Vibration presentation element and its manufacturing method

Abstract

To provide a technology by which a vibration presentation element presents vibration efficiently to a skin of an organism while reducing a size, thickness, and voltage.SOLUTION: A vibration presentation element presents vibration to a skin of an organism, and includes a piezoelectric actuator which generates vibration by piezoelectric effect, and a hair-like structure which has a plurality of hair-like bodies which resonate when receiving the vibration from the piezoelectric actuator and present the vibration to the skin of the organism.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration presentation element and a method for manufacturing a vibration presentation element. [Background technology]

[0002] 2. Description of the Related Art In recent years, haptic devices that stimulate a person's sense of touch, such as tablet terminals, game controllers, and feedback mechanisms for remotely controlling devices, have become known (for example, Patent Document 1, etc.).

[0003] Patent Document 1 discloses a configuration in which a vibration motor is disposed as an actuator at an end of a touch panel, and the entire touch panel is vibrated with a substantially uniform vibration amount.

[0004] Furthermore, Patent Document 2 describes a haptic device in which a PVC gel actuator is provided with multiple convex structures, and the convex structures are displaced by the actuator to increase the spacing between the convex structures, thereby applying a tensile strain to the skin and stimulating the sense of touch. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-137971 A [Patent Document 2] JP 2019-133274 A Summary of the Invention [Problem to be solved by the invention]

[0006] By the way, it is expected that the application of the technology will be further expanded by mounting the above-mentioned haptic device on clothing and making it wearable. However, when using actuators such as those described in Patent Documents 1 and 2, it is difficult to make the haptic device smaller (thinner) and lighter, which is a problem in making it wearable.

[0007] In contrast, by using a piezoelectric actuator that generates displacement through the piezoelectric effect, it is possible to make haptic devices smaller (thinner) and lighter. However, in order to obtain an effective haptic effect from that displacement, a high voltage (for example, several tens of volts) must be applied, which is problematic in that it is not suitable for wearable devices.

[0008] In view of the above-mentioned problems, the present invention aims to provide a technology that makes it possible to obtain a vibration presentation element that efficiently presents vibrations to the skin of a living body while being compact, thin, and requiring low voltage. [Means for solving the problem]

[0009] In order to solve the above problems, the vibration presentation element according to the present invention comprises: A vibration presentation element that presents vibration to the skin of a living body, A piezoelectric actuator that generates vibrations by the piezoelectric effect. A hair structure including a plurality of hairs that receive vibrations from the piezoelectric actuator, resonate, and present the vibrations to the skin of the living body. It is characterized by:

[0010] Here, the piezoelectric actuator may be an actuator using a piezoelectric material, whether inorganic (e.g., PZT, etc.) or organic (e.g., PVDF, etc.), but it is preferable that it is a thin film type with flexibility. In addition, the capillary body may be made of nylon fiber, polyester fiber, or laser. Any desired fiber material can be used, such as yon fiber.

[0011] With this configuration, the sensory receptors present in the skin of the living body are stimulated by the hairs that resonate with the vibrations from the piezoelectric actuator, making it possible for even a piezoelectric actuator that is driven at a low voltage to effectively present vibrations to the skin of the living body.

[0012] The piezoelectric actuator may generate vibrations in a direction perpendicular to the surface of the skin of the living body. With this configuration, it is possible to efficiently stimulate sensory receptors located deep below the surface of the skin of the living body.

[0013] The hair structure may include hairs whose tips vibrate horizontally relative to the skin surface of the living body. With this configuration, it is possible to efficiently stimulate sensory receptors located close to the skin surface of the living body.

[0014] The hair structure may include a plurality of types of hairs having different shapes. The plurality of types of hairs may vibrate at different natural frequencies. With this configuration, it is possible to provide a single hair structure with hairs that provide optimized vibrations for each of a plurality of types of sensory receptors present on the skin surface of a living body. The natural frequency may be adjusted to a desired value by adjusting the length, thickness (diameter), and other shapes of the hairs.

[0015] The living body may be a human body, and the hair-like structure may include at least a first hair-like body that vibrates at a frequency that maximizes stimulation of Meissner's corpuscles, which are sensory receptors present in the skin, when the hair-like structure comes into contact with the skin of the human body, and a second hair-like body that vibrates at a frequency that maximizes stimulation of Merkel's disks, which are sensory receptors present in the skin. The hair-like structure may further include a third hair-like body that vibrates at a frequency that maximizes stimulation of Pacinian corpuscles, which are sensory receptors present in the skin, when the hair-like structure comes into contact with the skin of the human body.

