Tactile device and method for manufacturing tactile device

Abstract

To suppress fluctuation of contact resistance between a tactile device and a surface of a living body.SOLUTION: A first conductor 20 that covers the tactile surface 11 in a first portion 14 of the porous base material 10 and inner surfaces of the plurality of pores 13 in the first portion 14, and a second conductor 21 that covers the tactile surface 11 in a second portion 15 different from the first portion 14 of the porous base material 10 and inner surfaces of the plurality of pores 13 in the second portion 15, in the tactile device 100, the first conductor 20 and the second conductor 21 are spaced apart from each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to technology for haptic devices. [Background technology]

[0002] Electrotactile technology is a technology that conveys tactile information by applying electrical stimulation to the surface (i.e., skin) of a living body, such as a human or animal, from a tactile device. This technology, also known as haptics, is also used primarily in the fields of virtual reality (VR) and augmented reality (AR). For example, it is used in VR games to reproduce the sensation of touching an object in the game. It is also used in the field of telemedicine using AR, where doctors can examine patients without directly touching them.

[0003] Conventionally, a technology using a flexible substrate and plated metal electrodes has been proposed as a tactile device. For example, Patent Document 1 discloses an electrotactile presentation device that is composed of an electrode substrate made of a flexible circuit body and metal electrodes that are metal plated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-219887 Summary of the Invention [Problem to be solved by the invention]

[0005] Flexible substrates are thin and flexible, making them easy to conform to the shape of the body. Furthermore, the high degree of freedom in forming conductive patterns by etching offers the advantage of making it easy to increase the number of tactile presentation units. However, metal electrodes are easily affected by the pressure on the surface of the living body, the contact condition (e.g., the distance between the metal electrode and the surface of the living body), the body's constitution (e.g., moisture on the surface of the living body), and the environment during use (e.g., humidity). As a result, the contact resistance (contact impedance) between the metal electrode and the surface of the living body varies significantly. In other words, a problem is that the perception of electrotactile sensations is likely to vary depending on the contact condition, body constitution, and the environment during use. In consideration of the above circumstances, one aspect of the present disclosure aims to suppress variations in contact resistance between a tactile device and the surface of the living body. [Means for solving the problem]

[0006] In order to solve the above problems, a tactile device according to one embodiment of the present disclosure comprises a porous substrate including a tactile surface facing a living body and having a plurality of pores formed therein, a first conductor covering the tactile surface in a first portion of the porous substrate and the inner surfaces of the plurality of pores in the first portion, and a second conductor covering the tactile surface in a second portion of the porous substrate different from the first portion and the inner surfaces of the plurality of pores in the second portion, the first conductor and the second conductor being arranged at a distance from each other.

[0007] A method for manufacturing a tactile device according to one embodiment of the present disclosure includes a molding process for molding a porous substrate having a tactile surface facing a living body and having a plurality of pores formed therein, and a conductive treatment process for impregnating the tactile surface of a first portion of the porous substrate and the inner surfaces of the plurality of pores in the first portion, and the tactile surface of a second portion of the porous substrate and the inner surfaces of the plurality of pores in the second portion with a conductive material. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a haptic device according to a first embodiment. [Figure 2] 1 is a plan view of a haptic device according to a first embodiment. [Figure 3] 1 is a cross-sectional view of a porous substrate according to a first embodiment. [Figure 4] 4 shows a manufacturing process of the haptic device according to the first embodiment. [Figure 5] 3 is an equivalent circuit diagram when the haptic device according to the first embodiment comes into contact with a living body. FIG. [Figure 6] FIG. 10 is a plan view of a haptic device according to a second embodiment. [Figure 7] 10 is a correlation graph between the internal resistance of the porous substrate and the substrate-to-substrate distance according to the second embodiment. [Figure 8] 10 is a table summarizing the distance between wiring boards and the degree of electrical stimulation in the haptic device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The embodiments for carrying out the present disclosure will be described with reference to the drawings. Note that the dimensions and scale of each element in each drawing may differ from those of the actual product. Furthermore, the embodiment described below is an exemplary embodiment that may be envisioned when carrying out the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiment exemplified below.

[0010] A: First embodiment Fig. 1 is a cross-sectional view of a haptic device 100 according to the first embodiment. Fig. 2 is a plan view of the haptic device 100 according to the first embodiment.

[0011] The tactile device 100 is a device for applying electrical stimulation to the surface of a living body (e.g., human skin). As shown in Figure 1 or 2, the tactile device 100 of the first embodiment is a biological electrode including a porous substrate 10, a first conductor 20, a second conductor 21, and an insulator 23.

[0012] The porous substrate 10 is a flat plate-shaped body molded to a predetermined thickness. The porous substrate 10 includes a tactile surface 11 and a back surface 12. The tactile surface 11 is the surface of the porous substrate 10 that faces the living body. The back surface 12 is the surface opposite to the tactile surface 11. The porous substrate 10 is formed into any planar shape, such as a rectangular or cylindrical shape.

