Electromechanical transducer element

Abstract

The electromechanical transducer element (1) has a first electrode layer (4) made of an electrically conductive material and a second electrode layer (6) arranged at a distance therefrom. The first and the second electrode layer (4, 6) each have an electrically conductive electrode layer contact (7, 8) which can be connected to one another via a first measuring device (9). An electret structure (2) made of an electrically insulating electret material is arranged between the first and the second electrode layer (4, 6) in such a way that the electret structure (2) and / or the first electrode layer (4) is deformed or the electret structure (2) and the at least one electrode layer (4, 6) are displaced relative to each other. The proportions of the quantities of electric charges located in the first and second electrode layers (4, 6), respectively, change. The electromechanical transducer element (1) has at least one conductor layer (10) made of an electrically conductive material, which conductor layer has a first electrically conductive conductor layer contact (11) and a second electrically conductive conductor layer contact (12), wherein a deformation of the first conductor layer (10) causes a change in electrical conductivity between the first electrical conductor layer contact (11) and the second electrical conductor layer contact (12) of the first conductor layer (10).

Description

Technical Field

[0001] The present invention relates to an electromechanical transducer element having a first electrode layer made of an electrically conductive material and a second electrode layer made of an electrically conductive material arranged at a distance therefrom, wherein the first and second electrode layers each have an electrically conductive electrode layer contact, which can be connected to one another via a first measuring device. Background Art

[0002] Electromechanical transducers can be used advantageously in many different fields of application. On the one hand, they can be used as force sensors or displacement sensors, detecting measured values ​​with varying sensitivities depending on the materials used and the structural design. On the other hand, they can also be used as actuators and, depending on the design, generate highly dynamic forces or movements.

[0003] Numerous different transducer principles are known from practice. Electromechanical transducer elements can be adapted to the respective purpose of use in terms of a number of properties according to the respective requirements and can accordingly be used in a multitude of different fields of application.

[0004] An example of an application for electromechanical transducer elements is pressure sensors. Pressure sensors with high sensitivity and a wide measuring range can be advantageously used, for example, for condition monitoring in process and plant construction. Portable and flexible pressure sensors can be used to monitor human activity and health. Numerous different pressure sensors are known from practice, which differ in their design but also in their sensitivity and measuring range, and thus cover a wide variety of applications.

[0005] Conventional pressure sensors are typically based on the principle of a single transducer. This poses significant structural and measurement challenges when simultaneously detecting both static and dynamic pressure changes, often resulting in significant limitations. Strain gauges, suitably applied to a deformable body, can detect the force or pressure acting on the body. Therefore, strain gauges are suitable for detecting static pressure. Capacitive sensors can simply detect the relative displacement or deformation of two electrodes spaced apart from one another. Consequently, capacitive sensors are also suitable for measuring dynamic pressure changes.

[0006] Various electromechanical transducer elements are also known from practice, which can be used to detect not only static pressure but also dynamic pressure changes. For example, a suitable composite material can be contacted at two areas arranged apart from each other. The composite material contains a sufficient number of charged particles embedded in a polymer material and has been made conductive. The action of force changes the structure of the composite material, thereby causing a change in the composite material's conductivity, which in turn causes a change in resistance. The deformation of the piezoelectric particles within the composite material simultaneously causes a change in voltage. However, simultaneous measurement of these two parameters is not easy to achieve.

[0007] In other electromechanical transducer elements, different layers made of piezoresistive and piezoelectric materials are arranged between electrode layers. When a piezoresistive layer is displaced or deformed relative to the associated electrode layer, its resistance changes, which can be used to detect the static pressure causing the deformation or relative displacement. Pressure changes can be detected using the piezoelectric layer.

[0008] However, the production of piezoresistive or piezoelectric materials and in particular suitable composite materials for pressure sensors is associated with great effort and is cost-intensive. Due to the properties of piezoresistive or piezoelectric materials, the economically viable application possibilities for pressure sensors containing these materials are relatively limited. Summary of the Invention

[0009] It is therefore considered an object of the present invention to design an electromechanical transducer element in such a way that it can be produced and used in a simple and cost-effective manner and that static pressure and dynamic pressure changes can be detected simultaneously.

