component

Abstract

The invention relates to the field of electrical engineering / electronics and relates to a component which can be used, for example, for microfluidic applications, for the prevention and / or elimination of icing on surfaces. The object of the present invention is to provide a component which can realize several functions on a substrate or on a layer without changes to the electrode arrangements. The problem is solved by a component which consists of at least one acoustic component, one signal component, and one potential control component, wherein the signal component comprises at least one signal generator component and at least one signal sensor component, and wherein the potential control component comprises at least one potential switch and at least one signal control component, and at least two electrodes are arranged as components of the acoustic component, and wherein the potential control component is provided for changing and / or reversing and / or switching the electrical potential of at least one electrode of the at least one acoustic component.

Description

Subject of the invention

[0001] The invention relates to the field of electrical engineering / electronics and relates to a component which can be used, for example, for microfluidic applications, for particle sorting and / or for the atomization of fluids and / or for the detection, prevention and / or removal of icing, coatings or contamination on surfaces. State of the art

[0002] Microacoustic components are known that utilize surface acoustic waves (SAW), which are solid-state sound waves and propagate along a surface with a penetration depth of a few wavelengths, i.e. almost only in two dimensions (Wikipedia, keyword surface acoustic wave).

[0003] Also known are such components that use acoustic bulk waves that propagate within materials or plate waves that can be excited in thin plates.

[0004] Such components are used in a wide variety of applications, for example, in microfluidics, for example, for sensor or actuator tasks, as so-called acoustofluidic components. Microacoustic technologies often require multifunctional, "smart" components capable of functioning as actuators and sensors, even simultaneously.

[0005] For the electrical excitation of surface acoustic waves, extended thin-film electrodes, flat electrodes, or comb-shaped electrodes, so-called interdigital transducers (IDTs), are arranged at least partially on a polished surface of a piezoelectric substrate and / or a piezoelectric layer on a non-piezoelectric substrate and / or a non-piezoelectric substrate on a piezoelectric layer. Flat electrodes are often used to excite plate or bulk acoustic waves. Depending on the application, additional functional layers can be used, e.g., as cover layers, protective layers, functional layers, adhesion promoters, barrier layers, or waveguides. Furthermore, the substrate can consist of several different material layers / plates, each of which can also be partially structured.

[0006] The piezoelectric substrate is generally a quartz plate with an STX cut, or a LiNbO3 plate with a crystal cut tailored to the desired wave mode to be excited, e.g., 64°YX or 128°YX, or another piezoelectric material or material film depending on the desired wave mode. In the case of a material stack, the piezoelectric layers, e.g., made of ZnO, AlN, or similar thin films with known piezoelectric properties, can be applied with a thickness that maximizes the excitability of acoustic waves.

[0007] The interdigital transducers or flat electrodes consist of mostly metallic, but at least electrically conductive electrodes with a thickness of up to several micrometers, which convert electrical signals into sound waves and vice versa.

[0008] US 2008 / 0084135 A1 discloses sensors based on surface acoustic waves that, depending on the application and the measured quantity, utilize a selective sensor film coating on the piezoelectric substrate. This involves one or more IDTs (interdigital transducers) between which the sensor film is arranged.

[0009] According to US 8,018,121 B1, a surface acoustic wave device consisting of a pair of unidirectional IDTs is known, which has an integrated TSM (Thickness Shear Mode) sensor between the IDTs for the simultaneous detection and removal of analytes.

[0010] An overview of known SAW motors and actuators, their structure and mode of operation is available in S. Zhang et al: Acoustic Waves, Book edited by Don W. Dissanayake, pp. 466, Sept. 2010, Sciyo, Croatia.

[0011] Furthermore, according to WO 2022 / 263701 A1, a device for removing and preventing the formation of ice on surfaces is known, which device comprises a piezoelectric or ferroelectric substrate on which ice is deposited, electrodes connected to the substrate, a vector network analyzer connected to the electrodes and configured to determine the resonant frequency of the substrate, and an excitation module with a function generator that communicates with the vector network analyzer and is connected to an amplifier, the amplifier being connected to the electrodes.

[0012] A disadvantage of the state-of-the-art solutions is that actuator components, e.g. for de-icing surfaces or for SAW-based aerosol generation, use Rayleigh waves, which in turn are not sufficiently sensitive with regard to the presence of ice or liquid on the surface and are therefore less suitable for sensing. Description of the invention

[0013] The object of the present invention is to provide a component which can realize several functions without changing the electrode arrangements on a substrate or on a layer.

[0014] The object is achieved by the invention defined in the claims. Advantageous embodiments are the subject of the dependent claims, whereby the invention also includes combinations of the individual dependent claims in the sense of an AND connection, as long as they are not mutually exclusive.

