Sensor device

Abstract

The invention relates to a sensor device (100) for detecting hydrogen, comprising a substrate (10) having a flexural body (11) and a functional layer stack (20) on a surface of the flexural body (11), the functional layer stack (20) comprising at least one sensor layer (21) and an adhesion promoter layer (22) between the surface and the sensor layer (21), and the sensor layer (21) being provided and designed to have a volume which is dependent on the hydrogen concentration.

Description

[0001] P2024, 0869 WO N July 18, 2025

[0002] 1

[0003] Description

[0004] Sensor device

[0005] A sensor device is specified. In particular, the sensor device can be designed and configured for the detection of hydrogen. Thus, the sensor device is particularly preferably configured as a hydrogen sensor.

[0006] Hydrogen sensors are known, for example, from publications US 7,340,941 B1, US 10,866,203 B2 and EP 2 520 928 B1.

[0007] At least one function of certain implementation forms is to specify a sensor device.

[0008] This problem is solved by an article according to the independent patent claim. Advantageous

[0009] The various forms and further developments of the subject matter are characterized in the dependent claims and are further shown in the following description and drawings.

[0010] A sensor device is specified according to at least one embodiment. The sensor device may, in particular, be configured as a sensor device for the detection of hydrogen. For example, the sensor device may be designed and configured for measuring the concentration of hydrogen in an environment surrounding the sensor device. P2024, 0869 WO N 18 July 2025

[0011] 2

[0012] According to another embodiment, the sensor device has a sensor layer that can change at least one physical property depending on the hydrogen content. The hydrogen content in the sensor layer can, in particular, depend on the hydrogen concentration surrounding the sensor layer. Accordingly, at least one physical property of the sensor layer can depend on the hydrogen concentration surrounding the sensor layer. Particularly preferably, the sensor layer is designed and configured to have a volume that depends on the hydrogen concentration. Thus, for example, the sensor layer can have an increasing volume with an increasing hydrogen concentration in the environment.The sensor layer material can be specifically designed and intended to absorb hydrogen, whereby the hydrogen atoms can be incorporated, for example, into interstitial sites within the atomic lattice of the sensor layer material. The higher the hydrogen concentration in the environment surrounding the sensor layer, the more hydrogen can be absorbed into the sensor layer. If the hydrogen concentration in the environment decreases, hydrogen can be released from the sensor layer back into the environment. This results in a volume change of the sensor layer that depends on the surrounding hydrogen concentration. This property is subsequently referred to as hydrogen-dependent volume change.

[0013] According to another embodiment, the sensor layer comprises one or more materials selected from: palladium, yttrium, scandium, a lanthanide, an acetylide, wolfram oxide, vanadium oxide, and mixtures thereof, P2024, 0869 WO N 18 July 2025

[0014] 3

[0015] Compounds and alloys with one or more of the aforementioned materials. The sensor layer particularly preferably comprises palladium or an alloy, mixture, or compound containing palladium. For example, the sensor layer comprises pure palladium or an alloy of palladium and one or more selected elements from gold, silver, and nickel, or is composed of these elements, i.e., Pd, PdAu, PdAg, and / or PdNi.

[0016] According to another embodiment, the sensor device includes a bending body. The bending body has a surface on which the sensor layer is applied. Here and in the following, the term "bending body" refers to a structure on which the sensor layer is applied. A change in the volume of the sensor layer due to a changing hydrogen concentration in the vicinity of the sensor layer can cause the sensor layer to exert mechanical stress on the surface of the bending body, and thus on the bending body itself, so that it can deform. In particular, the bending body can be designed such that it can deform in at least one spatial direction due to the hydrogen-dependent volume change of the sensor layer.The degree of deformation of the bending body can thus provide information about the amount of hydrogen fs incorporated into the sensor layer and, in turn, about the hydrogen concentration in the environment of the sensor layer.

[0017] According to another embodiment, the bending body is part of a substrate. In other words, the sensor device can have a substrate with the bending body. The substrate and the elements and structures applied therein and on it, such as the bending body, can be described in P2024, 0869 WO N 18 July 2025.

