Touch surface device

Abstract

A touch surface device (100) comprises at least: an element (102) comprising a first side (104) forming a touch surface and a second side (106) opposite the first side; an acoustic wave sensor (108) comprising at least one piezoelectric material portion arranged between two electrodes, the piezoelectric material portion and the two electrodes being constructed by forming surface corrugations as wrinkles, the sensor being fixed to the second side of the element such that the apexes or valleys of the wrinkles are in contact with the second side of the element; and an electronic circuit (118) coupled to the electrodes of the sensor and configured to recognize at least one touch gesture made on the touch surface from electrical signals intended to be output from the electrodes of the sensor.

Description

Technical Field

[0001] The technical field of the invention is that of human-machine interfaces or HMIs, and more generally that of spaces and / or objects whose interfaces are realized by means of touch or haptic functions. The invention is particularly applicable to the production of HMIs in the field of home automation or in harsh environments (e.g. in the presence of water, oil, dust, snow, or exposure to high or low temperatures). Background Art

[0002] The most robust, affordable, and adaptable touch solutions (which can be adapted to any shape of the surface to be made tactile) use capacitive sensors. These sensors are placed, for example, on the surface of the part or object to be functionalized and may be covered with a thin coating. When the sensor includes an array of capacitive elements, advanced touch functions are possible, such as detecting a finger sliding or swiping across the touch surface.

[0003] However, using capacitive sensors to give a surface a sense of touch leads to several disadvantages.

[0004] First, the brittle nature of capacitive sensors prevents their integration into the material of the object being functionalized. Therefore, for optimal integration onto the object, it is necessary to provide a printed material formed on the surface of the object to accommodate the sensor. Furthermore, the technologies implemented for attaching the sensor to the surface of the object are limited to bonding and cooling methods.

[0005] When capacitive sensors are covered with a coating used as a touch surface, additional requirements must be met to avoid crosstalk, low signal-to-noise ratios, false alarms (unwanted triggering), or even loss of sensor sensitivity:

[0006] - restrictions on the nature of the materials that can be used as coatings, which must not interfere with the capacitive detection performed by the sensor;

[0007] -Restriction on coating thickness, the thickness must be less than 2mm.

[0008] If a coating thicker than 2 mm must be used, the sensor will be subject to the following limitations:

[0009] -Sensor complexity;

[0010] – loss of formability of the part to be functionalized;

[0011] – Increasing the size of the sensor electrodes leads to a decrease in sensor resolution;

[0012] – Scaling up conventional sensor designs reduces the ability to evaluate advanced touch functionality, such as finger sliding across a touch surface.

[0013] Piezoelectric sensors exist that can impart a sense of touch to surfaces even in the presence of coatings thicker than 2mm. However, the touch functionality these sensors can address is limited to simple functions, such as pressing on the touch surface. Furthermore, the use of non-deformable piezoelectric elements limits their use to planar touch structures. Summary of the Invention

[0014] An object of the present invention is to provide a touch or touch-sensitive surface device that does not have the disadvantages of prior art solutions, is not restricted to capacitive sensors, has a touch surface thickness not limited to 2 mm, and is adaptable to any touch surface shape.

[0015] To this end, the present invention provides a touch surface device, comprising at least:

[0016] - an element comprising a first face forming a touch surface and a second face opposite the first face;

[0017] - an acoustic wave sensor comprising at least one portion of piezoelectric material arranged between two electrodes, the portion of piezoelectric material and the two electrodes being constructed by forming surface ripples or corrugations as corrugations, the sensor being fixed to the second face of the element so that the apexes or peaks or valleys of the corrugations are in contact with the second face of the element;

[0018] An electronic circuit coupled to the electrodes of the sensor and configured to recognize at least one touch or tactile gesture made on the touch surface from electrical signals intended to be output from the electrodes of the sensor.

[0019] In this device, touch gestures are detected by sensors using the transmission of sound waves through the component material. These sound waves are detected by the sensor and interpreted by the electronic circuit. This type of detection avoids the disadvantages encountered when using capacitive sensors.