[0010] According to the present invention, this object is achieved by arranging an electret structure made of an electrically insulating electret material between the first and second electrode layers, such that upon deformation of the electret structure and / or the first electrode layer, or upon displacement of the electret structure and at least one electrode layer relative to one another, the ratio of the charge quantities located in the first and second electrode layers to one another changes. The electromechanical transducer element comprises a first conductor layer made of an electrically conductive material, the first conductor layer having a first electrically conductive conductor layer contact and a second electrically conductive conductor layer contact, wherein the first conductor layer is designed such that deformation of the first conductor layer causes a change in the electrical conductivity between the first and second electrically conductive conductor layer contacts. By arranging the electret structure between the first and second electrode layers, a charge quantity predetermined by the electret structure is arranged between the first and second electrode layers, and due to the properties of the electret structure, a quasi-permanent electric field is generated in its surroundings. Each deformation of the electret structure results in a change in the electric field acting on the first and second electrode layers, thereby changing the charge quantities held or accumulated on the first and second electrode layers, respectively. This change in the amount of charge, or the ratio of the amounts of charge respectively present in the first and second electrode layers, can be detected using a suitable measuring device, allowing inferences to be drawn about a deformation of the electret structure that has caused the detected change based on the detected change in the amount of charge or the ratio of the amounts of charge on the first and second electrode layers. Similarly, displacement of the electret structure relative to at least one electrode layer also results in a change in the amount of charge retained or accumulated on the relevant electrode layer, which can be detected using a measuring device and similarly allows inferences to be drawn about the relative displacement of the at least one electrode layer relative to one another. It is also conceivable that the capacitance of the electromechanical transducer element or between two components of the electromechanical transducer element can be detected and used, for example, to determine the deformation that causes the capacitance change and the force that causes the deformation. Furthermore, the potential difference between two components, such as between the first and second electrode layers, can also be detected and used to determine the deformation or state of the electromechanical transducer element.

[0011] The electret structure is made of an electret material, which is an electrically insulating material that contains quasi-permanently stored electric charges or quasi-permanently oriented electric dipoles and thus generates a quasi-permanent electric field in or within its environment. The use of the electret structure generates the electric field required for detecting dynamic pressure changes, which is responsible for changing the amount of charge when the electret structure and the two electrode layers are deformed or displaced relative to each other. No external energy supply or external generation of a potential difference or electric field is required, making the electromechanical transducer element highly energy-efficient for detecting dynamic pressure changes.

[0012] It has been shown that, compared to conventional resistive sensors, the electromechanical transducer element according to the invention can detect dynamically changing forces with significantly shorter response times and, therefore, at faster intervals. An example of this is the use of electret structures to detect movement intentions, which cannot be measured with resistive sensors due to the generally slow response times. Furthermore, conventional resistive sensors are rarely or not suitable for dynamic force changes at frequencies above 100 Hz.

[0013] The change in the charge quantity on the first or second electrode layer caused by the deformation or displacement of the electret structure can be detected, for example, using a suitable charge amplifier and converted into a processable and evaluable voltage signal. Depending on the expected dynamics of the deformation or displacement of the electret structure and taking into account the structural design of the electromechanical transducer element, the measuring device can also be designed as a voltage measuring device and be contacted with the first and second electrode layers in a suitable manner.

[0014] The electromechanical transducer element is optionally designed such that the electret structure and / or at least one electrode layer can be deformed by a force acting thereon, and this deformation can be detected by a measuring device. It is also conceivable that the electret structure and / or at least one electrode layer are rigid and can be displaced relative to one another by the action of a force. In this case, the electret structure and at least one electrode layer can be connected to one another, for example, via a suitable spring arrangement, wherein the spring arrangement generates a restoring force upon relative deflection of the electret structure and the associated electrode layer, which resets the electret structure and electrode layer to their initial position. It is also conceivable that the electret structure and / or at least one electrode layer are connected and mounted to the housing or the frame of the electromechanical transducer element via a suitably designed spring arrangement. An electret structure or electrode layer is considered rigid if the action of a specified force on the electret structure or electrode layer does not cause a deformation of the electret structure or electrode layer that affects the measured value measured by the measuring device.