[0015] The component according to the invention consists of at least one acoustic component and one signal component and one potential control component, wherein the signal component has at least one signal generator component for exciting acoustic waves and at least one signal sensor component for detecting and / or analyzing acoustic waves and / or their data, and wherein the potential control component has at least one potential switch and at least one signal control component, and wherein the at least one acoustic component has at least one substrate, which is a piezoelectric substrate and / or a piezoelectric layer on a non-piezoelectric substrate and / or a non-piezoelectric layer on a piezoelectric substrate and / or a non-piezoelectric substrate on a piezoelectric layer and / or a piezoelectric layer on a piezoelectric substrate,and wherein the layers are arranged to at least partially cover the surface of the at least one substrate, and at least two electrodes are arranged on the surface of the at least one substrate as components of the acoustic component, and wherein the signal component is connected to the electrodes of the at least one acoustic component via the at least one potential switch, and wherein the potential control component is provided for changing and / or reversing and / or switching the electrical potential of at least one electrode of the at least one acoustic component.

[0016] It is advantageous if the piezoelectric substrate and / or the non-piezoelectric substrate and / or the piezoelectric layer and / or non-piezoelectric layer is constructed from at least two material layers made of at least two different materials.

[0017] Advantageously, the substrate and / or layer material is LiNbO3, ZnO, AIN, AlScN, LiTaO3, BaTiO3, KNbO3, PbTiO3, PZT, PZN-PT, PMN-PT, HfO, aluminum zinc oxide (AZO), PVDF, PVDF-TrF, Al2O3, SiO2, ZrO2, SiC, Si3N4, WC, TiN, ZrN, Al, stainless steel, glass ceramic, amorphous SiO2, borosilicate glass or a transparent polymer.

[0018] Furthermore, the at least one acoustic component advantageously has a plurality of electrodes, advantageously 2 to 100.

[0019] Also advantageously provided as electrodes are interdigital transducers, which advantageously are interlocking comb electrodes or have a double-comb-like structure and a straight, focused, tapered, chirped, flat and / or curved shape, or are arranged opposite one another or in a circle.

[0020] And also advantageously, electrodes for realizing acoustic surface waves and / or electrodes for realizing acoustic plate waves and / or electrodes for realizing acoustic volume waves and / or electrodes for realizing acoustic shear waves and / or electrodes as electrical and / or acoustic reflectors are present as electrodes.

[0021] It is also advantageous if the at least one signal generator component is an electrical signal generator that is present within a spatial environment with or spatially separated from the other components.

[0022] It is also advantageous if the at least one signal sensor component is a signal detector and / or signal analyzer and / or a vector network analyzer and / or a digital oscilloscope, which is present within a spatial environment with or spatially separated from the other components.

[0023] It is further advantageous if the signal component and / or the potential control component are present within a spatial environment with or spatially separated from the other components.

[0024] It is also advantageous if the signal component further comprises at least one high-frequency amplifier component for generated and / or detected and / or analyzed waves.

[0025] It is also advantageous if the at least one signal control component controls the function of the at least one signal generator component and the at least one signal sensor component, and more advantageously their temporally realized electrically conductive connection with the at least one acoustic component and / or with the at least one potential switch.

[0026] It is also advantageous if the signal component implements the adaptation, analysis or detection of further signal parameters, such as frequency, phase and amplitude of the signals and / or the modulation of the signals.

[0027] It is also advantageous if the at least one potential switch of the potential control component for changing and / or reversing and / or switching the electrical potential of at least one electrode contains at least one potential converter and / or at least one manual and / or at least one automatic and / or programmable switch and / or at least one transistor with programmable control and / or at least one relay and / or a relay circuit.

[0028] It is also advantageous if at least one electrode of the acoustic component has an electrically conductive connection with the at least one potential switch, which is temporarily implemented as electrically non-conductive.

[0029] It is also advantageous if, depending on the electrical potential of the electrodes of the acoustic component and the change and / or reversal and / or switching of the electrical potential of one or more of these electrodes by the signal component and / or by the potential control component, different acoustic wave types can be excited and / or detected and / or analyzed via the same electrodes.

[0030] It is also advantageous if the component according to the invention at least partially comprises one or more cover layers, protective layers, barrier layers, wetting layers, hydrophobic, hydrophilic or oleophobic layers or anti-icing layers, further functional layers, adhesion promoter layers and / or barrier layers and / or further components, wherein two or more of these layers can also be present together and wherein these layers can also be partially structured.