[0018] 4. The substrate is preferably manufactured using MEMS technology (MEMS: "micro electromechanical system"), so that the substrate with the bending body can be designed, in particular, as a MEMS chip. MEMS technology enables small dimensions and a high degree of integration. For example, lithographic process steps can be used in the manufacture of the sensor device and, in particular, the bending body. Furthermore, additional elements and components, such as electrically conductive layers and / or electrically insulating layers and / or electrical components, can be arranged in and / or on the substrate. In particular, at least one resistive element can be formed in the area of ​​the bending body.At least one resistive element of the bending body, or the bending body as a whole, or the substrate with the bending body as a whole, can, for example, comprise a piezoresistive material whose electrical resistance changes with deformation. Preferably, the substrate with the bending body can comprise silicon or consist essentially of silicon. Furthermore, several resistive elements can be present in the region of the bending body, which can be connected, for example, via a bridge circuit. Thus, the sensor device can comprise one or more voltage-sensitive MEMS elements. By measuring the electrical resistance of the at least one resistive element, conclusions can be drawn about the deformation and the change in deformation of the bending body, which in turn can be a measure of a change in the volume of the sensor layer.As described above, this allows conclusions to be drawn about the hydrogen content in the sensor layer and thus also about the hydrogen concentration in the vicinity of the sensor layer. P2024, 0869 WO N 18. July 2025.

[0019] 5

[0020] According to another embodiment, the bending body is designed as a membrane. The thinner the bending body, the greater the deformation it can exhibit due to a change in the volume of the sensor layer. For example, the bending body can be designed as a full-surface, and therefore closed, membrane. Furthermore, the substrate can have an opening, and the bending body can be designed as a structure spanning the opening. For example, the bending body can be beam-shaped as a beam fixed at both ends, or cross-shaped as two intersecting and connected beams, each fixed at both ends. Alternatively, the substrate can have an opening, and the bending body can be designed as a beam fixed at one end projecting into the opening. The beam can have a uniform width or, preferably, a width that decreases with increasing distance from an edge region of the opening.

[0021] According to another embodiment, the sensor device comprises a functional layer stack with the sensor layer. The functional layer stack is applied to the surface of the bending body, with the sensor layer preferably being applied to an upper surface of the functional layer stack facing away from the surface of the bending body. To protect the sensor layer and, in particular, the functional layer stack, it can, for example, be covered with a hydrogen-permeable protective layer. The protective layer can be silicon-based. For example, the protective layer can contain or be composed of silicon oxide. Furthermore, the protective layer can, for example, be based on or be composed of one or more polymers and / or P2024, 0869 WO N 18 July 2025

[0022] 6. They exhibit water-repellent properties. For example, the protective layer can be hydrophobic.

[0023] According to another embodiment, the sensor device has an adhesion promoter layer between the surface of the bent body and the sensor layer. The adhesion promoter layer is particularly a component of the functional layer stack, such that the functional layer stack between the surface of the bent body and the sensor layer includes the adhesion promoter layer. The adhesion promoter layer is particularly preferably applied directly to the surface of the bent body and is thus in direct mechanical contact with the surface of the bent body.

[0024] The adhesion promoter layer can be specifically designed and configured to exhibit good adhesion properties to the surface of the bending body. "Good adhesion properties" can, in particular, mean that the adhesion promoter layer has better adhesion properties to the surface of the bending body than the sensor layer, or than the sensor layer and all other layers of the functional layer stack. In other words, the material of the adhesion promoter layer can exhibit at least better adhesion than the aforementioned material of the sensor layer.

