Tactile sensation imparting apparatus and tactile sensation imparting system

Abstract

This tactile sensation imparting apparatus has: a housing; and a first actuator that is accommodated in the housing and imparts amplitude-modulated vibration to the housing. The vibration has carrier waves of Solfeggio frequencies and modulated waves in a gamma wave band.

Description

Haptic device and haptic system

[0001] The present disclosure relates to a haptic device and a haptic system.

[0002] Various devices for inducing gamma waves in users have been proposed.

[0003] Japanese Patent Application Laid-Open No. 2022-094137, Japanese Patent Application Laid-Open No. 2024-003859

[0004] Recently, there has been an increasing demand for devices that can provide a comfortable tactile sensation to users.

[0005] An object of the present disclosure is to provide a haptic device and a haptic system that can provide a comfortable tactile sensation to a user.

[0006] According to one aspect of the present disclosure, a haptic device includes a housing and a first actuator housed in the housing and configured to apply vibration amplitude-modulated to the housing, the vibration having a carrier wave of a solfeggio frequency and a modulation wave in a gamma wave band.

[0007] According to the present disclosure, a comfortable tactile sensation can be imparted to a user. <​​​The embodiments of this disclosure will be described in detail below, but this disclosure is not limited thereto. In this specification and drawings, components having substantially the same functional configuration may be denoted by the same reference numerals to avoid redundant descriptions. In the following description, the XYZ Cartesian coordinate system will be used, but this coordinate system is defined for illustrative purposes only and does not limit the orientation of the tactile device. Also, from any point, the +Z side may be referred to as upward, upper, or up, and the -Z side may be referred to as downward, lower, or down.

[0010] (First Embodiment) The first embodiment will now be described. The first embodiment relates to a tactile sensation-granting system. Figure 1 is a diagram showing the tactile sensation-granting system according to the first embodiment. Figure 2 is a schematic diagram showing the tactile sensation-granting device in the first embodiment.

[0011] As shown in Figure 1, the tactile sensation granting system 1 according to the first embodiment includes a tactile sensation granting device 10 and a control device 20. The control device 20 controls the tactile sensation granting device 10. The tactile sensation granting device 10 is, for example, a fidget toy.

[0012] The control device 20 is a computer and includes a bus 21, an arithmetic processing unit 22, an input unit 23, an output unit 24, a storage device 25, and a memory device 26. The arithmetic processing unit 22, the input unit 23, the output unit 24, the storage device 25, and the memory device 26 are connected to the bus 21. The arithmetic processing unit 22, the input unit 23, the output unit 24, the storage device 25, and the memory device 26 are interconnected via the bus 21. The input unit 23 is a part for the user to input instructions, such as switches. The tactile feedback device 10 is connected to the output unit 24.

[0013] The storage device 25 stores a control program for controlling the tactile feedback device 10. The memory device 26 reads the control program from the storage device 25 and stores it when the control device 20 is started. The arithmetic processing unit 22 then, according to the control program stored in the memory device 26, causes the output unit 24 to output a drive signal to the tactile feedback device 10 in response to instructions input from the input unit 23.

[0014] As shown in Figure 2, the tactile feedback device 10 comprises a housing 11 and an actuator 100. The shape of the housing 11 is, for example, ellipsoidal. The housing 11 is large enough to be grasped by a person with one hand. The material of the housing 11 is, for example, polyacetal resin. The actuator 100 has a longitudinal direction along the Y axis. The actuator 100 is housed in the housing 11. For example, the actuator 100 is positioned at the center of the housing 11. The control device 20 may be inside the housing 11, or it may be outside the housing 11.

[0015] Now, let's describe the actuator 100. Figure 3 is a cross-sectional view showing the actuator 100 in the first embodiment.

[0016] As shown in Figure 3, the actuator 100 includes a diaphragm 12, an adhesive layer 13, and a piezoelectric element 110. The piezoelectric element 110 is fixed to one side of the diaphragm 12 by the adhesive layer 13. Actuator 100 is an example of a first actuator. Piezoelectric element 110 is an example of a first piezoelectric element.

[0017] The piezoelectric element 110 comprises a piezoelectric body 111, a first external electrode 114, a second external electrode 115, a plurality of first internal electrodes 112, a plurality of second internal electrodes 113, a first surface electrode 116, and a second surface electrode 117.