[0031] It is also advantageous if the potential switch and / or the signal generator component and / or the signal sensor component and / or the signal control component and / or the potential control component and / or the signal component has a further component, or the further component is also arranged spatially outside these components, and wherein the further component changes the excitation mode and / or the signaling of the waves to be generated and / or received and evaluated depending on a change in the potential of the electrodes of the acoustic component or also independently thereof.

[0032] With the solution according to the invention, it is possible for the first time to provide a component which can realize several functions without changing the electrode arrangements on a substrate or on a layer.

[0033] This is achieved by a component that consists of at least one acoustic component, one signal component and one potential control component.

[0034] The acoustic component comprises at least one piezoelectric substrate and / or a piezoelectric layer on a non-piezoelectric substrate and / or a non-piezoelectric substrate on a piezoelectric layer and / or a piezoelectric layer on a piezoelectric substrate.

[0035] Advantageously, the piezoelectric substrate and / or the non-piezoelectric substrate and / or the piezoelectric layer can be constructed from at least two material layers made of at least two different materials.

[0036] The piezoelectric substrate and / or layer material can advantageously be LiNbO3, ZnO, AIN, AlScN, LiTaO3, BaTiO3, KNbO3, PbTiO3, PZT, PZN-PT, PMN-PT, HfO, aluminum zinc oxide (AZO), PVDF, PVDF-TrFE, or PVDF, PVDF-TrFE, Al2O3, SiO2, ZrO2, SiC, Si3N4, WC, TiN, ZrN, Al, stainless steel, glass ceramic, amorphous SiO2, borosilicate glass or a transparent polymer.

[0037] The acoustic component can also consist of a layer system or layer stack, of which at least one layer consists of a piezoelectric material.

[0038] Furthermore, the piezoelectric or non-piezoelectric layers can at least partially cover the surface or base area of ​​the substrates.

[0039] Likewise, protective layers, functional layers, for example with special wetting or anti-icing functions, barrier layers and / or cover layers may be present on the component according to the invention and / or only on the acoustic component, all of which do not impede or hinder at least the previous and further functions, in particular the acoustic sensor and / or actuator functions of the component according to the invention.

[0040] According to the invention, at least two electrodes are arranged on the surface of the piezoelectric substrate and / or the piezoelectric layer on a non-piezoelectric substrate and / or the non-piezoelectric substrate on a piezoelectric layer and / or the piezoelectric layer on a piezoelectric substrate. The at least two electrodes can also be a comb-like electrode pair of an IDT.

[0041] Advantageously, a plurality of electrodes, advantageously 2 to 100, can be present on the surface.

[0042] Advantageously, these electrodes can be made of transparent materials, such as transparent oxides such as indium tin oxide (ITO), aluminum zinc oxide (AZO), fluorine-doped indium tin oxide (FTO) or transparent metal wire meshes or conductive 2D materials such as graphene.

[0043] Also advantageously provided as electrodes are interdigital transducers, which further advantageously have a double comb-like, straight, focused, tapered, chirped, flat and / or curved or counter-rotating shape or are arranged opposite one another or in a circle.

[0044] Advantageously, the acoustic component has two interdigital transducers on the surface of a piezoelectric substrate and / or the piezoelectric layer on a non-piezoelectric substrate and / or the non-piezoelectric substrate on a piezoelectric layer and / or the piezoelectric layer on a piezoelectric substrate, which are arranged opposite one another.

[0045] Advantageously, the electrodes or IDTs arranged according to the invention for realizing surface acoustic waves and / or electrodes for realizing plate acoustic waves and / or electrodes for realizing bulk acoustic waves and / or electrodes for realizing shear acoustic waves are present on the piezoelectric substrate and / or on the piezoelectric layer on a non-piezoelectric substrate and / or on the non-piezoelectric substrate on a piezoelectric layer and / or on the piezoelectric layer on a piezoelectric substrate. The electrodes can also advantageously be used to excite actuator and sensor acoustic functions.

[0046] It is also advantageous if the potential switch and / or the signal generator component and / or the signal sensor component and / or the signal control component and / or the potential control component and / or the signal component has or have a further component, or if the further component is spatially arranged outside these components, and if the further component changes the wave mode of the waves to be generated and / or received and evaluated depending on a change in the potential of the electrodes of the acoustic component or independently thereof. This change can affect, for example, the frequency, amplitude, or phase of the signal.

[0047] Thanks to the additional component, in addition to the function of the component according to the invention for changing and / or reversing and / or switching the electrical potential of the electrodes, the signal generator component and / or the signal sensor component and / or the signal control component and / or the potential control component and / or the signal component can comprise a further component that changes the excitation mode or the signaling of the waves to be generated and / or received and evaluated. This allows, for example, switching between sensor operation (measurement) and actuator operation (generation of the wave mode).

