Friction force varying body and adsorption tool

Abstract

To provide a friction force varying body capable of varying friction force with a simpler configuration, and to provide an adsorption tool.SOLUTION: There is provided a friction force varying body. The friction force varying body includes a pair of slide members and an external force imparting mechanism. The pair of slide members is provided relatively slidably, and each slide member includes a base part having an arrangement surface and a plurality of pillars provided on the arrangement surface. In a state that at least partial pillars of one of the slide members are inserted into at least partial pillars of the other slide member, the external force imparting mechanism imparts external force to the pair of slide members in mutually approaching directions so as to increase the friction force between the pair of slide members and prevent the relative sliding.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a variable frictional force body and a suction tool. [Background technology]

[0002] A variable stiffness device capable of changing stiffness is known (see Patent Document 1). The variable stiffness device includes two flexible sheets, each having a base material made of a sheet-like elastic material and a friction material provided on one side. The two flexible sheets are covered by a bag-like cover with the friction materials facing each other, and the cover is configured so that air can be sucked from the outside of the flexible sheets and the cover. In such a variable stiffness device, when air is sucked from between the flexible sheets and inside the cover from outside the cover through the vent, the two flexible sheets adhere to each other and become one. At this time, the frictional force between the two flexible sheets increases, suppressing their relative deformation and increasing the bending stiffness of the variable stiffness device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 261332 Summary of the Invention [Problem to be solved by the invention]

[0004] However, this variable stiffness device requires the provision of low stiffness sections to adjust the stiffness of each base material, and grooves or through holes to ensure air passages, which results in a complex configuration. In view of the above circumstances, the present invention aims to provide a frictional force variable body and a suction tool that can change frictional force with a simpler configuration. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a frictional force variable body. The frictional force variable body includes a pair of slide members and an external force application mechanism. The pair of slide members are arranged to be slidable relative to one another, and each slide member has a base with an arrangement surface and a plurality of pillars provided on the arrangement surface. The external force application mechanism is configured to apply an external force to the pair of slide members in a direction that brings them closer to each other, with at least some of the pillars of one slide member inserted between at least some of the pillars of the other slide member, thereby increasing the frictional force between the pair of slide members and preventing them from sliding relative to one another.

[0006] According to the above aspect, the frictional force can be changed with a simpler configuration. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing a schematic configuration of a frictional force variable body according to the present embodiment (showing a state in which no external force is applied); FIG. [Figure 2] 2 is a diagram schematically showing a state in which an external force is applied to the frictional force variable body of FIG. 1. FIG. [Figure 3] 3 is an image of the slide member in the state shown in FIG. 2 taken from above. [Figure 4] FIG. 2 is a diagram schematically illustrating the arrangement of pillars. [Figure 5] 1 is a diagram showing a schematic configuration of a suction device according to the present embodiment (showing a state in which no external force is applied); [Figure 6] 1 is a photograph of the slide members of Samples No. 1 and 2 used in the examples taken from the pillar side. [Figure 7] FIG. 1 is a schematic diagram showing an overview of a friction force measuring device. [Figure 8] 10 is a graph showing the measurement results of friction force. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Various features shown in the following embodiments can be combined with each other. First, the frictional force variable body according to this embodiment will be described. FIG. 1 is a diagram showing a schematic configuration of a frictional force variable body according to this embodiment (showing a state in which no external force is applied). FIG. 2 is a diagram showing a schematic state in which an external force is applied to the frictional force variable body of FIG. 1. FIG. 3 is an image taken from above of the sliding member in the state shown in FIG. 2. FIG. 4 is a diagram showing a schematic arrangement of pillars. In the following description, the upper side in FIGS. 1 and 2 will be referred to as "top" or "upper side", and the lower side will be referred to as "bottom" or "lower side".

[0009] The frictional force variable body 1 shown in FIGS. 1 and 2 includes a pair of slide members, a lower slide member 21 and an upper slide member 22, and an external force application mechanism 3. The lower slide member 21 and the upper slide member 22 are provided so as to be able to slide relative to each other when no external force is applied (in a natural state). The lower slide member 21 has a flat plate- or sheet-shaped lower base 211 having an arrangement surface 211a, and a plurality of lower pillars 212 provided on the arrangement surface 211a. The upper slide member 22 has a flat plate- or sheet-shaped upper base 221 having an arrangement surface 221a, and a plurality of upper pillars 222 provided on the arrangement surface 221a.

