SENSOR DEVICE

Abstract

Sensor device (1), comprising: at least one first substrate (3); a capacitive sensor (4) for detecting the approach of an object; a piezoelectric sensor (5) for detecting pressure or pressure changes; wherein the capacitive sensor is arranged on a first side of the first substrate (3) and the piezoelectric sensor (5) is arranged on a second side of the first substrate (3), the second side being opposite the first side; or wherein the capacitive sensor (4) and the piezoelectric sensor (5) are arranged on the same side of the substrate (3), characterized in that the sensor device (1) comprises a shield (7) between the capacitive sensor (4) and the piezoelectric sensor (5), wherein the shield (7) is electrically coupled to ground.

Description

Field of invention

[0001] The invention relates to a sensor device. background

[0002] In collaborative robot environments, such as production lines where robot arms simultaneously perform various process steps, but also in combined human-machine environments, conflicts can arise between different robot arms or between humans and robots. Therefore, robot arms are equipped with sensors for environmental perception. Conventional pressure or tactile methods used in sensors rely on mechanical or pneumatic switches, carbon fibers, conductive silicone rubber, conductive elastomers, piezoelectric diodes, or strain gauges. Technologies that have been increasingly developed and used in recent years include capacitive or resistive touch, surface acoustic wave touch, infrared touch, and projective capacitive touch. However, operating collaborative robots at high speeds using these technologies is only possible to a limited extent.Reliable approach, grasping, and manipulation of objects using non-contact and touch sensors is also not satisfactorily possible.

[0003] US 2016 / 0299625A1 describes a sensor device with a capacitive sensor for detecting the approach of an object and a piezoelectric sensor for detecting pressure. Both sensors are integrated into a touch panel.

[0004] CN 2 02 442 824 U describes a bionic, flexible touch sensor array with capacitive and piezoresistive sensors on a common flexible substrate. The sensors are integrated layer by layer and are intended to enable the detection of proximity and pressure.

[0005] US 2010 / 0 156 127 A1 describes a robot gripper with a piezoelectric or capacitive force sensor that measures the contact and pressure force between gripper jaws and an object.

[0006] Against this background, the task is therefore to provide an improved sensor for environmental perception and / or for the reliable grasping and manipulation of objects by a robot arm.

[0007] This problem is solved by the invention specified in the independent claims. Advantageous embodiments are described in the dependent claims. Brief description of the invention

[0008] According to the invention, a sensor device is provided comprising at least a first substrate; a capacitive sensor for detecting the approach of an object; a piezoelectric sensor for detecting pressure or a pressure change; wherein the capacitive sensor is arranged on a first side of the first substrate and the piezoelectric sensor is arranged on a second side of the first substrate, the second side being opposite the first side; or wherein the capacitive sensor and the piezoelectric sensor are arranged on the same side of the substrate. The sensor device (1) further comprises a shield (7) between the capacitive sensor (4) and the piezoelectric sensor (5), wherein the shield (7) is electrically coupled to ground.

[0009] The arrangement of a piezoelectric sensor (P-sensor) and a capacitive sensor (C-sensor) either on the same side or on opposite sides of the same substrate combines the advantages of both sensors and creates an integrated sensor device. In particular, this arrangement makes it possible to detect the approach of an object using the capacitive sensor, as well as to determine pressure or holding force using the piezoelectric sensor.

[0010] The C-sensor, the P-sensor, and the substrate can be designed as flexible films. This allows, for example, robot grippers to be equipped with the sensor over a large area, and the sensor can be adapted to curved substrates.

[0011] The C-sensor detects movements, in particular the approach of objects in an area prior to contact, by a change in capacitance between two electrodes (Differential Measurement Mode) or between an electrode and GND (Single-ended Measurement Mode), or by the combinations of capacitances between several electrodes among themselves and / or GND and spatial reconstruction of the material distribution (Electrical Capacitance Tomography ECT).

[0012] The P-sensor detects forces by generating a surface charge proportional to the pressure (polarization). The integrated sensor, for example on a robot, detects the approach via the C-sensor as well as the force of contact using the P-sensor, thus improving the quality of object gripping. The approach information can be used, for example, to precisely align a robot arm into a better gripping position. The force measurement using the P-sensor ensures a reliable grip (i.e., a robot grips an object with sufficient force to prevent it from being dropped, but not so much as to damage it). The C-sensor is always oriented towards the object being gripped. The P-sensor is obscured by the C-sensor.

[0013] Integrating the C-sensor and P-sensor onto a substrate, i.e., onto a single film, increases the flexibility of the integrated sensor device.