[0020] The sensor includes surface ripples, often referred to as "corrugations," and is characterized by amplitude, wavelength, and orientation. Compared to planar piezoelectric sensors (i.e., those without corrugations), the corrugations provide the sensor with greater deformability, resulting in greater sensitivity to pressure and, therefore, greater detection sensitivity. By using such a sensor with corrugations, the element to which the sensor is attached can be made thicker than 2 mm without affecting touch detection, and complex touch gestures, such as a finger sliding across the contact surface, can be detected.

[0021] Furthermore, the corrugations enable the sensor to detect complex touch functions, such as sliding a finger across the touch surface or different press types (long, short, several fingers at once, etc.).

[0022] The advantage of such a device is that it is insensitive to usage conditions (heat, cold, rain, the presence of dust and / or oil on the touch surface, use of the device with gloves, etc.), as long as the detected sound waves are not affected by these usage conditions. For example, unlike capacitive sensors that immediately cease to operate when frost appears on the sensor surface (when the sensor is exposed to a temperature below 0°C), the device provided by the present application can still operate even when exposed to a temperature below 0°C.

[0023] This device also has the advantage that there is no printed matter on the surface housing the sensor and no restrictions on the nature of the material of the element forming the contact surface (which may be made of metal, plastic, wood, etc.). This provides greater freedom in the design of the touch surface, since, unlike capacitive sensors, the dielectric constant of the element has no influence on the acoustic wave sensor. The element can have a complex geometry, for example including one or more curvatures, or any shape (parallelepipedic, pyramidal, etc.).

[0024] The term "element" is used to refer to any type of object, structure, or component that is touch- or tactile-functionalized with the aid of an acoustic wave sensor.

[0025] The electrodes include at least one electrically conductive material, such as at least one metal.

[0026] Advantageously, the corrugations of the sensor may be linear or straight and parallel to each other. Such corrugations are well suited for detecting a finger sliding on the touch surface in a direction substantially perpendicular to the orientation of the corrugations.

[0027] Advantageously, the piezoelectric material may correspond to a ceramic material, i.e. an inorganic material. Unlike polymeric piezoelectric materials, such piezoelectric materials have the advantage of being able to withstand high temperatures (above approximately 300° C.). The use of ceramic piezoelectric materials in particular allows the sensor to be integrated into components manufactured by thermoforming or any other method involving steps performed at relatively high temperatures.

[0028] The sensor can be fixed to the second side of the component by means of at least one adhesive layer, or the sensor can be integrated into the component. Integrating the sensor into the component has the advantage, inter alia, that the sensor is not visible from the outside of the component and that the sensor is protected on all sides of the component.

[0029] The element may form a layer having a thickness greater than 2 mm between the first and second faces and against the sensor. This greater thickness is possible when using a piezoelectric sensor comprising corrugations. This greater thickness of the element provides greater strength to the device and greater protection to the sensor, for example, against vandalism.

[0030] The corrugations may have a period greater than 10 μm.Such a period makes the sensor well suited for detecting the sound waves generated by gestures made against the touch surface of the device.

[0031] The device may include a plurality of acoustic wave sensors fixed to the second side of the component. By coupling the plurality of acoustic wave sensors to the second side of the component, complex touch gestures may be detected or other information may be obtained, such as the direction in which a finger slides across the touch surface of the component.

[0032] According to a first embodiment, when the device comprises a plurality of sensors, the piezoelectric material portion of each sensor may be different, ie separated or spaced apart, from the piezoelectric material portions of the other sensors, and the electrodes of each sensor may be different from the electrodes of the other sensors.

[0033] According to a second embodiment, when the device comprises a plurality of sensors, the piezoelectric material portions of all sensors may be formed from a single continuous piezoelectric layer common to all sensors, and at least one of the electrodes of each sensor may be different from the electrodes of the other sensors.