[0018] The piezoelectric element 111 has a plurality of piezoelectric layers 118 stacked on top of each other. The piezoelectric element 111 has two end faces 111a and 111b perpendicular to the Y-axis, two side faces (not shown) perpendicular to the X-axis, and two main faces 111e and 111f perpendicular to the Z-axis. For example, each face is configured to be substantially rectangular. The piezoelectric element 111 has a longitudinal direction along the Y-axis.

[0019] A first external electrode 114 is positioned on the end face 111a of the piezoelectric element 111, and a second external electrode 115 is positioned on the end face 111b of the piezoelectric element 111. Multiple first internal electrodes 112 and second internal electrodes 113 are positioned inside the piezoelectric element 111. A first surface electrode 116 is positioned on the main surface 111e, and a second surface electrode 117 is positioned on the main surface 111f.

[0020] The first internal electrode 112 and the second internal electrode 113 are alternately arranged along the Z-axis direction between a plurality of piezoelectric layers 118 stacked in the Z-axis direction. The first internal electrode 112 is connected to the first external electrode 114 and spaced apart from the second external electrode 115. The second internal electrode 113 is connected to the second external electrode 115 and spaced apart from the first external electrode 114. Adjacent first internal electrodes 112 and second internal electrodes 113 in the Z-axis direction can apply a driving voltage to the piezoelectric layer 118 between them. The first internal electrode 112 and the second internal electrode 113 are formed, for example, in a rectangular shape.

[0021] The first surface electrode 116 and the second surface electrode 117 are respectively arranged on the outermost piezoelectric layer 118. The first surface electrode 116 is located on the main surface 111e, and the second surface electrode 117 is located on the main surface 111f. The first surface electrode 116 is connected to the first external electrode 114 and spaced apart from the second external electrode 115. The second surface electrode 117 is connected to the second external electrode 115 and spaced apart from the first external electrode 114.

[0022] The first surface electrode 116 can apply a driving voltage to the piezoelectric layer 118 between it and the second internal electrode 113 closest to the main surface 111e. The second surface electrode 117 can apply a driving voltage to the piezoelectric layer 118 between it and the first internal electrode 112 closest to the main surface 111f. The piezoelectric layer 118 between the first surface electrode 116 and the outermost second internal electrode 113 may be a single layer or multiple layers. Similarly, the piezoelectric layer 118 between the second surface electrode 117 and the outermost first internal electrode 112 may be a single layer or multiple layers. The first surface electrode 116 and the second surface electrode 117 can increase the piezoelectric active region of the piezoelectric body 111, allowing the entire piezoelectric body 111 to expand and contract. The first surface electrode 116 and the second surface electrode 117 may be formed in the same rectangular shape as the first internal electrode 112 and the second internal electrode 113, but they may also have a predetermined pattern. By applying a voltage between the first external electrode 114 and the second external electrode 115, the piezoelectric body 111 expands and contracts in the Y-axis direction due to the inverse piezoelectric effect. That is, in the piezoelectric element 110, expansion and contraction along the Y-axis direction is dominant, and the piezoelectric element 110 has a piezoelectric constant of d31. The piezoelectric layer 118 is an example of the first piezoelectric layer, the first internal electrode 112 and the first surface electrode 116 are examples of the first electrodes, and the second internal electrode 113 and the second surface electrode 117 are examples of the second electrodes. The Z-axis is an example of the first axis, and the Y-axis is an example of the second axis.

[0023] For example, the material for the piezoelectric layer 118 is lead zirconate titanate (PZT:Pb(Zr,Ti)O ３ ), barium titanate-based materials (BaTiO ３ (Ba may be Ca, and Ti may be Zr), Bismuth titanate-based material (BiTiO) ３ (Part of Bi may be Na), alkali niobate materials (NaNboO ３ (Na may be replaced with Li or K) can be used. As materials for the first internal electrode 112, second internal electrode 113, first external electrode 114, second external electrode 115, first surface electrode 116, and second surface electrode 117, metals such as Ag, Pd, Pt, Cu, Ni, and Au can be used.

[0024] In the tactile feedback system 1, the actuator 100 vibrates under the control of the control device 20, and the actuator 100 applies vibration to the housing 11. As a result, the housing 11 also vibrates, and the user touching the housing 11 can feel the vibration.

[0025] Here, we will describe a first example of the operation of the tactile feedback system 1. Figure 4 shows the vibrations applied to the housing 11 in the first example of the operation of the tactile feedback system 1.