[0014] The advantage of piezoelectric force measurement over other methods, such as capacitive force measurement, lies in the fact that no elastic materials are required for the sensor structure. Such elastic materials (for example, foamed plastics) exhibit poor dynamic behavior, hysteresis effects, and aging effects (irreversible deformation, hardening), resulting in a short lifespan. In comparison, piezoelectric force measurement can be implemented with significantly greater mechanical stability. Purely capacitive touch and proximity sensors (e.g., touchscreens), on the other hand, are not capable of determining the applied force, but rather the area being touched. Furthermore, they cannot be used with many materials (e.g., insulating plastics). Purely piezoelectric sensors, however, cannot register approach processes.However, the combination of both sensor principles is capable of quantitatively detecting both approach and touch.

[0015] In one embodiment of the invention, the sensor device comprises a second substrate, wherein the capacitive sensor is arranged on the first substrate and the piezoelectric sensor is arranged on the second substrate, and wherein the second substrate is laminated onto the first substrate. The P-sensor and C-sensor are thus arranged on different substrates (backplane / frontplane concept). This reduces the yield risk because the two components can initially be manufactured and evaluated independently. This allows for the selection of high-performance C-sensors and P-sensors during the manufacturing process and reduces rejects in the final product.

[0016] The first substrate is bonded to the second substrate by lamination. Through lamination, the C-sensor and P-sensor are combined in a simple and cost-effective way to form the integrated sensor.

[0017] In one embodiment of the invention, a base area of ​​the capacitive sensor essentially coincides with a base area of ​​the piezoelectric sensor, and / or the capacitive sensor and the piezoelectric sensor form a sensor stack. The sensors are arranged either on the same first substrate or stacked one above the other on the first or the second substrate, forming a sensor stack comprising multiple layers. Because the base areas of the capacitive sensor and the piezoelectric sensor coincide, a force can be detected in every approach region (the region where a detected object comes into contact with the sensor device after approaching). In other words, neither sensor has a "blind spot" with respect to the other.

[0018] For laminating the two sensors, a double-sided adhesive film approximately 30 µm thick, commonly used in the medical field, can be employed. This film, with its suitable carrier films and noticeable but not excessive plasticity, can be applied bubble-free and does not significantly affect the mechanical properties of the integrated sensor device. For precise alignment, the lamination can be performed using a C-sensor mounted on a stiffer auxiliary film, which is completely covered by the double-sided adhesive film. The P-sensor can then be unrolled onto this film and precisely aligned.

[0019] The sensor device includes a shield between the capacitive sensor and the piezoelectric sensor. To ensure that both the capacitive (C) and piezoelectric (P) sensors can operate independently and without interaction, the C sensor is shielded from the P sensor by the shield. This shielding requires a shielding electrode between a bottom electrode of the C sensor and a bottom electrode layer of the P sensor. The buffer layer is therefore designed as a shielding electrode and is electrically connected to ground.

[0020] In one embodiment of the invention, the shielding is arranged on the side of the first substrate facing away from the capacitive sensor. In this arrangement, the shielding can be applied directly to the back of the first substrate by screen printing. This can be done in conjunction with the fabrication of the P-sensor on the first substrate during the manufacturing process. The shielding is not part of the P-sensor itself, but can be integrated into it by printing, for example, silver paste (which has high surface conductivity) onto the back of the first substrate. This simplifies the overall manufacturing process.

[0021] In one embodiment of the invention, the capacitive sensor comprises an electrode layer and a bottom electrode, wherein the electrode layer and the bottom electrode are insulated from each other by the first substrate or by a first dielectric insulating layer. In those embodiments of the integrated sensor device in which a first and a second substrate are used, the first substrate assumes the function of the first dielectric insulating layer between the electrode layer and the bottom electrode of the capacitive sensor. This eliminates the need for a separate first dielectric insulating layer. In embodiments in which only the first substrate is provided, the electrode layer must be insulated from the bottom electrode by the first dielectric insulating layer to ensure the proper functioning of the capacitive sensor.

