective mechanical moment of resistance, a bend in the respective desired direction can be achieved or exploited.

A bending element, as can be used in the invention, can be designed as a monolithic multilayer element. But it can also be formed more than one bending element. In this case, a plurality of bending elements can be produced from a common substrate, on which the components of the deformation elements are formed on the areas forming the bending elements, which can be achieved in a printing process for the individual layers in one go or with one construction. By means of a separation process, slots can be formed and, in turn, the respective number of bending elements can be formed. The bending elements are in each case connected to the rest of the substrate on one end face, which in turn can form a platform on which other elements (eg optical, electrical or electronic elements) can be mounted or arranged.

With these methods, it is also possible to efficiently manufacture a plurality of individual flexures or arrays of flexures by separating and singulating these elements or assemblies fabricated as a whole on a common substrate, e.g. B. by sawing, milling, cutting, laser or ultrasonic machining can be achieved.

In a bending element arrangement according to the invention, at least two bending elements can each be held on one end face by means of a fixed clamping and connected directly to each other or to a platform on the opposite end face. For example, three, four or even more bending elements can form a bending element arrangement.

It is also possible to connect two bending elements together on one end face. Two bending elements connected in this way can then lie parallel to one another in the uninfluenced state or form a V. In this case, a bending element is held on a front side in a fixed clamping and the connection of the two bending elements is realized on the opposite end face. If the deformation elements are activated, then a bending of the bending elements can be achieved or detected by applying or measuring electrical voltage to the electrodes of the deformation elements.

The achievable deformation / bending can also be influenced by the cross section of the carrier, the carrier material and the length of the carrier with the arrangement and dimensioning of the deformation elements on the carrier.

A bending element arrangement according to the invention can be used as an actuator, sensor, transformer, capacitor, ultrasonic transducer or generator.

With an S-shaped bending of one or more bending elements (s) of a bending element arrangement, a raised object moved with it can be moved in parallel without tilting. For example, an object can be raised vertically. As a result, in the bending mechanical stresses can be avoided, at least significantly reduced, which also applies to the restraint.

In a double-S-bend flexure assembly, two stacked flexures or juxtaposed flexures configured for S-bend may additionally compensate for lateral movement of an S-bend flexure and thus may become completely perpendicularly tilt-free Hub can be reached.

In the invention, in addition to the production-related reduced costs and the possible arrangement of deformation elements on the same surface of a carrier and a high dimensional stability can be met with very good reproducibility. The components of the deformation elements can be easily structured according to requirements.

Additional joining steps and joining methods are not required. There is also a high degree of integration, since deformation elements can be formed on carriers, which are also commonly used in electronics technology.

A ready-made bending element assembly can be used free of solvents, so that nothing stands in the way of use under vacuum conditions.

Summarizing and defining should be noted that under flat electrodes such electrodes are to be understood, which are applied to a carrier or to a structure or surface finish thereon. The electromechanically active material is applied to the electrode structure and finally provided with a cover electrode. Touch points of the two electrodes or their electrical leads can be provided with an insulating layer at the latest before the application of the cover electrode.

Interdigital electrodes or interdigitated electrodes are an array of interdigitated finger-like electrodes of which the fingers coming from one side are at a different electrical potential than the fingers coming from the other side. Characteristic features of such an electrode structure are the width of the fingers, the distance between the fingers located at different potentials, and the distance between the fingertips and the collecting electrode of the respective other potential.

The electrode structure can be realized under the electromechanically active material, above the electromechanically active material or in a layered structure of the electromechanically active material in its interior. For the formation of an electric field within the electromechanically active material, one of these positions is sufficient, but preferably several positions can be combined to improve the homogeneity of the formed electric field.

It is also possible to provide an electromechanically active material first with structures, in particular the electrodes, and then connect them in a joining step with a carrier.