[0048] For example, the potential switch can be used to set the potential of the acoustic component's electrodes so that they operate in SAW mode. The signal control component can then use the signal generator component for the actuator and generate surface acoustic waves. At regular intervals, the potential switch can change the electrode potential to plate wave mode, and the signal sensor component can then be used via the signal control component to measure the electrical response signal to detect the acoustic component's resonant frequency.

[0049] However, by adjusting the respective potentials at the electrodes, it is also possible to use the SAW mode for detection and the plate waves for the actuators. This could even be achieved simultaneously, since, for example, the reflected power can be measured in parallel during signal generator operation. Wave modes for the sensors and / or actuators can be, for example, shear-polarized surface waves, edge waves, waveguide waves, plate waves, bulk waves, Love waves, Blaustein-Gulyaev waves, Scholte waves, leaky waves, Rayleigh waves, Sezawa waves, Lamb waves, membrane waves, Kirchhoff-Love waves, or Mindlin-Reissner waves.

[0050] The electrodes according to the invention can also be advantageously used for the excitation and / or detection of acoustic shear waves or shear-horizontally polarized acoustic surface waves by applying electrical potentials. Since the response of acoustic shear wave modes is essentially always narrowband and also reacts very sensitively to, for example, temperature or load changes with a frequency shift and to mechanical stresses with an additional amplitude change, the thickness shear wave acoustic mode is more suitable for various applications than the surface acoustic wave mode.

[0051] Various experiments have also shown that the conversion of water into ice produces a strong change in amplitude as well as frequency.

[0052] Furthermore, according to the invention, at least one potential control component is provided, which comprises at least one potential switch and one signal control component. The potential switch is electrically connected to electrodes of the microacoustic component, advantageously to several electrodes simultaneously. Advantageously, the electrically conductive connection can also be temporarily interrupted. The electrical connection to the electrodes can be established via various electrical contacts of the potential switch.

[0053] Furthermore, the potential switch is electrically connected to the signal control component, whereby the electrical connection can be made via different electrical contacts of the potential switch and / or the signal control component.

[0054] Advantageously, each electrode of the acoustic component is directly electrically connected to the potential switch.

[0055] Also advantageously, at least two potentials, such as ground and an oscillating electrical potential, are combined between the potential switch and the signal control component. The electrically conductive connection can be realized, for example, via high-frequency-compatible electrical connections. Control signals from the signal control component are also applied to the potential switch via additional electrically conductive connections.

[0056] The signal control component monitors and controls the potential switch, ensuring that the signals provided by the signal generator component are forwarded to the electrodes of the microacoustic component, or that electrical signals are forwarded between the microacoustic component and the signal sensor component. Furthermore, the signal control component controls the state of the potential switch. Based on the electrical control signals provided by the signal control component, the potential switch provides the electrical potentials of the signal generator component to the respective electrodes used.

[0057] Furthermore, the signal component comprises at least one signal generator component and at least one signal sensor component and is connected to the signal control component. The at least one signal generator component is controlled by the signal control component and provides electrical signals for microacoustic actuator and / or sensor functions. The at least one signal sensor component is controlled by the signal control component and detects and / or analyzes the electrical signals from microacoustic actuator and / or sensor functions.

[0058] The signal generator component, signal sensor component, signal control component and potential switch can be spatially separated or advantageously integrated, at least partially together, in one component.

[0059] In addition, the signal generator component and / or the signal sensor component may also comprise an amplifier component for generated and / or detected and / or analyzed acoustic waves.

[0060] One function of the signal control component can be to enable the temporal electrical connection between the acoustic component and the signal generator component and / or the signal sensor component by controlling the potential switch. This signal control component can, for example, enable switching from an actuator function of the acoustic component to a sensor function and vice versa.

[0061] According to the invention, at least one potential control component is provided for changing and / or reversing and / or switching the electrical potential of at least one electrode of the microacoustic component. The electrical potential can be the electrical potential of the earth, or advantageously oscillate periodically and be defined by a frequency and an amplitude. A fixed phase shift can also exist between the potentials of different electrodes. The potential can also be a composite signal composed of several such electrical potentials superimposed on one another, or a modulation of the potential can occur. DC potentials can also be superimposed.

[0062] In the at least one potential control component for changing and / or reversing and / or switching the electrical potential of at least one electrode, there is advantageously at least one potential switch, for example in the form of a potential converter or a manual and / or automatic and / or programmable switch, such as a transistor with programmable control or one or more relays or a relay circuit.

[0063] It is also advantageous that at least one electrode, advantageously at least half of all electrodes, even more advantageously all electrodes, are electrically conductively connected to the potential switch, whereby this connection can also be temporarily realized as electrically non-conductive.

