Functionalized objects with integrated mechanical wave sensors and associated production methods

Abstract

The invention relates to a functionalized object (100) having at least one mechanical wave sensor (10) providing the object with vibration and deformation detection capabilities. The mechanical wave sensor (10) comprises a sensitive cell (11) having a thickness less than or equal to 50 microns and comprising an active layer (1) made of a single or polycrystalline piezoelectric material, and two electrodes (2, 3) in contact with the active layer and accessible at a first surface of the sensitive cell, and a support layer integral with a second surface of the sensitive cell (11) and integral with the object (100). The functionalized object (100) comprises at least two electrically conductive strips (20) disposed on the first surface of the sensitive cell (11) and on a surface (100a) of the object, each strip connecting an electrode to an electrical contact pad (30). The invention also relates to a method for generating such a functionalized object.

Description

Technical Field

[0001] This invention relates to the field of functionalized objects with mechanical wave detection capabilities. Specifically, it relates to objects functionalized by integrating mechanical wave sensors onto their surface. Background Technology

[0002] The detection and measurement of mechanical waves are essential in many fields, including preventative maintenance, development, supervision, calibration, and monitoring of equipment (to ensure safety). Applications can extend to consumer devices, tools, and industrial equipment (pumps, etc.), as well as land and air transportation.

[0003] It should be recalled that a mechanical wave is a phenomenon in which a disturbance propagates in a material medium without transmitting matter. The disturbance corresponds to changes in the mechanical properties (velocity, position, energy, etc.) at multiple points in the material medium; it includes vibration and deformation.

[0004] For all industrial or transportation-related applications, accurate measurement of vibration or deformation is a major advantage by maximizing equipment uptime, minimizing maintenance costs, and avoiding emergency repairs.

[0005] Currently, vibration measurements are performed a posteriori by installing discrete devices onto the object (equipment or parts thereof) to be functionalized. Installation can be accomplished, particularly via threaded connections, with special precautions at the connectors (connecting wires) to prevent vibration during operation; otherwise, vibration measurements will be severely contaminated by errors.

[0006] Therefore, the trade-offs in mechanical wave measurement are governed by the congruence of performance, integration, and cost. Performance levels, including detection range (frequency), accuracy (signal-to-noise ratio), and environmental compatibility, must be sufficient. The size and weight of the measuring device must be small enough that its integration does not negatively impact the system or target equipment. Finally, assembly and signal processing costs must remain reasonable to facilitate widespread deployment of the detection solution.

[0007] Devices used to detect vibrations and deformations are typically made of piezoelectric materials. Piezoelectric materials can be composed of solid ceramics, such as lead titanate (PZT); or polymers, such as, in particular, polyvinylidene difluoride trifluoroethylene (PVDF-TrFE).

[0008] The advantages of ceramics are that they impart stability and high performance to sensors over time and temperature; however, the disadvantages stem from the sensor's mass (which needs to balance the weight to eliminate the sensor's inherent frequency) and its fragility (which requires a large-volume protective package that negatively impacts integration parameters). Moreover, such sensors based on thick ceramic layers (between 150 micrometers and a few millimeters thick) do not open up the possibility of integration onto soft and flexible components.

[0009] Piezoelectric polymer-based sensors are inherently flexible because very thin polymer layers (from a few micrometers to tens of micrometers) can be achieved; however, their performance levels and temperature resistance are much lower than those of ceramics. Piezoelectric polymers also suffer from polarization instability, which affects their reliability over time. Summary of the Invention

[0010] This invention relates to alternative solutions to existing technologies, with the aim of meeting the performance, integration, and cost targets required for the widespread use of such solutions. In particular, this invention relates to an object functionalized by integrating a ceramic mechanical wave sensor and its connectors onto the surface of the object.

[0011] Overview of the Invention

[0012] This invention relates to a functionalized object equipped with at least one mechanical wave sensor that provides the object with vibration and deformation detection capabilities. A significant feature of this functionalized object is that the mechanical wave sensor comprises:

[0013] - A sensing element having a thickness of 50 micrometers or less, comprising an active layer made of a single-crystal or polycrystalline piezoelectric material, and two electrodes in contact with the active layer and accessible at a first surface of the sensing element.

[0014] - Support layer, which is fixed to the second surface of the sensitive unit and to the object.