[0025] According to another embodiment, the adhesion promoter layer comprises one or more materials selected from chromium, platinum, titanium, nickel, and vanadium. For example, the adhesion promoter layer can be made of a pure material and thus consist essentially of one of the aforementioned materials. A “pure” material and “in P2024, 0869 WO N 18 July 2025

[0026] 7

[0027] The phrase "consist substantially of one material" can mean, in particular, that the material is present in the adhesion promoter layer at a level of purity that is technically feasible. Thus, a pure material may contain impurities that are unavoidable for technical reasons. For example, the adhesion promoter layer may contain at least 90%, at least 95%, at least 99%, or at least 99.9% of the material of which the adhesion promoter layer essentially consists. Percentages here and in the following may be, in particular, mass percent. Furthermore, the adhesion promoter layer may contain an alloy, in particular an alloy with one or more of the aforementioned materials. For example, the adhesion promoter layer may contain a chromium-rich CrAl alloy, for example, with 67% Cr and 33% Al, or a nickel-rich NiV alloy, for example, with 93% Ni and 7% V.

[0028] A gold-free adhesion promoter layer is particularly preferred. "Gold-free" can mean, in particular, that the adhesion promoter layer contains no gold within the scope of usual technical possibilities, and that gold is present only as an impurity.

[0029] According to another embodiment, the adhesion promoter layer has a thickness sufficient to form a complete and gapless layer. For example, the adhesion promoter layer can have a thickness greater than or equal to 1 nm, or greater than or equal to 2 nm, or greater than or equal to 5 nm. Furthermore, the adhesion promoter layer can have a thickness less than or equal to 15 nm, or less than or equal to 10 nm. The thinner the adhesion promoter layer, the less it can prevent the deformation of the bending body. P2024, 0869 WO N 18 July 2025

[0030] 8. influence and hinder. The adhesion promoter layer can preferably be applied by sputtering, atomic layer deposition or vapor deposition.

[0031] The adhesion promoter layer can, for example, be directly adjacent to the sensor layer. In this case, the functional layer stack can consist of the adhesion promoter layer and the sensor layer, with the adhesion promoter layer being applied directly to the surface of the bending body.

[0032] Furthermore, the functional layer stack can include a diffusion barrier layer between the sensor layer and the adhesion promoter layer. The diffusion barrier layer can be designed and configured to be impermeable to hydrogen, so that preferably no hydrogen can pass from the sensor layer to the adhesion promoter layer. Particularly preferably, the diffusion barrier layer can comprise or consist of one or more metals, an alloy, or a compound containing one or more metals. For example, the diffusion barrier layer can comprise or consist of one or more materials selected from gold, silver, platinum, a nitride such as silicon nitride (Si₂Na), and an oxide such as aluminum oxide (Al₂O₃) and / or silicon oxide (SiO₂). Particularly preferably, the diffusion barrier layer can comprise or consist of gold.The diffusion barrier layer is preferably as thin as possible, with a thickness sufficient to achieve the desired barrier effect. For example, the diffusion barrier layer has a thickness greater than or equal to 5 nm and less than or equal to 15 nm. P2024, 0869 WO N 18. July 2025.

[0033] 9

[0034] The sensor device described here is preferably designed as a hydrogen MEMS sensor, as described above. Its measuring function is based on the volume change of the sensor layer, preferably palladium-based, and the resulting deformation of the bending body. This deformation can be detected by reading the electrical resistance of one or more voltage-sensitive MEMS elements. A weak and / or unstable adhesion of the sensor layer to the bending body, which could reduce the sensitivity and stability of the sensor layer and thus its performance and service life, is prevented by the adhesion promoter layer. This layer is particularly preferably applied directly to the surface of the bending body, which may, for example, have silicon or silicon oxide as its surface material.

[0035] Further advantages, advantageous implementation forms and further developments result from the exemplary implementations described below in conjunction with the figures.

[0036] Figures 1A and 1B show schematic representations of a sensor device according to one embodiment, Figure 2 shows a schematic representation of a sensor device according to another embodiment.

[0037] Figure 3 shows a schematic representation of part of a sensor device according to a further embodiment.