[0022] In one embodiment of the invention, the piezoelectric sensor comprises a bottom electrode layer, preferably made of PEDOT:PSS, a ferroelectric copolymer layer (5b), and a top electrode layer. The P-sensor can be fabricated by screen printing, whereby a layer stack is produced by repeated printing processes. The layer stack forming the P-sensor comprises the bottom electrode layer. This can be formed from approximately 1 µm thick PEDOT:PSS and is deposited on the first or second substrate. Subsequently, for example, an approximately 5 µm thick, pressure-sensitive ferroelectric copolymer layer made of PVDF:TrFE (70:30) and another 1 µm thick top electrode layer made of PEDOT:PSS in the form of a segmented 4x2 array are formed. After printing, the ferroelectric crystallites (PVDF) in the copolymer (PVDF:TrFE) have no preferred orientation. The polarization process aligns these in fields of approximately...The polarization process sets the piezoelectric sensitivity of the layer to 200 V / µm. This polarization process also provides insights into the function and sensitivity, delivering data on the yield and sensitivity variation. Therefore, it serves as a process control in the manufacturing of the P-sensors. The 4x2 array is designed to detect the contact point during gripping. It provides an 8-pixel resolution of the contact point. The segmentation (both number and shape) can be modified for each specific application. The same applies to the shape of the capacitive sensor electrodes.

[0023] In one embodiment of the invention, the sensor device comprises a coating layer for protecting a surface of the sensor device, wherein the coating layer is formed on the electrode layer of the capacitive sensor. The coating layer protects the sensor device from damage caused by contact when gripping and / or handling objects.

[0024] In one embodiment of the invention, the sensor device comprises a second dielectric insulating layer between the shield and the piezoelectric sensor. This second dielectric insulating layer isolates the bottom electrode layer of the P-sensor from the shield, which is a conductive layer at ambient potential. In embodiments of the invention that include a second substrate, the second PET substrate assumes the function of the second dielectric insulating layer.

[0025] According to a second aspect of the invention, a method for producing an integrated piezoelectric and capacitive sensor is provided, comprising providing a first substrate, arranging a capacitive sensor on a first side of the first substrate, and arranging a piezoelectric sensor on a second side of the first substrate, wherein the first side of the substrate faces the second side. The method offers an industrially scalable approach for producing large-area sensors according to the invention in the form of films.

[0026] In one embodiment, the method includes providing a second substrate. Furthermore, the assembly includes depositing the capacitive sensor onto the first substrate, depositing the piezoelectric sensor onto the second substrate, and laminating the first substrate onto the second substrate. Both the capacitive sensor and the piezoelectric sensor are deposited either together on the first substrate or individually on a first and a second substrate. The deposition is carried out layer by layer using industrially scalable printing processes, resulting in a multilayer film that forms the sensor. This allows the sensor to be manufactured cost-effectively on an industrial scale.

[0027] In one embodiment of the process, lamination is carried out using a double-sided adhesive film, the film having a thickness of approximately 30 µm. Compared to embodiments of the invention that use only the first substrate, this lamination offers the advantage of a simpler process configuration. Due to the film's low thickness, the mechanical properties of the sensor film are not significantly affected. Furthermore, two partial sensors (P / C) with a corresponding yield can be bonded together. This reduces the number of rejected end products.

[0028] In one embodiment of the process, the deposition of the capacitive sensor comprises the deposition of an electrode layer and a bottom electrode, and is carried out by inkjet printing. Furthermore, the deposition of the piezoelectric sensor comprises the deposition of a bottom electrode layer, a ferroelectric copolymer layer, and a top electrode layer, and is carried out by screen printing.

[0029] In one embodiment, the method comprises aligning the capacitive sensor with respect to the piezoelectric sensor by aligning the first substrate with respect to the second substrate and / or depositing a shield between the capacitive sensor and the piezoelectric sensor. For combining a capacitive sensor (e.g., ECT-based) and a piezoelectric sensor (e.g., PyzoFlex®-based), the two sensors are geometrically integrated with respect to each other in a multilayer film. This geometric integration is achieved by aligning geometric features of the capacitive sensor with geometric features of the piezoelectric sensor. In embodiments where the piezoelectric sensor is applied to a second substrate and the capacitive sensor is applied to a first substrate, the two substrates are aligned with each other during lamination.For precise alignment, lamination can be performed using a C-sensor attached to a stiffer auxiliary film, which is completely covered by the laminate. The P-sensor can then be unrolled onto this and aligned very accurately.

