JP2011232322A - Force sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a force sensor which can deform in greater way compared with the conventional art.SOLUTION: A force sensor 1 includes a main body 2 which elastically deforms upon force applied from the outside, one or more inner spaces provided in the main body 2 and a conductive fluid 15 filled in the inner spaces. By measuring the impedance of the fluid 15, the force applied to the main body 2 is measured.

Description

  The present invention relates to a force sensor, and more particularly to a force sensor having elasticity.

  Currently, in the field of robots, research on robots that work in human living spaces is ongoing. One of the challenges is the realization of a robot that can touch people safely. In this case, in order to improve safety, a tactile sensor that detects that the operating robot has come into contact with a person or a surrounding object is important. In particular, it is considered that it is necessary to detect the presence or absence of contact because a movable part such as an indirect part is likely to cause entrainment.

  As a tactile sensor of this type, a mesh-shaped surface member is formed by cross-linking a plurality of element forming portions with a plurality of cross-linking portions by processing a plurality of substantially rectangular openings in a thin film formed of a polymer material. In addition, a pressure surface sensor is disclosed in which pressure sensor elements are formed in a plurality of element forming portions of the surface member, and wiring to the pressure sensor elements is formed in a bridging portion (for example, Patent Document 1). The pressure surface sensor can be extended in a diagonal direction where no bridging portion is formed and can be deformed into a curved surface.

JP 2006-90983 A

  In the case of the above-mentioned Patent Document 1, the pressure surface sensor can be extended in the diagonal direction where the bridge portion is not formed, but the deformation amount is limited by the metal wiring formed in the bridge portion.

  In view of the above problems, an object of the present invention is to provide a force sensor that can be deformed more greatly than in the past.

  The invention according to claim 1 of the present invention includes a main body that is elastically deformed by an externally applied force, one or more internal spaces provided in the main body, and a conductive material filled in the internal space. And measuring a force applied to the main body by measuring an impedance of the fluid.

  According to a second aspect of the present invention, the internal space includes a first space and a second space connected to the first space, and the second space is applied by a force in the compression direction applied from the outside. A convex portion for deforming the space is provided on the surface of the main body.

  In the invention according to claim 3 of the present invention, the internal space includes a first space, a second space, and a third space that are provided in the thickness direction of the main body, and the second space is The main body is disposed on a neutral axis.

  The invention according to claim 4 of the present invention is characterized in that the fluid is an ionic liquid.

  According to the present invention, since the force sensor can be deformed as a whole as long as the main body can be deformed, the force sensor can be remarkably deformed as compared with the conventional case where the deformation amount is limited by the wiring.

It is a perspective view which shows the whole structure of the force sensor which concerns on 1st Embodiment. It is II-II sectional drawing in FIG. It is III-III sectional drawing in FIG. It is a perspective view (1) which shows the manufacturing process of a force sensor in steps. It is a perspective view (2) which shows the manufacturing process of a force sensor in steps. It is a perspective view (3) which shows the manufacturing process of a force sensor in steps. It is VII-VII sectional drawing in FIG. It is a perspective view (4) which shows the manufacturing process of a force sensor in steps. It is IX-IX sectional drawing in FIG. It is a perspective view (5) which shows the manufacturing process of a force sensor in steps. It is a longitudinal cross-sectional view in FIG. It is a longitudinal cross-sectional view which shows the use condition (1) of the force sensor which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the use condition (2) of the force sensor which concerns on 1st Embodiment. It is a graph which shows the impedance change rate at the time of applying the force of the extension direction to a force sensor. It is a longitudinal cross-sectional view which shows the use condition (3) of the force sensor which concerns on 1st Embodiment. It is a graph which shows the relationship between the curvature of a tubular member, and an impedance change rate. It is a longitudinal cross-sectional view which shows the use condition (4) of the force sensor which concerns on 1st Embodiment. It is a graph which shows the impedance change rate at the time of applying the force of a compression direction to a force sensor. It is a longitudinal cross-sectional view which shows the whole structure of the force sensor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the use condition (1) of the force sensor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the use condition (2) of the force sensor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the use condition (3) of the force sensor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the use condition (4) of the force sensor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the use condition (5) of the force sensor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the use condition (6) of the force sensor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the whole structure of the force sensor which concerns on a modification. It is a longitudinal cross-sectional view (1) which shows the manufacturing process of the force sensor which concerns on a modification in steps. It is a longitudinal cross-sectional view (2) which shows the manufacturing process of the force sensor which concerns on a modification in steps.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1. First embodiment (overall configuration)
A force sensor 1 shown in FIG. 1 includes a main body 2 and an electrode 3. The main body 2 is deformed, for example, expanded or contracted by an external force. In the case of this embodiment, the main body 2 has a plate shape and is made of silicon rubber. The silicon rubber is not particularly limited, and for example, PDMS (polydimethylsiloxane) can be used. More specifically, Sylgard 184 (manufactured by Toray Dow Corning Co., Ltd.), KE- 1241 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.