[0038] Figure 4 shows a schematic representation of part of a sensor device according to a further embodiment, P2024, 0869 WO N 18 July 2025

[0039] 10

[0040] Figure 5 shows a schematic representation of a sensor device according to a further embodiment ,

[0041] Figure 6 shows a schematic representation of a sensor device according to a further embodiment ,

[0042] Figure 7 shows a schematic representation of a sensor device according to a further embodiment ,

[0043] Figure 8 shows a schematic representation of a sensor device according to a further embodiment ,

[0044] Figure 9 shows a schematic representation of a sensor device according to a further embodiment.

[0045] Figure 10 shows a schematic representation of a sensor device according to a further embodiment.

[0046] In the examples and figures, identical, similar, or similarly functioning elements may each be designated with the same reference symbols. The depicted elements and their relative sizes are not to be considered to scale; rather, individual elements, such as layers, components, building elements, and areas, may be exaggeratedly large for better illustration and / or understanding.

[0047] Figures 1A and 1B show an exemplary embodiment of a sensor device 100 for the detection of hydrogen. In particular, the sensor device 100 can be designed and configured for measuring the concentration of hydrogen in the vicinity of the sensor device 100. P2024, 0869 WO N 18 July 2025

[0048] 11

[0049] The sensor device comprises a substrate 10 with a bending body 11. Furthermore, the sensor device 100 has a functional layer stack 20 with a sensor layer 21 on the substrate 10. The functional layer stack 20 is preferably applied to the surface of the bending body 11, with the sensor layer 21 preferably being applied to a top surface of the functional layer stack 20 facing away from the surface of the bending body 11.

[0050] The sensor layer 21 is configured to change at least one physical property depending on the hydrogen concentration contained within it. Particularly preferably, the sensor layer 21 is designed and configured to have a volume that depends on the amount of hydrogen present in the sensor layer 21. As described in the general section, the sensor layer 21 has an increasing volume with increasing hydrogen content, since the material of the sensor layer 21 can absorb hydrogen and, for example, incorporate it into interstitial sites. This allows a hydrogen-dependent volume change of the sensor layer 21 to be achieved, with the amount of incorporated hydrogen depending on the hydrogen concentration in the atmosphere surrounding the sensor layer 21.For example, the sensor layer 21 contains palladium or an alloy of palladium and one or more selected from gold, silver and nickel, such as PdAu, PdAg and / or PdNi.

[0051] A change in volume of sensor layer 21 due to a changing hydrogen concentration in the environment of sensor layer 21 leads to the sensor layer having a P2024 , 0869 WO N 18 July 2025

[0052] 12. Mechanical stress is exerted on the surface of the bending body 11, and thus on the bending body 11 itself, causing it to deform, as indicated in Figure 1B. The degree of deformation of the bending body 11 can therefore provide information about the amount of hydrogen incorporated into the sensor layer 21 and thus about the hydrogen concentration in the vicinity of the sensor layer 21. The bending body 11 is designed as a membrane to deform as easily as possible when the volume of the sensor layer 21 changes. The thinner the bending body 11, the greater the deformation of the bending body 11 that can be caused by a change in the volume of the sensor layer 21.

[0053] The substrate 10 and the elements and structures applied therein and on it, such as the bending body 11, can preferably be manufactured using MEMS technology (MEMS: "micro electro-mechanical system"), so that the substrate 10 with the bending body 11 can be configured, in particular, as a MEMS chip characterized by small dimensions and a high degree of integration. For example, lithographic process steps can be used in the manufacture of the sensor device 100 and, in particular, the substrate 10 with the bending body 11. Furthermore, additional elements and components, such as electrically conductive layers and / or electrically insulating layers and / or electrical components, can be arranged or formed in and / or on the substrate 10. In particular, at least one resistive element 12 can be formed in the region of the bending body 11.At least one resistance element 12 of the bending body 11, or the entire bending body 11, or the substrate 10 with the bending body 11, can be, for example, a piezoresistive P2024, 0869 WO N 18. July 2025.