[0030] In one embodiment of the method, the shield is arranged on the side of the second substrate facing the capacitive sensor, or the shield is formed on the side of the first substrate facing the piezoelectric sensor. The shield serves as an electrode at ambient potential for decoupling the electronic processes in the C-sensor and P-sensor. Therefore, the shield is always positioned between the bottom electrode of the C-sensor (ActiveGuard) and the bottom electrode layer of the P-sensor. The bottom electrode of the C-sensor (ActiveGuard) carries the same signal as the electrode layer. This eliminates parasitic capacitances for the shield and reduces interference from the environment. Instead of the bottom electrode, an additional ground electrode can also be provided. This is advantageous for differential measurements.The buffer layer must be insulated from both the bottom electrode and the bottom electrode layer. Therefore, insulating layers must be provided on each side of the shield. Depending on the embodiment, one of the insulating layers can be formed by either the first or the second substrate.

[0031] In one embodiment, the method comprises depositing a first dielectric insulating layer between the bottom electrode and the electrode layer of the capacitive sensor, and / or depositing a second dielectric insulating layer between the shield and the piezoelectric sensor. The first dielectric insulating layer is part of the capacitive sensor and, in embodiments with only one substrate, insulates its electrode layer from the bottom electrode. In embodiments with only one substrate, the second dielectric insulating layer insulates the bottom electrode layer of the piezoelectric sensor from the shield. In embodiments with both a first and second substrate, the substrates themselves perform the function of the first and second dielectric insulating layers.

[0032] According to a further aspect of the invention, a manipulator device with at least one manipulator finger is provided, each individual manipulator finger comprising at least one sensor device according to the invention. The invention combines the possibility of determining the location of approaching objects with the possibility of determining tactile information upon contact by arranging both a proximity sensor (C-sensor) and a touch sensor (P-sensor) on a film and having them interact with each other. The film can be applied over a large area to the surfaces of robots / machines. Due to the design of the capacitive C-sensor as a film, it is possible for the applied force to be transmitted to the underlying piezoelectric or (piezoelectric and pyroelectric) P-sensor without significantly affecting it.

[0033] According to a further aspect of the invention, a sensor device according to the invention is used to determine the approach of an object to a manipulator device in a collaborative environment. This aspect further includes the general use of a sensor device according to the invention for determining approach. In particular, a signal output by the sensor device can be decomposed into a proximity signal and a touch signal. This allows the approach of an object to the sensor device and the contact of the sensor device by the object to be detected separately.

[0034] For the purposes of this application, approach does not include the approaching object touching the sensor device or a sensor surface.

[0035] According to another aspect of the invention, a sensor device according to the invention is used for the tactile detection of a holding force during a gripping process of a manipulator device. Brief description of the drawings

[0036] Several exemplary embodiments of the invention are described in more detail below. They show: the Fig. Figure 1 shows a schematic structure of a first exemplary embodiment of the sensor device according to the invention; the Fig. Figure 2 shows a schematic structure of a second exemplary embodiment of the sensor device according to the invention; the Fig. Figure 3 shows an exemplary embodiment of a capacitive sensor; the Fig. Figure 4 shows an exemplary embodiment of a piezoelectric sensor; and the Fig. Figure 5 shows an exemplary embodiment of a robot finger according to the invention; the Fig. 6 A schematic overview of signals output by the sensor device. Character description

[0037] Fig. Figure 1 shows a schematic diagram of a first exemplary embodiment of a sensor device 1 according to the invention. The sensor device 1 is formed by a layer stack 2. The layer stack 2 comprises a first substrate 3. A capacitive sensor 4 is arranged on a first side (in the illustration, the upper side) of the first substrate 3. The capacitive sensor 4 serves to detect the approach of an object to the sensor 1 without contact.

[0038] A piezoelectric sensor 5 is arranged on a second side of the first substrate 3 (the lower side in the illustration). The piezoelectric sensor 5 serves to detect pressure and thus to determine a holding force that the object exerts on the sensor 1 when it is in contact with a surface of the sensor device 6.

[0039] The capacitive sensor 3 is formed by an electrode layer 4a and a bottom electrode 4b. A first dielectric insulating layer 4c is arranged between the electrode layer 4a and the bottom electrode 4b, which insulates the electrode layer 4a and the bottom electrode 4b of the capacitive sensor 4 from each other. The electrodes of the electrode layer 4a preferably consist of an ink containing silver.

[0040] The piezoelectric sensor 5 is formed by three layers. A first layer 5a of the piezoelectric sensor 5 forms a bottom electrode layer. The bottom electrode layer 5a is preferably made of PEDOT. It has a thickness of approximately 1 µm. A second layer 5b of the piezoelectric sensor 5 is a ferroelectric copolymer layer, preferably made of PVDF:TrFE in a ratio of 70:30 mol / L, and has a thickness of approximately 5 µm. A third layer 5c of the piezoelectric sensor 5 is a top electrode, preferably made of PEDOT, and has a thickness of approximately 1 µm. A shield (shield GND) 7 is arranged on the second side of the first substrate 3. The shielding 7 serves to electrically shield the capacitive sensor 4 and the piezoelectric sensor 5 from each other. The shielding 7 preferably consists of silver paste and is electrically coupled to ground.