[0015] The arrangement of the electret structure between the first and second electrode layers makes it possible, in particular, to detect dynamic changes in the forces acting on the electromechanical transducer element. The first conductor layer, on the other hand, particularly advantageously enables the detection of static forces acting on it and, therefore, on the electromechanical transducer element. Deformation of the first conductor layer causes a change in its electrical conductivity, which can be detected via the first and second conductor layer contacts arranged at a distance from one another. By combining these two action and measurement principles, the electromechanical transducer element according to the present invention makes it possible to precisely detect not only static but also highly dynamic force effects or pressures and pressure changes and to transmit them to a suitable evaluation device. Numerous suitable materials and production methods are known for producing the electrode layers or the first conductor layer, which enable the cost-effective production of the electromechanical transducer element according to the present invention in large quantities.

[0016] Numerous electret materials are known from practice, which allow suitable electret structures to be produced simply and cost-effectively. In principle, it is possible for the electret structure to consist of layers of such suitable electret materials. The individual layers of the electromechanical transducer element can then be arranged one on top of the other and, if necessary, constructed so that adjacent layers of the electromechanical transducer element are in planar contact with one another. Such an electromechanical transducer element can, for example, be printed using a suitable printing device onto the surface of a component or finished product, where static and dynamic forces acting on the component or finished product are to be detected. The conductive electrode layer contacts and the conductor layer contacts can also be printed separately. Using a suitable printing device, the electromechanical transducer element according to the present invention can be printed particularly cost-effectively onto almost any surface of a component or finished product. The electret structure arranged between the first and second electrode layers forms an electrically insulating layer, which is required to prevent electrical short circuits between the two electrode layers.

[0017] Here, the electrode layer and / or the first conductor layer can each be constructed over the entire surface and can each partially or completely cover the electret structure. However, in particular, the first conductor layer can also be constructed as a planar layered conductor structure. This layered conductor structure can, for example, have a linear path in a layer plane that is three-dimensionally curved if necessary. This layered conductor structure can also have a curved or meandering path in a planar or three-dimensionally curved layer plane. Each electrode layer or conductor layer can be constructed as a planar layer structure and completely fill or cover the area within the peripheral edge that limits the planar layer structure. Each electrode layer or conductor layer can also have a two-dimensional or three-dimensional structured portion, wherein the three-dimensional structured portion is either constructed only on one side and opposite to the planar outer side, or is constructed on both sides. The three-dimensional structured portion can be produced by locally varying the thickness of the electrode layer or conductor layer, or by bending the electrode layer or conductor layer extending parallel to the electret structure while maintaining a constant thickness.

[0018] A particularly advantageous embodiment of the present invention provides that the first electrode layer is designed as a first conductor layer. This allows for a particularly simple and compact design of the electromechanical transducer element. A corresponding variant of the electromechanical transducer element comprises a first electrode layer designed as a conductor layer and a second electrode layer arranged spaced apart therefrom, with an electret structure arranged between the first and second electrode layers. This electret structure is also designed as another layer of electret material. Deformation of the first electrode layer designed as a conductor layer causes a change in the electrical conductivity of the first conductor layer, which can be detected, for example, by a change in the voltage drop between the first and second conductor layer contacts. Simultaneously, the deformation of the first electrode layer designed as a conductor layer causes a change in the electric field generated by the electret material acting on the first electrode layer, which can be detected by means of a first measuring device connected to the first and second electrode layers via the electrode layer contacts. If both the first and second electrode layers and the electret structure are designed as layers arranged one above the other and, if necessary, printed one above the other, then the action of external forces regularly deforms not only the first electrode layer, but all layers. Pressure acting on the electromechanical transducer element can, for example, deform and compress the electret structure, thereby also changing the spacing between the electrode layers surrounding the electret structure on both sides and, therefore, the amount of charge held or accumulated on both electrode layers. In many cases, this can also lead to increased sensitivity of the electromechanical transducer element.

[0019] It can be expedient and optionally provided that the electromechanical transducer element has a second conductor layer made of an electrically conductive material, the second conductor layer having a first electrically conductive conductor layer contact and a second electrically conductive conductor layer contact, wherein the second conductor layer is designed such that a deformation of the second conductor layer causes a change in the electrical conductivity between the first and second electrically conductive conductor layer contacts of the second conductor layer. The second conductor layer can be either an additional, separately produced second conductor layer arranged in addition to the second electrode layer, or a corresponding design of the second electrode layer. The second conductor layer can be used to detect forces acting on the second conductor layer independently of the first conductor layer, and in particular, it is advantageous to measure static forces acting on the second conductor layer using an associated measuring device.

