阅读说明：本技术 力和/或压力传感器 (Force and/or pressure sensor ) 是由 P.雅温恩 M.图如恩 J.黑托坎加斯 J.万哈拉 P.伊索-科托拉 于 2017-06-20 设计创作，主要内容包括：本发明涉及用于用作压力和/或力传感器的传感器(900)。传感器(900)包括：弹性且可拉伸的层(050、100、200),其包括具有第一杨氏模量(Y-(200))和第一屈服应变(ε-(y,200))的材料；至少第一可拉伸电极(301)和第二可拉伸电极(302),其附接至弹性且可拉伸的层(050、100、200),且被布置成彼此相距第一距离(d-1、d-(1,301,302))；具有第二杨氏模量(Y-(500))的柔性箔(500)；以及附接至柔性箔(500)的导电线路(400)。导电线路(400)的至少一部分以导电方式耦合到可拉伸电极(301、302)；第一屈服应变(ε-(y,200))是至少百分之10；第一杨氏模量(Y-(200))小于第二杨氏模量(Y-(500))；并且,柔性箔(500)的厚度(t-(500))是最多0.5 mm。(The invention relates to a sensor (900) for use as a pressure and/or force sensor. The sensor (900) comprises: an elastic and stretchable layer (050, 100, 200) comprising a first Young's modulus (Y) 200 ) And first yield strain (. epsilon.) y,200 ) The material of (a); at least a first stretchable electrode (301) and a second stretchable electrode (302) attached to the elastic and stretchable layer (050, 100, 200) and arranged at a first distance (d) from each other 1 、d 1,301,302 ) (ii) a Having a second Young's modulus (Y) 500 ) The flexible foil (500); and a conductive line (400) attached to the flexible foil (500). At least a portion of the conductive line (400) is conductively coupled to the stretchable electrode (301, 302); first yield strain (. epsilon.) y,200 ) Is at least one percent10; first Young's modulus (Y) 200 ) Less than the second Young's modulus (Y) 500 ) (ii) a And the thickness (t) of the flexible foil (500) 500 ) Is at most 0.5 mm.)

1. A capacitive force and/or pressure sensor (900), the sensor comprising:

-an elastic and stretchable layer (050) comprising a material having a first young's modulus (Y)₂₀₀) And first yield strain (. epsilon.)_y,200) Or a layer having a first Young's modulus (Y)₂₀₀) And first yield strain (. epsilon.)_y,200) The composition of the layers of (a) and (b),

-at least a first stretchable electrode (301) and a second stretchable electrode (302) attached to the elastic and stretchable layer (050) and arranged at a first distance (d) from each other₁、d_1,301,302），

-has a second Young's modulus (Y)₅₀₀) Of a flexible foil (500) of (a),

-a conductive line (400) attached to the flexible foil (500), and

-a first electrically conductive layer (600, 600a), wherein,

-the first and second stretchable electrodes (301, 302), the flexible foil (500) and the electrically conductive line (400) are left on the same side of the elastic and stretchable layer (050),

-at least a portion of the conductive line (400) is conductively coupled to the first stretchable electrode (301),

-at least a portion of the conductive line (400) is conductively coupled to the second stretchable electrode (302),

-the elastic and stretchable layer (050) is arranged between the first electrically conductive layer (600, 600a) and the first stretchable electrode (301) in a direction of a thickness of the sensor (900),

-said first yield strain (ε)_y,200) Is at least 10 percent of the total weight of the composition,

-a thickness (t) of the flexible foil (500)₅₀₀) Is at most 0.5mm, and

-said first Young's modulus (Y)₂₀₀) Less than said second Young's modulus (Y)₅₀₀) And the sensor (900) comprises

-an additional elastically deformable layer (100 b), and

-a second electrically conductive layer (600 b),

so that

-the first conductive layer (600, 600a) and the second conductive layer (600 b) are left on opposite sides of the first stretchable electrode (301), and

-the additional elastically deformable layer (100 b) is arranged between the second conductive layer (600 b) and the first stretchable electrode (301) in the direction of the thickness of the sensor (900).

2. The sensor (900) of claim 1,

-the elastic and stretchable layer (050) comprises:

an elastically deformable layer (100), and

the layer (200) can be stretched such that

-the stretchable layer (200), the first and second stretchable electrodes (301, 302), the flexible foil (500) and the electrically conductive line (400) are left on the same side of the elastically deformable layer (100).

3. The sensor (900) of claim 2,

-the stretchable layer (200) is arranged between the first stretchable electrode (301) and the elastically deformable layer (100).

4. The sensor (900) of claim 2 or 3,

-said elastically deformable layer (100) having a Young's modulus (Y)₁₀₀) Less than the first Young's modulus (Y)₂₀₀）。

5. The sensor (900) of any of claims 2 to 4,

-the stretchable layer (200) comprises one of a Thermoplastic Polyurethane (TPU), a polyamide and a polyester.