[0015] The functionalized object also includes at least two conductive strips disposed on the first surface of the sensitive unit and on the surface of the object, each conductive strip connecting an electrode to an electrical contact pad.

[0016] Advantageous features according to the invention, taken alone or in any feasible combination:

[0017] • The support layer is made of the same material as the material constituting the object or a material that can be adhered to the material constituting the object;

[0018] • Integrate all or part of the support layer with or into the material of the object;

[0019] • The piezoelectric materials are selected from lead zirconate titanate (PZT), aluminum nitride (AlN), zinc oxide (ZnO), lithium tantalate (LiTaO3), potassium niobate (KNbO3), lithium niobate (LiNbO3), lead magnesium niobate titanium (PMN-PT), quartz, strontium titanate (SrTiO3), and barium titanate (BaTiO3).

[0020] • The active layer has surface undulations in the form of wrinkles on at least one side of the first surface;

[0021] • The functionalized object is made of at least one material selected from plastics such as thermoplastic polymers, metals, carbon fiber matrices and other composite materials, excluding materials having a sound absorption coefficient greater than 0.6 in the frequency range of 1 Hz to 40 kHz.

[0022] The support layer is formed from materials selected from poly(methyl methacrylate) (PMMA), acrylonitrile butadiene styrene (ABS), high-density polyethylene (HDPE), polypropylene polyvinyl chloride (PVC), acrylonitrile styrene (SAN), acetal, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polycarbonate (PC), polyetheretherketone (PEEK), polyetherimide (PEI), polyethersulfone polyethylene ether (PPE), polyamide (NYLON), poly(phenylene sulfide) (PPS), and carbon fiber matrix.

[0023] • The thickness of the support layer is between 10 micrometers and 1 mm;

[0024] • This functionalized object includes multiple mechanical wave sensors;

[0025] The multiple mechanical wave sensors share the same support layer;

[0026] • The sensing element has a lateral dimension between 500 μm and 20 cm at its first and second surfaces;

[0027] • This functionalized object forms structural components of vehicles or buildings, engine parts, bicycle frames, covers for industrial or household equipment, etc.

[0028] The present invention also relates to a method for producing the functionalized object as described above. The production method includes the following steps:

[0029] a) Supply a mechanical wave sensor, the mechanical wave sensor comprising:

[0030] - A sensing element having a thickness of 50 micrometers or less, comprising an active layer made of a single-crystal or polycrystalline piezoelectric material, and two electrodes in contact with the active layer and accessible at a first surface of the sensing element.

[0031] - A support layer having a front surface and a rear surface, the front surface of which is fixed to the second surface of the sensitive element.

[0032] b) Forming objects from solid materials through molding, injection molding, or 3D printing.

[0033] c) Fix the mechanical wave sensor to the object

[0034] - Alternatively, during step b), the mechanical wave sensor may be positioned such that the rear surface of the support layer is at least in contact with or integrated into the material forming the object, and the electrodes remain accessible during the formation of the object.

[0035] - Alternatively, after step b), the rear surface of the support layer is fixed to the surface of the formed object by adhesion.

[0036] d) Two conductive strips are deposited on the first surface of the sensitive cell and the surface of the object, each conductive strip connecting an electrode to an electrical contact pad disposed on the surface.

[0037] Advantageous features according to the invention, taken alone or in any feasible combination:

[0038] • The mechanical wave sensor set in step a) includes a temporary handling layer disposed on the rear surface of the support layer, and this temporary handling layer is removed before step c) of fixing the mechanical wave sensor to the object;

[0039] Step a) includes providing multiple mechanical wave sensors sharing the same support layer, and step c) includes simultaneously fixing the multiple mechanical wave sensors to the object;

[0040] Step d) is performed by screen printing, spraying, electrolytic growth, or direct laser sintering of metal. Attached Figure Description

[0041] Referring to the accompanying drawings and the following detailed description, other features and advantages of the invention will become clear, wherein:

[0042] Figure 1 A variant of the sensitive unit of a mechanical wave sensor intended for integration into a functionalized object according to the invention is shown;

[0043] Figure 2 , Figure 3a , Figure 3b as well as Figure 4 A variant of a mechanical wave sensor designed for integration into a functionalized object according to the invention is shown;

[0044] Figure 5a and Figure 5b A functionalized object according to the present invention is shown;

[0045] Figure 6 The steps of a method for producing a functionalized object according to a first embodiment of the present invention are shown;

[0046] Figure 7 The steps of a method for producing functionalized objects according to the present invention are shown.