[0020] Depending on the structural design of the electromechanical transducer element, it can be provided that, when an external force is applied, substantially the same force is applied to the first and second conductor layers. In this case, the changes in the conductivity of the detected conductor layer and the second conductor layer should be identical, so that a particularly precise assessment of the force acting on the electromechanical transducer element based on the two measured values ​​is possible. Optionally, it can also be provided that the first and second conductor layers either have different deformabilities or are positioned differently relative to the electret structure and / or the respective further conductor layer, in order to thereby advantageously influence the accuracy and, if necessary, the measuring range of the electromechanical transducer element. The first and second conductor layers can also be made of different materials.

[0021] Alternatively, it may also be provided by a different structural design of the electromechanical transducer element that the external force should affect the first and second conductor layers differently and that these different effects on the first and second conductor layers can be detected separately.

[0022] One embodiment according to the present invention can provide that the first electrode layer is arranged on a first surface of the electret structure and, under the action of a predetermined force, causes deformation of the electret structure including the first electrode layer arranged on the first surface. It is also conceivable that, as an alternative or in addition, the second electrode layer is arranged on a second surface of the electret structure opposite the first surface and, under the action of a predetermined force, causes deformation of the electret structure including the second electrode layer arranged on the second surface. By suitable material selection and corresponding dimensioning of, for example, the thickness of the individual layers, the respective deformability of the electret structure and the first and / or second electrode layers arranged directly on the surface of the electret structure can be influenced and predetermined. This embodiment of the electromechanical transducer element is particularly advantageous in that it can be applied or printed directly onto the surface of a component or finished product at low cost.

[0023] According to another embodiment of the present invention, the first electrode layer and / or the second electrode layer are optionally arranged at a distance from the electret structure, and when a predetermined force is applied, the first and / or second electrode layers arranged at a distance from the electret structure are displaced relative to the electret structure. This embodiment enables the electret structure and / or one or both electrode layers to be designed as rigid layers or rigid structures. This structural embodiment can be advantageous in various applications.

[0024] In particular, with this design of the individual layers, it can be advantageously optionally provided that the first and / or second electrode layers, which are spaced apart from the electret structure, are positioned displaceably relative to the electret structure counter to a spring force. For this purpose, it can also be optionally provided that the first and / or second electrode layers, which are spaced apart from the electret structure, are operatively connected to the electret structure via a spring device. By appropriately designing the spring device and thereby prescribing the spring force, a measuring range for the electromechanical transducer element can be easily predefined, within which the electromechanical transducer element can detect forces acting on the electromechanical transducer element with sufficient sensitivity for the relevant application. Consequently, the measuring range and sensitivity of the electromechanical transducer element are less dependent on the material and dimensions of the electret structure and the individual electrode or conductor layers and can be predefined over a wide range by appropriately designing the spring device and the spring force or restoring force generated thereby. If necessary, the spring device can be designed to be manually or automatically adjustable, so that the restoring force generated by the spring device is varied and the electromechanical transducer element can be adapted to different fields of application or different measuring ranges and sensitivities.

[0025] Optionally, provision can be made for the first and / or second electrode layers and / or the electret structure, which are arranged spaced apart from the electret structure, to be connected to a support structure of the electromechanical transducer element via a spring device. This support structure can be, for example, a housing or a frame. This support structure enables the electromechanical transducer element to be equipped with a spring device without having to support the spring device on an external component or object, which typically requires separate placement or installation when the electromechanical transducer element is installed at the intended location of use. The support structure allows the spring device to be arranged and configured during the manufacture of the electromechanical transducer element independently of its subsequent use.

[0026] Depending on the intended use of the electromechanical transducer element, it may be provided that the first conductor layer and / or, if appropriate, the second conductor layer consists of a piezoresistive material. In the case of piezoresistive materials, which are often manufactured as semiconductor materials, deformation generally leads to a significantly greater change in resistance than in the case of metals, so that high sensitivity and, advantageously, a high signal-to-noise ratio can be achieved using piezoresistive materials.

[0027] According to a design advantageous for various fields of application, the electromechanical transducer element may include a first electret structure and a second electret structure spaced apart therefrom, both of which are arranged between a first electrode layer and a second electrode layer. Air or another conductive or non-conductive spacer structure may be arranged between the two electret structures. The spacer structure may be deformable or compressible, so that the spacing between the two electret structures is changed by the action of pressure.