[0034] The electronic circuit may be configured to identify a sliding movement of the finger on the touch surface according to a direction substantially perpendicular to the direction in which the wrinkles extend.

[0035] The thickness of the sensor can be less than 100 μm. Such a sensor can be mounted on thin components.

[0036] The present invention also relates to a method for manufacturing a touch surface device, comprising the following steps:

[0037] - providing at least one acoustic wave sensor comprising at least one piezoelectric material portion arranged between two electrodes, the piezoelectric material portion and the two electrodes being constructed by forming surface corrugations as corrugations;

[0038] - providing at least one element comprising a first face intended to form a touch surface and a second face opposite to the first face;

[0039] - fixing the sensor to the second side of the element so that the apex or peak or valley of the corrugation contacts the second side of the element;

[0040] - coupling the electrodes of the sensor to an electronic circuit configured to recognize at least one touch gesture made on the touch surface from electrical signals intended to be output from the electrodes of the sensor.

[0041] According to a first embodiment, fixing the sensor to the second face of the component may comprise bonding the sensor against the second face of the component.

[0042] According to a second embodiment, providing the component and securing the sensor to the second side of the component may include:

[0043] - Positioning the sensor on the support;

[0044] The element is thermoformed or injection-molded, the sensor being positioned against the second face during the thermoforming or injection-molding process and being integrated into the element at the end of the thermoforming or injection-molding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The invention will be better understood on reading the description of exemplary embodiments given by way of purely indicative and non-limiting purposes with reference to the accompanying drawings, in which:

[0046] - Figure 1 and Figure 2 a cross-sectional view and a top view, respectively, showing a sensor of a touch surface device, the subject of the invention, according to a first embodiment;

[0047] - Figure 3 shows a touch surface device, the subject of the invention, according to a first embodiment;

[0048] - Figure 4 and Figure 5 shows a touch surface device, the subject of the invention, according to a second embodiment;

[0049] - Figures 6 to 9 shows an example of electrical signals obtained during a touch gesture on the touch surface of the device that is the subject of the invention;

[0050] - Figure 10 and Figure 11 shows a touch surface device according to an alternative embodiment of the subject matter of the invention;

[0051] - Figure 12 An example of electrical signals obtained during a touch gesture on the touch surface of the device that is the subject of the invention is shown.

[0052] Identical, similar or equivalent parts of the different figures described below have the same reference signs to facilitate moving from one figure to another.

[0053] To improve clarity of the drawings, different parts shown in the figures are not necessarily drawn to the same scale.

[0054] The different possibilities (alternatives and embodiments) are to be understood as not excluding one another and can be combined with one another. DETAILED DESCRIPTION

[0055] Combined with Figures 1 to 3A touch surface device 100 according to a first embodiment is described. Figure 1 Corresponds to a cross-sectional view of the acoustic wave sensor 108 of the device 100 . Figure 2 Corresponds to a top view of sensor 108 . Figure 3 Corresponds to a perspective view of the device 100 .

[0056] The device 100 includes an element 102 having a first face 104. The first face 104 forms the touch surface or touch-sensitive surface of the device 100, i.e., the surface on which a user of the device 100 is to perform touch gestures (press, slide, etc.). The element 102 also includes a second face 106 opposite the first face 104. The element 102 may be of any shape. Figure 3 In the example shown, the element 102 is curved.

[0057] In a first embodiment, the distance between the faces 104 , 106 , corresponding here to the thickness e of the layer formed by the element 102 , is greater than 2 mm.

[0058] The device 100 comprises an acoustic wave sensor 108. The sensor 108 comprises a piezoelectric material portion 110 arranged between two electrodes 112, 114 to ensure collection of electrical charge generated by the piezoelectric effect when the piezoelectric material of the piezoelectric material portion 110 is deformed.