[0047] The accompanying drawings are schematic representations and are not necessarily drawn to scale for ease of reading. The same reference numerals in the drawings can be used for the same type of elements.

[0048] Various possibilities (variations and implementations illustrated and / or detailed in the following description) should be understood as not mutually exclusive and can be combined with each other. Detailed Implementation

[0049] This invention relates to a functionalized object 100 provided with at least one mechanical wave sensor 10, which provides the object 100 with vibration and deformation detection capabilities. As stated above, the detection and measurement of vibration and deformation can prove important in various fields, particularly in anticipating the deterioration of certain mechanical parts: for example, as cracks or other structural defects appear in these parts, the frequency characteristics of sound waves will change, and warnings can be issued before the parts break or other serious failures occur. Without forming an exhaustive list, the functionalized object 100 may specifically consist of the following:

[0050] - Vehicle structural components, such as all or part of an aircraft wing, a car chassis, or a bicycle frame.

[0051] - Engine parts, such as carburetor covers, turbine components, shafts, bearings, etc.

[0052] -Building structural components,

[0053] - An industrial or household piece of equipment (e.g., a pump), etc.

[0054] - Typically, fatigue or fracture modeling of parts made of composite materials is complex, and they can greatly benefit from the presence of mechanical wave sensors to predict the occurrence of defects in their structure.

[0055] The functionalized object 100 according to the invention includes a mechanical wave sensor 10, which includes a sensitive unit 11 fixed to a support layer 12 fixed to the object 100.

[0056] Sensitive unit 11 is typically in the form of a tag, with its main surfaces 11a and 11b (hereinafter referred to as first surface 11a and second surface 11b) on... Figure 1 The sensing element extends in a plane (x, y). Its lateral dimension in the plane (x, y) is between 0.2 mm and a few cm, typically between 0.5 mm and 5 cm. The sensing element 11 of the sensor 10 also has a total thickness of less than or equal to 50 micrometers, advantageously less than or equal to 30 micrometers (along the z-axis in the figure). The sensing element includes an active layer 1 made of a ceramic-type piezoelectric material, and two electrodes 2, 3 in contact with the active layer 1 and accessible at a first surface 11a of the sensing element 11. The piezoelectric material (single crystal or polycrystalline) is selected, for example, from lead zirconate titanate (PZT), aluminum nitride (AlN), zinc oxide (ZnO), lithium tantalate (LiTaO3), potassium niobate (KNbO3), lithium niobate (LiNbO3), lead magnesium titanium niobate (PMN-PT), quartz, strontium titanate (SrTiO3), and barium titanate (BaTiO3).

[0057] The thickness of active layer 1 is typically between 500 nm and 40 micrometers.

[0058] According to an advantageous embodiment, the active layer 1 has surface undulations in the form of wrinkles on at least one side of the first surface 11a of the sensing element 11. Methods for forming such surface undulations are described in documents WO2015 / 055788, WO2015 / 055783 and WO2015 / 055786, and are applied, for example, to the production of the sensing element 11 of the present invention.

[0059] Electrodes 2 and 3 of the sensing unit 11 are made of metallic material and are in close contact with the active layer 1: they collect the charge generated by the piezoelectric effect during deformation of the active layer 1. Specifically, deformation of the active layer 1 occurs when it is subjected to a mechanical wave. The electrical signals generated at the terminals of electrodes 2 and 3 represent the intensity and frequency of the deformation associated with the mechanical wave.

[0060] like Figure 1 As shown, the two electrodes 2 and 3 are accessible at the first surface 11a of the unit 11. Typically, electrodes 2 and 3 are disposed on either side of the active layer 1, that is, on one side of the first surface 11a and the other side of the second surface 11b of the sensitive unit 11, in order to benefit from the piezoelectric effect across the entire thickness of the active layer 1. Therefore, in Figure 1 In configuration (a), electrode 3 includes: a lower portion 3' located on the second surface 11b, a side portion 3" disposed on the edge of the active layer 1, and an upper portion located on the first surface 11a of the sensing unit 11. Figure 1 In configuration (b), the conductive via 3" electrically connects the lower part 3' and the upper part of the electrode 3. In both configurations, the two electrodes 2 and 3 are accessible at the first surface 11a of the sensing unit 11.