[0064] With the solution according to the invention, different acoustic wave types can also be excited and / or detected and / or analyzed simultaneously or successively via the same electrodes, depending on the electrical potential of the electrodes and the change and / or reversal and / or switching of the electrical potential of one or more electrodes by the potential control component in combination with the signal component.

[0065] The component according to the invention not only enables the known function of SAW components of exciting acoustic surface waves propagating along the substrate by utilizing a high-frequency alternating voltage signal, but also, depending on the design, can be used to excite, detect, and / or analyze acoustic plate waves and / or acoustic bulk waves and / or acoustic shear waves. This can advantageously be achieved according to the invention using various electrodes on the piezoelectric substrate and / or on the piezoelectric layer on a non-piezoelectric substrate and / or on the non-piezoelectric substrate on a piezoelectric layer and / or on the piezoelectric layer on a piezoelectric substrate.

[0066] However, this can be achieved particularly advantageously through the use of the potential control component, in which different types of acoustic sound waves can be excited, detected, and / or analyzed using the same electrodes by changing and / or reversing and / or switching the electrical potential of the electrodes of the acoustic component. This eliminates the need to modify or expand the electrode arrangements on the microacoustic component. The change in the electrical potentials that may be necessary to excite other wave modes, e.g., in the form of a change in frequency, phase, amplitude, and / or a DC voltage component and / or a modified superposition of such electrical potentials, is ensured by combining the functions of the signal generator component and the signal control component.

[0067] However, existing designs of acoustic components with electrode arrangements can also be expanded to include a multitude of new application possibilities, since only the potential control component needs to be added and the existing electrodes need to be connected with different electrical conductivities to a signal generator component and / or a signal sensor component and connected to an adapted electrical potential.

[0068] Thus, no additional acoustic components are required if existing acoustic components are to be modified for additional applications, which makes the construction of more complex, expensive and error-prone acoustic components unnecessary and enables a simple implementation of the inventive solution.

[0069] The inventive solution can be used for a wide range of applications. For example, alternating or simultaneous sensor and / or actuator functions can be used on the acoustic component. This can be achieved, for example, in the initiation and detection of phase changes in materials located on the acoustic component. However, the inventive solution can also be used to implement profound system changes to the acoustic function of the acoustic components. For example, the acoustic components can be used as shear wave resonators and simultaneously enable sensing of the surface loading with liquids, gases, or solids and / or sensing of phase transitions in chemical processes and precise temperature measurement.

[0070] With the solution according to the invention, it is also possible to specify components which, in addition to the function of the surface wave mode, utilize resonances of the substrate or one of the layers by exciting plate waves and / or bulk waves.

[0071] Particularly advantageous is an arrangement of the component according to the invention in which, in the acoustic component, two interdigital transducers are provided opposite one another on the surface of the piezoelectric substrate and / or the piezoelectric layer on a non-piezoelectric substrate and / or the non-piezoelectric substrate on a piezoelectric layer and / or the piezoelectric layer on a piezoelectric substrate, wherein the comb-like electrodes of each interdigital transducer have a different electrical potential.

[0072] For example, one electrode of each of the two interdigital transducers has the electrical potential of earth (=0V), and the other electrode of each of the two interdigital transducers has the electrical, temporally high-frequency oscillating potential ≠ 0V. This causes each of the interdigital transducers to emit an acoustic surface wave, exciting a standing acoustic surface wave between the interdigital transducers.

[0073] By using the potential control component to change and / or reverse and / or switch the electrical potential of at least one electrode, the electrical potential of both comb-like electrodes of one interdigital transducer, for example, is changed to the electrical potential of ground (=0), and the electrical potential of the two comb-like electrodes of the other interdigital transducer is changed to the electrical, temporally high-frequency oscillating potential ≠ 0V. This excites an acoustic shear wave on the acoustic component through both interdigital transducers.

[0074] This acoustic shear wave is ideal for performing measurements, for example, of the temperature or a mechanical property of a material on the surface of the component according to the invention. Advantageously, the frequency and amplitude of the electrical potentials are adapted to the requirements of the wave type to be excited. Electrical S-parameters, such as scattering parameters, and all electrical quantities derived from them, can generally be used as the measured variable.

[0075] In order to switch from, for example, the “SAW mode” (generation of a standing acoustic surface wave) of the component according to the invention to another mode, for example the “shear wave detection mode”, in the case mentioned as an example, the electrical potentials of two electrodes must be changed by means of the potential control component according to the invention.