[0059] Advantageously, the piezoelectric material of the piezoelectric material portion 110 corresponds to a ceramic material, i.e., an inorganic material, such as AlN, PZT, ZnO, LiNbO 3 , LiTaO 3 , KNbO 3 , quartz, SrTiO 3 , BaTiO 3 or langasite. Alternatively, if the piezoelectric material is not exposed to high temperatures during the manufacture of the device 100 , the piezoelectric material may be a polymer, such as P(VDF-TrFE).

[0060] Each of the electrodes 112 and 114 comprises, for example, a metal material such as aluminum, tungsten, titanium, copper, nickel, platinum, palladium, gold, silver, or an alloy of several of these metals. Possibly, one or each of the electrodes 112 and 114 may be a metallic multilayer element comprising one or more diffusion barrier layers, including, for example, TiN and / or TaN and / or WN. One or each of the electrodes 112 and 114 may also comprise at least one transparent conductive oxide, corresponding, for example, to one of the following materials: indium tin oxide (ITO), fluorine-doped tin oxide (FTO), doped zinc oxide, or a conductive polymer such as poly(3,4-ethylenedioxythiophene) or PEDT, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) or PEDOT:PSS, poly(4,4-dioctylcyclopentadithiophene). One or each of the electrodes 112 and 114 may correspond to a layer based on a 2D material, such as graphene, or include carbon nanotubes (CNTs).

[0061] The length L of the sensor 108 is, for example, between 1 mm and the length of the second face 106 of the element 102. The width l of the sensor 108 is, for example, between 0.5 mm and the width of the second face 106 of the element 102. The thickness of the piezoelectric material portion 110 is, for example, between 500 nm and 20 μm. The electrode 112 (corresponding to the electrode provided on the side opposite to the second face 106) may have a thickness between approximately 2 μm and 100 μm. The surface area of ​​the electrode 112 may be equal to the surface area of ​​the piezoelectric material portion 110, or greater than the surface area of ​​the piezoelectric material portion 110 (a portion of the electrode 112 may be in direct contact with the element 102). The electrode 114 (corresponding to the electrode provided on one side of the second face 106, abutting against the element 102) may have a thickness between approximately 3 nm and 2 μm. The surface area of ​​the electrode 114 may be between approximately 50 μm×50 μm and the surface area of ​​the piezoelectric material portion 110. The thickness of the sensor 108 (at Figure 1 The thickness of the piezoelectric material portion 110 and the electrodes 112 and 114 is preferably less than 100 μm. For example, the sensor 108 may have the following characteristics:

[0062] - length L = 10 mm;

[0063] - width l = 3 mm;

[0064] - thickness of the piezoelectric material portion 110 = 1 μm;

[0065] - thickness of electrode 112 (arranged on the side opposite to face 106 )=4 μm;

[0066] - Thickness of electrode 114 (arranged on the side of face 106 , against component 102 ) = 50 nm.

[0067] Regardless of the shape of the element 102 , the sensor 108 is positioned against the face of the element 102 opposite the contact surface.

[0068] The piezoelectric material portion 110 and electrodes 112, 114 are constructed by forming surface corrugations as corrugations. In the exemplary embodiment described herein, the corrugations are straight and parallel to each other (and parallel to the Figure 1 ). The corrugations have an amplitude A, for example, equal to 10 μm, and a period λ. Advantageously, the period λ is greater than 10 μm, for example, equal to 50 μm. The value of the period λ is proportional to the value of the amplitude A. The amplitude A corresponds to half the peak-to-peak height 2A of the same layer of sensor 108. The vertices or peaks of the corrugations are denoted by reference numeral 116, and the valleys of the corrugations are denoted by reference numeral 117. The period λ corresponds to the distance between two adjacent vertices or peaks 116.

[0069] Examples of methods implemented to form the sensor 108 , and more specifically to form corrugations, are described, for example, in documents WO 2015 / 055788 A1 , WO 2015 / 055783 A1 , and WO 2015 / 055786 A1 , and may be used to manufacture the sensor 108 described herein.