[0010] 2, the external force exerting mechanism 3 exerts an external force on the lower slide member 21 and the upper slide member 22 in a direction that brings them closer to each other, with at least some of the lower pillars 212 of the lower slide member (one slide member) 21 inserted between at least some of the upper pillars 222 of the upper slide member (the other slide member) 22. In this way, the external force exerting mechanism 3 is configured to increase the frictional force between the lower slide member 21 and the upper slide member 22, thereby preventing relative sliding. In the area "A" in the image shown in FIG. 3, the lower pillars 212 of the lower slide member 21 are inserted between the upper pillars 222 of the upper slide member 22, and the tips of the lower pillars 212 can be observed.

[0011] At this time, the lower slide member 21 and the upper slide member 22 (the pair of slide members 21, 22) come into close contact with each other, increasing the frictional force therebetween and causing them to become one. This (due to so-called jamming transition) increases the bending rigidity of the integrated slide members 21, 22. As a result, the frictional force variable body 1 is prevented from deforming (i.e., its shape is maintained). If an external force is applied by the external force application mechanism 3 while the lower slide member 21 and the upper slide member 22 are in a bent state, the frictional force variable body 1 will maintain the bent state. 1, the external force application mechanism 3 is configured to weaken the frictional force between the lower slide member 21 and the upper slide member 22 and allow relative sliding by releasing the application of external force to the lower slide member 21 and the upper slide member 22. At this time, the bending rigidity of the slide members 21 and 22 decreases, and deformation of the frictional force variable body 1 becomes permitted.

[0012] The frictional force variable body 1 is configured to generate a repulsive force in a direction in which the lower slide member 21 and the upper slide member 22 move away from each other by releasing the application of the external force to the lower slide member 21 and the upper slide member 22 by the external force application mechanism 3. In this case, simply releasing the application of the external force causes the lower slide member 21 and the upper slide member 22 to move away from each other, allowing them to slide relative to each other, which simplifies the configuration of the frictional force variable body 1 and makes it easy to use. Such repulsive force can be configured to be generated, for example, by an elastic body arranged between the lower slide member 21 and the upper slide member 22. The elastic body can be, for example, a spring body such as a coil spring or a torsion spring, a block body made of an elastic material (rubber material), a capsule body filled with gas, or the like.

[0013] In this embodiment, the repulsive force is generated by contact and deformation of a lower pillar 212 that is a part of the lower slide member (one of the slide members) 21 and an upper pillar 222 that is a part of the upper slide member (the other slide member) 22. With this configuration, the number of parts of the frictional force variable body 1 can be reduced. In the area "B" in the image shown in Figure 3, the lower pillars 212 of the lower slide member 21 are not observed inserted between the upper pillars 222 of the upper slide member 22, and it is thought that some of the lower pillars 212 and some of the upper pillars 222 are in contact with each other and are deformed.

[0014] In each slide member 21, 22, the proportion of the arrangement surface 211a, 221a occupied by the multiple pillars 212, 222 is preferably approximately 20% to 91%, more preferably approximately 30% to 91%, and even more preferably approximately 40% to 91%. In this case, the proportion of the lower pillars 212 inserted between the upper pillars 222 and the proportion of the lower pillars 212 contacting and deforming with some of the upper pillars 222 tend to be appropriate. Therefore, when an external force is applied by the external force application mechanism 3, the lower slide member 21 and the upper slide member 22 are reliably prevented from sliding relative to each other. When the application of external force by the external force application mechanism 3 is released, the lower slide member 21 and the upper slide member 22 are reliably separated from each other, allowing their relative sliding.

[0015] The cross-sectional area (cross-sectional area along a direction parallel to the arrangement surfaces 211a, 221a) of each pillar 212, 222 decreases with increasing distance from the arrangement surfaces 211a, 221a. With pillars 212, 222 having such a shape, even if the proportion of the arrangement surfaces 211a, 221a occupied by the pillars 212, 222 is increased, the lower pillar 212 can be smoothly inserted into and removed from between the upper pillars 222. Note that, if the proportion of the arrangement surfaces 211a, 221a occupied by the pillars 212, 222 is reduced, the cross-sectional area of ​​each pillar 212, 222 can be made approximately constant along the height direction, i.e., the pillars can be made columnar. 1, the ratio (H / W) of the maximum height H to the maximum width W of each pillar 212, 222 is preferably about 6 or less, more preferably about 0.2 to 4, and even more preferably about 0.5 to 3. This configuration sufficiently improves the shape stability of each pillar 212, 222, allowing the lower pillar 212 to be inserted more reliably between the upper pillars 222.