[0061] The thickness of electrodes 2 and 3 (along the z-axis) is typically between 50 nm and 25 micrometers. They may include conductive materials selected from aluminum, gold, titanium, silver, tungsten, copper, nickel, or conductive metal alloys; they may also include other diffusion-barrier layers (titanium nitride TiN, tantalum nitride TaN, tungsten nitride WN).

[0062] The mechanical wave sensor 10 also includes a support layer 12, the front surface 12a of which is fixed to the second surface 11b of the sensing element 11. Figure 2 The thickness of the support layer 12 is typically between 10 micrometers and 1 mm, for example, 200 micrometers.

[0063] Advantageously, the support layer 12 is made of the same material as or capable of adhering to the material constituting the functionalized object 100. In practice, as will be described below with reference to an embodiment of the production method according to the invention, the support layer 12 can be integrated into the material of the object 100, for example, during molding, injection molding, or 3D printing steps: therefore, it is important that the material of the support layer 12 is compatible with the material of the object 100, and allows for reliable and high-quality integration into the material of the functionalized object 100.

[0064] In addition to the above, the functionalized object may be made of at least one material selected from thermoplastic polymers, metals, carbon fiber matrices, glass fibers, aramid fabrics, high molecular weight polypropylene, natural fibers, basalt fibers, and other composite materials, excluding materials having a sound absorption coefficient greater than 0.6 in the frequency range of 1 Hz to 40 kHz. It is understood that materials with excessively high sound absorption coefficients are incompatible with the measurement principle of the integrated mechanical wave sensor 10 according to the invention. Therefore, the functionalized object 100 is formed of one (or more) materials that allow sound waves to propagate sufficiently.

[0065] For example, the support layer 12 is formed of a material selected from polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene (ABS), high-density polyethylene (HDPE), polyvinyl chloride (PVC), acrylonitrile styrene (SAN), acetal, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polycarbonate (PC), polyetheretherketone (PEEK), polyetherimide (PEI), polyethersulfone polyethylene ether (PPE), polyamide (NYLON), polyphenylene sulfide (PPS), polyepoxide, and carbon fiber matrix.

[0066] According to the first variant, the support layer 12 has a connection with the sensitive unit 11 ( Figure 2 They have essentially the same lateral dimensions (in the plane (x, y)).

[0067] According to the second variant, the size of the support layer 12 is larger than the size of the unit 11, such as... Figure 3a (in the cross section) and Figure 3b (In the plan view) illustrated: the sensitive unit 11, for example, represents a label disposed on a larger sheet acting as a support layer 12. Such a configuration facilitates the positioning of the sensitive unit 11 during attachment to the functionalized object 100; this will be described with reference to a manufacturing method that is the subject of the invention. Still in a second variation, multiple sensitive units 11 can be present on the same support layer 12. Figure 3bThis specifically allows for the integration of multiple mechanical wave sensors 10 on the same object 100, all of which share the same support layer 12. This variant also allows for the easy and precise positioning of the sensing element 11 on the flat support layer 12 before integrating the component (sensor 10) onto the object 100, which may be flat or curved.

[0068] Finally, according to the third variant, the mechanical wave sensor 10 includes a transfer layer 13 temporarily attached to the rear surface 12b of the support layer 12. Figure 4 When the total thickness of sensor 10 is small (especially less than 50 micrometers, or even less than 20 micrometers), the transfer layer 13 makes it particularly possible to transfer sensor 10. For example, the transfer layer may consist of a self-adhesive plastic film made of polyethylene terephthalate (PET). The transfer layer 13 is temporary and intended to be removed before sensor 10 is fixed to object 100.

[0069] Therefore, regardless of the variant considered, the rear surface 12b of the support layer 12 is fixed to the object 100, for example, such as Figure 5a exemplified.

[0070] According to the present invention, the functionalized object 100 further includes at least two conductive strips 20, said at least two conductive strips being disposed on the first surface 11a of the sensing unit 11 and the surface 100a of the object 100. Figure 5a Each strip 20 electrically connects electrodes 2 and 3 to electrical contact pads 30. Strip 20 may be made of a material selected from silver, copper, aluminum, or carbon-based paste.