[0026] In the first example, as shown in Figure 4, the actuator 100 applies amplitude-modulated (AM-modulated) vibration to the housing 11. Specifically, the vibration applied by the actuator 100 has a carrier wave at a Solfeggio frequency and a modulated wave in the gamma wave band. In the example shown in Figure 4, the Solfeggio frequency is 174 Hz and the frequency of the modulated wave is 40 Hz, but it is not limited to these. For example, the Solfeggio frequency may be 63 Hz, 285 Hz, 396 Hz, 417 Hz, 528 Hz, or 963 Hz. From the viewpoint of suppressing vibration noise, it is preferable that the Solfeggio frequency is 528 Hz or less.

[0027] When the actuator 100 applies the first example of vibration to the housing 11, the user can feel vibrations in the Solfeggio frequency range and vibrations in the gamma wave band. Therefore, the user can be provided with vibrations that have healing effects such as those of the Solfeggio frequency range, and vibrations in the gamma wave band that have effects such as those of improving dementia. In this way, the tactile sensation application device 10 and the tactile sensation application system 1 can provide the user with a pleasant tactile sensation.

[0028] Next, a second example of the operation of the tactile feedback system 1 will be described. Figure 5 shows the vibrations applied to the housing 11 in the second example of the operation of the tactile feedback system 1.

[0029] In the second example, as shown in Figure 5, the actuator 100 applies frequency-shift modulated (FSK modulated) vibrations to the housing 11. Specifically, the vibrations applied by the actuator 100 alternate between a first wave of Solfeggio frequencies and a second wave in the gamma wave band. For example, the duration of the first wave vibration and the duration of the second wave vibration are equal. In the example shown in Figure 5, the frequency of the first wave is 174 Hz, the frequency of the second wave is 40 Hz, and the frequency at which the first and second waves switch is 4 Hz, but this is not limited to these frequencies. For example, the Solfeggio frequencies may be 63 Hz, 285 Hz, 396 Hz, 417 Hz, 528 Hz, or 963 Hz. From the viewpoint of suppressing vibration noise, it is preferable that the Solfeggio frequency is 528 Hz or less. Also, the frequency at which the first and second waves switch may be between 0.4 Hz and 4 Hz.

[0030] When the actuator 100 applies the vibrations of the second example to the housing 11, the user can feel vibrations of Solfeggio frequencies and vibrations in the gamma wave band, similar to the first example. Therefore, the user can be provided with vibrations that have healing effects such as those of Solfeggio frequencies, and vibrations in the gamma wave band that have effects such as improving dementia. Furthermore, since frequencies between 0.4 Hz and 4 Hz are close to the heartbeat frequency of small animals, if the frequency at which the first and second waves switch is between 0.4 Hz and 4 Hz, the user can be given a healing effect similar to that felt when holding a small animal.

[0031] (Second Embodiment) The second embodiment will now be described. The second embodiment differs from the first embodiment mainly in the configuration of the actuator. Figure 6 is a cross-sectional view showing the actuator in the second embodiment.

[0032] The vibration application system according to the second embodiment has an actuator 200 instead of actuator 100. As shown in Figure 6, the actuator 200 in the second embodiment has a diaphragm 12, an adhesive layer 13, an adhesive layer 14, a piezoelectric element 110, and a piezoelectric element 120. The piezoelectric element 110 is fixed to one side of the diaphragm 12 by the adhesive layer 13. The piezoelectric element 120 is fixed to the other side of the diaphragm 12 by the adhesive layer 14. The piezoelectric element 120 has the same configuration as the piezoelectric element 110. Actuator 200 is an example of the first actuator. Piezoelectric element 120 is an example of the second piezoelectric element. In the piezoelectric element 120, the piezoelectric layer 118 is an example of the second piezoelectric layer, the first internal electrode 112 and the first surface electrode 116 are examples of the third electrode, and the second internal electrode 113 and the second surface electrode 117 are examples of the fourth electrode.

[0033] In the tactile feedback system according to the second embodiment, the control device 20 outputs a control signal to the tactile feedback device 10 such that the direction of expansion and contraction differs between the piezoelectric element 110 and the piezoelectric element 120. In other words, the actuator 200 is bimorph-driven.

[0034] Other configurations of the second embodiment are the same as those of the first embodiment, and, as in the first embodiment, AM-modulated or FSK-modulated vibrations are applied from the actuator 200 to the housing 11. The second embodiment also provides the same effects as the first embodiment.