[0016] In each of the slide members 21, 22, the constituent material of the plurality of pillars 212, 222 is preferably more flexible than the constituent material of the bases 211, 221. In this case, the slide members 21, 22 can maintain a high degree of shape retention, and when some of the lower pillars 212 and some of the upper pillars 222 come into contact with each other, they can be sufficiently deformed. Thermoplastic resin is preferable as the constituent material of the bases 211, 221. Examples of this thermoplastic resin include styrene-based resin, olefin-based resin, polyvinyl chloride resin, thermoplastic elastomer, fluorine-based resin, polyester-based resin, and nylon-based resin. On the other hand, the constituent material of the pillars 212, 222 may be the same as or different from the constituent material of the bases 211, 221. Examples of the constituent material of the pillars 212, 222 include thermoplastic resin such as styrene-based resin, olefin-based resin, polyvinyl chloride resin, thermoplastic elastomer, and fluorine-based resin.

[0017] In each slide member 21, 22, methods for forming pillars 212, 222 on the placement surfaces 211a, 221a of the bases 211, 221 include, for example, a manufacturing method using an extrusion molding method, a manufacturing method using a photolithography method, a manufacturing method using a heat press method, a manufacturing method using a pattern roll and UV-curable resin, a manufacturing method using a 3D printer, and a method in which hair-like bodies are embedded in a resin layer and then covalently bonded by a polymerization reaction. It is preferable that each of the slide members 21, 22 is optically transparent. In this case, the members used in combination with the frictional force variable body 1 can be seen through the frictional force variable body 1. Furthermore, for example, when a surgical instrument is configured using the frictional force variable body 1, the surgical field of an organ or the like can be seen through the frictional force variable body 1, allowing surgery to be performed with a high degree of safety. The planar shape of each of the slide members 21, 22 (each of the bases 211, 221) may be, for example, a rectangular shape, a square shape, a polygonal shape such as a hexagonal shape, a circular shape, an oval shape, an elliptical shape, or an irregular shape.

[0018] In this embodiment, the thickness of each base 211, 221 is not particularly limited, but is preferably about 10 μm or more and 10 mm or less, more preferably about 20 μm or more and 2 mm or less, and even more preferably about 50 μm or more and 1 mm or less. The maximum height H of each pillar 212, 222 is not particularly limited, but is preferably about 1 μm to 10 mm, more preferably about 10 μm to 2 mm, and even more preferably about 50 μm to 1 mm.

[0019] Furthermore, the maximum width W of each pillar 212, 222 is not particularly limited, but is preferably about 1 μm or more and 5 mm or less, more preferably about 10 μm or more and 1 mm or less, and even more preferably about 50 μm or more and 400 μm or less. It is preferable that the pillars 212, 222 are arranged to have rotational symmetry in each of the slide members 21, 22. In this case, the lower pillars 212 can be inserted between the upper pillars 222 more accurately and reliably.

[0020] In Fig. 4(a), the multiple pillars 212, 222 are arranged to have six-fold rotational symmetry. In Fig. 4(b), the multiple pillars 212, 222 are arranged to have four-fold rotational symmetry. In Fig. 4(c), the multiple pillars 212, 222 are strictly arranged to have two-fold rotational symmetry, but in this specification, they are treated as being arranged to have four-fold rotational symmetry within a range of deviation equal to or less than the maximum width W of the pillars 212, 222. The above arrangement preferably has 3 to 12-fold rotational symmetry, more preferably 3 to 10-fold rotational symmetry, and even more preferably 4 to 6-fold rotational symmetry, in which case the above effects can be further improved.

[0021] When the boundary between each pillar 212, 222 and its base 211, 221 is a circle with a radius r, the pitch Pit between adjacent pillars 212, 222 is preferably approximately 2r or more and 8r or less, more preferably approximately 2r or more and 6r or less, and even more preferably approximately 2r or more and 4r or less. In this case, the ratio of the lower pillars 212 inserted between the upper pillars 222 and the ratio of the lower pillars 212 contacting and deforming with the upper pillars 222 tend to be more appropriate. Therefore, when an external force is applied by the external force application mechanism 3, relative sliding between the lower slide member 21 and the upper slide member 22 is more reliably prevented. When the application of external force by the external force application mechanism 3 is released, the lower slide member 21 and the upper slide member 22 are more reliably separated from each other, allowing relative sliding therebetween.