[0013] FIG. 3 is a cross-sectional view of a porous substrate 10 according to this embodiment. As shown in FIG. 3, a plurality of pores 13 are formed inside the porous substrate 10. Each pore 13 is a spherical bubble formed with a diameter sufficiently smaller than the plate thickness of the porous substrate 10. The porous substrate 10 of this embodiment has a continuous pore structure in which the plurality of pores 13 communicate between the tactile surface 11 and the back surface 12. Pores 13 open in each of the tactile surface 11 and the back surface 12, and the space facing the tactile surface 11 communicates with the space facing the back surface 12 via the plurality of pores 13. Note that the plurality of pores 13 in the porous substrate 10 also includes individual pores 13 that do not communicate with other pores 13.

[0014] The porous substrate 10 is a flexible substrate made of an insulating resin material. That is, the porous substrate 10 is flexible and elastically deformable so as to conform to the shape of the surface of a living body. Specifically, the porous substrate 10 is made of a rubber material such as polyurethane rubber (PUR), polyolefin rubber (PO), silicone rubber (SR), ethylene propylene diene rubber (EPDM), or fluorosilicone rubber (FVMQ). The porous substrate 10 of this embodiment does not include a conductive material such as a conductive filler.

[0015] 1, 2, or 3, the porous substrate 10 includes a first portion 14, a second portion 15, and a third portion 17. As shown in FIG. 3, a plurality of pores 13 are formed approximately uniformly throughout the porous substrate 10 including the first portion 14, the second portion 15, and the third portion 17.

[0016] The first portion 14 is a portion of the porous substrate 10 that is covered with the first conductor 20. The first conductor 20 is a conductive coating that covers the first portion 14. Specifically, the first conductor 20 covers the tactile surface 11 and the back surface 12 of the first portion 14 and the inner surfaces of the plurality of pores 13 in the first portion 14. That is, the first conductor 20 is formed not only on the outer surface of the first portion 14 but also inside the first portion 14. The portions of the first conductor 20 that cover the tactile surface 11 and the back surface 12 are formed in a planar shape with a predetermined film thickness.

[0017] The film thickness of the first conductor 20 is sufficiently smaller than the radius of each pore 13. Therefore, a space is formed inside the first conductor 20 that covers the inner surface of each pore 13. In other words, the first conductor 20 inside each pore 13 is formed in a spherical shell shape. The first conductor 20 is formed so as to be continuous across the multiple pores 13 that communicate between the tactile surface 11 and the back surface 12. Therefore, the portion of the first conductor 20 that covers the tactile surface 11 and the portion that covers the back surface 12 are mutually conductive via the portion that covers the inner surface of each pore 13.

[0018] The second portion 15 is a portion of the porous substrate 10 that is covered with a second conductor 21. The second conductor 21 is a conductive coating that covers the second portion 15. Specifically, the second conductor 21 covers the tactile surface 11 and the back surface 12 of the second portion 15 and the inner surfaces of the plurality of pores 13 in the second portion 15. That is, the second conductor 21 is formed not only on the outer surface of the second portion 15 but also inside the second portion 15. The portions of the second conductor 21 that cover the tactile surface 11 and the back surface 12 are formed in a planar shape with a predetermined film thickness.

[0019] The relationship between the film thickness of the second conductor 21 and the radius of each pore 13 is the same as the relationship between the film thickness of the first conductor 20 and the radius of each pore 13. For example, the second conductor 21 is formed so as to be continuous across the multiple pores 13 that communicate between the tactile surface 11 and the back surface 12.

[0020] The first conductor 20 and the second conductor 21 are made of an intrinsically conducting polymer (ICP). Specifically, the first conductor 20 and the second conductor 21 contain PEDOT (poly(3,4-ethylenedioxythiophene)), an example of a conductive polymer. For example, the first conductor 20 and the second conductor 21 are formed of a mixture of PEDOT and PSS (polystyrene sulfonate). As described above, in this embodiment, the first conductor 20 and the second conductor 21 are made of a conductive polymer. Therefore, the first conductor 20 and the second conductor 21 can be easily formed on the inner surfaces of the multiple pores 13 in the porous substrate 10 (the first portion 14 and the second portion 15). Note that the materials of the first conductor 20 and the second conductor 21 are not limited to the above examples.

[0021] The third portion 17 is a portion of the porous substrate 10 between the first portion 14 and the second portion 15. That is, the third portion 17 connects the first portion 14 and the second portion 15. The width of the third portion 17 is approximately equal to the width of the first portion 14 or the second portion 15. However, a configuration in which the width of the third portion 17 is greater than the width of the first portion 14 or the second portion 15, or a configuration in which the width of the third portion 17 is smaller than the width of the first portion 14 or the second portion 15, may also be employed.

[0022] The third portion 17 is a portion of the porous substrate 10 that is covered with an insulator 23. The insulator 23 is an insulating coating that covers the third portion 17. Specifically, the insulator 23 covers the tactile surface 11 and the back surface 12 of the third portion 17 and the inner surfaces of the plurality of pores 13 in the third portion 17. That is, the insulator 23 is formed not only on the outer surface of the third portion 17 but also inside the third portion 17. Therefore, the resistance value between the first conductor 20 and the second conductor 21 is increased by the insulator 23. The portions of the insulator 23 that cover the tactile surface 11 and the back surface 12 are formed in a planar shape with a predetermined film thickness.