[0041] The sensor device 1 further comprises a second dielectric insulating layer 8. The second insulating layer 8 is arranged between the first substrate 3 and the piezoelectric sensor 5 and serves to isolate the piezoelectric sensor 5 from the first substrate 3. The shielding 7 is arranged between the first substrate 3 and the second dielectric insulating layer 8.

[0042] A further insulating layer (protective layer) 9 is arranged on the capacitive sensor 4. It is formed by a varnish and serves to protect the sensor device 1 when detecting pressure forces resulting from contact with objects.

[0043] Within the layer stack 2, the capacitive sensor 4 and the piezoelectric sensor 5 are aligned with each other. The base areas of the capacitive sensor 4 and the piezoelectric sensor 5 are essentially identical. The entire sensor device 1 forms a flexible film.

[0044] Fig. Figure 2 shows a schematic structure of a second exemplary embodiment of the sensor device 1 according to the invention. The sensor device 1 has, in relation to the Fig. 1. An additional second substrate 10 is applied. The second substrate 10 is a PET substrate. The capacitive sensor 4 is arranged on the first substrate 3, i.e., the electrode layer 4a is applied to the first substrate 3. On one side of the first substrate 3 opposite the electrode layer 4a, the bottom electrode 4b of the capacitive sensor 4 is arranged. The first substrate 3 insulates the electrode layer 4a from the bottom electrode 4b. In this embodiment, it assumes the function of the first dielectric layer 4c. The piezoelectric sensor 5 is arranged on the second substrate 10, i.e., layers 5a, 5b, and 5c are applied to the second substrate 10. The shield 7 is arranged between the first substrate 3 and the second substrate 10. The first substrate 3 is connected to the second substrate 10 by a laminate layer 11, the laminate layer 11 being arranged between the bottom electrode 4b and the shield 7.Laminate layer 11 is an adhesive layer.

[0045] Fig. Figure 3 shows an exemplary embodiment of a capacitive sensor 4. The capacitive sensor is designed as a film and comprises the first substrate 3, onto which the electrode layer 4a is applied. The electrode layer consists of three top electrodes and has a first geometric pattern 12. Beneath the top electrode is a common bottom electrode 4b (also referred to as the ActiveGuard layer). The top electrode and the bottom electrode are insulated from each other by the first substrate 3.

[0046] Fig. Figure 4 shows an exemplary embodiment of a piezoelectric sensor 5. The piezoelectric sensor 5 is designed as a film and comprises the second substrate 10, onto which the layers 5a, 5b, and 5c are applied. The first layer 5a of the piezoelectric sensor 5 has a second geometric pattern 13. The first layer 5a of the piezoelectric sensor 5 is segmented and forms a 4x2 array. In the sensor device 1, the geometric patterns 12 and 13 of the two sensors 4 and 5 are aligned with each other.

[0047] Fig. Figure 5 shows an exemplary embodiment of a manipulator finger 14 according to the invention. The manipulator finger 14 has a front and a back, the back of which carries a circuit board 15 for controlling the sensor 1. The sensor device 1 is arranged on the (not visible) front of the manipulator finger 14. The front of the manipulator finger 14 forms the gripping surface of the manipulator and carries the sensor device 1. The manipulator finger 14 preferably has a flat gripping surface of 62 mm x 62 mm. In an operating state, the sensor device 1 is arranged on the manipulator element 14. The sensor is oriented such that the protective layer 9 forms a sensor surface 6 facing the objects to be detected. The approach of an object to the sensor device 1 is detected without contact by means of the capacitive sensor 4.When an object is to be manipulated using the manipulator element 14, the piezoelectric sensor 5 determines the forces occurring between the manipulator element 14 and the object after the object has made contact with the surface of the sensor device 6. Because the sensors are designed as flexible sensor stack films, the forces are mechanically transmitted from the capacitive sensor 4 to the piezoelectric sensor 5 and measured by it.