[0071] Therefore, the aim is to re-acquire the electrical signal generated by the sensor 10 at the contact pad 30 and transmit the signal to the controller or an electronic unit capable of processing and interpreting the signal.

[0072] These strips are deposited and fixed to the surface 100a of the functionalized object 100. This eliminates any vibration problems with the connector of the mechanical wave sensor 10, which can easily contaminate the sensor's measurements with errors.

[0073] In some cases, the insulating film 40 can be disposed on the conductive strip 20, the mechanical wave sensor 10, and a portion of the surface 100a of the object 100 to insulate and protect the components. Figure 5b ).

[0074] exist Figure 5a and Figure 5b In the example, the functional object 100 takes the form of a flat cover for ease of representation. Of course, it can take any shape—flat, curved, or more complex—depending on the target area and application.

[0075] Due to the integration of the sensor 10 as described above, the functionalized object 100 according to the invention can accurately detect mechanical waves (vibrations or deformations) that gradually form within the object. The sensing element 11 is based on a crystalline piezoelectric material, which provides excellent sensitivity and high measurement reliability. Moreover, the small thickness of the sensing element 11 avoids the need to take countermeasures regarding the inherent frequency of the crystal in the active layer 1. The conductive strip 20, which is directly deposited on the surface 100a of the object 100, allows for effective connectivity, which does not contribute noise to the measurement of the sensor 10. Furthermore, the mechanical wave sensor 10 with its connector 20 contributes very little additional mass to the functionalized object 100 due to its size and composition.

[0076] Finally, the mechanical wave sensor 10 is particularly easy to integrate into the object 100 due to its support layer 12: fixing the support layer 12 to the object 100 or the material of the object 100 makes it easy and precise to position one or more sensitive layers 10 in the area of ​​interest of the object 100.

[0077] The present invention also relates to a method for producing the functionalized object 100 as described above. This method includes a first step a) of supplying a mechanical wave sensor 10. The mechanical wave sensor includes a sensing element 11 fixed to a support layer 12. The features of the sensing element 11 and the support layer 12 are as previously described and therefore will not be repeated here.

[0078] Sensing cell 11 can be assembled onto support layer 12 using known adhesive techniques. Alternatively, support layer 12 can be deposited on a second surface of sensing cell 11, for example by centrifugal coating (“spin coating”) or ribbon casting, dip coating (“dip coating”), jet deposition (“spray coating”), or screen printing. In particular, reference can be made to the published work of T. Dufay et al. concerning a process for transferring PZT thin film onto a polymer substrate (“New process for transferring PZT thin film onto polymer substrate”, 2016 Joint IEEE International Symposium on the Applications of Ferroelectrics, European Conference on Application of Polar Dielectrics, and Piezoelectric Force Microscopy Workshop (ISAF / ECAPD / PFM)).

[0079] In step a) of the process, one or more sensitive layers 11 (for forming one or more mechanical wave sensors 10 respectively) are fixed to the support layer 12 and can be precisely positioned on the support layer by known techniques (e.g., "pick and place").

[0080] The method then includes step b) forming an object 100 intended to be functionalized from a solid material. This step is based on molding, thermoforming, injection molding, or 3D printing, techniques known in the art.

[0081] The object 100 may be made of at least one material selected from plastics (such as thermoplastic polymers), metals, carbon fiber matrices, glass fibers, aramid fabrics, high molecular weight polypropylene, natural fibers, basalt fibers, and other composite materials or combinations thereof. According to the invention, the object 100 is made of one or more materials having a sound absorption coefficient of less than or equal to 0.6 in the frequency range of 1 Hz to 40 kHz, so as to allow mechanical waves to propagate in said material.

[0082] The manufacturing method also includes step c) of fixing the mechanical wave sensor 10 to the object 100. This step can be performed according to different implementation methods.

[0083] According to the first embodiment, during step b), the fixing step is accomplished by positioning the sensor 10 in such a way that the rear surface 12b of the support layer 12 is in contact with or integrated into the material forming the object 100, and the electrodes 2 and 3 remain accessible during the formation of the object 100.