[0023] The relationship between the film thickness of the insulator 23 and the radius of each pore 13 is the same as the relationship between the film thickness of the first conductor 20 and the radius of each pore 13. For example, the insulator 23 is formed so as to be continuous across the multiple pores 13 that communicate between the tactile surface 11 and the back surface 12.

[0024] The insulator 23 is made of a silicone-based water repellent or the like. For example, the insulator 23 is made of POLON-T (registered trademark) manufactured by Shin-Etsu Chemical Co., Ltd. As described above, in this embodiment, the insulator 23 is made of a silicone-based water repellent. Therefore, the insulator 23 can be easily formed on the inner surfaces of the plurality of pores 13 in the third portion 17. Note that the material of the insulator 23 is not limited to the above examples.

[0025] FIG. 4 is a flowchart illustrating a method for manufacturing the haptic device 100 according to the present embodiment described above.

[0026] First, in the molding step P1, a porous substrate 10 having a plurality of pores 13 formed therein is formed. Specifically, a resin material mixed with a foaming agent is heated and foamed to form a flat plate. As described above, various conditions for the molding step P1 are selected so that a continuous pore structure is formed inside the porous substrate 10. Note that the method for forming the porous substrate 10 is not limited to the above examples.

[0027] In the insulating treatment step P2 after the molding step P1, an insulating insulator 23 is formed to cover the third portion 17. As described above, the insulator 23 is formed so as to cover the tactile surface 11 and the back surface 12 of the third portion 17 and the inner surfaces of the plurality of pores 13. As explained above, in this embodiment, the insulating material is not added when the third portion 17 is molded (molding step P1), but the insulator 23 is formed after the porous substrate 10 is molded. The insulating treatment step P2 of this embodiment includes an impregnation step P21 and a drying step P22.

[0028] In the impregnation step P21, the third portion 17 is impregnated with an insulating solution containing an insulating material. That is, the insulating solution is selectively supplied to the third portion 17 of the porous substrate 10, thereby impregnating the third portion 17 with the insulating solution. By impregnating the third portion 17 of the porous substrate 10 with the insulating material, the porous substrate 10 is divided into a first portion 14 and a second portion 15. The insulating solution is, for example, a silicone-based water repellent. The solvent of the insulating solution is, for example, pure water or an organic solvent (e.g., ethanol). For example, while the entire third portion 17 is immersed in the insulating solution, the air in the working space is discharged to the outside (vacuum drawing), whereby the insulating solution penetrates into the multiple pores 13 inside the third portion 17.

[0029] In the drying step P22, the third portion 17 impregnated with the insulating solution is dried to form the insulator 23. That is, for example, the solvent of the insulating solution is evaporated by heating, and as a result, the thin film-like insulator 23 is formed that covers the tactile surface 11 and the back surface 12 of the third portion 17 and the inner surfaces of the plurality of pores 13.

[0030] In the conductive treatment step P3 after the insulation treatment step P2, a conductive first conductor 20 that covers the first portion 14 and a conductive second conductor 21 that covers the second portion 15 are formed. As described above, the first conductor 20 is formed so as to cover the tactile surface 11 and back surface 12 of the first portion 14 and the inner surfaces of the plurality of pores 13. Similarly, the second conductor 21 is formed so as to cover the tactile surface 11 and back surface 12 of the second portion 15 and the inner surfaces of the plurality of pores 13. As described above, in this embodiment, the conductive polymer is not added when the porous substrate 10 is formed (forming step P1), but rather the first conductor 20 and the second conductor 21 are formed after the porous substrate 10 is formed and the third portion 17 is coated with the insulator 23. The conductive treatment step for the first portion 14 and the conductive treatment step for the second portion 15 may be performed simultaneously or with a time lag. The conductivity treatment step P3 of this embodiment includes an impregnation step P31 and a drying step P32.

[0031] In the impregnation step P31, the first portion 14 and the second portion 15 are impregnated with a conductive solution containing a conductive polymer (PEDOT). The conductive solution is, for example, a solution in which a mixture of PEDOT and PSS is dispersed in a solvent. The solvent for the conductive solution is, for example, pure water or an organic solvent (e.g., ethanol). For example, the entire porous substrate 10, including the third portion 17, is immersed in the conductive solution. Because the third portion 17 is coated with a water repellent, which is an insulating solution, the conductive solution does not adhere to the third portion 17. The conductive solution that adheres to the third portion 17 is quickly removed. Therefore, even if the conductive solution penetrates into the multiple pores 13 inside the entire porous substrate 10 by vacuuming while the entire porous substrate 10 is immersed in the conductive solution, only the first portion 14 and the second portion 15 can be selectively impregnated with the conductive solution.

[0032] In the drying step P32, the first portion 14 and the second portion 15 impregnated with the conductive solution are dried to form the first conductor 20 and the second conductor 21, respectively. That is, for example, heating causes the solvent of the conductive solution impregnated in the first portion 14 to volatilize, resulting in the formation of the thin-film first conductor 20 that covers the tactile surface 11 and back surface 12 of the first portion 14 and the inner surfaces of the plurality of pores 13. Like the first conductor 20, the second conductor 21 formed in the second portion 15 also covers the tactile surface 11 and back surface 12 of the second portion 15 and the inner surfaces of the plurality of pores 13.