[0076] A further exemplary arrangement of the component according to the invention consists in that, in the case of the presence of several interdigital transducers, at least two interdigital transducers are advantageously always arranged opposite one another and the further interdigital transducers are either also arranged opposite one another in pairs or, in the case of an odd number of interdigital transducers, the remaining interdigital transducers are arranged next to an interdigital transducer which has an interdigital transducer arranged opposite one another.

[0077] In this exemplary arrangement, a "SAW mode" can be realized with the opposing interdigital transducers. By connecting the remaining interdigital transducer, which has a different potential than the opposing interdigital transducers in "SAW mode," via the potential control component, instead of the adjacent interdigital transducer, an acoustic shear wave, bulk wave, or plate wave is realized depending on the potential of the remaining interdigital transducer.

[0078] In this case, the potentials of the electrodes of the interdigital transducers do not even have to be changed in “SAW mode”, but another interdigital transducer with a different potential is coupled to an opposite interdigital transducer so that other acoustic waves can be transmitted.

[0079] An exemplary arrangement of the component according to the invention could also consist of multiple electrodes, some of which are not electrically connected to the potential switch or, by controlling the potential switch, are not electrically connected to the at least one signal generator component and / or the at least one signal sensor component by the signal control component. Those electrodes that are not electrically connected to the signal and / or potential component can be used as reflectors of the acoustic waves in the component according to the invention.

[0080] A further advantage of the solution according to the invention is that various disadvantages of the solutions of the prior art do not occur with the component according to the invention.

[0081] Thus, the changes in the resonant frequency of the SAW signal are smaller than the electrical bandwidth of the reflection signal (reflection coefficient) of the interdigital transducer or are on the order of magnitude of the signal-to-noise ratio. The former primarily affects the measurement of the resonant frequency shift, the latter the measurement of the signal amplitude. However, frequency shift, amplitude, and phase changes are the central system response to changes in ambient conditions.

[0082] This is often very detrimental to sensor technology, since many, and increasingly more, applications require precise knowledge of the current system state, for example in order to react to changes and thus avoid malfunctions.

[0083] These disadvantages do not occur with the component according to the invention.

[0084] Furthermore, the solution according to the invention can advantageously detect and even remove icing, contamination or coatings on the surface of the acoustic component.

[0085] With the solution according to the invention, the disadvantages of the known solutions, such as excessive sensitivity and insufficient ice removal, can be reduced or eliminated when removing ice, since in particular the conditions necessary for ice removal can be set more easily and quickly.

[0086] The solution according to the invention is explained in more detail below using an exemplary embodiment.

[0087] This shows Fig. 1 the polarity of the electrodes of a SAW device in “standard SAW mode” and Fig. 2 the component according to the invention with changed polarity in “shear wave mode” Example 1

[0088] A SAW component as an acoustic component 100, whose surface is to be cleaned, comprises a standard 128° YX-LiNb03 wafer as a piezoelectric substrate with lateral dimensions of 50 mm x 50 mm and a thickness of 0.5 mm. Two interdigital transducers are arranged on the acoustic component 100 as comb-like electrodes made of 300 nm thick aluminum on an intermediate layer of 10 nm thick titanium. They have an aperture of 40 mm and an electrode width and width between the finger electrodes of 30 µm each (lambda / 4 design), and a number of 10 finger pairs with a spacing of 30 mm. The electrical contacts to the IDTs are routed to contact pads via bus bars connected to the IDTs.

[0089] In addition to the acoustic component 100, there is a signal generator as signal generator component 300 and a signal detector and analyzer as signal sensor component 400, which are integrated together as signal component 700 in a device and which are connected to the acoustic component 100 via a potential control component 600. In Fig. 1 and Fig. 2 the representation of the electrical high-frequency lines was omitted.

[0090] The signal generator 300 is an electrical signal source from which a high-frequency signal with a frequency of 34 MHz is sent to the electrodes of the interdigital transducers via the electrically conductive connections. The electrical output power of the signal generator component 300 is approximately 2 W.

[0091] The signal detector and analyzer 400 consists of a computer with a high-frequency measurement card, which detects the measurement data of the acoustic waves and analyzes them using special known computer programs.

[0092] When the acoustic component 100 is in “SAW mode”, one of the two comb-like electrodes (A1 and B1 in Fig. 1) of the two interdigital transducers the electrical potential of the earth (=0) and the other comb-like electrode (A2 and B2 in Fig. 1) of the two interdigital transducers exhibits an electrical, temporally high-frequency oscillating potential.