[0022] The external force exerting mechanism 3 can be configured, for example, as a compression mechanism that compresses the slide members 21, 22 in a direction that brings them closer to each other. In this embodiment, the external force exerting mechanism 3 includes a deformable housing 31 that houses the pair of slide members 21, 22 in an internal space 31a, and a pump (discharge device) P that discharges the working fluid from the internal space 31a. The pump P is connected via a connection part 32 provided in the housing 31. The external force exerting mechanism 3 is configured to apply an external force to the pair of slide members 21, 22 in a direction that brings them closer to each other by discharging the working fluid and reducing the volume of the internal space 31a. This configuration is preferable because it allows an external force (compressive force) to be applied to the pair of slide members 21, 22 relatively easily. In addition, since a gap (flow path) through which the working fluid can move is secured between the upper pillar 222 and the lower pillar 212, there is no need to form a separate flow path in one or both of the slide members 21, 22, which also contributes to simplifying the configuration.

[0023] Examples of the working fluid include gases such as air, nitrogen gas, and inert gases, liquids such as water, alcohols, and oils, and solids such as resin particles, metal particles, and ceramic particles. These working fluids may be used alone or in combination of two or more. Among these, the working fluid preferably contains a gas, and more preferably is a gas. By using such a working fluid, it is possible to achieve reliable and accurate operation of the external force exerting mechanism 3 while reducing its weight. The pump P may be, for example, a piston pump, a diaphragm pump, a tube pump, or the like.

[0024] The housing 31 may be flexible. Examples of its constituent material (flexible material) include thermoplastic elastomer materials such as polystyrene-based thermoplastic elastomer, polyolefin-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, polyurethane-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, and polybutadiene-based thermoplastic elastomer. The constituent material of the housing 31 may also be rubber materials such as silicone rubber, chloroprene rubber, nitrile butadiene rubber, ethylene propylene rubber, fluororubber, natural rubber, isoprene rubber, styrene butadiene rubber, butyl rubber, and butadiene rubber.

[0025] Using the frictional force variable body 1 as described above, for example, a suction tool 10 can be constructed. 5 is a diagram showing a schematic configuration of the suction device according to this embodiment (showing a state in which no external force is applied). In the following description, the upper side of FIG. 5 will be referred to as "top" or "upper side," and the lower side will be referred to as "bottom" or "lower side." This suction device 10 is provided with the above-mentioned frictional force variable body 1. A part of the housing 31 is made up of a porous sheet 33, and the lower slide member 21 is joined to this porous sheet 33. Examples of materials that can be used for the porous sheet 33 include polyolefins (polyethylene, polypropylene, etc.), polyesters, and fluorine-based resins.

[0026] The suction device 10 is used as follows. That is, first, the suction device 10 is deformed and brought into contact with the object to be suctioned so that the porous sheet 33 conforms to the surface shape of the object to be suctioned. In this state, the pump P is operated to discharge the working fluid and reduce the pressure inside the internal space 31a. At this time, the pressure inside the pores of the porous sheet 33 is also reduced, so that the suction device 10 can be suctioned and fixed to the object to be suctioned. At this time, the contraction force of the housing 31 applies an external force to the pair of slide members 21, 22 in a direction that brings them closer to each other. As a result, the slide members 21, 22 come into close contact with each other, increasing the frictional force between them and uniting them. As a result, the bending rigidity of the united slide members 21, 22 increases, and as a result, deformation of the suction device 10 is prevented.

[0027] Furthermore, if each part of the suction device 10 is made of the above-mentioned materials, it can be made light-transmitting, so that the object to be sucked can be visually recognized through the suction device 10. In this case, for example, if the object to be adsorbed is an organ, the movement of the organ can be restricted while ensuring visibility of the organ, thereby enabling treatment (such as surgery) to be carried out smoothly. In this case, a gripping portion that can be gripped with forceps or the like may be provided at a predetermined location on the housing 31. This allows the organ to be moved or a part of the organ to be deformed by manipulating the suction device 10 that has been sucked onto the organ with the forceps or the like. Furthermore, it may be provided in the following aspects.