[0054] 13

[0055] The material must have an electrical resistance that changes with deformation. Preferably, the substrate 10 with the bending body 11 can have silicon or consist essentially of silicon and silicon compounds. For example, several resistance elements can also be present in the area of ​​the bending body, which can be connected in the form of a Wheatstone bridge circuit. Thus, the sensor device 100 can have one or more voltage-sensitive MEMS elements. By measuring the electrical resistance, conclusions can be drawn about the deformation and change in deformation of the bending body 11, which in turn can be a measure of a change in volume of the sensor layer 21. As described above, this can be used to determine the hydrogen concentration in the sensor layer 21 and thus also the hydrogen concentration in the environment.

[0056] Furthermore, the sensor device 100 has connection elements 30 for mechanical and electrical mounting of the sensor device 100 on a substrate such as a printed circuit board. The orientation of the sensor device 100 can be defined by the connection elements 30 and the mounting direction they define. Accordingly, the side of the sensor device 100 with the connection elements 30 can be defined as the underside, and the side opposite the connection elements 30 as the top side of the sensor device 100 and thus of the substrate 10. Similarly, the bent body 11 has a top side facing the top side of the sensor device 100 and a bottom side facing the underside of the sensor device 100. In the embodiment shown in Figures 1A and 1B, the functional layer stack 20 is located on the top side of the bent body. P2024, 0869 WO N 18. July 2025

[0057] 14

[0058] 11. The connection elements 30 can, for example, also be provided for mechanical mounting only and thus be mechanical connection elements. In this case, additional electrical connection elements (not shown) can be present, which can particularly preferably be arranged on the top side of the sensor device 100, i.e., in particular next to the functional layer stack 20.

[0059] Alternatively, as shown in a further embodiment in Figure 2, the functional layer stack 20 can be arranged on the underside of the bending body 11, with all other features and properties of the embodiment shown in Figure 2 being designed as in the embodiment of Figures 1A and 1B. All embodiments, features, and properties described below can refer to a functional layer stack 21 arranged on the top or bottom of the bending body 11.

[0060] Figure 3 shows a section of the sensor device 100, including a part of the bending body 11 and the functional layer stack 20 with the sensor layer 21, which, as described above, is arranged on a side of the functional layer stack 20 facing away from the bending body 11 and is designed as described above.

[0061] Furthermore, the sensor device 100, and thus the functional layer stack 20, has an adhesion promoter layer 22 between the surface of the bending body 11 and the sensor layer 21. The adhesion promoter layer 22 is particularly preferably applied directly to the surface of the P2024, 0869 WO N 18, July 2025.

[0062] 15

[0063] applied to the bending body 11 and is therefore in direct mechanical contact with the surface of the bending body 11 .

[0064] The adhesion promoter layer 22 is designed and configured to exhibit good adhesion properties on the surface of the bending body 11 and, in particular, to facilitate good adhesion between the surface of the bending body 11 and the layer applied to the adhesion promoter layer 22, i.e., in the illustrated embodiment, the sensor layer 21. In particular, the adhesion promoter layer 22 can exhibit better adhesion properties with respect to the surface of the bending body 11 than the sensor layer 21 or than the sensor layer 21 and all other layers of the functional layer stack 20.

[0065] The adhesion promoter layer 22 comprises one or more materials selected from chromium, platinum, titanium, nickel, and vanadium. For example, the adhesion promoter layer 22 can consist substantially of one of the aforementioned materials and comprise at least 90%, 95%, 99%, or 99.9% of said material. Furthermore, the adhesion promoter layer 22 can comprise an alloy, in particular an alloy with one or more of the aforementioned materials. For example, the adhesion promoter layer 22 can comprise a chromium-rich CrAl alloy, for example, with 67% Cr and 33% Al, or a nickel-rich NiV alloy, for example, with 93% Ni and 7% V. Particularly preferably, the adhesion promoter layer 22 is free of Au.