  A convex portion 4 is provided on the upper surface of the main body 2. The convex portion 4 deforms the upper surface of the main body 2 in the compression direction by a force in the compression direction. An electrode 3 is provided at the longitudinal end of the main body 2. In the case of the present embodiment, two sets of electrodes 3 are arranged as a pair (a total of four), each of which is arranged one by one at the opposite ends in the longitudinal direction of the main body 2.

  As shown in FIG. 2, the main body 2 includes a groove portion 6 and a lid portion 7 provided on the upper surface of the groove portion 6. In the case of this embodiment, the groove part 6 is comprised by the 1st groove part 8 and the 2nd groove part 9 integrally provided in the transversal direction of the said 1st groove part 8. FIG.

  The openings of the first groove 8 and the second groove 9 are covered with a protective film 10, thereby forming a first space 12 and a second space 13 as internal spaces. The first space 12 and the second space 13 are separated by a side wall 14 and filled with a conductive fluid 15. The protective film 10 is formed by depositing polyparaxylene (trade name Parylene) to a predetermined thickness using a CVD (Chemical Vapor Deposition) method.

  In the case of this embodiment, an ionic liquid is used as the fluid 15. As the ionic liquid, for example, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-1-methylpyrrolidinium tetracyanoborate, N-butyl-1-methylpyrrolidinium bis (trifluoromethylsulfonyl) imide and the like can be used.

  The convex part 4 is formed so that the second space 13 can be deformed by a force in the compression direction. In the case of the present embodiment, the convex portion 4 is constituted by a protrusion provided on the upper surface of the lid portion 7, and is disposed at substantially the center of the second space 13 and substantially parallel to the longitudinal direction of the second space 13. ing.

  Electrodes 3 are disposed in the first space 12 and the second space 13 respectively, and an AC voltage supplied from a power source (not shown) is applied to the fluid 15 filled in the first space 12 and the second space 13. Configured to get.

The configuration of the electrode 3 will be described with reference to FIG. Since the electrode 3 is not structurally different between the first space 12 and the second space 13, the electrode 3 disposed in the second space 13 will be described as an example. In the case of this embodiment, the electrode 3 includes an inner electrode portion 18 disposed in the second space 13 and an outer electrode portion 19 disposed outside the main body 2. The inner electrode portion 18 and the outer electrode portion 19 are formed of a thin plate and are integrally formed. The electrode 3 is not particularly limited. For example, a thin film having a thickness of about 30 nm such as Cu, Pt, or Au can be used.
(Production method)
Next, a method for manufacturing the force sensor 1 configured as described above will be described with reference to the drawings. First, the mold 21 for molding the first groove 8 is formed (FIG. 4). In the present embodiment, the mold 21 is formed by patterning a resist on a pure silicon wafer and performing RIE (Reactive Ion Etching). For etching, two kinds of gases of SF6 and C4F8 are alternately used. In the case of SF6, the flow rate can be 420 sccm and the output of the upper / lower high-frequency power supply can be 2000 W / 40 W. In the case of C4F8, the flow rate can be 180 sccm and the output of the upper / lower high-frequency power supply can be 2000 W / 0 W. The pure silicon wafer is cooled to 20 ° C. The pressure in the etching tank is about 1.0 × 10 ⁻⁶ Pa in the initial state. After the etching, the resist is removed.

Next, the electrode 3 is disposed on the mold 21 (FIG. 5). In this case, the inner electrode portion 18 is disposed on the island portion 22 of the mold 21 that becomes the bottom surface of the first groove portion 8, and the outer electrode portion 19 is disposed outside the mold 21. In a state where the spacer 24 is disposed on the edge 23 of the mold 21, liquid silicon rubber is poured into the mold 21 and cured to mold the first groove 8 (FIG. 6). In this embodiment, a glass plate is used as the spacer. Thereby, the electrode 3 is integrally molded in the first groove 8 (FIG. 7). The first groove 8 is removed from the mold 21 and the inside is hydrophilized with O ₂ plasma.