[0093] In this mode, the interdigital transducers excite a standing surface wave between the interdigital transducers via the high-frequency signal, which is used to detect water on the surface. It is also possible for only one of the two interdigital transducers to be excited with a high-frequency signal and thus act as the transmitting transducer to generate a traveling surface wave that travels to the other interdigital transducer, which acts as the receiving transducer (= "delay line" arrangement). In this function, the energy transferred from the transmitting transducer to the receiving transducer depends on the properties of the acoustic path between the two transducers (IDTs). The energy is mainly dissipated by the water located on the surface between the two interdigital transducers. For this analysis, the electrical reflection and transmission coefficients (S-parameters) can be analyzed in the frequency or time domain.

[0094] If the ambient temperature drops below the freezing point of water, the water freezes and ice forms on the surface. Detection of ice on the surface is not possible in the "SAW mode" of the SAW component.

[0095] Then, a programmable potential control component 600 via the potential switch 200 switches the polarity of the two electrodes of one interdigital transducer (A1 and A2 in Fig. 2) is changed to the electrical potential of the earth (=0) and the electrical potential of the two electrodes of the other interdigital transducer (B1 and B2 in Fig. 2) are changed to the electrical, temporally high-frequency oscillating potential of 5 V. At the same time, the electrical signal of the signal generator component 300 is adjusted / changed by the signal control component 500 to the frequency range of 3.5 MHz - 3.7 MHz at an electrical output power of the signal generator component 300 of 10 mW and is forwarded via the potential switch 200 to the electrodes of the acoustic component 100. Fig. 1 and Fig. 2, the connections for transmitting the control signals from the signal control component 500 to the potential switch 200 and to the signal generator component 300 and / or the signal sensor component 400 are marked as double arrows.

[0096] This excites a shear wave between the interdigital transducers, which can be used to detect that there is ice on the surface.

[0097] The shear wave is suitable for determining temperature via the frequency of the shear wave resonance. The transformation of water into ice at temperatures below zero degrees Celsius is detected by a slight shift in the resonance frequency, a change in the wave propagation speed, and a decrease in the amplitude of the shear wave resonance.

[0098] Of particular importance is that the potential changes by means of the potential control component 600 allow continuous switching between shear wave mode and SAW mode, whereby the critical temperature at which ice forms can be detected and a de-icing protocol can then be started for the surface.

[0099] The continuous switching between different wave modes can be monitored and implemented in automatic operation by the signal control component 500 in combination with the signal sensor component 400 and the signal generator component 300. In this case, the signal control component 500 can operate independently (automatically) or be controlled by or part of a computer system.

[0100] In the first step, the reflection signal is recorded in shear wave mode, starting from the thickness shear wave mode of the acoustic component 100, by scanning in the limited frequency range of 3.5 - 3.7 MHz and evaluated for resonance frequency and amplitude on the signal sensor component 400. This scan is repeated every 15 minutes. Then, the nth scan is compared with a stored ideal scan (target behavior). If a resonance frequency shift is present at approximately the same amplitude, no temperature change has occurred that would have caused the phase transition from water to ice.

[0101] However, if a resonance frequency shift with a significant change in the amplitude of the S-parameter (S11, reflection factor) is detected, then a temperature change has occurred, resulting in a phase transition from water to ice. The resonance frequency shift as a function of temperature and the amplitude change as a function of mechanical load are mathematically modelable processes (e.g., linear behavior), which is why the system can be calibrated and measurements are comparable.

[0102] The amplitude change results from the stronger coupling of the ice with the surface of the acoustic component 100. Due to the mechanical hardening (ice formation), a greater energy transfer from the thickness shear wave to the ice takes place.

[0103] By taking scans and comparing them with the desired behavior, this amplitude change is detected and the ice formation is analyzed. However, it is also possible that these results can be used as a trigger for the control command to switch the polarity of the electrodes to surface acoustic wave (SAW) mode using the potential control component 600. The SAW waves then generated introduce energy into the ice, which can lead to melting of the ice on the surface. List of reference symbols: 100 - 700 components 100 acoustic components 200 potential switches 300 Signal generator component 400 signal sensor component 500 signal control component 600 Potential control component 700 signal component QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2008 / 0084135 A1

[0008] US 8,018,121 B1

[0009] WO 2022 / 263701 A1

[0011]