[0084] exist Figure 6 In the example shown, sensor 10 is typically held in mold 200 by a vacuum gripping system; electrodes 2 and 3 are placed on the sides of mold 200. Figure 6 (a) The material intended to form the object 100 (for example, a thermoplastic or composite material as mentioned above) is introduced into the mold and subjected to temperature and pressure conditions permissible for molding the object 100. Figure 6 (b) Alternatively, the sensor 10 is combined with the material intended to form the object 100 before the component is introduced into the mold 200.

[0085] When object 100 is removed from mold 200, mechanical wave sensor 10 is integrated into the material of object 100. This integration is more reliable if the material of support layer 12 is selected to be the same as, or compatible with, the material of object 100 in terms of adhesion, and compatible with the technology used to form object 100: all or part of the material of support layer 12 can mix with or diffuse into the material of object 100. Sensing element 11 made of crystalline and metallic materials readily supports the aforementioned technology used to form object 100.

[0086] According to the second embodiment, after step b), the mechanical wave sensor 10 is fixed by adhering the rear surface 12b of the support layer 12 onto the surface 100a of the formed object 100. Adhesion can be achieved by means of an adhesive (for example, cyanoacrylate or acrylic adhesive), by hot pressing, or by dissolution.

[0087] According to one or another of the embodiments, step a) may include supplying multiple mechanical wave sensors 10 that share or do not share the same support layer 12, as shown in reference. Figure 3b As mentioned above, in this case, step c) includes simultaneously securing the plurality of mechanical wave sensors 10 to the object 100. In the specific case where the sensors 10 share the same support layer 12, it is conceivable that the support layer has a specific shape and / or size suitable for precisely positioning the sensors 10 within the mold 200 or positioning them relative to the object 100 on which they must be integrated or assembled. Proper positioning of the support layer 12 within the mold 200 also facilitates providing sensors 10 to hard-to-access areas of the object 100 (e.g., corners), where the sensitive elements 11 have been pre-distributed on the support layer 12, given the geometry of the object 100.

[0088] According to a variant compatible with the first and second embodiments mentioned above, the mechanical wave sensor 10 disposed in step a) includes a temporary transfer layer 13 disposed on the rear surface 12b of the support layer 12. Such layer 13 is removed before step c) of fixing the mechanical wave sensor 10 to the object 100.

[0089] After fixing the mechanical wave sensor 10 to the surface 100a of the object 100 ( Figure 7 (a) The manufacturing method according to the present invention includes step d) depositing two conductive strips 20 on the first surface 11a of the sensing unit 11 of the sensor 10 and on the surface 100a of the object 100. Figure 7(b) Each conductive strip 20 electrically connects the electrodes 2 and 3 to the electrical contact pads 30 disposed on the surface 100a. Deoxidation treatment (e.g., based on dilute acid) can be applied to the surface of the contact pads 30 and / or the surfaces of the electrodes 2 and 3 to ensure conductive contact with the strips 20.

[0090] In practice, step d) can be performed by screen printing, spraying, electrolytic growth, or direct laser sintering of the metal.

[0091] Advantageously, after the conductive strip 20 is formed, an insulating layer 40 is deposited on the sensor 10, the strip 20, and a portion of the surface 100a of the object 100 to insulate and protect the components.

[0092] The insulating layer 40 is made of, for example, epoxy resin, polyurethane, or even silicone (e.g., cold-cured silicone elastomer, or RTV for “room temperature curing”); the insulating layer can be deposited by screen printing, coating, spraying, etc.

[0093] Of course, the present invention is not limited to the described embodiments, and alternative embodiments may be added without departing from the scope of the invention as defined by the claims.

Claims

1. A functionalized object (100) comprising a material having a sound absorption coefficient of less than 0.6 in a frequency range varying from 1 Hz to 40 kHz, and provided with at least one mechanical wave sensor (10) providing the object with vibration and deformation detection capabilities, the functionalized object (100) characterized in that the mechanical wave sensor (10) comprises: - Sensing unit (11), the sensing unit having a thickness of less than or equal to 50 micrometers, and comprising an active layer (1) made of a single crystal or polycrystalline piezoelectric material, and two electrodes (2, 3) in contact with the active layer (1) and accessible at the first surface (11a) of the sensing unit (11). - A support layer (12), which is made of the same material as the material constituting the object (100) or of a material capable of adhering to the material constituting the object, the support layer being fixed to the second surface (11b) of the sensitive unit (11) and to the object (100), the support layer (12) being integrated into the material of the object (100). Furthermore, the functionalized object (100) includes at least two conductive strips (20), which are disposed on the first surface (11a) of the sensitive unit (11) and on the surface (100a) of the object (100), and each strip (20) connects the electrodes (2, 3) to the electrical contact pads (30).