[0028] However, it may also be provided that a conductor layer having a first conductor layer contact and a second conductor layer contact is arranged between the two electret structures. However, it may also be preferably provided that the two conductor layers are arranged electrically insulated from one another between the first electret structure and the second electret structure. The two conductor layers are preferably arranged electrically insulated from one another. For this purpose, air or another non-conductive spacer structure may be arranged between the two conductor layers. The two conductor layers may also be arranged on the mutually facing outer sides of the two electret structures so that, when the electret structures are in contact, the two conductor layers extend laterally adjacent to one another, and no electrically conductive connection can be established between the two conductor layers when the electromechanical transducer element is used as intended. The two electret structures are preferably made of a deformable electret material so that, when a force is applied to the electromechanical transducer element as intended, at least one electret structure and, consequently, the conductor layer arranged on the electret structure in question deforms, allowing this deformation to be detected via a resulting change in resistance in the conductor layer.

[0029] The various possibilities and aspects of the electromechanical transducer element according to the invention have been described primarily with reference to its intended use as a force or pressure sensor. However, the electromechanical transducer element can also be used as an actuator or for generating heat, for example by applying a variable voltage between two electrode layers or by generating a current flow through at least one conductor layer, which, depending on the respective resistance of the conductor layer, causes the conductor layer to heat up.

[0030] Therefore, the present invention also relates to an actuator or a sensor, each having an electromechanical transducer element with the aforementioned features or combination of features. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various embodiments are described below, which are shown schematically and exemplarily in the accompanying drawings, wherein:

[0032] Figure 1A first embodiment of an electromechanical transducer element is shown, which comprises an electret structure, a first electrode layer, and a second electrode layer, which is designed as a conductor layer and is contact-connected.

[0033] Figure 2 Different embodiments of electromechanical transducer elements are shown, in which the two electrode layers are each designed as conductor layers and are contact-connected.

[0034] Figure 3 shows a modified embodiment of an electromechanical transducer element, in which the electrode layer, designed as a conductor layer, is arranged spaced apart from the electret structure via a spring device.

[0035] Figure 4 A further modified embodiment of an electromechanical transducer element is shown, in which, in addition to the first electrode layer and the conductor layer arranged on mutually opposite outer sides of the electret structure, a second electrode layer is mounted at a distance therefrom via a spring arrangement.

[0036] Figure 5 A further modified design of the electromechanical transducer element is shown in Figure 4 In contrast to the variant shown in , instead of the second electrode layer, the electret structure together with the first electrode layer and the conductor layer arranged thereon is arranged displaceably relative to the second electrode layer via a spring device.

[0037] Figure 6 A further modified embodiment of an electromechanical transducer element is shown, in which two electret structures are arranged spaced apart from one another, an electrode layer and a conductor layer are arranged on each electret structure, and in which the electret structures are displaceable relative to the other electret structures via a spring device.

[0038] Figure 7 Shown with Figure 6 A further modified embodiment of an electromechanical transducer element similar to the variant shown in , in which the two electret structures are each arranged displaceably relative to one another via a spring device,

[0039] Figure 8 Shown with Figure 1 A further modified design of an electromechanical transducer element similar to the variant shown in , in which a voltage measuring device is used instead of a charge measuring device,

[0040] Figure 9 Shown with Figure 5 A further modified design of an electromechanical transducer element similar to the variant shown in , in which a voltage measuring device is used instead of a charge measuring device, and

[0041] Figure 10 Shown with Figure 7 A further modified embodiment of an electromechanical transducer element is similar to the variant shown in , in which a voltage measuring device is used instead of a charge measuring device. DETAILED DESCRIPTION

[0042] exist Figure 1 Schematically depicting a first exemplary embodiment of an electromechanical transducer element 1 designed according to the present invention, the electromechanical transducer element 1 comprises a layered electret structure 2 made of an electrically insulating electret material, which contains quasi-permanent electrical charges and thus generates a quasi-permanent electric field in the environment of the electret structure 2. When the electromechanical transducer element 1 is used as intended, the electret structure 2 is deformable and can be bent as well as compressed.