[0048] Fig.Figure 6 shows a schematic overview of the signals output by the sensor device 1, or the decomposition of an output signal into different signal components. The layer stack 2, which forms the sensor device 1, generates a signal comprising two signal components. The capacitive sensor 4 generates a first signal component 16, which is interpreted and output as a proximity signal by a proximity detection device 17. The proximity detection device 17 is connected to the sensor stack 2 via an electrical connection. The piezoelectric sensor 5 generates a second signal component 18, which is interpreted as a touch signal by a touch detection device 19. The touch detection device 19 is also connected to the sensor stack 2 via an electrical connection. A proximity signal can be a three-dimensional reconstruction of the surrounding space (x, y, z).An approach signal can also be interpreted as a cross-sectional image, i.e., a two-dimensional reconstruction (x,z or y,z) of the surrounding space. Pure distance information (z) can also be output. A threshold value for the distance can be defined. Below this threshold, a detection signal can be output, or the output of the approach signal can be limited to cases where the distance threshold is not met. This reduces unwanted detections. Reference symbol list 1 Sensor device 2 layer stacks 3 first substrate 4 capacitive sensors 4a Electrode layer 4b Bottom electrode 4c first dielectric insulating layer 5 piezoelectric sensor 5a First layer of the piezoelectric sensor (bottom electrode layer) 5b Second layer of the piezoelectric sensor (ferroelectric layer) 5c third layer of the piezoelectric sensor (top electrode layer) 6 Surface of the sensor device 7 Shielding 8 second dielectric insulating layer 9 Protective layer 10 second substrate 11 laminate layers 12 first geometric pattern 13 second geometric pattern 14 manipulator fingers 15 circuit boards 16 First signal component (approach signal) 17 Proximity detection device 18 second signal component (touch signal) 19 Device for touch detection

Claims

[1] Sensor device (1) comprising: at least one first substrate (3); a capacitive sensor (4) for detecting the approach of an object; a piezoelectric sensor (5) for detecting pressure or pressure changes; wherein the capacitive sensor is arranged on a first side of the first substrate (3) and the piezoelectric sensor (5) is arranged on a second side of the first substrate (3), the second side being opposite the first side; or wherein the capacitive sensor (4) and the piezoelectric sensor (5) are arranged on the same side of the substrate (3), characterized by , that the sensor device (1) comprises a shield (7) between the capacitive sensor (4) and the piezoelectric sensor (5), wherein the shield (7) is electrically coupled to ground. [2] Sensor device (1) according to claim 1, comprising: a second substrate (10); wherein the capacitive sensor (4) is arranged on the first substrate (3); and wherein the piezoelectric sensor (5) is arranged on the second substrate (10); and wherein the second substrate (10) is laminated onto the first substrate (3). [3] Sensor device (1) according to claim 1 or 2, wherein a base surface of the capacitive sensor (4) substantially coincides with a base surface of the piezoelectric sensor (5), and / or wherein the capacitive sensor (4) and the piezoelectric sensor (5) form a sensor stack (2). [4] Sensor device (1) according to claim 1, 2 or 3, wherein the shielding (7) is arranged on a side of the first substrate (3) facing away from the capacitive sensor (4). [5] Sensor device (1) according to one of the preceding claims, wherein the capacitive sensor (4) comprises: an electrode layer (4a); a bottom electrode (4b); wherein the electrode layer (4a) and the bottom electrode (4b) are insulated from each other by the first substrate (3) or by a first dielectric insulating layer (4c). [6] Sensor device (1) according to one of the preceding claims, wherein the piezoelectric sensor (5) further comprises: a bottom electrode layer (5a) preferably formed from PEDOT:PSS. a ferroelectric copolymer layer (5b); and a top electrode layer (5c). [7] Sensor device (1) according to one of the preceding claims, comprising a paint layer (9) for protecting a surface of the sensor device (6), wherein the paint layer (9) is formed on the electrode layer (4a) of the capacitive sensor (4). [8] Sensor device (1) according to any one of the preceding claims, comprising: a second dielectric insulating layer (8) between the shielding (7) and the piezoelectric sensor (5). [9] Sensor device (1) according to any one of the preceding claims, comprising: a proximity detection device (17) for detecting a first signal (16) from the capacitive sensor (4), wherein the first signal (16) is a proximity signal; and / or a touch detection device (19) for detecting a second signal (18) from the piezoelectric sensor (5), wherein the second signal (18) is a touch signal. [10] Manipulator device, comprising at least one manipulator finger (14), wherein each individual manipulator finger (14) comprises at least one sensor device (1) according to any one of claims 1-9. [11] Use of a sensor device (1) according to one of claims 1-9 for determining the approach of an object; in particular to a manipulator device in a collaborative environment and for tactilely detecting a holding force during a gripping process of a manipulator device.

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