[0033] The manufacturing method described above makes it possible to manufacture a flexible haptic device 100. When actually using the haptic device 100, it is necessary to connect the haptic device 100 to an external control device 200 (for example, an EMS device or low-frequency therapy device) and apply a current or voltage to the haptic device 100. For this reason, the haptic device 100 further includes a first wiring board 30 and a second wiring board 40. The haptic device 100 and the control device 200 constitute a haptic system that applies stimuli to the surface of a living body.

[0034] As shown in FIG. 1 or 2 , the first wiring board 30 is connected to the back surface 12 of the first section 14. The first wiring board 30 is an element that connects the first section 14 and the control device 200. Similarly, the second wiring board 40 is connected to the back surface 12 of the second section 15. The second wiring board 40 is an element that connects the second section 15 and the control device 200.

[0035] First wiring board 30 and second wiring board 40 are printed wiring boards such as FPC (Flexible Printed Circuit) or FFC (Flexible Flat Cable), for example.

[0036] The first wiring board 30 includes a first substrate 31 and first wiring 32, and the second wiring board 40 includes a second substrate 41 and second wiring 42.

[0037] The first substrate 31 and the second substrate 41 are flexible printed circuit boards. The first substrate 31 and the second substrate 41 may be made of a resin material such as polyimide (PI) or polyester (PET). Note that the materials of the first substrate 31 and the second substrate 41 are not limited to the above examples. The first substrate 31 has a first wiring 32 formed thereon, and the second substrate 41 has a second wiring 42 formed thereon.

[0038] Specifically, the first wiring 32 is a conductive pattern formed on the surface of the first substrate 31 facing the back surface 12 of the porous substrate 10. Similarly, the second wiring 42 is a conductive pattern formed on the surface of the second substrate 41 facing the back surface 12 of the porous substrate 10. The first wiring 32 and the second wiring 42 are wirings for connection to the control device 200.

[0039] The first wiring 32 is connected to the first conductor 20. Specifically, an end of the first wiring 32 is adhered to the back surface 12 of the first portion 14 using a conductive adhesive 60. The adhesive 60 contacts not only the first conductor 20 on the back surface 12 with which the adhesive 60 contacts, but also the first conductors 20 on the inner surfaces of the multiple pores 13 on the back surface 12 with which the adhesive 60 contacts. The second wiring 42 is connected to the second conductor 21. The connection relationship between the second wiring 42 and the second conductor 21 is similar to the connection relationship between the first wiring 32 and the first conductor 20. Metal materials may be used as materials for the first wiring 32 and the second wiring 42. However, as long as a current or voltage can be applied from the control device 200 to the haptic device 100, the materials are not limited to the above examples.

[0040] When using the haptic device 100, for example, the tactile surface 11 of the haptic device 100 is first brought into contact with the surface of a living body, and a current or voltage is applied from the control device 200 to impart an electrical stimulus to the surface of the living body.

[0041] Before contacting the tactile surface 11 with the surface of a living body, the porous substrate 10 is impregnated with water to equalize the contact resistance between the tactile device 100 and the surface of the living body. After the porous substrate 10 is impregnated with water, the tactile surface 11 is brought into contact with the surface of the living body. In the contact device of this embodiment, the porous substrate 10 deforms to follow the shape of the surface of the living body, so the tactile surface 11 adheres stably to the surface of the living body. In other words, changes in the state in which the tactile surface 11 contacts the surface of the living body are suppressed. Therefore, fluctuations in the contact resistance between the tactile device 100 and the surface of the living body can be suppressed.

[0042] Figure 5 is an equivalent circuit diagram when the tactile device 100 comes into contact with the surface of a living body. Resistance Rs in Figure 5 is the resistance component between the first conductor 20 and the second conductor 21 in the porous substrate 10. In other words, resistance Rs corresponds to the resistance component of the porous substrate 10. Resistance Rk1 corresponds to the contact impedance between the first conductor 20 and the surface of the living body, and resistance Rk2 corresponds to the contact resistance between the second conductor 21 and the surface of the living body. Resistance Rh corresponds to the resistance component inside the living body.

[0043] The control device 200 is a voltage source that applies a voltage between the first conductor 20 and the second conductor 21. When the first conductor 20 and the second conductor 21 come into contact with the surface of the living body, a current path is formed from the first conductor 20 to the second conductor 21 via resistance Rk1, resistance Rh of the living body, and resistance Rk2. As shown in FIG. 5 , resistances Rk1, Rh, and Rk2 are connected in parallel to resistance Rs of the porous substrate 10.

[0044] A third portion 17 exists between the first conductor 20 and the second conductor 21 in the porous substrate 10, and an insulator 23 is formed in the third portion 17. That is, the resistance Rs of the porous substrate 10 is sufficiently greater than the combined resistance of the resistances Rk1, Rh, and Rk2. Therefore, the current Is flowing from the first conductor 20 to the second conductor 21 via the third portion 17 is inhibited, and as a result, a sufficient amount of current Ih can be supplied to the inside of the living body compared to the inside of the porous substrate 10. Therefore, the tactile device 100 of this embodiment can apply a sufficiently large electrical stimulus to the living body.