[0070] The sensor 108 is fixed to the second face 106 of the element 102 such that the apexes or peaks 116 of the corrugations are in contact with the second face 106. In the first embodiment described herein, the sensor 108 is secured by bonding, i.e., by a bonding layer interposed between the sensor 108 and the second face 106 (at Figures 1 to 3 106 ), is secured to the second face 106. Other bonding types may be implemented to secure the sensor 108 against the second face 106 of the element 102.

[0071] According to a second embodiment, sensor 108 is integrated into element 102 and at least partially surrounded by element 102. In this second embodiment, element 102 is manufactured, for example, by thermoforming. In this case, sensor 108 is disposed within element 102, i.e., completely surrounded by the material of element 102. The face of element 102 against which sensor 108 is disposed does not correspond to second face 106, which forms the outer surface of element 102, but rather to a face designated 107, which is formed within (i.e., internally) the material portion of element 102 and against which electrode 114 is disposed. Figure 4 and Figure 5 An apparatus 100 according to this second embodiment is schematically shown.

[0072] According to a third embodiment, similar to the aforementioned integration according to one of the two aforementioned embodiments, the sensor 108 can be integrated against or into the intermediate element. This intermediate element can then be assembled to the element 102 by any mechanical attachment means (e.g., screws, rivets, attachment clips, etc.). In this case, the sensor 108 is actually coupled to the element 102 so that the apex or peak or valley of the wrinkles is in contact with the second face of the element 102 via the intermediate element.

[0073] In the three previously described embodiments, the device 100 further includes an electronic circuit 118 connected to the electrodes 112, 114 of the sensor 108. The circuit 118 is configured to identify one or more touch gestures made on the touch surface of the element 102 (i.e., on the first side 104) from the electrical signals output from the electrodes 112, 114 by the sensor 108. Advantageously, the electronic circuit 118 can be configured to identify a finger sliding on the first side 104 in a direction substantially perpendicular to the direction in which the wrinkles extend. In the second embodiment, the electrical connections connecting the electrodes 112, 114 to the electronic circuit 118 pass through the element 102.

[0074] In addition to the finger sliding motion on the first surface 104, the device 100 according to the two embodiments previously described is also capable of recognizing other touch gestures made on the first surface 104, such as the motion of pressing and releasing one or more fingers on the first surface 104 (long or short), contact motion, vibration motion, etc.

[0075] Figure 6 An example of electrical signals obtained between electrodes 112 , 114 of sensor 108 during vibrations on touch surface 104 of device 100 is shown.

[0076] Figure 7 An example of electrical signals obtained between electrodes 112 , 114 of sensor 108 during a short press of a finger on touch surface 104 of device 100 is shown.

[0077] Figure 8 An example of electrical signals obtained between electrodes 112 , 114 of sensor 108 during a long press of a finger on touch surface 104 of device 100 is shown.

[0078] Figure 9 An example of electrical signals obtained between electrodes 112 , 114 of sensor 108 during sliding of a finger across touch surface 104 of device 100 is shown.

[0079] All of these signals exhibit different characteristics (different intervals between peaks, repetition of peaks, etc.), which the electronic circuit 118 uses by performing processing on these signals to identify the type of touch gesture made on the touch surface of the device 100. The details of this processing are not described herein, but can be easily implemented by those skilled in the art, for example, by performing digital and / or computer processing on the electrical signals output by the electrodes of the sensors of the device 100.

[0080] To manufacture the device 100 according to the first embodiment, the sensor 108 and the element 102 are first manufactured independently of each other, and then the sensor 108 is placed on a temporary substrate and bonded against the second side 106 of the element 102 using, for example, an adhesive layer. The temporary substrate can then be removed. The electrodes 112, 114 of the sensor 108 are then coupled to the electronic circuit 118.

[0081] To manufacture the device 100 according to the second embodiment, the sensor 108 is first manufactured, and then the element 102 is manufactured by integrating the sensor 108 into the element 102. To this end, the sensor 108 can be positioned on a support, and then the element 102 can be manufactured by thermoforming around the sensor 108. An opening can be formed in the element 102 to access the electrodes 112, 114. The electrodes 112, 114 of the sensor 108 are then coupled to the electronic circuit 118.