Next, the fluid 15 is injected into the first groove 8. Here, since the inside of the first groove 8 is hydrophilized by O ₂ plasma, the fluid 15 easily flows in. Further, a protective film 10 having a predetermined thickness, for example, 1 μm, is formed on the upper surface of the first groove 8 by the CVD method (FIGS. 8 and 9). The CVD conditions may be, for example, the chemical Parylene-C used, a vaporization temperature of 175 ° C., a decomposition temperature of 690 ° C., and a deposition pressure of 25 mm Torr. Thereby, the fluid 15 is in a state where the first space 12 of the first groove 8 is sealed by the protective film 10 and the fluid 15 is filled in the first space 12.

  Although not particularly illustrated, the second groove portion 9 having the second space 13 filled with the fluid 15 is formed in the same manner.

  Next, as shown in FIGS. 10 and 11, the first groove portion 8 and the second groove portion 9 formed as described above are bonded with silicon rubber in the lateral direction. Finally, the lid portion 7 is fixed to the upper surfaces of the first groove portion 8 and the second groove portion 9 with silicon rubber.

(Function and effect)
In the force sensor 1 configured as described above, the electrode 3 is electrically connected to an AC power source (not shown). The AC voltage supplied from the AC power source is applied to the fluid 15 filled in the first space 12 and the second space 13 through the inner electrode portion 18. Thereby, the impedance of the fluid 15 filled in the first space 12 and the second space 13 is measured. The impedance of the fluid 15 depends on the longitudinal length of the first space 12 and the second space 13 and the area of the longitudinal section in the short direction.

Here, the impedance Z of the fluid 15 is Z = √ (R ² + (2 / 2πfC) ² ). R is the resistance value of the fluid 15, f is the frequency of the input AC power supply, and C is the capacitance of the capacitor between the fluid and the electrode. In this case, by making the frequency W of the AC power source sufficiently large as 1 to 10 kHz, the capacitor component can be ignored, and it can be approximated as “Z = R”. That is, when the first space 12 and the second space 13 change in the longitudinal direction, the impedance is expressed by Z + ΔZ _L = ρ (L + ΔL) / A. Z: impedance before stretching, ΔZ _L : amount of change in impedance caused by stretching, ρ: resistivity of fluid 15, L: length of inner space in the longitudinal direction, ΔL: elongation of inner space, A: in the longitudinal direction It is the area of the internal space in a vertical cross section. When the fluid 15 is 1-ethyl-3-methyl-imidazolium ethyl sulfate, 1 / ρ = 0.398 (S / m). 1 / ρ is conductivity, and S is Ω ⁻¹ (Siemens). From the above, when extending in the longitudinal direction, the impedance increases proportionally.

When the area in the cross section perpendicular to the longitudinal direction changes, the impedance is expressed as Z + ΔZ _P = ρ · L / (A−ΔA). Note that ΔA is the amount of decrease in the area of the internal space, and ΔZ _P is the amount of change in impedance caused by compression. That is, the impedance is inversely proportional to the cross-sectional area.

  In the case of this embodiment, as shown in FIG. 12, when only a force in the longitudinal direction (arrow in the figure), that is, a force in the extending direction is applied to the body 2 of the force sensor 1, the body 2 is caused by the force. Extends in the longitudinal direction. Then, both the first space 12 and the second space 13 extend in the longitudinal direction. Therefore, both the impedances of the fluid 15 in the first space 12 and the second space 13 are increased. In this case, the force sensor 1 can measure the magnitude of the force in the extension direction by measuring the impedance of the fluid 15 in the first space 12 or the second space 13.

  In addition, as shown in FIG. 13, when only the force (arrow in the figure) pushing the surface against the main body 2 of the force sensor 1, that is, the force in the compression direction, is applied to the surface of the main body 2 by the force. The convex part 4 compresses the main body 2. Since the convex part 4 is provided only on the 2nd space 13 of the cover part 7, the 2nd space 13 deform | transforms with the force of a compression direction. If it does so, the area in the cross section of the transversal direction of the 2nd space 13 becomes small. Therefore, the impedance of the fluid 15 in the second space 13 is increased. In this case, by measuring the impedance of the fluid 15 in the second space 13, the force sensor 1 can measure the magnitude of the force in the compression direction.