[0016] The applied voltage of the piezoelectric actuator may be set so that the piezoelectric actuator vibrates with a waveform including the resonance frequencies of all the hairs, thereby making it possible to collectively resonate the hairs, each having a different natural frequency, by a single piezoelectric actuator.

[0017] The piezoelectric actuator may further include a sealing portion that seals the piezoelectric actuator, the hair-like structure being provided on a surface of the sealing portion, and vibrations from the piezoelectric actuator may be transmitted to the hair-like structure via the sealing portion.

[0018] Here, the sealing portion may be formed by filling a flexible sealing material, by bonding a film with an adhesive, or by thermocompression bonding a film with a laminator. The hair-like structure may be formed by nanoimprinting using a mold, by making a plate of the hair-like structure out of polydimethylsiloxane (PDMS) and transferring it, by bonding a plate formed by a 3D printer, or by forming a brushed structure by electrostatic flocking.

[0019] In addition, a method for producing a vibration presentation element according to the present invention includes the steps of: A first step of applying an adhesive to a first laminate film as a sealing material; a second step of placing a piezoelectric actuator on the adhesive applied in the first step; A third step of connecting wiring to the piezoelectric actuator arranged in the second step. , a fourth step of covering an area including the piezoelectric actuator and the wiring with a second laminate film as a sealing material; a fifth step of laminating the first laminate film and the second laminate film to form a sealing portion that seals the piezoelectric actuator and the wiring; and a sixth step of exposing a part of the wiring sealed in the fifth step as a terminal. It is characterized by:

[0020] The method for producing the vibration presentation element further comprises the steps of: a seventh step of applying an adhesive to a surface of the sealing portion in an area where the piezoelectric actuator is sealed; The method may further include an eighth step of forming a hair-like structure by electrostatically implanting hair-like bodies in the adhesive applied in the seventh step. Effect of the Invention

[0021] According to the present invention, it is possible to provide a technique that makes it possible to obtain a vibration presentation element that efficiently presents vibration to the skin of a living body while achieving miniaturization, thinning, and low voltage. [Brief description of the drawings]

[0022] [Figure 1] Fig. 1A is a schematic cross-sectional view of a vibration presentation element according to an embodiment, and Fig. 1B is a schematic plan view of the vibration presentation element according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an outline of the piezoelectric actuator according to the embodiment. [Diagram 3] FIG. 3 is a diagram illustrating the sensory receptors present on the skin and the vibration characteristics of hairs relative to the skin surface. [Figure 4] Figure 4 is a table showing the depth and maximum sensitivity frequency of sensory receptors in the skin. [Diagram 5] FIG. 5 is a flowchart showing a flow of a method for manufacturing a vibration presentation element according to the embodiment. [Figure 6] 6A, 6B, 6C, 6D, 6E, 6F, 6G, and 6H are schematic diagrams illustrating steps in the manufacture of a vibration presentation element according to an embodiment. [Figure 7] Fig. 7A is a first diagram showing a modified example of the vibration presentation element according to the embodiment, and Fig. 7B is a second diagram showing a modified example of the vibration presentation element according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] An example of an embodiment to which the present invention is applied will be described below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention to those alone.

[0024] <Embodiment> Fig. 1 is a diagram showing an outline of a vibration presentation element 1 according to this embodiment, Fig. 1A is a schematic cross-sectional view of the vibration presentation element 1, and Fig. 1B is a schematic plan view of the vibration presentation element 1. The vibration presentation element 1 is a wearable haptic device that is mounted on clothing, accessories, etc. worn by a person and presents vibrations to the skin of the wearer.

[0025] (Configuration of vibration presentation element) As shown in FIG. 1, the vibration presentation element 1 generally includes a piezoelectric actuator 10, a sealing portion 30 that seals the piezoelectric actuator 10, and a hair-like structure 20. When the vibration presentation element 1 is mounted, the piezoelectric actuator 10 is placed against the surface of the wearer's skin. The hair-like structures 20 are positioned so as to generate vibrations in a direction perpendicular to the surface of the skin of the wearer.

[0026] The piezoelectric actuator 10 may be an extremely thin (eg, 5 μm thick) MEMS (Micro Electro Mechanical Systems) device formed by, for example, a semiconductor process. FIG.