[0082] In addition to thermoforming, depending on the properties of the materials used and the geometric characteristics of the element 102, the element 102 can be manufactured by other techniques, such as molding, freeze casting, impregnation or infiltration, pyrolysis, tape casting, injection or extrusion molding, blow molding or foaming process, assembly, inkjet, aerosol spraying, deposition, etc.

[0083] In both previously described embodiments, the device 100 comprises a single sensor 108, which is arranged against the second face 106 or 107 of the element 102. Alternatively, the device 100 may comprise a plurality of sensors 108 in contact with the second face 106 or 107.

[0084] Figure 10 A first exemplary embodiment of a device 100 is schematically shown, comprising a plurality of sensors 108 arranged adjacent to one another against the second face 106 of the same element 102. The sensors 108 are used to collectively functionalize the first face 104 of the element 102. In this first exemplary embodiment, the sensors 108 comprise a piezoelectric material portion 110 and electrodes 112, 114, which vary from one sensor to another. In other words, the piezoelectric material portion 110 of each sensor 108 is spaced and separated from the piezoelectric material portions 110 of the other sensors 108. Similarly, the electrodes 112, 114 of each sensor 108 are also spaced and separated from the electrodes 112, 114 of the other sensors 108.

[0085] Figure 11A second exemplary embodiment of a device 100 is schematically shown, comprising a plurality of sensors 108 arranged adjacent to one another against the second face 106 of the same element 102. As in the first exemplary embodiment, the sensors 108 serve to functionalize together the first face 104 of the element 102. In this second exemplary embodiment, the piezoelectric material portion 110 of the sensors 108 is formed by a single continuous piezoelectric layer common to all sensors 108. Furthermore, at least one of the electrodes 112, 114 of each sensor 108 is different from the electrodes of the other sensors 108, i.e. is separated and spaced apart from the electrodes of the other sensors 108. Figure 11 In the example shown, the electrode 114 of each sensor 108 is formed from the same layer of continuous conductive material and is common to all sensors 108 (forming an electrode common to all sensors 108), and the electrode 112 of each sensor 108 is formed from a conductive material portion that is different from and spaced apart from the conductive material portions forming the electrodes 112 of the other sensors 108.

[0086] Regardless of the exemplary embodiment of device 100, using multiple sensors 108 associated with the same surface enables recognition of more complex touch gestures, such as detecting multiple simultaneous different pressing actions on the touch surface or detecting the direction of a finger sliding on the touch surface and its speed.

[0087] When device 100 includes multiple sensors 108, the corrugations of these sensors can be oriented in the same direction or in different directions. For example, device 100 can include two sensors 108 that are affixed to second side 106 and positioned so that the corrugations of the two sensors 108 are oriented perpendicular to each other. In this case, device 100 is well suited to distinguishing between sliding motions in two perpendicular directions on the touch surface of device 100, for example, a sliding motion in an up-down direction and a sliding motion in a left-right direction. Other combinations of sensors 108 on second side 106 of device 100 are contemplated.

[0088] Figure 12 An example of electrical signals obtained across two sensors 108 of device 100 during a finger slide on the touch surface of device 100 is shown. The presence of two sensors 108 enables identification of the finger slide direction on the touch surface of device 100 based on the time offset between the two signals.

[0089] The device 100 may include one or more other parts or components to which the element 102 may be assembled. The sensor 108 may in particular be interposed between the element 102 and one or more other components of the device 100.

[0090] When the device 100 corresponds to the previously described second exemplary embodiment, ie by integrating the sensor 108 into the element 102 of the device 100 , a plurality of sensors 108 may also be present on the same surface of the device 100 .