[0035] (Third Embodiment) The third embodiment will now be described. The third embodiment differs from the second embodiment mainly in the configuration of the tactile sensation-providing device. Figure 7 is a diagram showing the tactile sensation-providing device in the third embodiment.

[0036] The vibration imparting system according to the third embodiment has a tactile imparting device 30 instead of a tactile imparting device 10. The tactile imparting device 30 is, for example, a fidget toy. As shown in Figure 7, the tactile imparting device 30 in the third embodiment has a housing 31, an actuator 200, and an actuator 300. The shape of the housing 31 is, for example, modeled after a rabbit. The housing 31 is large enough for a person to grasp with one hand. The material of the housing 31 is, for example, polyacetal resin. The actuators 200 and 300 are housed in the housing 31. For example, the actuator 200 is positioned at the center of the housing 31 in the Z-axis and X-axis directions, and offset from the center to the -Y side in the Y-axis direction, and the actuator 300 is positioned to the +Y side of the actuator 200. The actuator 300 has a longitudinal direction along the X-axis. Both ends of the actuator 300 in the longitudinal direction are roughly at the position of the rabbit's cheeks in the housing 31. The actuator 300 is an example of a second actuator.

[0037] Now, let's describe the actuator 300. Figure 8 is a cross-sectional view showing the actuator 300 in the third embodiment.

[0038] As shown in Figure 8, the actuator 300 includes piezoelectric elements 311 and 312, support members 321 and 322, and a housing 310. The actuator 300 generates vibrations in the ultrasonic band, for example. The frequency of the ultrasonic band is, for example, 20 kHz or higher. The frequency of the ultrasonic band may be between 20 kHz and 60 kHz.

[0039] The housing 310 includes a cylindrical body 350 and fastening members 330 and 340. Figure 9 is a cross-sectional view showing the cylindrical body 350. Figures 10A and 10B are cross-sectional views showing the fastening members 330 and 340. Figure 10A shows the fastening member 330, and Figure 10B shows the fastening member 340.

[0040] As shown in Figure 9, the cylindrical body 350 has a through hole 370 extending along the X-axis. The through hole 370 has a central part 371 and ends 372 and 373. End 372 is located on the +X side of the central part 371, and end 373 is located on the -X side of the central part 371.

[0041] The shape of the cross-section perpendicular to the X-axis of the central portion 371 is substantially rectangular, and the shape of the cross-section perpendicular to the X-axis of the end portions 372 and 373 is substantially circular. Threads 374 serving as female threads are formed on the inner surface of the end portion 372, and threads 375 serving as female threads are formed on the inner surface of the end portion 373. No threads are formed on the inner surface of the central portion 371.

[0042] As shown in FIG. 8, the piezoelectric elements 311 and 312 are arranged side by side along the X-axis within the central portion 371. The piezoelectric element 311 is disposed on the +X side of the piezoelectric element 312. The support member 321 is provided within the end portion 372 on the +X side of the piezoelectric element 311. The support member 322 is provided within the end portion 373 on the -X side of the piezoelectric element 312.

[0043] Thus, within the through-hole 370, the support member 321, the piezoelectric element 311, the piezoelectric element 312, and the support member 322 are arranged side by side along the X-axis in this order. For example, the support member 321, the piezoelectric element 311, the piezoelectric element 312, and the support member 322 are separated from the inner surface of the through-hole 370 and do not contact the inner surface.

[0044] As shown in FIG. 10A, the fastening member 330 has a head portion 331 and a threaded portion 332. The shape of the cross-section perpendicular to the X-axis of the head portion 331 is substantially circular. Threads 333 serving as male threads are formed on the outer surface of the threaded portion 332. The threads 333 fit into the threads 374 of the end portion 372. As shown in FIG. 10B, the fastening member 340 has a head portion 341 and a threaded portion 342. The shape of the cross-section perpendicular to the X-axis of the head portion 341 is substantially circular. Threads 343 serving as male threads are formed on the outer surface of the threaded portion 342. The threads 343 fit into the threads 375 of the end portion 373. By tightening the screws, the fastening member 330 presses the support member 321 toward the -X side, and the fastening member 340 presses the support member 322 toward the +X side. As a result, compressive stress along the X-axis acts on the piezoelectric elements 311 and 312.

[0045] The materials of the cylinder 350 and the fastening members 330 and 340 are, for example, metal or resin. The Young's modulus of each of the support members 321 and 322 is greater than the Young's modulus of each of the piezoelectric elements 311 and 312, the cylinder 350, and the fastening members 330 and 340. The materials of the support members 321 and 322 are, for example, stainless steel, aluminum, or an aluminum alloy.