[0043] On a first surface 3 of the electret structure 2, a first electrode layer 4 is arranged in direct contact, covering the electret structure 2 in a planar manner, but not completely overlapping it laterally. The first electrode layer 4 can be of essentially planar design or can have a two-dimensional or three-dimensional structure. On an opposite second surface 5 of the electret structure 2, a second electrode layer 6 is arranged, also in direct contact, covering the electret structure 2 in a planar manner, but not completely overlapping it laterally. The first electrode layer 4 and the second electrode layer 6 are each made of an electrically conductive material, the electret structure 2 forming an electrical insulation between the two electrode layers 4, 6 and preventing them from coming into direct electrically conductive contact with each other.

[0044] The first electrode layer 4 has a first conductive electrode layer contact 7, and the second electrode layer 6 has a second conductive electrode layer contact 8. The first and second conductive electrode layer contacts 7, 8 are interconnected via a first measuring device 9. The first measuring device 9 comprises, for example, a suitable charge amplifier, which can detect any change in charge on the first electrode layer 4 and the second electrode layer 6 and convert it into an evaluable voltage signal. The change in charge can be caused by a deformation of the electret structure 2 or at least one of the two electrode layers 4, 6, or by a relative displacement of the electret structure 2 and at least one of the two electrode layers 4, 6, making it possible to detect forces acting on the electromechanical transducer element 1 and causing the corresponding deformation or displacement using the electromechanical transducer element 1. This makes it particularly advantageous to detect dynamic forces or pressure changes acting on the electromechanical transducer element 1 using the first measuring device 9.

[0045] The first electrode layer 4 is configured as a first conductor layer 10 made of an electrically conductive material and has a first conductor layer contact 11 and a second conductor layer contact 12, which contact the first conductor layer 10 at a distance from one another. The first conductor layer 10 is configured such that deformation of the first conductor layer 10 causes a change in the electrical conductivity between the first conductor layer contact 11 and the second conductor layer contact 12. The first conductor layer contact 11 and the second conductor layer contact 12 are connected to a second measuring device 13, which can be used to detect, for example, the resistance between the first and second conductor layer contacts 11, 12 and convert it into an electrical measurement signal. This makes it particularly advantageous to use the second measuring device 13 to detect deformations of the first conductor layer 10 and, therefore, static forces or pressure acting on the electromechanical transducer element 1.

[0046] The simultaneous use of first electrode layer 4 as first conductor layer 10 allows for a particularly simple, space-saving, and cost-effective construction of electromechanical transducer element 1. Furthermore, first electrode layer 4, electret structure 2, and second electrode layer 6 can be applied as a layer sequence to the surface of an object, wherein a force or pressure acting on the object and on electromechanical transducer element 1 arranged on the surface of the object is to be detected. The individual layers can be printed cost-effectively with a suitable choice of material, thereby enabling the economically viable use of electromechanical transducer element 1 according to the invention in large quantities and in a wide range of applications.

[0047] The further figures show exemplary and schematic representations of various variants of an electromechanical transducer element 1 according to the invention. In the following description of the individual figures, in particular different aspects and features are described without separately mentioning the invariant aspects and features for each variant.

[0048] exist Figure 2 is shown by way of example in another variant of an electromechanical transducer element 1. The second electrode layer 6 is also designed as a second conductor layer 14 and has a first conductor layer contact 15 and, spaced apart therefrom, a second conductor layer contact 16. The first and second conductor layer contacts 15, 16 are likewise connected to one another via a third measuring device 17, with which the resistance between the first and second conductor layer contacts 15, 16 of the second conductor layer 14 can be detected.

[0049] According to this structural design of the electromechanical transducer element 1, the first conductor layer 10 and the second conductor layer 14 or the second and third measuring devices 13, 17 can be evaluated so that either the two measuring devices 13, 17 should generate consistent measurement signals and the accuracy of the measurement can be improved by simultaneously detecting deformations of the first and second conductor layers 10, 14 that are assumed to be similar, or different deformations of the first and second conductor layers 10, 14 can be expected and the difference in the measurement signals of the second and third measuring devices 13, 17 can be detected and evaluated, thereby improving the sensitivity of the electromechanical transducer element 1.