[0045] B: Second embodiment A second embodiment of the present disclosure will be described. Note that, for elements in the following exemplary aspects that have the same functions as those in the first embodiment, the same reference numerals as those in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

[0046] 6 is a plan view of the haptic device 100 of this embodiment. In the following description, the X direction is a direction parallel to a plane perpendicular to the direction from the tactile surface 11 toward the back surface 12, and the Y direction is a direction perpendicular to the X direction. The X direction is an example of a "first direction," and the Y direction is an example of a "second direction."

[0047] The tactile device 100 of this embodiment includes a porous substrate 10, a plurality of conductors 22, a plurality of insulators 23, and a plurality of wiring boards 50.

[0048] The porous substrate 10 of this embodiment is a flat, molded body that is long in the X direction. As in the first embodiment, the porous substrate 10 includes a tactile surface 11 that faces the living body and a back surface 12 that is the surface on the opposite side, and a plurality of pores 13 are formed inside the porous substrate 10. The thickness of the porous substrate 10 from the tactile surface 11 toward the back surface 12 is 2 mm, but the thickness of the porous substrate 10 is not limited to the above example.

[0049] The porous substrate 10 includes a plurality of conductive portions 16 and a plurality of insulating portions 18. Each of the insulating portions 18 is provided between each of the plurality of conductive portions 16 of the porous substrate 10. That is, the plurality of conductive portions 16 and the plurality of insulating portions 18 are alternately arranged along the X direction. An insulating portion 18 is located between each of the conductive portions 16 adjacent to each other in the X direction. Specifically, the plurality of insulating portions 18 are provided at intervals of 1 cm along the X direction. The porous substrate 10 is continuous across the plurality of conductive portions 16 and the plurality of insulating portions 18.

[0050] Each of the multiple conductive portions 16 is elongated in the Y direction. Each of the multiple conductive portions 16 is a portion of the porous substrate 10 that is covered by a conductor 22. That is, the haptic device 100 includes multiple conductors 22, and the haptic device 100 of this embodiment has three or more conductors 22. The conductors 22 are conductive coatings that cover each of the multiple conductive portions 16. The relationship in which the conductors 22 cover the conductive portions 16 is similar to the relationship in which the first conductor 20 covers the first portion 14 of the first embodiment. Specifically, the conductors 22 cover the tactile surface 11 and back surface 12 of each of the multiple conductive portions 16 and the inner surfaces of the multiple pores 13 of each of the multiple conductive portions 16. That is, the porous substrate 10 is continuous across the multiple conductors 22. The material of the conductors 22 is the same as the material of the first conductor 20 of the first embodiment.

[0051] Each of the multiple insulating portions 18 is a portion of the porous substrate 10 that is covered by an insulator 23. The insulator 23 is an insulating coating that covers each of the multiple insulating portions 18. That is, the haptic device 100 includes multiple insulators 23. The relationship in which the insulator 23 covers the insulating portions 18 is similar to the relationship in which the insulator 23 covers the third portion 17 in the first embodiment. Specifically, the insulator 23 covers the tactile surface 11 and the back surface 12 in each of the multiple insulating portions 18 and the inner surfaces of the multiple pores 13 in each of the multiple conductive portions 16. Therefore, the resistance between two adjacent conductive portions 16 is increased by the insulator 23. The material of the insulator 23 is the same as the material of the insulator 23 in the first embodiment.

[0052] The width of each conductive portion 16 is approximately equal to the width of the insulating portions 18. However, a configuration in which the width of each conductive portion 16 is greater than the width of the insulating portions 18, or a configuration in which the width of each conductive portion 16 is smaller than the width of the insulating portions 18 may also be employed.

[0053] Each of the plurality of wiring boards 50 is connected to each of the plurality of conductive portions 16. The connection relationship between each of the plurality of wiring boards 50 is the same as the connection relationship between the first wiring board 30 of this embodiment.

[0054] In a situation where the haptic device 100 of this embodiment is used, the control device 200 selects, for example, two of the multiple conductors 22 and applies a voltage to the two selected conductors 22. The combination of the two selected conductors 22 is changed arbitrarily, for example, in response to an instruction from the user. Therefore, the distance between the two conductors 22 to which the voltage is applied by the control device 200 is variable. In other words, the position or area on the surface of the living body to which electrical stimulation is applied is controlled according to the position of the conductor 22 to which the voltage is applied by the control device 200.

[0055] Furthermore, by changing the combination of conductors 22 to which a voltage is applied over time, it is possible to change the position and range of electrical stimulation over time. For example, it is possible to move the position of electrical stimulation in the X or Y direction over time, or to narrow the range of electrical stimulation from a wide range to a narrow range over time. Note that voltage may be applied to three or more conductors 22. When voltage is applied to three or more conductors 22, electrical stimulation can be applied to many parts of the living body.

[0056] Here, the results of measuring the internal resistance (resistance Rs) of the porous substrate 10 according to this embodiment are shown.

[0057] In measuring the internal resistance (resistance Rs), a constant voltage was applied to two of the multiple wiring substrates 50, and the internal resistance (resistance Rs) was measured while changing the distance between the two wiring substrates 50 (hereinafter referred to as the inter-substrate distance). As a comparative example, the internal resistance of a porous substrate 10 having a configuration in which the insulating portion 18 is not covered with the insulator 23 was also measured in the same manner.