[0046] Next, the piezoelectric elements 311 and 312 will be described. FIG. 11 is a cross-sectional view showing the piezoelectric element 311 in the third embodiment. The piezoelectric element 312 has the same configuration as the piezoelectric element 311.

[0047] As shown in FIG. 11, the piezoelectric element 311 includes a piezoelectric body 360 composed of a plurality of piezoelectric layers 361, a plurality of third internal electrodes 362, and a plurality of fourth internal electrodes 364. The plurality of piezoelectric layers 361 are laminated in the X-axis direction. The piezoelectric layer 361, the third internal electrode 362, and the fourth internal electrode 364 are in a flat plate shape extending in the YZ plane. The plurality of third internal electrodes 362 and the plurality of fourth internal electrodes 364 are alternately provided in the X-axis direction. One piezoelectric layer 361 is sandwiched between one third internal electrode 362 and one fourth internal electrode 364 in the X-axis direction. A third external electrode 363 is provided on the +Z side surface of the piezoelectric body 360, and a fourth external electrode 365 is provided on the -Z side surface of the piezoelectric body 360. The plurality of third internal electrodes 362 are electrically connected to the third external electrode 363. The plurality of fourth internal electrodes 364 are electrically connected to the fourth external electrode 365. By applying a voltage between the third external electrode 363 and the fourth external electrode 365, due to the inverse piezoelectric effect, the piezoelectric body 360 expands and contracts in the X-axis direction. That is, in the piezoelectric element 311, the expansion and contraction along the X-axis direction are dominant, and the piezoelectric element 311 has a piezoelectric constant of d33. The piezoelectric elements 311 and 312 are an example of the third piezoelectric element. The piezoelectric layer 361 is an example of the third piezoelectric layer, the third internal electrode 362 is an example of the fifth electrode, and the fourth internal electrode 364 is an example of the sixth electrode. The X-axis is an example of the third axis.

[0048] The piezoelectric element 360 comprises a fourth region 366, a fifth region 367, and a sixth region 368. The fourth region 366 and the fifth region 367 are arranged alternately in the X-axis direction. The sixth region 368 is located outside the outermost fourth region 366 in the X-axis direction. The fourth region 366 is a region in which the third internal electrode 362 and the fourth internal electrode 364 are arranged alternately at regular intervals in the X-axis direction. The number of piezoelectric layers 361 in the fourth region 366 is, as an example, 50 layers. The fifth region 367 and the sixth region 368 are regions in which the third internal electrode 362 and the fourth internal electrode 364 are not provided. The fifth region 367 may not be provided. Reliability may be improved by providing the fifth region 367.

[0049] The piezoelectric layer 361 can be made of the same material as the piezoelectric layer 118. The third internal electrode 362, the fourth internal electrode 364, the third external electrode 363, and the fourth external electrode 365 can be made of the same material as the first internal electrode 112, the second internal electrode 113, the first external electrode 114, the second external electrode 115, the first surface electrode 116, and the second surface electrode 117.

[0050] Other configurations of the third embodiment are the same as those of the second embodiment, and similar to the second embodiment, AM-modulated or FSK-modulated vibrations are applied from the actuator 200 to the housing 31. Therefore, the same effects as the second embodiment can be obtained with the third embodiment as well. Furthermore, if a user touches the housing 31 near the longitudinal end of the actuator 300, ultrasonic vibrations generated by the actuator 300 are transmitted to the user. For example, the actuator 300 transmits a smooth, sliding sensation to the user.

[0051] The tactile feedback device 30 may also have an actuator 100 instead of an actuator 200.

[0052] Although embodiments have been described in detail above, this disclosure is not limited to any particular embodiment, and various modifications and changes are possible within the scope of the claims.

[0053] This application claims priority based on Japanese Patent Application No. 2024-198231, filed with the Japan Patent Office on November 13, 2024, and the entire contents of Japanese Patent Application No. 2024-198231 are incorporated herein by reference.

[0054] The aspects of this disclosure are, for example, as follows:

[0055] <1> A tactile sensory device comprising: a housing; a first actuator housed in the housing and applying amplitude-modulated vibration to the housing, wherein the vibration comprises a carrier wave in the Solfeggio frequency range and a modulated wave in the gamma wave band.