6. The sensor (900) of any of claims 1 to 5,

-the elastic and stretchable layer (050) comprises at least one of: polyurethanes, polyethylenes, poly (ethylene-vinyl acetate), polyvinyl chloride, boronated polydimethylsiloxanes, polystyrene, acrylonitrile-butadiene-styrene, styrene-butadiene styrene, ethylene propylene rubber, neoprene, cork, latex, natural rubber, silicone, and thermoplastic elastomeric gels.

7. The sensor (900) of any of claims 1 to 6,

-leaving an electrode-free space (210) on the elastic and stretchable layer (050, 100, 200), the electrode-free space being outside all stretchable electrodes (300, 301, 302, 303, 304, 305, 306) attached to the elastic and stretchable layer (050, 100, 200), and

-at least some of the electrically conductive lines (400) are arranged on the electrode-free space (210) or below the electrode-free space (210);

preferably, the first and second electrodes are formed of a metal,

-at least 75% of the electrically conductive line (400) is arranged on the electrode-free space (210) or below the electrode-free space (210).

8. The sensor (900) of any of claims 1 to 7,

-the electrically conductive line (400) comprises a width (W) of at most 200 [ mu ] m₄₀₀) The lines (401, 402);

preferably, the first and second electrodes are formed of a metal,

-the conductive line (400) consists of lines (401, 402) such that: at least 50% of the wire has a width (W) of at most 200 [ mu ] m₄₀₀）。

9. The sensor (900) of any of claims 1 to 8,

-the first stretchable electrode (301) comprises conductive particles, such as flakes or nanoparticles, attached to each other in a conductive manner;

preferably, the first and second electrodes are formed of a metal,

-the electrically conductive particles comprise at least one of carbon, copper, silver and gold.

10. The sensor (900) of any of claims 1 to 9,

-the flexible foil (500) comprises at least one of polyester, polyimide, polyethylene naphthalate and polyetheretherketone.

11. The sensor (900) of any of claims 1 to 9, comprising:

-at least one integrated circuit (700) attached to the electrically conductive line (400) in an electrically conductive manner, wherein,

-the integrated circuit (700) is configured to measure the capacitance of at least the first stretchable electrode (301).

12. The sensor (900) of any of claims 1 to 11, comprising:

-a plurality of stretchable electrodes (300) attached to the elastic and stretchable layer (050) such that

-each of the stretchable electrodes (300) is arranged at a distance (d) from all other of the stretchable electrodes (300)_1,i,j）；

Preferably

-said distance (d)_1,i,j) Is at least 1 mm.

13. The sensor (900) of any of claims 1 to 12,

-at least a portion of said first and/or said second conductive layer (600, 600a, 600 b) is made of a conductive ink, and/or

-said first and/or said second conductive layer (600, 600a, 600 b) comprises a conductive fabric, and/or

-said first and/or said second conductive layer (600, 600a, 600 b) comprises a conductive polymer.

14. The sensor of any one of claims 1 to 13,

-the cross-sectional area of the flexible foil (500) is at most half of the cross-sectional area of the elastic and stretchable layer (050).

15. A wearable article, such as an item of apparel, e.g. a shoe, an insole, a sock, a glove or a mitt, comprising a sensor (900) according to any of claims 1-14.

Technical Field

The present invention relates to force sensors. The present invention relates to a pressure sensor. The present invention relates to capacitive force and/or pressure sensors. The present invention relates to wearable capacitive force and/or pressure sensors.

Background

The concern for happiness has increased. This relates to personal well-being and health care. This has led to the creation of a number of personal and medical monitoring devices, such as sensors. Such sensors can be embedded in a garment, such as a glove, mitt, footwear, helmet, or the like. As regards the force or pressure sensor for the garment, it may be, for example, piezoresistive, piezoelectric, or capacitive. Capacitive force/pressure sensors typically involve only simply available materials.

In a capacitive sensor, the capacitance of an electrode is measured. The capacitance can be measured relative to the environment or relative to another electrode, such as a grounded electrode. There are generally two working principles: (1) the dielectric material near the electrodes (e.g., between two electrodes) changes, which changes the capacitance; and/or (2) the distance between two electrodes changes, which changes the capacitance between the electrodes. These principles are known to those skilled in the art.

For example, patent application DE102009055121 discloses a force sensor having a plurality of conductors and an elastic, non-conductive layer therebetween. By applying a force, the elastic non-conductive layer deforms, which results in a change in capacitance between the conductors (i.e., electrodes).

In such sensors, there are several related problems. For example, the area of the electrodes should be reasonably large in order to accurately measure the force. Furthermore, the measurement of the capacitance of an electrode should not affect the measurement of the capacitance of another electrode. In addition, it would be beneficial to be able to measure multiple capacitances in parallel, i.e., simultaneously or substantially simultaneously. For example, when monitoring the performance of a high jump athlete, it should be possible to measure the pressure distribution under the foot as a function of time at a moderately high sampling rate. Furthermore, the spatial resolution should be moderately high, whereby the number of electrodes should also be moderately high. Still further, the sensor should be comfortable to wear and mechanically reliable.