[0066] The adhesion promoter layer 22 is applied by sputtering, atomic layer deposition or vapor deposition and has a thickness sufficient to accommodate a P2024, 0869 WO N 18 July 2025

[0067] 16. A complete and uninterrupted layer is formed to act as an adhesion promoter over the entire surface. Preferably, the adhesion promoter layer 22 has a thickness of ≥ 1 nm, ≥ 2 nm, or ≥ 5 nm. Furthermore, the adhesion promoter layer 22 has a thickness of ≤ 15 nm, ≤ 10 nm, with a smaller thickness being advantageous to minimize or prevent the deformation of the bending body 11.

[0068] In the embodiment shown in Figure 3, the adhesion promoter layer is directly adjacent to the sensor layer 21, so that the functional layer stack 20 in this embodiment consists of the adhesion promoter layer 22 and the sensor layer 21, and the adhesion promoter layer 22 is applied directly to the surface of the bending body.

[0069] Figure 4 shows a further embodiment in a view corresponding to Figure 3, in which the functional layer stack 20 between the sensor layer 21 and the adhesion promoter layer 22 additionally comprises a diffusion barrier layer 23. The diffusion barrier layer 23 is impermeable to hydrogen, so that no hydrogen can escape from the sensor layer.

[0070] 21 can reach the adhesion promoter layer 22. This prevents the adhesive effect of the adhesion promoter layer 22 from being impaired by hydrogen, which may, for example, react with a material of the adhesion promoter layer.

[0071] 22 could react, could be affected.

[0072] For example, the D f fusion barrier layer 23 comprises one or more materials selected from gold, silver, platinum, a nitride such as silicon nitride (Si2Na), and an oxide such as P2024, 0869 WO N 18. July 2025

[0073] 17

[0074] The fusion barrier layer 23 comprises or is composed of aluminum oxide (Al₂O₃) and / or silicon oxide (SiO₂). The fusion barrier layer 23 particularly preferably comprises or is composed of gold. The fusion barrier layer 23 preferably has a thickness greater than or equal to 5 nm and less than or equal to 15 nm.

[0075] To protect the functional layer stack 20, it can be covered with a hydrogen-permeable protective layer 40, as shown by way of example in Figure 5 in an embodiment corresponding to the embodiment shown in Figures 1A and 1B. In other words, the functional layer stack 20 can be encapsulated by the protective layer 40. The protective layer 40 can particularly preferably protect the functional layer stack 20 from damaging environmental influences such as moisture or harmful gases and is particularly preferably based on silicon. In particular, the protective layer can comprise or be composed of silicon oxide. Furthermore, the protective layer 40 can, for example, be based on or be composed of one or more polymers and / or have water-repellent properties. For example, the protective layer can be hydrophobic.

[0076] Figures 6 to 10 show the sensor device 100 in top views of the functional layer stack 20 and in particular the sensor layer 21 in several exemplary embodiments for the geometric design of the bending body 11 and the functional layer stack 20 with the sensor layer 21.

[0077] As shown in Figure 6, the bending body 11 can be configured as a fully surfaced and closed membrane. For example, the bending body 11 and the functional layer stack 20 with the sensor layer 21 P2024 , 0869 WO N 18 July 2025

[0078] 18. They must be circular in shape. Alternatively, other shapes are also possible, such as a polygonal or elliptical shape.

[0079] Furthermore, the substrate 10, as shown in Figures 7 to 10, can have an opening 19, and the bending body 11 can be configured as a structure spanning the opening 19 or as a structure projecting into the opening 19. As shown in Figure 7, the bending body 11 can be configured in a cross shape as two intersecting beams, each fixed at two sides and connected to one another. In other words, the bending body 11, together with the functional layer stack 20 and the sensor layer 21, is configured in the shape of a window cross.

[0080] Figure 8 shows another embodiment in which the bending body 11 is designed as a beam fixed on two sides. In other words, the bending body 11 spans the opening 19 like a bridge.

[0081] According to the exemplary embodiments shown in Figures 9 and 10, the bending body 11 is designed as a beam fixed at one end. The beam can have a uniform width, as indicated in Figure 9, or preferably a width that decreases with increasing distance from an edge region of the opening 19, as indicated in Figure 10.