If two deformation elements are combined on one bending element, of which the electrodes are formed on one surface above and below the electromechanically active layer, and on the other electrodes, which are designed as interdigitated fingers and acted on with different electrical potentials, then it can be applied be deformed by electrical voltages so that in cross-section an S-shaped bend can be achieved. This bend is characterized in particular in that the tangents to the carrier surface near the front ends of the bending elements remain parallel during the deflection. When the bending element is clamped to an end face, a load attached to the other end can be moved almost without tilting almost perpendicular to the carrier surface. There is only a small movement towards the fixed clamping, which is negligible because of the large ratio of the length of the respective bending element to its deflection / bending.

The shortening of a bending element with S-shaped bend and the associated minimal lateral movement of the load in such an arrangement can be compensated by an arrangement with which a double S-shaped bend can be achieved. For this purpose, two bending elements, each of which can be bent in an S shape, are used, which are either adjacent to one another, ie their longitudinal axes lie parallel to one another at a distance from one another, or are arranged one above the other with a joining step. The first bending element is firmly clamped on one end face and on the opposite end face the connection to the second bending element is formed. The effect of the two bending elements can be parallel in this arrangement be switched. The stroke adds and the shortening of the flexures equalizes to zero.

On a support, several deformation elements can be placed to form a bending element. The deformation elements can be separated from each other by a gap in the active material or without interruption only by regions of different electrode geometry. The design of the deformation elements (to be discussed later) determines the bend / curvature and its direction in the region of the support on which it is applied.

An arrangement of deformation elements or groups that is not aligned along only one axis is likewise possible.

According to the invention, at least two deformation elements are combined on a common carrier, which thus form a bending element. In the following, by way of example, combinations of two deformation elements and their design are described, however, as described, other deformation elements can also be used.

On a support there may be two deformation elements, one of which has a deformation element surface and the other finger-shaped electrodes. The electromechanically active material can be present continuously throughout or interrupted by a gap. The two different deformation elements can cause a deflection / curvature of the carrier in different directions when an electrical voltage is applied.

• – Veränderung der Breite der aktiven Fläche von Verformungselementen entlang des Biegeelementes durch geometrische Formung und Dimensionierung der Elektrodenbereiche oder des elektromechanisch aktiven Werkstoffs in der entsprechenden Schicht. Hierbei ist die Dickschichttechnologie besonders vorteilhaft einsetzbar, da sich hochgradig maßhaltige und individuell optimierte Strukturen herstellen lassen.
• – Die Verformungselemente können unterschiedlich lang und breit gestaltet sein.
• – Sie können auf durch einen Spalt/Fuge getrennten elektromechanisch aktiven Werkstoff oder einem gemeinsamen flächigen elektromechanisch aktiven Werkstoffausgebildet werden.
• – Fingerabstand und Fingerbreite fingerförmiger ineinandergreifender Elektroden müssen bei einem Verformungselement nicht konstant sein, sondern können z. B. kontinuierlich im Verlauf des Elementes variiert werden, um einen ebenso kontinuierlich variierten Verlauf des in den Träger eingebrachten Momentes zu erreichen, die zu bestimmten Biegeradien führt.

It is advantageous to use a matched to the load or the application history of the introduced into the carrier moment. This can be done by:

• - Changing the width of the active surface of deformation elements along the bending element by geometric shaping and dimensioning of the electrode areas or the electromechanically active material in the corresponding layer. In this case, the thick-film technology can be used particularly advantageously, since highly dimensionally stable and individually optimized structures can be produced.
• - The deformation elements can be designed differently long and wide.
• - They can be formed on separated by a gap / joint electromechanically active material or a common planar electromechanically active material.
• - Finger distance and finger width finger-shaped interdigitated electrodes need not be constant in a deformation element, but can, for. B. can be varied continuously in the course of the element in order to achieve a continuously varied course of the introduced into the carrier torque, which leads to certain bending radii.

The invention will be explained in more detail by way of examples.