2. The functionalized object (100) according to claim 1, wherein, The piezoelectric material is selected from lead zirconate titanate (PZT), aluminum nitride (AlN), zinc oxide (ZnO), lithium tantalate (LiTaO3), potassium niobate (KNbO3), lithium niobate (LiNbO3), lead magnesium titanium niobate (PMN-PT), quartz, strontium titanate (SrTiO3), and barium titanate (BaTiO3).

3. The functionalized object (100) according to claim 1 or 2, wherein, The active layer (1) has surface undulations in the form of wrinkles on at least one side of the first surface (11a).

4. The functionalized object (100) according to claim 1, wherein the functionalized object is composed of at least one material selected from the group consisting of thermoplastic polymers, plastics, metals, carbon fiber matrices, glass fibers, aramid fabrics, high molecular weight polypropylene, natural fibers, basalt fibers, and other composite materials.

5. The functionalized object (100) according to claim 1, wherein, The support layer (12) is formed from materials selected from polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene (ABS), high-density polyethylene (HDPE), polypropylene polyvinyl chloride (PVC), acrylonitrile styrene (SAN), acetal, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polycarbonate (PC), polyether ether ketone (PEEK), polyetherimide (PEI), polyether sulfone polyethylene ether (PPE), polyamide (NYLON), polyphenylene sulfide (PPS), polyepoxide, and carbon fiber matrix.

6. The functionalized object (100) according to claim 1, wherein, The thickness of the support layer (12) is between 10 micrometers and 1 mm.

7. The functionalized object (100) according to claim 1, wherein the functionalized object comprises a plurality of mechanical wave sensors (10).

8. The functionalized object (100) according to claim 7, wherein, The multiple mechanical wave sensors (10) share the same support layer (12).

9. The functionalized object (100) according to claim 1, wherein the functionalized object forms a structural component of a vehicle or building, an engine part, a bicycle frame, or a cover for an industrial or household appliance.

10. A method for producing a functionalized object (100), said functionalized object being a functionalized object according to any one of claims 1 to 9, said method comprising the steps of: a) Supplying a mechanical wave sensor (10), the mechanical wave sensor comprising: - Sensing unit (11), the sensing unit having a thickness of less than or equal to 50 micrometers, and comprising an active layer (1) made of a single crystal or polycrystalline piezoelectric material, and two electrodes (2, 3) in contact with the active layer (1) and accessible at the first surface (11a) of the sensing unit (11). - A support layer (12) having a front surface (12a) and a rear surface (12b), the front surface (12a) of the support layer being fixed to the second surface (11b) of the sensitive unit (11), then b) Forming objects from solid materials through molding, injection molding, or 3D printing. c) During step b), the mechanical wave sensor (10) is fixed to the object by positioning it in such a way that the rear surface (12b) of the support layer (12) is at least in contact with or integrated into the material forming the object, and the electrodes (2, 3) remain accessible during the formation of the object. d) Deposit two conductive strips (20) on the first surface (11a) of the sensitive unit (11) and on the surface (100a) of the object (100), each strip (20) connecting the electrodes (2, 3) to the electrical contact pads (30) provided on the surface (100a).

11. The method for producing a functionalized object (100) according to claim 10, wherein: - The mechanical wave sensor (10) set in step a) includes a temporary transfer layer (13) disposed on the rear surface (12b) of the support layer (12), and - The transfer layer (13) is removed before step c) of fixing the mechanical wave sensor (10) onto the object (100).

12. The method according to claim 10 or 11, wherein: - Step a) includes providing multiple mechanical wave sensors (10) sharing the same support layer (12), and - Step c) includes simultaneously fixing the plurality of mechanical wave sensors (10) to the object (100).

13. The method according to claim 10 or 11, wherein, Step d) is performed by screen printing, spraying, electrolytic growth, or direct laser sintering of metal.

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