[0050] In the electromechanical transducer element 1 Figure 3 In the embodiment variant shown by way of example in FIG, the first electrode layer 4 is arranged spaced apart from the electret structure 2 and is mounted displaceably on a support device 19 (not shown in greater detail) via a spring device 18. The first electrode layer 4 is simultaneously designed as a first conductor layer 10 and is electrically contacted or connected to the first measuring device 9 and to the second measuring device 13, respectively. Figure 1 and Figure 2 In the case of both embodiment variants, the mechanical properties of the electromechanical transducer element 1 are essentially predetermined by the mechanical properties of the electret structure 2 and the first and second electrode layers 4 , 6 or the object on which the electromechanical transducer element 1 is arranged during its use. Figure 3 In the embodiment variant shown in , the displacement of the first electrode layer 4 relative to the electret structure 2 can be influenced or predetermined by the spring properties of the spring device 18 and by the support device 19. In this way, in addition to the corresponding material selection and structural design of the electret structure 2 and the two electrode layers 4, 6, the sensitivity and the measuring range of the electromechanical transducer element 1 can be influenced and predetermined by the spring device 18 and the support device 19.

[0051] In the electromechanical transducer element 1 Figure 4 In the embodiment variant shown schematically and by way of example, the first conductor layer 10 is designed as an additional layer in addition to the first electrode layer 4 and the second electrode layer 6. The first conductor layer 10 is arranged on the first surface 3 of the electret structure 2. The second electrode layer 6 is arranged on the second surface 5 of the electret structure 2. The electrode layer 4 is mounted at a distance from the first conductor layer 10 so as to be displaceable relative to the first conductor layer 10 and the electret structure 2 via a spring device 18 and a support device 19 (not shown in greater detail). A first measuring device 9 is connected to the first electrode layer 4 and to the second electrode layer 6. A second measuring device 13 is connected to the two electrically conductive conductor layer contacts 11, 12.

[0052] exist Figure 5 Shown in Figure 4A further modified variant of an electromechanical transducer element similar to the variant shown in . Figure 4 Unlike the variant shown in , the electret structure 2 together with the first conductor layer 10 and the second electrode layer 6 arranged thereon are not fixed in position to the object or the support device 19, but are displaceably arranged relative to the first electrode layer 4 fixed in position to the object or the support device 19 via a spring device 18 and a support device 19.

[0053] exist Figure 6 Neutralization Figure 7 The two embodiment variants shown in FIG each show an electromechanical transducer element 1 having two electret structures 2 arranged at a distance from one another. In each electret structure 2, a first electrode layer 4 is arranged on a first surface 3, which simultaneously serves as a first conductor layer 10 and has electrically conductive conductor layer contacts 11, 12 arranged at a distance from one another. In each electret structure 2, a second electrode layer 6 is arranged on an opposite second surface 5. The two electret structures 2 are arranged and oriented relative to one another such that the two conductor layers 10 face one another and are arranged at a distance from one another.

[0054] exist Figure 6 In the embodiment variant shown in , one of the two electret structures 2 is fixed in position on an object or on a support device 19 (not shown in more detail), while the other electret structure 2 is arranged displaceably relative to the first-mentioned electret structure 2 via a spring device 18 and via the support device 19. Figure 7 In the embodiment variant shown in FIG, two electret structures 2 are mounted so as to be displaceable relative to one another via a spring device 18 and via a support device 19 .

[0055] exist Figure 8 and Figure 10 The Figure 1 and Figure 7 There are different implementation variants of Figure 8 and Figure 10 The variants shown in are distinguished essentially by the different designs of the first measuring device 9 , which does not have a charge amplifier but rather a voltage measuring device with which a change in the potential difference caused by a deformation or displacement of the electromechanical transducer element 1 can be detected.

[0056] Electromechanical transducer elements Figure 9 The embodiment shown in Figure 5However, an additional electret structure 2 is fixed to the first electrode layer 4, which is arranged spaced apart from the second electret structure 2 and the conductor layer 10 arranged thereon. Figure 8 and Figure 10 As in the embodiment variant shown in , the first measuring device 9 does not have a charge amplifier, but rather a voltage measuring device.

[0057] If a voltage source is connected to the first and second conductive electrode layer contacts 7, 8 instead of the first measuring device 9, the electromechanical transducer element 1 can be operated as an actuator and forced displacement or deformation of the two electrode layers 4, 6 relative to each other. If a current source is used instead of the second or third measuring device 13, 17 and is connected to the first and second conductive conductor layer contacts 11, 12, respectively, the conductor layer 10 thus connected to the current source can be used for heat generation.