[0058] FIG. 7 is a graph showing the correlation between the internal resistance of the porous substrate 10 and the substrate-to-substrate distance in this embodiment and a comparative example. As shown in FIG. 7, when compared under the same substrate-to-substrate distance, the resistance value of the porous substrate 10 in this embodiment is higher than that in the comparative example. Therefore, by covering the insulating portion 18 connecting two adjacent conductive portions 16 of the porous substrate 10 with an insulator 23, the resistance value (resistance Rs) between the two adjacent conductive portions 16 is increased compared to a configuration in which the insulating portion 18 does not have an insulator 23. As described above, the resistance (resistance Rs) between the two adjacent conductive portions 16 increases, and as a result, as explained with reference to FIG. 5 above, a sufficient level of electrical stimulation can be applied to the living body. It was also confirmed that the internal resistance of the porous substrate 10 tends to increase as the substrate-to-substrate distance increases.

[0059] Next, the results of a sensory evaluation experiment of electrotactile stimulation in this embodiment will be shown.

[0060] The sensory evaluation of electrotactile stimulation was performed using the following procedure. First, the porous substrate 10 was impregnated with water to equalize the contact resistance with the surface of the living body (i.e., the subject's skin) with which it was to come into contact. Next, the tactile surface 11 of the tactile device 100 was brought into contact with the subject's skin. Next, a constant voltage was applied from the control device 200 to two of the multiple wiring substrates 50, and the sensory evaluation was performed while changing the distance between the substrates. As a comparative example, a similar sensory evaluation was also performed using a configuration in which the insulating portion 18 was not covered with the insulator 23.

[0061] FIG. 8 is a table summarizing the distance between the wiring boards and the degree of electrical stimulation. As shown in FIG. 8, even when the distance between the boards was 1 cm, where no electrical stimulation was felt in the comparative example, the electrical stimulation was felt in this embodiment. Therefore, compared to a configuration in which the insulator 23 is not formed in the insulating portion 18, it is shown that the electrical stimulation applied to the surface of the living body can be made stronger even with the same applied voltage. It was also shown that the greater the distance between the boards, the greater the degree of stimulation.

[0062] C: Modified Example Specific modified embodiments that can be added to each of the embodiments exemplified above are exemplified below. Two or more embodiments arbitrarily selected from the following examples may be appropriately combined within a range that does not contradict each other.

[0063] (1) In the second embodiment, the insulating portions 18 are provided at intervals of 1 cm along the X direction, but the length of the intervals at which the insulating portions 18 are provided is not limited to the above configuration.

[0064] (2) Of the above-described configurations, the first embodiment has an insulator 23 provided between the first conductor 20 and the second conductor 21, and the second embodiment has a configuration in which a plurality of insulators 23 are provided alternately with a plurality of conductors 22. However, the present invention is not limited to the above configurations as long as there is a gap between the conductors. For example, a configuration in which the conductors are not covered with the insulator 23, or a configuration in which the conductors (first conductor 20, second conductor 21, conductor 22) are separate members spaced apart from one another is conceivable.

[0065] (3) In the above-described embodiment, the porous substrate 10 is impregnated with water before the tactile device 100 is brought into contact with the surface of a living body. However, the substance to be impregnated is not limited to water. For example, a conductive gel or a conductive cream may be used. However, compared to a configuration in which the porous substrate 10 is impregnated with conductive gel or conductive cream, the configuration in which the porous substrate 10 is impregnated with water has the advantages of being less likely to cause inflammation on the surface of a living body, being suitable for long-term use, and being easy to clean the impregnated porous substrate 10.

[0066] (4) In the above-described embodiment, a configuration was exemplified in which wiring boards (first wiring board 30, second wiring board 40, wiring board 50) including wiring and a board were individually formed for each conductor (first conductor 20, second conductor 21, conductor 22), but a single board may be shared by multiple wirings. In other words, multiple wirings corresponding to different conductors may be formed on a single flexible board.

[0067] (5) In the above embodiment, the pores 13 are distributed approximately uniformly throughout the porous substrate 10, but the pores 13 may be distributed unevenly. For example, the distribution density of the pores 13 may differ between a portion close to the tactile surface 11 and a portion close to the back surface 12 in the thickness direction of the porous substrate 10. Furthermore, for example, within a plane along the surface (tactile surface 11, back surface 12) of the porous substrate 10, the distribution density of the pores 13 may differ between a portion close to the periphery of the porous substrate 10 and a portion close to the center.

[0068] (6) In the above embodiment, the porous substrate 10 is shaped like a flat plate, but the shape of the porous substrate 10 is not limited to the above example. For example, the porous substrate 10 may be shaped into a three-dimensional shape, such as a band shape that can be wrapped around a part of the body, such as the wrist or ankle.

[0069] (7) The haptic device 100 can be used for any purpose. That is, the scope of application of the present disclosure is not limited to the EMS device or low-frequency therapy device exemplified in the above embodiments.