  Next, the case where the force sensor 1 is simultaneously applied with the force in the extension direction and the force in the compression direction will be described. In this case, the first space 12 is deformed only by the force in the extending direction. That is, the first space 12 extends in the longitudinal direction, and the impedance of the fluid 15 increases.

  On the other hand, the second space 13 is deformed by a force in the compression direction and at the same time is deformed by a force in the compression direction. That is, the second space 13 extends in the longitudinal direction, and at the same time, the area in the cross section in the short direction is reduced. At this time, the length of the second space 13 in the longitudinal direction is substantially the same as that of the first space 12.

  In this case, the force sensor 1 can measure the magnitude of the force in the extension direction by measuring the impedance of the fluid 15 in the first space 12. At the same time, by calculating the difference between the impedance of the fluid 15 in the first space 12 and the impedance of the fluid 15 in the second space 13, the force sensor 1 can measure the magnitude of the force in the compression direction.

  Impedance was measured using the force sensor 1 actually formed. Body 2 width 10 mm, length 70 mm, thickness 1 mm, material (Toray Dow Corning Sylgard 184), first space 12 and second space 13 width 1 mm, length 40 mm, height 0.5 mm, volume The force sensor 1 having 20 cc and fluid 15 of 1-ethyl-3-methylimidazolium ethyl sulfate and an initial impedance of 30 kΩ was formed.

  FIG. 14 shows the impedance change rate when only the force in the extending direction is applied to the force sensor 1. From this result, it was confirmed that when only the force in the extending direction was applied to the force sensor 1, the impedance of the fluid 15 in the first space 12 and the second space 13 changed similarly.

  As shown in FIG. 15, the impedance of the fluid 15 was measured with the force sensor 1 attached to the surface of the tubular member 25 without extending in the longitudinal direction. In this case, since the first space 12 and the second space 13 are formed on the neutral axis, they do not extend by bending. FIG. 16 shows the relationship between the curvature of the tubular member 25 and the impedance change rate. From this result, it was confirmed that the impedance of the fluid 15 did not change even when the force sensor 1 was deformed into a curved shape.

  Further, as shown in FIG. 17, only a force in the compression direction was applied to the force sensor 1. The force sensor 1 was attached to the surface of a tubular member 26 having a radius of 30 mm. A force in the compression direction was applied to the force sensor 1 by pressing the surface against the structure 27. In this state, the impedance of the fluid 15 was measured. FIG. 18 shows the relationship between the force in the compression direction and the impedance change rate. From this result, it was confirmed that when only the force in the compression direction was applied to the force sensor 1, the impedance of the fluid 15 in the first space 12 did not change, and only the impedance of the fluid 15 in the second space 13 changed.

  As described above, the force sensor 1 according to this embodiment forms the first space 12 and the second space 13 in the main body 2 that is elastically deformed by an externally applied force, and the first space 12 and the second space. 13 is configured to measure the impedance of the fluid 15 filled in the inside. As a result, the force sensor 1 can be deformed as a whole as long as the main body 2 can be deformed. Therefore, the force sensor 1 can be remarkably deformed as compared with the conventional case where the deformation amount is limited by the wiring. Therefore, the force sensor 1 can be easily attached to a movable part such as an indirect robot.

  The force sensor 1 can measure the force in the compression direction by providing the convex portion 4 that deforms the second space 13 by the force in the compression direction applied to the main body 2. Further, the force sensor 1 connects the first space 12 and the second space 13, so that the force in the extension direction and the force in the compression direction are applied to the main body 2 at the same time. The force in the compression direction can be measured respectively.

  Furthermore, since the first space 12 and the second space 13 are sealed with the protective film 10 by the CVD method in a state where the first groove portion 8 and the second groove portion 9 are filled with the fluid 15, the force sensor 1 can be easily used. Can be manufactured.

2. Second embodiment (overall configuration)
Next, a force sensor according to the second embodiment will be described. In addition, the same code | symbol is attached | subjected about the structure similar to the said 1st Embodiment, and description is abbreviate | omitted for simplicity. The force sensor according to the present embodiment differs from the first embodiment in the configuration of the main body.