[0027] 2, the piezoelectric actuator 10 includes a base 91 made of silicon (Si), electrode layers 92 and 94 made of, for example, platinum (Pt) electrodes, a piezoelectric layer 93 made of, for example, lead zirconate titanate (PZT), and an insulating layer 95 made of, for example, silicon dioxide (SiO2). Since the piezoelectric actuator 10 is a MEMS device formed by a semiconductor process, a semiconductor circuit (not shown) is built into the base 91, and this semiconductor circuit may include circuit elements such as active elements such as integrated circuits, capacitors, inductors, and wiring, as necessary.

[0028] In addition, a wiring 11 (e.g., a copper wire) is connected to the piezoelectric actuator 10, and when a voltage is applied to the piezoelectric actuator 10 from an external power source via the wiring 11, vibrations are generated due to the piezoelectric effect, and the vibrations are transmitted to the wearer's skin via each hair that makes up the hair structure 20.

[0029] The sealing portion 30 can be formed, for example, by thermocompression bonding a film such as polyimide (PI) that covers the piezoelectric actuator 10. Note that the material of the film is not limited to PI, and other materials such as polyethylene terephthalate (PET) can also be used.

[0030] The hairy structure 20 is formed by implanting three types of hairs, first hairs 21, second hairs 22, and third hairs 23, each having a different shape, by, for example, electrostatic implantation technology, on the adhesive layer 40 provided on the surface of the sealing part 30. The material of each hair can be any desired fiber material, such as nylon fiber, polyester fiber, or rayon fiber.

[0031] The first hairy body 21 and the second hairy body are formed so that their tips vibrate horizontally relative to the wearer's skin surface, and the third hairy body is formed so that it vibrates vertically relative to the skin surface. Figure 3 is an explanatory diagram showing a model diagram of human skin H and the sensory receptors present on the skin, and the vibration characteristics of each hairy body relative to the skin surface.

[0032] As shown in Figure 3, the sensory receptors present in the skin of the human body include Meissner's corpuscles H1 and Merkel's disks H2 that are present near the surface layer, and Pacinian corpuscles H3 and Ruffini endings (not shown) that are present deep below the surface layer. For Meissner's corpuscles H1 and Merkel's disks H2 that are present near the surface layer of the skin, horizontal vibration of the hair-like body stimulates the sensory receptors as if scratching them, and can effectively stimulate the sense of touch. On the other hand, horizontal vibration is difficult to transmit to Pacinian corpuscles H3 (and Ruffini endings) that are present deep in the skin, so applying vertical vibration is effective.

[0033] In addition, the Meissner's corpuscles H1, Merkel's disks H2, and Pacinian corpuscles H3 each have a different vibration frequency at which they are most sensitive. Figure 4 shows a table showing the depth at which sensory receptors exist and the frequency at which they are most sensitive.

[0034] Therefore, the first hair 21, the second hair 22, and the third hair 23 are The hairs are formed to have different natural frequencies (natural vibration frequencies) depending on the maximum sensitivity frequency of the sensory receptors. For example, the length, diameter, and other shapes of the hairs may be adjusted to obtain a desired frequency.

[0035] Specifically, the first hair 21 has a natural frequency (e.g., 40 Hz) set so as to vibrate at a frequency that maximizes the stimulation to the Meissner's corpuscles H1. Similarly, the second hair 22 has a natural frequency (e.g., 70 Hz) set so as to maximize the stimulation to the Merkel's disks H2, and the third hair 23 has a natural frequency (e.g., 200 Hz) set so as to maximize the stimulation to the Pacinian corpuscles H3.

[0036] Each hair efficiently stimulates each sensory receptor by resonating at its own inherent frequency upon receiving vibration from the piezoelectric actuator 10. That is, the applied voltage of the piezoelectric actuator 10 is set so that the piezoelectric actuator 10 vibrates with a waveform including the resonance frequency of each of the first hair 21, the second hair 22, and the third hair 23 (for example, a composite wave of the inherent frequencies of each hair).

[0037] (Method of manufacturing vibration presentation element) Next, a method for manufacturing the vibration presentation element 1 according to the present embodiment will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a flow chart showing a flow of manufacturing the vibration presentation element 1 according to the present embodiment, and Fig. 6 is a schematic diagram showing each step of manufacturing the vibration presentation element 1.

[0038] 5 and 6, in order to manufacture the vibration presentation element 1, first, an adhesive for adhering the piezoelectric actuator is applied onto a laminate film 31 that will become a part of the sealing portion 30 (S101, FIG. 6A). Next, the piezoelectric actuator 10 is placed on the adhesive and adhered (S102, FIG. 6B). Then, the wiring 11 that is connected to the piezoelectric actuator 10 is provided (S103, FIG. 6C).