[0070] (8) The term "nth" (n is a natural number) in this application is used only as a formal and convenient label to distinguish each element in the description and does not have any substantive meaning. Therefore, there is no room for restrictive interpretation of the position of each element or the order of manufacture, etc., based on the term "nth."

[0071] D: Notes From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0072] A tactile device according to one aspect (aspect 1) of the present disclosure includes a tactile surface facing a living body, and includes a porous substrate having a plurality of pores formed therein; a first conductor covering the tactile surface in a first portion of the porous substrate and the inner surfaces of the pores in the first portion; and a second conductor covering the tactile surface in a second portion of the porous substrate different from the first portion and the inner surfaces of the pores in the second portion, the first conductor and the second conductor being disposed at a distance from each other. In the above aspect, the first conductor covers the first portion of the porous substrate, and the second conductor covers the second portion of the porous substrate, and the first conductor and the second conductor are disposed at a distance from each other. In the tactile device of this aspect, the porous substrate deforms to conform to the shape of the surface of the living body, thereby ensuring stable adhesion of the tactile surface to the surface of the living body. In other words, changes in the state of contact of the tactile surface with the surface of the living body are suppressed. Therefore, compared to conventional techniques using a flexible substrate and metal electrodes, fluctuations in contact resistance between the contact surface and the surface of the living body can be suppressed.

[0073] Furthermore, since the first and second conductors are spaced apart, direct current flow between them is prevented. This ensures sufficient current flow from one of the first and second conductors to the other via the living body. This means that it is easy to apply a large electrical stimulus to the living body.

[0074] In a tactile device according to a specific example (Aspect 2) of Aspect 1, the porous substrate includes a back surface opposite the tactile surface, the first conductor further covers the back surface of the first portion, and the second conductor further covers the back surface of the second portion. In the above aspect, the first conductor covers not only the tactile surface of the first portion and the inner surfaces of each pore, but also the back surface of the first portion. Therefore, compared to a configuration in which the first conductor does not cover the back surface, this has the advantage of making it easier to connect the first conductor to a control device from the back side. The same applies to the second conductor.

[0075] In a tactile device according to a specific example (Aspect 3) of Aspect 1 or Aspect 2, the porous substrate further includes a third portion connecting the first portion and the second portion. In the above-described aspects, the first portion and the second portion of the tactile device are connected by the third portion. This configuration makes the tactile device easier to handle and manufacture than a configuration in which the first portion and the second portion are separate members spaced apart from each other.

[0076] A tactile device according to any one of the first to third specific examples (aspect 4) further includes an insulator that covers the contact surface in the third portion and the inner surfaces of the pores in the third portion. In the above aspects, the inner surfaces of each pore in the third portion of the porous substrate are covered with an insulator, thereby increasing the resistance between the first conductor and the second conductor compared to a configuration in which no insulator is formed in the third portion. Therefore, the current flowing from one of the first conductor and the second conductor to the other via the living body can be increased.

[0077] A tactile device according to a specific example (Aspect 5) of any of Aspects 1 to 4 further includes a first wiring connected to the first conductor, a second wiring connected to the second conductor, a flexible first substrate on which the first wiring is formed, and a flexible second substrate on which the second wiring is formed.

[0078] A tactile device according to one embodiment (embodiment 6) of the present disclosure includes a tactile surface facing a living body, a porous substrate having a plurality of pores formed therein, and a plurality of conductors formed at intervals in the porous substrate, each of which covers the tactile surface in a portion of the porous substrate corresponding to the conductor and the inner surfaces of the plurality of pores in that portion. In the above embodiment, the plurality of conductors are arranged at intervals in the porous substrate. The porous substrate deforms to conform to the shape of the surface of the living body, thereby ensuring stable adhesion of the tactile surface to the surface of the living body. In other words, changes in the state of contact of the tactile surface with the surface of the living body are suppressed. Therefore, fluctuations in contact resistance between the contact surface and the surface of the living body can be suppressed compared to conventional techniques using a flexible substrate and metal electrodes.

[0079] Furthermore, since the multiple conductors are spaced apart, direct current flow between them is prevented, ensuring sufficient current flow from one conductor to the other conductors via the living body, making it easier to apply a large electrical stimulus to the living body.

[0080] In a tactile device according to a specific example (aspect 7) of aspect 6, the plurality of conductors are three or more conductors. In the above aspect, the number of conductors between the three or more conductors is always two or more. Because the current flowing between two adjacent conductors passes through the living body, the number of electrical stimuli given to the living body increases by the number of conductors. Therefore, compared to a configuration with only two conductors, electrical stimuli can be given to more parts of the living body.

[0081] In a tactile device according to a specific example (Aspect 8) of Aspect 6 or Aspect 7, the porous substrate is continuous across the plurality of conductors. In the above-described embodiments, each of the plurality of conductors is connected. This configuration makes the tactile device easier to handle and manufacture than a configuration in which each of the plurality of conductors is a separate, spaced-apart member.