  As shown in FIG. 19, the force sensor 30 according to the present embodiment includes a first groove portion 32, a second groove portion 33, and a third groove portion 34 in which the main body 31 is sequentially stacked from one side 31 a. Each is closed by a protective film 10 and a lid 7. As a result, a first space 36, a second space 37, and a third space 38 are formed in the main body 31 as internal spaces. The first space 36, the second space 37, and the third space 38 are stacked in the main body 31 sequentially from one side 31a. When the main body 31 is considered as one beam, the main body 31 is formed so that the second space 37 is disposed on the neutral axis.

  The force sensor 30 is filled with a fluid 15 and sealed with a protective film 10, and thereafter, three first groove portions 32, second groove portions 33, and third groove portions 34 each having a lid portion 7 fixed on the upper surface are stacked in the vertical direction. Can be manufactured by bonding them together.

(Function and effect)
The operation when the force sensor 30 is attached to the joint 39 of the robot will be described. First, as shown in FIG. 20, a case where the force sensor 30 is attached in a state where the end portion is fixed and the central portion is not fixed will be described.

  When only a force in the extending direction is applied to the force sensor 30, the main body 31 is extended in the longitudinal direction by the force as shown in FIG. Then, the first space 36, the second space 37, and the third space 38 similarly extend in the longitudinal direction. Accordingly, the impedance of the fluid 15 in the first space 36, the second space 37, and the third space 38 is similarly increased. Thereby, the magnitude of the force in the extending direction can be measured from the impedance of any of the first space 36, the second space 37, and the third space 38.

  When only a force in the bending direction is applied to the force sensor 30, the main body 31 is bent and deformed by the force as shown in FIG. As a result, the first space 36 expands and the third space 38 contracts. Since the second space 37 is provided on the neutral axis, the length in the longitudinal direction does not change. Therefore, the impedance of the fluid 15 in the first space 36 is increased, and the impedance of the fluid 15 in the third space 38 is decreased. Further, the impedance of the fluid 15 in the second space 37 does not change. Thereby, the magnitude of the force in the bending direction can be measured from the impedance of the first space 36 and the third space 38.

  When only a force in the compression direction is applied to the force sensor 30, the surface of the main body 31 is pushed by the force as shown in FIG. If it does so, only the 1st space 36 will become small in the area in the cross section of a transversal direction. Accordingly, only the impedance of the fluid 15 in the first space 36 is increased. In this case, by measuring the impedance of the fluid 15 in the second space 37, the force sensor 30 can measure the magnitude of the force in the compression direction.

Thus, the impedance Z ₂ of the fluid 15 in the second space 37 does not respond to the bending direction, and compression force. Therefore, the force sensor 30, by measuring the variation [Delta] Z ₂ of the impedance Z _2, can be measured elongation force.

Impedance Z ₃ of the fluid 15 in the third space 38 does not respond to the force in the compression direction, responsive to elongation direction, and bending force. Therefore, only the force in the bending direction can be extracted by taking the difference between the change amounts ΔZ ₃ and ΔZ ₂ of the impedance Z ₃ and removing the influence of the force in the extension direction. That is, the force sensor 30 can measure the force in the bending direction by calculating ΔZ ₂ −ΔZ ₃ .

Impedance Z ₁ of the fluid 15 in the first space 36, the elongation direction, responsive bending direction, all forces in the compressing direction. Therefore, the change amount [Delta] Z ₁ impedance Z _1, removes the effects of taking the difference between the elongation force of a [Delta] Z _2, only the force in the compression direction by removing the influence of the bending force by adding the [Delta] Z ₃ Can be extracted. That is, the force sensor 30 can measure the force in the compression direction by calculating ΔZ ₁ −ΔZ ₂ + ΔZ ₃ .

  Next, as shown in FIG. 24, a case will be described in which the force sensor 30 is attached in a state where the entire bottom surface is fixed.

When only the force in the extending direction is applied to the force sensor 30, the first space 36, the second space 37, and the third space 38 similarly extend in the longitudinal direction. Therefore, ΔZ ₁ = ΔZ ₂ = ΔZ ₃ = ΔZ _L. ΔZ _L is the amount of change in impedance caused by elongation.

When only a force in the compression direction is applied to the force sensor 30, only the first space 36 is deformed. Therefore, ΔZ ₁ = ΔZ _P and ΔZ ₂ = ΔZ ₃ = 0. ΔZ _P is the amount of change in impedance caused by compression.