Showing:

1 an example of a bending element assembly according to the invention with four bending elements;

2 an example with two differently shaped deformation elements for an S-shaped bend;

3 three representations of an example of a bending element assembly according to the invention in different operating positions (1 times uncontrolled and two times activated);

4 another example of a bending element assembly according to the invention;

5 a further example of a bending element arrangement according to the invention, are formed in the deformation elements with different orientation on an angled support;

6 an example of a bending element arrangement according to the invention in which a carrier is formed with two legs, which are connected together in the region of a common end face and on the legs in each case two different deformation elements are present and

7 Examples of usable in a bending element assembly according to the invention electrodes.

In the examples described below, the term "electromechanically active layer" is generally used. Of course, this term also includes piezoelectric layers.

In 1 is an example of a bending element arrangement according to the invention with four bending elements 1 shown. The bending elements 1 can be bent in an S-shape when attached to the electrodes 4 and 5 the deformation elements 7 and the electrodes 4 ' / 5 ' such as 4 '' / 5 '' the deformation elements 7 ' electrical voltages are applied. Every bending element 1 is with two deformation elements 7 and 7 ' formed, wherein in each case a deformation element 7 with two flat electrodes 4 and 5 and a deformation element 7 ' with interlocking finger-shaped electrodes 4 ' / 4 '' and 5 ' / 5 '' is formed.

In the 1 shown flexure assembly is monolithic on a 270 micron thick carrier 2 made of 99.6 percent alumina ceramic. It is equipped with four S-shaped deformable bending elements 1 formed out of the carrier 2 be cut free by laser processing and only on one end side still with the outer region of the carrier 2 (Frame) are connected and at the other end face one of the four bending elements 1 held platform 8th located. The platform 8th can then in relation to the outer frame 8th' along an axis perpendicular to its surface through the bending elements 1 to be moved.

The carrier 2 has the dimensions 100 mm × 100 mm. By means of a UV laser vias (Via's) are formed with a diameter of 200 microns at selected locations. Next are structured ground electrodes 4 and 4 ' / 4 '' in thick film technology with a screen printer on the carrier 2 applied. In this case, a conductive paste is used which contains electrically conductive particles. The paste is typically first dried in a two-stage thermal process and then with the carrier 2 sintered (850 ° C). The structure of the base electrode 4 forms flat and finger-shaped electrodes 4 ' / 4 '' and their electrical leads (not shown) on the carrier 2 , The finger-shaped electrodes 4 ' and 4 '' are connected to two separate different electrical potentials. The flat electrode 4 remains uncontacted.

Next will be on the back of the carrier 2 Printed conductors with the same process that lead to the vias (VIA), which are not shown. This is the surface electrode 4 on the top through the vias (VIA) through electrically contacted with these electrical conductors.

The use of the back is done, in this example, only for reasons of space savings. A completely one-sided structure in which all three electrical potentials are guided on the top, is also easily possible.

In the next step, a piezoelectric thick film paste "PZ5100" (Fraunhofer IKTS, Dresden, Germany), which is formed with ferroelectric particles, in the form of four rectangles and with a thickness of about 130 microns on the electrode structures for the four S-shaped bendable flexures 1 applied and sintered. In the areas where the tips of the finger-shaped electrodes 4 ' and 4 '' very close to the collecting electrode of the other potential, an electrically insulating barrier in the form of a strip is applied and sintered by means of thick-film technology. Subsequently, the cover electrode 5 and their electrical leads with the same process as the base electrode 4 printed. Here are the flat top electrodes 5 each electrically from the last finger of the finger-shaped interdigital electrodes 5 ' contacted and thus lies at the same electrical potential. The pressure of the insulating barriers is repeated.

Finally, cuts are made in the support by means of UV laser processing 2 executed the the S-shaped bendable bending elements 1 uncover. This may cause the part of the bending elements 1 who is no longer stuck with the carrier 2 connected, bend when an electrical voltage is applied. On one end face are the bending elements 1 with the carrier 2 rigidly connected, so that a fixed clamping is present.