[0028] (1) A frictional force variable body comprising a pair of slide members and an external force application mechanism, wherein the pair of slide members are arranged to be slidable relative to one another, each of the slide members having a base with an arrangement surface and a plurality of pillars provided on the arrangement surface, and the external force application mechanism is configured to apply an external force to the pair of slide members in a direction that brings them closer to each other while at least some of the pillars of one of the slide members are inserted between at least some of the pillars of the other slide member, thereby increasing the frictional force between the pair of slide members and preventing relative sliding.

[0029] (2) In the frictional force variable body described in (1) above, the external force application mechanism is configured to reduce the frictional force between the pair of sliding members by releasing the application of the external force to the pair of sliding members, thereby allowing the relative sliding.

[0030] (3) The frictional force variable body described in (2) above, wherein the frictional force variable body is configured to generate a repulsive force in a direction in which the pair of slide members move away from each other by releasing the application of the external force to the pair of slide members by the external force application mechanism.

[0031] (4) A frictional force variable body as described in (3) above, wherein the repulsive force is generated by the pillar of one of the slide members coming into contact with and deforming the pillar of the other of the slide members.

[0032] (5) The frictional force variable body according to any one of (1) to (4) above, wherein the proportion of the surface on which the pillars are arranged in each of the slide members is 20% or more and 91% or less.

[0033] (6) The frictional force variable body according to any one of (1) to (5) above, wherein the cross-sectional area of ​​each of the pillars decreases with increasing distance from the arrangement surface.

[0034] (7) The frictional force variable body according to any one of (1) to (6) above, wherein the ratio of the maximum height to the maximum width of each of the pillars is 6 or less.

[0035] (8) The frictional force variable body according to any one of (1) to (7) above, wherein in each of the slide members, the material constituting the plurality of pillars is more flexible than the material constituting the base.

[0036] (9) The frictional force variable body according to any one of (1) to (8) above, wherein in each of the slide members, the pillars are arranged to have rotational symmetry.

[0037] (10) The frictional force variable body according to (9) above, wherein the arrangement has a rotational symmetry of 3 to 12 times.

[0038] (11) The frictional force variable body described in (10) above, wherein the shape of the boundary between each pillar and the base is a circle with a radius r, and the pitch between adjacent pillars is 2r or more and 8r or less.

[0039] (12) The frictional force variable body according to any one of (1) to (11) above, wherein the base portion of each of the slide members is in the shape of a flat plate or a sheet.

[0040] (13) The frictional force variable body according to any one of (1) to (12) above, wherein each of the sliding members is optically transparent.

[0041] (14) A frictional force variable body according to any one of (1) to (13) above, wherein the external force exerting mechanism has a deformable housing that accommodates the pair of slide members within an internal space, and an exhaust device that discharges the working fluid within the internal space, and is configured to exert an external force on the pair of slide members in a direction that brings them closer to each other by discharging the working fluid to reduce the volume of the internal space.

[0042] (15) An adsorption device comprising the frictional force variable body described in (14) above, wherein a portion of the container is made of a porous sheet. Of course, this is not the case.

[0043] Finally, while various embodiments of the present disclosure have been described, they are presented as examples and are not intended to limit the scope of the invention. The novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. Such embodiments and modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as defined in the claims.

[0044] For example, the frictional force variable body can be made of a metal material depending on the application. Alternatively, the base may be formed of a cylinder that can rotate around an axis, with its peripheral surface serving as the mounting surface, or the base may be formed of a disk that can rotate around an axis, with its main surface serving as the mounting surface. In the latter case, a clutch mechanism can be formed using a frictional force variable body. [Example]

[0045] The present invention will be described in more detail below using the following examples, but the present invention is not limited to the following examples.

[0046] 1.Preparing the slide members (Sample No. 1) The specifications of the slide member of Sample No. 1 shown in FIG. 6(a) are as follows: ·base Shape: Sheet Planar size: 20mm x 20mm Thickness: 0.1mm Construction material: Polycarbonate Pillar Shape: Cone Maximum width W: 120μm Maximum height H: 120 μm Pitch: 120 μm Material: Polyurethane thermoplastic elastomer

[0047] (Sample No. 2) The specifications of the slide member of sample No. 2 shown in FIG. 6(b) are as follows: ·base Shape: Sheet Planar size: 20mm x 20mm Thickness: 0.1mm Construction material: Polycarbonate Pillar Shape: Cone Maximum width W: 60μm Maximum height H: 120 μm Pitch: 120 μm Material: Polyurethane thermoplastic elastomer

[0048] 2. Measurement of friction force Example 1 As shown in Figure 7, two slide members of Sample No. 1 were placed with their pillars facing inward and clamped between a lower clamping plate and an upper clamping plate. A 200 g weight was placed on the upper clamping plate, and a spring balance was connected to the lower clamping plate, and the end opposite the lower clamping plate was pulled. The load when sliding (misalignment) occurred between the two slide members was measured.