[0091] Regardless of the exemplary embodiment, the present invention can functionalize the surface of an object, structure, or part with touch capabilities. Thus, after being provided with these touch capabilities, the surface becomes sensitive to touch loads and can directly or indirectly trigger a response to these loads. The response can include tactile (e.g., tactile and / or visual and / or audio and / or mechanical) feedback and / or trigger one or more actions, such as mechanical actions (such as turning a system on / off) and / or electrical actions (such as turning a lighting system on, off, or changing the light).

Claims

1. A touch surface device (100), comprising at least: - an element (102) comprising a first face (104) forming the touch surface and a second face (106, 107) opposite the first face (104); - an acoustic wave sensor (108) comprising at least one piezoelectric material portion (110) arranged between two electrodes (112, 114), said piezoelectric material portion (110) and the two electrodes (112, 114) being constructed by forming surface corrugations as corrugations, said sensor (108) being fixed to said second face (106, 107) of said element (102) such that the apexes or valleys (116) of said corrugations are in contact with said second face (106, 107) of said element (102); - an electronic circuit (118) coupled to the electrodes (112, 114) of the sensor (108) and configured to recognize at least one touch gesture made on the touch surface from electrical signals intended to be output from the electrodes (112, 114) of the sensor (108), The wrinkles have a period greater than 10 μm.

2. The device (100) according to claim 1, wherein The corrugations of the sensor (108) are linear and parallel to each other.

3. The device (100) according to claim 1, wherein The piezoelectric material corresponds to a ceramic material.

4. The device (100) according to claim 1, wherein The sensor (108) is fixed to the second face (106) of the element (102) by at least one adhesive layer, or the sensor (108) is integrated into the element (102).

5. The device (100) according to claim 1, wherein The element (102) forms a layer having a thickness greater than 2 mm between the first face (104) and the second face (106, 107) and against the sensor (108).

6. The device (100) according to one of claims 1 or 2, comprising a plurality of acoustic wave sensors (108) fixed to the second face (106, 107) of the element (102).

7. The device (100) according to claim 6, wherein The piezoelectric material portion (110) of each sensor (108) is different from the piezoelectric material portion (110) of the other sensors (108), and wherein the electrodes (112, 114) of each sensor (108) are different from the electrodes (112, 114) of the other sensors (108).

8. The device (100) of claim 6, wherein the piezoelectric material portions (110) of all sensors (108) are formed from a single continuous piezoelectric layer common to all sensors (108), and wherein at least one of the electrodes (112) of each sensor (108) is different from the electrodes (112) of the other sensors (108).

9. The device (100) according to one of claims 1 or 2, wherein The sensor (108) has a thickness of less than 100 μm.

10. A method for manufacturing a touch surface device (100), comprising the steps of: - providing at least one acoustic wave sensor (108), said acoustic wave sensor (108) comprising at least one piezoelectric material portion (110) arranged between two electrodes (112, 114), said piezoelectric material portion (110) and the two electrodes (112, 114) being constructed by forming surface corrugations as corrugations; - providing at least one element (102), said element (102) comprising a first face (104) for forming said touch surface and a second face (106, 107) opposite said first face (104); - fixing the sensor (108) to the second face (106, 107) of the element (102) so that the apexes or valleys (116) of the corrugations are in contact with the second face (106, 107) of the element (102); - coupling the electrodes (112, 114) of the sensor (108) to an electronic circuit (118), the electronic circuit being configured to recognize at least one touch gesture made on the touch surface from electrical signals intended to be output from the electrodes (112, 114) of the sensor (108), The wrinkles have a period greater than 10 μm.

11. The method according to claim 10, wherein: Securing the sensor (108) to the second face (106) of the component (102) includes bonding the sensor (108) against the second face (106) of the component (102).

12. The method according to claim 10, wherein: Providing the element (102) and securing the sensor (108) to the second face (107) of the element (102) comprises: - positioning the sensor (108) on a support; - The element (102) is thermoformed or injection-molded, the sensor (108) being positioned against the second face (107) during the thermoforming or injection-molding, and the sensor (108) being integrated into the element (102) at the end of the thermoforming or injection-molding.

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