  As shown in FIG. 25, when a force in the bending direction is applied to the force sensor 30, the entire bottom surface is fixed. Therefore, even if the joint 39 of the robot is bent, the elongation of the bottom surface becomes zero. Therefore, the bending angle θ is θ = L / R. R is the radius of curvature of the force sensor 30 and L is the initial length of the force sensor 30.

Assuming that the elongation of the first space 36, the second space 37, and the third space 38 caused by the force in the bending direction is ΔL ₁ , ΔL ₂ , and ΔL ₃ , respectively, ΔL ₁ = 5 rL / R, ΔL ₂ = 3 rL / R, ΔL ₃ = rL / R. Note that r is the distance from the bottom surface of the force sensor 30 to the central axis of the third space.

Thereby, the impedances of the first space 36, the second space 37, and the third space 38 generated by the force in the bending direction are ΔZ ₁ = 5ΔZ _r , ΔZ ₂ = 3ΔZ _r , and ΔZ ₃ = ΔZ _r . [Delta] Z _r is the amount of change in impedance caused by the bending.

Solving these equations as simultaneous equations, a _{Z P = ΔZ 1 + ΔZ 3} -2ΔZ 2, ΔZ L = 3ΔZ 3/2-ΔZ 2/2, ΔZ r = ΔZ 2/2-ΔZ 3/2.

[Delta] Z _r, because bending a change in impedance caused by the direction of the force is proportional to the amount of extension and bending angle caused by bending. Therefore, it is possible to determine the bending angle by previously obtained the relationship between the bending angle and [Delta] Z _r.

  As described above, the force sensor 30 according to the present embodiment forms the first space 36, the second space 37, and the third space 38 in the main body 31 that is elastically deformed by an externally applied force. The impedance of the fluid 15 filled in the first space 36, the second space 37, and the third space 38 is measured. Thereby, the force sensor 30 can be remarkably deformed as compared with the conventional case, similarly to the first embodiment.

  Further, the force sensor 30 includes a first groove portion 32, a second groove portion 33, and a third groove portion 34, which are stacked in order from one side, so that the force sensor 30 can be bent in addition to the force in the extension direction and the compression direction. Directional force can be measured.

3. The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the gist of the present invention. As shown in FIG. 26, in the present modification, the configuration of the lid portion 7 is different from that of the above embodiment. That is, in the force sensor 40 according to this modification, the lid portion 41 is a plug that closes the formation lid portion 42, the planar lid portion 43, and the vent hole 45 and the inlet 46 formed in the planar lid portion 43. A body 44 is provided. In the case of this modification, two plug bodies 44 are provided. In order to manufacture the force sensor 1, the planar lid portion 43 is fixed to the opening of the groove portion 47 to form the internal space 48. Next, the fluid 15 is injected from the inlet 46 into the internal space 48 (FIG. 27). The vent hole 45 and the injection port 46 are respectively closed with the plug body 44 (FIG. 28). Finally, the periphery is surrounded by a side wall (not shown), and silicon rubber is poured into the upper surface of the planar lid portion 43 to form the formation lid portion 42, and the stopper is fixed to the lid portion 7. As described above, the force sensor 1 can be manufactured by filling the main body with the fluid 15 without using the protective film 10.

  In the first embodiment, the force sensor 1 has been described with respect to the case where the main body 2 is rectangular in plan view. However, the present invention is not limited to this, and the main body 2 may be square in plan view.

DESCRIPTION OF SYMBOLS 1 Force sensor 2 Main body 4 Convex part 12 1st space (internal space)
13 Second space (internal space)
15 Fluid 30 Force sensor 36 1st space (internal space)
37 Second space (internal space)
38 3rd space (internal space)

Claims (4)

A body that is elastically deformed by a force applied from the outside;
One or more internal spaces provided in the main body;
A conductive fluid filled in the internal space,
A force sensor for measuring a force applied to the main body by measuring an impedance of the fluid. The internal space consists of a first space and a second space connected to the first space,
The force sensor according to claim 1, wherein a convex portion that deforms the second space by a force in a compression direction applied from the outside is provided on a surface of the main body. The internal space consists of a first space, a second space, and a third space that are provided in the thickness direction of the main body,
The force sensor according to claim 1, wherein the second space is disposed on a neutral axis of the main body.   The force sensor according to claim 1, wherein the fluid is an ionic liquid.

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