Claims

1. An electromechanical transducer element (1), comprising a first electrode layer (4) made of an electrically conductive material, a second electrode layer (6) made of an electrically conductive material arranged at a distance therefrom, wherein the first and second electrode layers (4, 6) each comprise an electrically conductive electrode layer contact (7, 8), which can be connected to one another via a first measuring device (9), characterized in that: An electret structure (2) made of an electrically insulating electret material is arranged between the first and second electrode layers (4, 6), so that when the electret structure (2) and / or the first electrode layer (4) are deformed, or when the electret structure (2) and at least one electrode layer (4, 6) are displaced relative to each other, the ratio of the charge quantities respectively located in the first and second electrode layers (4, 6) to each other changes, and the electromechanical transducer element (1) has a first conductor layer (10) made of an electrically conductive material, the first conductor layer having a first electrically conductive conductor layer contact portion (11) and a second electrically conductive conductor layer contact portion (12), wherein the first conductor layer (10) is constructed so that deformation of the first conductor layer (10) causes a change in the electrical conductivity between the first conductor layer contact portion (11) and the second conductor layer contact portion (12) of the first conductor layer (10).

2. The electromechanical transducer element (1) according to claim 1, characterized in that The first electrode layer (4) is configured as a first conductor layer (10).

3. The electromechanical transducer element (1) according to claim 1 or claim 2, characterized in that The electromechanical transducer element (1) has a second conductor layer (14) made of an electrically conductive material, the second conductor layer (14) having a first electrically conductive conductor layer contact portion (15) and a second electrically conductive conductor layer contact portion (16), wherein the second conductor layer (14) is configured such that deformation of the second conductor layer (14) causes a change in electrical conductivity between the first electrically conductive conductor layer contact portion (15) and the second electrically conductive conductor layer contact portion (16) of the second conductor layer (14).

4. The electromechanical transducer element (1) according to any one of the preceding claims, characterized in that The first electrode layer (4) is arranged on a first surface (3) of the electret structure (2) and causes deformation of the electret structure (2) together with the first electrode layer (4) arranged on the first surface (3) when a predetermined force is applied.

5. The electromechanical transducer element (1) according to any one of the preceding claims, characterized in that The second electrode layer (6) is arranged on a second surface (5) of the electret structure (2) opposite to the first surface (3) of the electret structure (2), and causes deformation of the electret structure (2) together with the second electrode layer (6) arranged on the second surface (5) when a predetermined force is applied.

6. The electromechanical transducer element (1) according to any one of the preceding claims, characterized in that The first electrode layer (4) and / or the second electrode layer (6) are arranged at a distance from the electret structure (2), and when a predetermined force is applied, the first and / or second electrode layer (4, 6) arranged at a distance from the electret structure (2) is displaced relative to the electret structure (2).

7. The electromechanical transducer element (1) according to claim 6, characterized in that A first and / or second electrode layer (4, 6) arranged at a distance from the electret structure (2) is arranged so as to be displaceable relative to the electret structure (2) counter to a spring force.

8. The electromechanical transducer element (1) according to claim 7, characterized in that A first and / or second electrode layer (4, 6) arranged at a distance from the electret structure (2) is in operative connection with the electret structure (2) via a spring device (18).

9. The electromechanical transducer element (1) according to claim 7, characterized in that A first and / or second electrode layer (4, 6) arranged at a distance from the electret structure (2) and / or the electret structure (2) is connected to a support structure (19) of the electromechanical transducer element (1) via a spring device (18).

10. The electromechanical transducer element (1) according to any one of the preceding claims, characterized in that The first conductor layer (10) and / or the second conductor layer (14) as appropriate consists of a piezoresistive material.

11. The electromechanical transducer element (1) according to any one of the preceding claims, characterized in that The electromechanical transducer element (1) comprises a first electret structure (2) and a second electret structure (2) arranged spaced apart therefrom, wherein both the first electret structure and the second electret structure are arranged between the first electrode layer (4) and the second electrode layer (6).

12. The electromechanical transducer element (1) according to claim 11, characterized in that Two conductor layers (10) are arranged between the first electret structure (2) and the second electret structure (2) in an electrically insulated manner.

13. A sensor, characterized in that: The sensor comprises an electromechanical transducer element (1) according to any one of claims 1 to 12.

14. An actuator, characterized in that: The actuator comprises an electromechanical transducer element (1) according to any one of claims 1 to 12.

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