• 1. Fingerförmige Elektroden (oben 5' und unten 4') + Deckelektrode 5 (flächig): 0 V
• 2. Fingerförmige Elektroden 2 (oben 5'' und unten 4''): A × 1000 V
• 3. Flächige Grundelektrode 4 (durch Via von Rückseite): A × 200 V

Mit dem Ansteuerfaktor A [0..1]There are now three independent electrical potentials on each S-bendable flexure 1 :

• 1. Finger-shaped electrodes (above 5 ' and below 4 ' ) + Cover electrode 5 (area): 0 V
• 2. Finger-shaped electrodes 2 (above 5 '' and below 4 '' ): A × 1000V
• 3. Flat bottom electrode 4 (through via from the back): A × 200V

With the drive factor A [0..1]

The respective electrodes of the S-bendable bending elements 1 are through the bottom electrode 4 and the back electrode combined, but can also be kept separate to the four S-shaped bendable bending elements 1 individually to control. So they can be operated in a network.

The required preferred direction of the polarization in the piezoelectric layer formed can be achieved since the piezoelectric particles are also ferroelectric. Thus, in the piezoelectric layer, by applying an electric field, which is typically 2 kV / mm, in the piezoelectric layer in the respective deformation elements, a preferential direction of the remanent polarization can be generated, which is directed along the electric field in this area.

The distance between the individual finger-shaped electrodes 4 ' and 5 ' to each other and the thickness of the electromechanically active layer 3 are designed so that when applying the electrical voltages described an equally strong electric field in the two deformation elements 7 and 7 ' the S-shaped bendable bending elements 1 results. The mechanical effect of the electromechanically active material on the carrier 2 is greater by a factor of about 2 when the electric field is laterally formed, compared to a field which is formed by the thickness, that is perpendicular thereto. The area with the finger-shaped interdigital electrodes 4 ' and 5 ' is therefore located at the frame-side end of the bending elements 1 , because by the lever effect also larger forces act on this area by the lifted load. The aspect ratio of the two deformation elements 7 and 7 ' , the individual bending elements 1 is tuned so that under inclusion of the load and the different strong effect of the two areas when excited S-shaped bending of the bending elements 1 results. The surface at the front ends of the bending elements 1 stay parallel. The differently oriented and across the platform 8th connected S-shaped bendable bending elements 1 do not tense each other. In the experiment, the S-curve and the rigidity of the S-bendable bending elements were 1 demonstrated.

The 2 shows a plan view of an example of a usable in the invention bending element 1 with two on an elastically deformable carrier 2 trained deformation elements 7 and 7 ' , which are arranged side by side and in this example at a distance from each other. This is a deformation element 7 namely the one shown in the drawing above, with two flat electrodes 4 and 5 between which an electromechanically active layer 3 is arranged, formed. The second deformation element shown below 7 ' is with finger-shaped interdigitated electrodes 4 ' / 4 '' and 5 ' / 5 '' educated. The electrodes 4 ' and 5 ' on the one hand and the electrodes 4 '' and 5 '' On the other hand congruent above and below the electromechanically active material are formed and electrically connected to each other in the region of the lateral collecting electrode. In this case, the finger-shaped electrodes 4 ' / 4 '' and 5 ' / 5 '' also on the electromechanically active layer 3 be educated. To the electrodes 4 . 5 . 4 ' and 5 ' are via electrical contacts the electrical potentials pot. 1 to pot 4, with which the respective bending radii and the bending direction over each between the pot. 1 and pot. 2 and between pot. 3 and Pot 4 applied potentials can be influenced.

The 3 shows a bending element 1 that in a tight restraint 9 is held on a front side. On the elastically deformable carrier 2 whose length is typically significantly greater than its width, and in particular its thickness, is the electromechanically active layer 3 between two flat electrodes 4 and 5 educated. In this example, the finger-shaped interdigitated electrodes 4 ' / 4 '' and 5 ' / 5 '' , in the direction of the firm restraint 9 arranged deformation element 7 ' also each on an opposite surface of the electromechanically active layer 3 arranged.