Claims

[1] Component (100 - 700), at least consisting of at least one acoustic component (100) and one signal component (700) and one potential control component (600), wherein the signal component (700) has at least one signal generator component (300) for exciting acoustic waves and at least one signal sensor component (400) for detecting and / or analyzing acoustic waves and / or their data, and wherein the potential control component (600) has at least one potential switch (200) and at least one signal control component (500), and wherein the at least one acoustic component (100) has at least one substrate,which is a piezoelectric substrate and / or a piezoelectric layer on a non-piezoelectric substrate and / or a non-piezoelectric layer on a piezoelectric substrate and / or a non-piezoelectric substrate on a piezoelectric layer and / or a piezoelectric layer on a piezoelectric substrate, wherein the layers are arranged to at least partially cover the surface of the at least one substrate, and at least two electrodes are arranged on the surface of the at least one substrate as components of the acoustic component (100), and wherein the signal component (700) is connected to the electrodes of the at least one acoustic component (100) via the at least one potential switch (200),and wherein the potential control component (600) is provided for changing and / or reversing and / or switching the electrical potential of at least one electrode of the at least one acoustic component (100). [2] Component according to claim 1, wherein the piezoelectric substrate and / or the non-piezoelectric substrate and / or the piezoelectric layer and / or the non-piezoelectric layer is constructed from at least two material layers, from at least two different materials. [3] Component according to claim 1, in which the substrate and / or layer material is LiNbO3, ZnO, AIN, AlScN, LiTaO3, BaTiO3, KNbO3, PbTiO3, PZT, PZN-PT, PMN-PT, HfO, aluminum zinc oxide (AZO), PVDF, PVDF-TrFE, Al2O3, SiO2, ZrO2, SiC, Si3N4, WC, TiN, ZrN, Al, stainless steel, glass ceramic, amorphous SiO2, borosilicate glass or a transparent polymer. [4] Component according to claim 1, wherein the at least one acoustic component (100) has a plurality of electrodes, advantageously 2 to 100. [5] Component according to claim 1, in which interdigital transducers are present as electrodes, which are advantageously intermeshing comb electrodes or have a double-comb-like structure and a straight, focused, tapered, chirped, flat and / or curved shape, and / or are arranged opposite one another or in a circle. [6] Component according to claim 1, in which electrodes are present as electrodes for realising acoustic surface waves and / or electrodes for realising acoustic plate waves and / or electrodes for realising acoustic volume waves and / or electrodes for realising acoustic shear waves and / or electrodes as electrical and / or acoustic reflectors. [7] Component according to claim 1, wherein the at least one signal generator component (300) is an electrical signal generator which is present within a spatial environment with or spatially separated from the other components, [8] Component according to claim 1, wherein the at least one signal sensor component (400) is a signal detector and / or a signal analyzer and / or a vector network analyzer and / or a digital oscilloscope, which is present within a spatial environment with or spatially separated from the other components. [9] Component according to claim 1, wherein the signal component (700) and / or the potential control component (600) are present within a spatial environment with or spatially separated from the other components. [10] Component according to claim 1, wherein the signal component (700) further comprises at least one high-frequency amplifier component for generated and / or detected and / or analyzed waves. [11] Component according to claim 1, wherein the at least one signal control component (500) controls the function of the at least one signal generator component (300) and the at least one signal sensor component (400), advantageously their temporally realized electrically conductive connection with the at least one acoustic component (100) and / or with the at least one potential switch (200). [12] Component according to claim 1, wherein the signal component (700) realizes the adaptation, analysis or detection of further signal parameters, such as frequency, phase and amplitude of the signals and / or the modulation of the signals. [13] Component according to claim 1, wherein the at least one potential switch (200) of the potential control component (600) for changing and / or reversing and / or switching the electrical potential of at least one electrode contains at least one potential converter and / or at least one manual switch and / or at least one automatic switch and / or at least one programmable switch and / or at least one transistor with programmable control and / or at least one relay and / or at least one relay circuit. [14] Component according to claim 1, wherein at least one electrode of the acoustic component (100) has an electrically conductive connection with the at least one potential switch (200), which is temporarily implemented as electrically non-conductive. [15] Component according to claim 1, wherein, depending on the electrical potential of the electrodes of the acoustic component (100) and the change and / or reversal and / or switching of the electrical potential of one or more of these electrodes by the signal component (700) and / or by the potential control component (600), different acoustic wave types can be excited and / or detected and / or analyzed via the same electrodes. [16] Component according to claim 1, in which the component at least partially comprises one or more cover layers, protective layers, barrier layers, wetting layers, hydrophobic, hydrophilic or oleophobic layers or anti-icing layers, further functional layers, adhesion promoter layers and / or barrier layers and / or further components, wherein two or more of these layers can also be present together and wherein these layers can also be partially structured. [17] Component according to claim 1, in which the potential switch (200) and / or the signal generator component (300) and / or the signal sensor component (400) and / or the signal control component (500) and / or the potential control component (600) and / or the signal component (700) has a further component, or the further component is also arranged spatially outside these components (300 to 700), and wherein the further component changes the excitation mode and / or the signaling of the waves to be generated and / or received and evaluated as a function of a change in the potential of the electrodes of the acoustic component or independently thereof.

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