[0056] <2> A tactile sensation device comprising: a housing; and a first actuator housed in the housing and which applies frequency-shift modulated vibration to the housing, wherein the vibration alternates between a first wave of Solfeggio frequencies and a second wave in the gamma wave band.

[0057] <3> The tactile sensation-providing device according to <2>, wherein the frequency at which the first wave and the second wave switch in the vibration is 0.4 Hz or more and 4 Hz or less.

[0058] <4> The tactile sensation-providing device according to any one of <1> to <3>, wherein the Solfeggio frequency is 528 Hz or less.

[0059] <5> The tactile device according to any one of <1> to <4>, wherein the first actuator has a first piezoelectric element, the first piezoelectric element has a first piezoelectric layer, and a first electrode and a second electrode that sandwich the first piezoelectric layer along a first axis, and the first piezoelectric layer expands and contracts along a second axis perpendicular to the first axis when a voltage is applied between the first electrode and the second electrode.

[0060] <6> The tactile device according to <5>, wherein the first actuator has a diaphragm having a first surface to which the first piezoelectric element is fixed and a second surface opposite to the first surface, and a second piezoelectric element fixed to the second surface, and the second piezoelectric element has a second piezoelectric layer and a third electrode and a fourth electrode that sandwich the second piezoelectric layer along the first axis, and the second piezoelectric layer expands and contracts along the second axis when a voltage is applied between the third electrode and the fourth electrode.

[0061] <7> The tactile sensation-providing device according to any one of <1> to <6>, comprising a second actuator housed in the housing and for applying vibration to the housing, wherein the second actuator has a third piezoelectric element, and the third piezoelectric element has a third piezoelectric layer and a fifth electrode and a sixth electrode sandwiching the third piezoelectric layer along a third axis, wherein the third piezoelectric layer expands and contracts along the third axis when a voltage is applied between the fifth electrode and the sixth electrode.

[0062] <8> A tactile sensation granting system comprising a tactile sensation granting device described in any of <1> to <7>, and a control device for controlling the tactile sensation granting device.

[0063] 1. Tactile sensation system 10, 30. Tactile sensation device 11, 31. Housing 12. Vibrator 13, 14. Adhesive layer 20. Control device 30. Tactile sensation device 100, 200, 300. Actuator

Claims

1. A tactile sensory device comprising: a housing; a first actuator housed in the housing and applying amplitude-modulated vibration to the housing, wherein the vibration comprises a carrier wave in the Solfeggio frequency range and a modulated wave in the gamma wave band.

2. A tactile sensation-providing device comprising: a housing; and a first actuator housed in the housing and applying frequency-shift modulated vibration to the housing, wherein the vibration alternates between a first wave of Solfeggio frequencies and a second wave in the gamma wave band.

3. The tactile sensation-providing device according to claim 2, wherein the frequency at which the first wave and the second wave switch in the vibration is 0.4 Hz or more and 4 Hz or less.

4. The tactile sensation-providing device according to any one of claims 1 to 3, wherein the Solfeggio frequency is 528 Hz or less.

5. The tactile sensation-providing device according to any one of claims 1 to 3, wherein the first actuator has a first piezoelectric element, the first piezoelectric element has a first piezoelectric layer, and a first electrode and a second electrode sandwiching the first piezoelectric layer along a first axis, and the first piezoelectric layer expands and contracts along a second axis perpendicular to the first axis when a voltage is applied between the first electrode and the second electrode.

6. The tactile device according to claim 5, wherein the first actuator comprises a diaphragm having a first surface to which the first piezoelectric element is fixed and a second surface opposite to the first surface, and a second piezoelectric element fixed to the second surface, the second piezoelectric element comprising a second piezoelectric layer and a third electrode and a fourth electrode sandwiching the second piezoelectric layer along the first axis, and the second piezoelectric layer expands and contracts along the second axis by applying a voltage between the third electrode and the fourth electrode.

7. A tactile sensation-providing device according to any one of claims 1 to 3, comprising a second actuator housed in the housing and for applying vibration to the housing, wherein the second actuator has a third piezoelectric element, the third piezoelectric element having a third piezoelectric layer, and fifth and sixth electrodes sandwiching the third piezoelectric layer along a third axis, and the third piezoelectric layer expands and contracts along the third axis when a voltage is applied between the fifth and sixth electrodes.

8. A tactile sensation-granting system comprising: a tactile sensation-granting device according to any one of claims 1 to 3; and a control device for controlling the tactile sensation-granting device.

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