[0049] Example 2 The load was measured in the same manner as in Example 1, except that the slide member of Sample No. 1 and the slide member of Sample No. 2 were used. Example 3 The load was measured in the same manner as in Example 1, except that two slide members of Sample No. 2 were used.

[0050] The results are shown in Figure 8. As shown in Figure 8, it was confirmed that the load required to cause sliding (misalignment) between the two sliding members changes depending on the combination of sliding members. [Explanation of symbols]

[0051] 1: Variable friction force 10: Suction tool 21: Lower slide member 211: Lower base 211a: Placement surface 212: Lower pillar 22: Upper slide member 221: Upper base 221a: Placement surface 222: Upper pillar 3: External force application mechanism 31: Storage body 31a: Internal space 32: Connection part 33: Porous sheet H: Maximum height P: Pump Pit: Pitch W: Maximum width r: radius

Claims

1. A frictional force variable body, A pair of slide members and an external force applying mechanism are provided, The pair of slide members are provided so as to be slidable relative to each other, and each slide member has a base portion having an arrangement surface and a plurality of pillars provided on the arrangement surface, The external force exerting mechanism is configured to increase the frictional force between the pair of slide members and prevent relative sliding by exerting an external force on the pair of slide members in a direction that brings them closer to each other while at least some of the pillars of one of the slide members are inserted between at least some of the pillars of the other slide member, thereby varying the frictional force between the pair of slide members and preventing relative sliding.

2. The frictional force variable body according to claim 1, The external force exerting mechanism is configured to weaken the frictional force between the pair of sliding members and allow the relative sliding by releasing the application of the external force to the pair of sliding members.

3. The frictional force variable body according to claim 2, The frictional force variable body is configured to generate a repulsive force in a direction in which the pair of slide members move away from each other by releasing the application of the external force to the pair of slide members by the external force application mechanism.

4. The frictional force variable body according to claim 3, A frictional force variable body configured so that the repulsive force is generated by contact and deformation of the pillar that is a part of the one slide member and the pillar that is a part of the other slide member.

5. The frictional force variable body according to claim 1, A frictional force variable body, wherein the proportion of the arrangement surface of the plurality of pillars in each of the slide members is 20% or more and 91% or less.

6. The frictional force variable body according to claim 1, A frictional force variable body, wherein the cross-sectional area of ​​each pillar decreases as it becomes farther from the placement surface.

7. The frictional force variable body according to claim 1, A frictional force variable body, wherein each pillar has a ratio of its maximum height to its maximum width of 6 or less.

8. The frictional force variable body according to claim 1, A frictional force variable body, in which in each of the slide members, the constituent material of the plurality of pillars is more flexible than the constituent material of the base.

9. The frictional force variable body according to claim 1, A frictional force variable body, wherein in each of the slide members, the plurality of pillars are arranged to have rotational symmetry.

10. The frictional force variable body according to claim 9, The arrangement of the variable frictional force body has a rotational symmetry of 3 to 12 times.

11. The frictional force variable body according to claim 10, The shape of the boundary between each of the pillars and the base is a circle with a radius r, A frictional force variable body, wherein the pitch between adjacent pillars is equal to or greater than 2r and equal to or less than 8r.

12. The frictional force variable body according to claim 1, In each of the slide members, the base portion is in the form of a flat plate or a sheet.

13. The frictional force variable body according to claim 1, Each of the slide members is a frictional force variable body having optical transparency.

14. The frictional force variable body according to claim 1, The external force exerting mechanism has a deformable housing that accommodates the pair of slide members within an internal space, and a discharge device that discharges the working fluid within the internal space, and is configured to exert an external force on the pair of slide members in a direction that brings them closer to each other by discharging the working fluid to reduce the volume of the internal space.

15. A suction device, The frictional force variable body according to claim 14 is provided, The suction device, wherein a portion of the container is made of a porous sheet.

Images