[0039] Next, the piezoelectric actuator 10 and the wiring 11 are covered with the laminate film 32 (S104, FIG. 6D), and the laminate films 31 and 32 are thermocompression bonded by a laminate heater (not shown) (S105, FIG. 6E), thereby forming the sealing portion 30. Next, the sealing portion at the end of the wiring 11 is cut out to expose the wiring 11, and a terminal is formed (S106, FIG. 6F).

[0040] Next, adhesive is applied to the surface of the sealing portion in the area where the piezoelectric actuator 10 is sealed (S107, FIG. 6G), and the fibers that will become the hairs are planted in the adhesive using an electrostatic planting technique to form the hairy structure 20 (S108, FIG. 6H), and the manufacturing process is completed.

[0041] As described above, the vibration presentation element 1 of this embodiment is a vibration presentation element using a small piezoelectric actuator driven at a low voltage, but it is capable of effectively presenting vibrations by providing optimized stimuli to each of the sensory receptors with different characteristics.

[0042] <Modification> The vibration presentation element 1 according to the above embodiment merely exemplifies the present invention, and the present invention is not limited to the above specific embodiment. The present invention can be modified in various ways within the scope of its technical concept. For example, the hair structure 20 of the vibration presentation element 1 according to the above embodiment has three types of hairs on only one surface of the sealing portion 30, but the present invention is not limited to such a configuration. FIG. 7 shows several modified examples of the vibration presentation element 1.

[0043] For example, as shown in Fig. 7A, the number of types of hairs may be two, or the hair structure may be composed of only one type of hairs. The length, diameter and other shapes of the hairs can be freely changed.

[0044] In this way, the hair-like structure can be formed with the desired hair-like bodies, and the length and diameter of the hair-like bodies can be adjusted to match the unevenness of the human body structure (making the diameter thicker, for example, as making the hair longer will lower the natural frequency), making it possible to transmit vibrations appropriately even in concave areas.

[0045] In addition, in the above embodiment, the hair-like structures are formed by electrostatic hair transplantation, but they may also be formed by nanoimprinting using a mold, or by making a plate of the hair-like structures out of PDMS and transferring this, or by attaching structures formed by a 3D printer.

[0046] Furthermore, in the above embodiment, the piezoelectric actuator is a MEMS device having an organic piezoelectric material made of PZT, but the present invention is not limited to this and any desired piezoelectric actuator can be adopted.

[0047] In the above embodiment, the sealing portion is formed by thermocompression bonding of the laminate film, but the sealing portion may be formed by filling with a sealing material, bonding a film with an adhesive, or the like. [Explanation of symbols]

[0048] 1. Vibration display element 10. Piezoelectric actuator 11. Wiring 20...hair-like structure 21...first ciliary body 22...second ciliary body 23...Third ciliary body 30....Sealing part 31, 32: Laminate film 40...Adhesive layer H...Skin H1: Meissner corpuscles H2 Merkel disc H3 Pacinian corpuscles

Claims

1. A vibration presentation element that presents vibration to the skin of a human body, A piezoelectric actuator that generates vibrations by the piezoelectric effect. a hair structure including a plurality of hairs that receive vibrations from the piezoelectric actuator, resonate, and present the vibrations to the skin of the human body; The hair structure includes a plurality of types of hairs having different shapes that vibrate at different natural frequencies, and includes at least a first hair that vibrates at a frequency that maximizes stimulation of Meissner's corpuscles, which are sensory receptors present on the skin, when in contact with the skin, and a second hair that vibrates at a frequency that maximizes stimulation of Merkel's disks, which are sensory receptors present on the skin. A vibration presentation element comprising:

2. The piezoelectric actuator generates vibrations in a direction perpendicular to the surface of the skin of the human body. The vibration presentation element according to claim 1 .

3. The hair-like structure includes a hair-like body whose tip vibrates horizontally relative to the skin surface of the human body. The vibration presentation element according to claim 1 or 2, characterized in that:

4. The hair-like structure further includes a third hair-like body that vibrates at a frequency that maximizes stimulation of Pacinian corpuscles, which are sensory receptors present in the skin, when the hair-like structure contacts the skin of a human body. The vibration presentation element according to claim 1 .

5. An applied voltage is set so that the piezoelectric actuator vibrates with a waveform including the resonant frequencies of all of the capillaries. The vibration presentation element according to claim 1 ,

6. The piezoelectric actuator further includes a sealing portion that seals the piezoelectric actuator. The hair-like structure is provided on the surface of the sealing portion, Vibrations from the piezoelectric actuator are transmitted to the capillary structure via the sealing portion. The vibration presentation element according to claim 1 ,

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