In the upper part of 3 lies on the electrodes 4 . 5 . 4 ' / 5 ' and 4 '' / 5 '' no electrical voltage, so no bending of the flexure 1 occurs. The two states shown below are to the electrodes 4 and 5 as well as the electrodes 4 ' / 5 ' and 4 '' / 5 '' applied an electrical voltage, each with an electrical potential difference, so that a bend could be achieved. In the two states shown, only the clamping has been rotated. It can be clearly seen that an S-shaped bend of the bending element 1 can be achieved, wherein the two end-side end portions of the bending element 1 at least almost parallel to the initial position, as seen in the upper diagram, remain and there almost no tilting occurs.

With 4 should be clarified that more than two deformation elements on a bending element 1 may be present, one after the other along the longitudinal axis of the bending element 1 can be arranged. It can be differently configured deformation elements 7 and 7 ' be educated. The example shown is a deformation element 7 with flat electrodes 4 and 5 which is arranged down here and two deformation elements arranged above it 7 ' with finger-shaped interdigitated electrodes 4 ' / 4 '' and 5 ' / 5 '' , wherein the finger-shaped electrodes 4 ' / 4 '' and 5 ' / 5 '' these two deformation elements 7 ' differ in their execution. With the dotted line between these two deformation elements 7 ' should be hinted that more than three deformation elements 7 and 7 ' on a bending element 1 can be present.

A bending element 1 with a two-legged carrier 2 , in which the two legs are aligned perpendicular to each other, is in 5 shown. On the two legs are each two differently configured deformation elements 7 and 7 ' available. In the example shown, it is in each case a deformation element 7 with flat electrodes 4 and 5 and a deformation element 7 ' with finger-shaped electrodes 4 ' / 4 '' and 5 ' / 5 '' , Here are the finger-shaped electrodes 4 ' / 4 '' and 5 ' / 5 '' aligned on both legs perpendicular to the longitudinal axis of the legs.

At the in 6 shown example, for a double S-shaped bend, are two bending elements 1 on a front in one area 10 , here the right arranged, interconnected and otherwise by a fugue 11 separated from each other parallel to their longitudinal axes. That in the upper part of 6 Bending element shown above 1 is at the left end face in the tight restraint 9 held. Both bending elements 1 again have two deformation elements 7 and 7 ' , each with different electrodes 4 and 5 such as 4 ' / 4 '' and 5 ' / 5 '' The corresponding deformation elements 7 and 7 ' with the different electrodes 4 . 5 . 4 ' / 4 '' and 5 ' / 5 '' as seen in plan view, offset from one another. Both bending elements 1 can be bent S-shaped, if appropriate electrical voltages to the electrodes 4 and 5 such as 4 ' / 5 ' and 4 '' / 5 '' as previously explained.

With such an embodiment, the achievable stroke for a load on the left end of the bending element shown in plan view below 1 is set to be increased, which is indicated in the side view shown below with the arrow.

In the 7 are in seven representations examples of possible variations for training of deformation elements 7 and 7 ' with their electromechanically active layers 3 and electrodes 4 . 5 . 4 ' / 4 '' and 5 ' / 5 '' shown. However, the variants shown can also arbitrarily and independently of the examples shown for deformation element training on bending elements 1 be used in a variety of combinations.

So is in 7 an example is shown above, as it may be formed in previously described examples.

In the embodiment shown immediately below are electromechanically active layers 3 and / or the electrodes 4 . 5 such as 4 ' / 4 '' and 5 ' / 5 '' designed so that in each case a trapezoidal deformation element 7 has been obtained.

In the third example arranged from above, geometrically shaped deformation elements are completely different 7 have been used, which illustrate the free configurability, especially in printing processes.