[0082] The features and embodiments described in connection with the figures can be combined with one another according to further embodiments, even if not all combinations are explicitly described. Furthermore, the features and embodiments described in connection with figures P2024, 0869 WO N 18 July 2025

[0083] The embodiments described in Section 19 may alternatively or additionally have further features as described in the general part. The invention is not limited to the description based on the embodiments. Rather, the invention encompasses every new feature as well as every combination of features, which in particular includes every combination of features in the claims, even if that feature or combination itself is not explicitly stated in the claims or embodiments.

[0084] P2024, 0869 WO N July 18, 2025

[0085] 20

[0086] Reference symbol list

[0087] 10 substrate

[0088] 11 Bending body 12 Resistance element

[0089] 19 Opening

[0090] 20 functional layer stacks

[0091] 21 Sensor layer

[0092] 22 Bonding agent layer 23 Diffusion barrier layer

[0093] 30 Connection element

[0094] 40 protective layer

[0095] 100 sensor device

Claims

P2024, 0869 WO N July 18, 2025 21 Patent claims 1. Sensor device (100) for the detection of hydrogen, comprising - a substrate (10) with a bending body (11) and - a functional layer stack (20) on a surface of the Bending body (11) , wherein the functional layer stack (20) has at least one sensor layer (21) and an adhesion promoter layer (22) between the surface and the sensor layer (21), wherein the sensor layer (21) is provided and configured to have a volume dependent on a hydrogen concentration.

2. Sensor device (100) according to claim 1, wherein the sensor layer (21) comprises or is made of palladium.

3. Sensor device (100) according to one of the preceding claims, wherein the adhesion promoter layer (22) is applied directly to the surface of the bending body (11).

4. Sensor device (100) according to one of the preceding claims, wherein the adhesion promoter layer (22) comprises one or more materials selected from chromium, platinum, titanium, nickel and vanadium.

5. Sensor device (100) according to one of the preceding claims, wherein the adhesion promoter layer (22) is free of gold. P2024, 0869 WO N July 18, 2025 22 6. Sensor device (100) according to one of the preceding claims, wherein the adhesion promoter layer (22) comprises an alloy.

7. Sensor device (100) according to one of the preceding claims, wherein the adhesion promoter layer (22) comprises a chromium-rich CrAl alloy or a nickel-rich NiV alloy.

8. Sensor device (100) according to one of the preceding claims, wherein the adhesion promoter layer (22) has a thickness greater than or equal to 1 nm and less than or equal to 15 nm.

9. Sensor device (100) according to one of the preceding claims, wherein the sensor layer (21) is applied to a top surface of the functional layer stack (20) facing away from the surface of the bending body (11).

10. Sensor device (100) according to one of the preceding claims, wherein the functional layer stack (20) has a diffusion barrier layer (23) between the sensor layer (21) and the adhesion promoter layer (22).

11. Sensor device (100) according to claim 10, wherein the diffusion barrier layer (23) comprises or is made of gold.

12. Sensor device (100) according to one of the preceding claims, wherein the bending body (11) is designed as a membrane. P2024, 0869 WO N July 18, 2025 23 13. Sensor device (100) according to one of the preceding claims, wherein the bending body (11) is designed as a full-surface membrane.

14. Sensor device (100) according to one of the preceding claims, wherein the substrate (10) has an opening (19) and the bending body (11) is designed as a structure spanning the opening.

15. Sensor device (100) according to claim 14, wherein the bending body (11) is cross-shaped.

16. Sensor device (100) according to claim 14, wherein the bending body (11) is beam-shaped.

17. Sensor device (100) according to one of claims 1 to 13, wherein the substrate (10) has an opening (19) and the bending body (11) is designed as a beam fixed on one side projecting into the opening (19).

18. Sensor device (100) according to claim 17, wherein the beam has a decreasing width with increasing distance from an edge region of the opening (19).

19. Sensor device (100) according to one of the preceding claims, wherein the bending body (11) comprises a piezoresistive material.

20. Sensor device (100) according to one of the preceding claims, wherein the sensor device (100) is a MEMS component.

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