[0082] In a tactile device according to a specific example (aspect 9) of any of aspects 6 to 8, the porous substrate is a member that is elongated in a first direction, the multiple conductors are arranged at intervals along the first direction, and each of the multiple conductors has a planar shape that is elongated in a second direction that intersects the first direction. In the above aspects, the tactile device is configured to be large in both the first and second directions. That is, the tactile device contacts a wide area of ​​the surface of the living body. Therefore, compared to a configuration in which the porous substrate is a member that is short in the first direction and each of the multiple conductors has a planar shape that is short in the second direction, electrical stimulation can be applied to a wide area of ​​the living body in both the first and second directions.

[0083] A method for manufacturing a tactile device according to one aspect (aspect 10) of the present disclosure includes a molding step of molding a porous substrate having a tactile surface facing a living body and a plurality of pores formed therein, and a conductive treatment step of impregnating the tactile surface in a first portion of the porous substrate and the inner surfaces of the pores in the first portion, and the tactile surface in a second portion of the porous substrate and the inner surfaces of the pores in the second portion, with a conductive material. In the above aspect, a first conductor covers the first portion of the porous substrate, and a second conductor covers the second portion of the porous substrate. In the tactile device of this aspect, the porous substrate deforms to conform to the shape of the surface of the living body, thereby ensuring stable adhesion of the tactile surface to the surface of the living body. In other words, changes in the state of contact between the tactile surface and the surface of the living body are suppressed. Therefore, compared to conventional techniques, fluctuations in contact resistance between the contact surface and the surface of the living body can be suppressed.

[0084] Furthermore, by a simple process of impregnating a porous substrate with a conductive material, a first conductor can be formed that covers the contact surface of a first portion of the porous substrate and the inner surface of each pore, and a second conductor can be formed that covers the contact surface of a second portion of the porous substrate and the inner surface of each pore.

[0085] A method for manufacturing a tactile device according to a specific example (Aspect 11) of Aspect 10 includes an insulating process step of dividing the porous substrate into the first and second portions by impregnating a third portion of the porous substrate with an insulating material. In the above aspect, the third portion that electrically insulates the first and second portions can be formed by the simple process of impregnating the porous substrate with an insulating material. [Explanation of symbols]

[0086] 10...porous substrate, 11...tactile surface, 12...back surface, 13...pores, 14...first portion, 15...second portion, 16...conductive portion, 17...third portion, 18...insulating portion, 20...first conductor, 21...second conductor, 22...conductor, 23...insulator, 30...first wiring board, 31...first board, 32...first wiring, 40...second wiring board, 41...second board, 42...second wiring, 50...wiring board, 60...adhesive, 100...tactile device, 200...control device , P1...molding process, P2...insulating process, P3...conductive process, P21...impregnation process in the insulating process, P22...drying process in the insulating process, P31...impregnation process in the conductive process, P32...drying process in the conductive process, Ih...current flowing inside the living body, Is...current flowing through the porous substrate, Rh...resistance inside the living body, Rk1...contact resistance of the first conductor, Rk2...contact resistance of the second conductor, Rs...resistance of the porous substrate.

Claims

1. a porous substrate including a tactile surface facing a living body and having a plurality of pores formed therein; a first conductor covering the tactile surface in a first portion of the porous substrate and the inner surfaces of the plurality of pores in the first portion; a second conductor covering the tactile surface and the inner surfaces of the plurality of pores in a second portion of the porous substrate that is different from the first portion; The first conductor and the second conductor are spaced apart from each other. Tactile device.

2. the porous substrate includes a back surface opposite the tactile surface; the first conductor further covers the back surface of the first portion; The second conductor further covers the back surface of the second portion. The haptic device of claim 1 .

3. The porous substrate further includes a third portion connecting the first portion and the second portion. The haptic device of claim 1 or claim 2.

4. an insulator covering the tactile surface in the third portion and the inner surfaces of the plurality of pores in the third portion; The haptic device of claim 3 further comprising:

5. a first wiring connected to the first conductor; a second wiring connected to the second conductor; a flexible first substrate on which the first wiring is formed; a flexible second substrate on which the second wiring is formed; and The haptic device of claim 1 further comprising:

6. a porous substrate including a tactile surface facing a living body and having a plurality of pores formed therein; a plurality of conductors formed on the porous substrate at intervals from one another; Each of the plurality of conductors covers the tactile surface of the porous substrate in a portion corresponding to the conductor and the inner surfaces of the plurality of pores in that portion. Tactile device.

7. The plurality of conductors is three or more conductors. The haptic device of claim 6.

8. The porous substrate is continuous across the plurality of conductors. The haptic device of claim 6 or claim 7.

9. The porous substrate is a member that is elongated in a first direction, the plurality of conductors are arranged at intervals along the first direction, Each of the plurality of conductors has a planar shape that is elongated in a second direction that intersects with the first direction. The haptic device of claim 6 or claim 7.

10. a molding step of molding a porous substrate including a tactile surface facing a living body and having a plurality of pores formed therein; a conductive treatment step of impregnating the tactile surface of the first portion of the porous substrate and the inner surfaces of the plurality of pores in the first portion, and the tactile surface of the second portion of the porous substrate and the inner surfaces of the plurality of pores in the second portion with a conductive material; A method for manufacturing a haptic device comprising:

11. an insulating treatment step of impregnating a third portion of the porous substrate with an insulating material to divide the porous substrate into the first portion and the second portion; The method for manufacturing the haptic device of claim 10, comprising:

Images