At the in 7 in the middle and the two examples arranged underneath, the deformation elements differ 7 and 7 ' in their areal dimensioning. So are the left arranged deformation elements 7 with flat electrodes 4 and 5 dimensioned differently, which applies to the length and the width, as the right-hand deformation elements 7 ' with finger-shaped electrodes 4 ' / 4 '' and 5 ' / 5 '' ,

At the in 7 at the bottom of the example, the individual fingers are the finger-shaped electrodes 4 ' / 4 '' and 5 ' / 5 '' of the deformation element 7 ' dimensioned differently, indicating their width (perpendicular to the longitudinal axis of the bending element 1 ) applies. The individual fingers become broader starting from the far right. In addition, the distance between the individual fingers changes. In this example, it becomes larger from right to left.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2006/110908 A1 [0005]

Claims (12)

Bending element arrangement with at least one bending element ( 1 ), in which on a surface of an elastically deformable carrier ( 2 ) of a bending element ( 1 ) side by side along an axis A at least two differently formed, from a piezoelectric layer ( 3 ) or another electromechanically active material layer and electrodes ( 4 . 5 . 4 ' . 4 '' ) formed deformation elements ( 7 . 7 ' ), wherein at least one deformation element ( 7 ) with at least one planar electrode ( 4 or 5 ) is formed, which is a piezoelectric layer ( 3 ) or formed from another electromechanically active material layer in the form of a layer at least partially covered as a closed surface and at least on one of the deformation elements ( 7 ' ) the electrodes ( 4 ' . 4 '' ) are formed as interlocking finger electrodes and the carrier ( 2 ) is held by a fixed clamping. Bending element arrangement according to claim 1, characterized in that in each case in the region of a deformation element ( 7 or 7 ' ) in the piezoelectric layer, a preferred direction of the polarization is present or this can be impressed in the special case of a ferroelectric layer by an electric field. Bending element arrangement according to claim 1 or 2, characterized in that a piezoelectric layer ( 3 ) or a layer of a deformation element formed from another electromechanically active material ( 7 ) on two sides of flat layer-shaped electrodes ( 4 . 5 ), wherein one electrode ( 4 ) on the surface of the elastically deformable carrier ( 2 ) is trained. Bending element arrangement according to one of the preceding claims, characterized in that the deformation elements ( 7 . 7 ' ) on the same surface of the carrier ( 2 ) and / or are formed at a distance from each other. Bending element arrangement according to one of the preceding claims, characterized in that interdigitated finger electrodes ( 4 ' . 4 '' ) at least one deformation element ( 7 ' ) different distances to each other and / or fingers of a finger-shaped electrode ( 4 ' . 4 '' ) a different length and / or width and / or two deformation elements each have a different number of fingers of their finger-shaped electrodes ( 4 ' . 4 '' ) and / or the deformation elements ( 7 . 7 ' ) are formed with different electromechanically active materials. Bending element arrangement according to one of the preceding claims, characterized in that the interlocking finger electrodes ( 4 ' / 4 '' ) between the piezoelectric layer ( 3 ) or from another electromechanically active material-formed layer and the carrier ( 2 ) and / or in their interior and / or on their surface ( 5 ' / 5 '' ) are formed. Bending element arrangement according to one of the preceding claims, characterized in that on electrodes ( 4 . 5 . 4 ' . 4 '' ) of deformation elements ( 7 . 7 ' ) of a bending element different electrical voltages can be applied. Bending element arrangement according to one of the preceding claims, characterized in that the carrier ( 2 ) is formed of a material selected from Al ₂ O ₃ , LTCC, ZrO, silicon, a metal, preferably a steel, and a polymer. Bending element arrangement according to one of the preceding claims, characterized in that the piezoelectric layers ( 3 ) or the layers formed from another electromechanically active material and the electrodes ( 4 . 5 . 4 ' . 4 '' ) is formed by means of thick film technology and / or the / the bending element (s) as a monolithic multilayer element / are. Bending element arrangement according to one of the preceding claims, characterized in that at least two bending elements ( 1 ) are each held on one end face by means of a fixed clamping and are connected directly to each other at the opposite end face or to a platform or two bending elements ( 1 ) are connected to each other at an end face. Bending element arrangement according to one of the preceding claims, characterized in that electrodes ( 4 . 5 . 4 ' . 4 '' ) and / or piezoelectric layers ( 3 ) or layers formed of another electromechanically active material over their length with respect to the axis A of the carrier ( 2 ) have a varying width. Use of a bending element arrangement according to one of the preceding claims as an actuator, sensor, transformer. Capacitor, ultrasonic transducer or generator.

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