Disclosure of Invention

A force sensor and/or a pressure sensor having a good balance between the aforementioned aspects is disclosed. The force sensor and/or pressure sensor comprises one or more layers that are stretchable and elastic. The sensor also includes a stretchable electrode attached to the layer or one of the layers. The stretchability improves the comfort of the force sensor. However, it has been recognized that wiring (winding) of the electrodes poses a problem. On a stretchable layer, the stretchable line will have to be moderately wide because of the stretchable material available for such purpose. This poses a problem because the wide lines reduce the size of the electrodes, thereby only being able to measure local pressure, not total force. To solve this problem, the wiring for the electrodes is arranged on a flexible foil. In contrast to the electrodes, the lines on the foil need not be stretchable. The lines can be made significantly narrower and the electrodes correspondingly larger. More specifically, the invention is disclosed in claim 1.

In addition, when the line is arranged to extend mainly in the region between the electrodes, the measurement of one capacitance does not hinder the measurement of the other capacitance. This and other embodiments are disclosed in the dependent claims.

Drawings

Figure 1a illustrates an embodiment of a force and/or pressure sensor in a side view,

figure 1b shows a section 1b-1b of the force and/or pressure sensor of figure 1a in a bottom view,

figure 1c shows a section 1c-1c of the force and/or pressure sensor of figure 1a in a top view,

figure 1d shows the layers of the force and/or pressure sensor of figure 1a in a bottom view,

figure 1e shows an embodiment of a force and/or pressure sensor with stretchable electrodes attached to an elastic and stretchable layer 050 in a side view,

figure 2 shows in bottom view the stretchable layer and the stretchable electrode arranged thereon,

figure 3a shows in bottom view the stretchable layer and the stretchable electrode arranged thereon,

figure 3b shows in top view a flexible foil to be used with the stretchable electrode and the stretchable layer of figure 3a,

figure 3c shows the flex foil of figure 3b and the lines arranged on the flex foil in a top view,

figure 3d shows in top view another flexible foil that can be used with the stretchable electrode and the stretchable layer of figure 3a,

figure 4a shows in bottom view a stretchable layer and a stretchable printed electrode arranged thereon,

figure 4b shows in bottom view the stretchable layer and the stretchable textile electrode arranged thereon,

figure 4c shows the layers of the force and/or pressure sensor with stretchable textile electrodes and stretchable layers of figure 4b in a bottom view,

figure 5a shows an embodiment of a force and/or pressure sensor with a conductive layer in a side view,

figure 5b shows an embodiment of the force and/or pressure sensor with two conductive layers in a side view,

fig. 6a shows in bottom view a stretchable layer, shaped for an insole (insole),

figure 6b shows in top view a flexible foil to be used with the stretchable electrode and the stretchable layer of figure 6a,

fig. 6c shows in bottom view a stretchable layer, shaped for an insole,

figure 6d shows in top view a flexible foil to be used with the stretchable electrode and the stretchable layer of figure 6c,

figures 7 a-7 c illustrate in top view the elastically deformable layer of the force and/or pressure sensor,

FIGS. 7 d-7 f illustrate the elastically deformable layer of the force and/or pressure sensor in a side view, and

fig. 8 a-8 c show an embodiment of a force or pressure sensor with a thermoplastic support layer in a side view.

Detailed Description

The present invention relates to a sensor 900 suitable for use as a pressure and/or force sensor. The force or pressure sensor according to embodiments of the invention is relatively thin. That is, the thickness is less than the smaller of the length and the width. The shape of the sensor may be flat. Furthermore, the sensor is conformable, whereby in use its shape may be different from the shape when stored. For example, the sensor may be stored in a flat form, while when incorporated in, for example, a mitt, the shape may conform to the shape of the mitt. Embodiments are presented in a flat form; however, it should be understood that the sensor can be attached to an arbitrarily curved object.

Fig. 1a and 1e illustrate an embodiment of a force and/or pressure sensor 900 in a side view. In the figure, the direction Sz refers to the thickness direction of the force and/or pressure sensor 900. The other directions Sx and Sy are perpendicular to Sz and to each other. In this context, hereinafter, the force and/or pressure sensor 900 is referred to as force sensor 900, even for some embodiments of sensors adapted to measure pressure and in this way measure at least part of the force. This problem will be clarified hereinafter.

Referring to fig. 1e, an embodiment includes an elastic and stretchable layer 050. Referring to fig. 1a, an elastic and stretchable layer 050 can include an elastic layer 100 and a stretchable layer 200. The stretchable layer 200 is also elastic, at least to some extent.

The force sensor 900 of FIG. 1a includes an elastically deformable layer 100 (or is illustrated as100a in 5 b). In use, the layer deforms and, as a result, the capacitance of the electrode 300 changes. To ensure moderate deformation in use, the elastically deformable layer 100 (i.e., the material of the elastically deformable layer 100) has a third Young's modulus Y₁₀₀. For example, the material of the layer 100 may be selected such that, in typical use, the layer 100 is compressed by about 1 to 15%, such as up to 30%. Naturally, compression depends on pressure, which need not be spatially or temporally uniform. Typical pressures may be about 2 kPa to 1000 kPa, which may be induced by a person standing on one or both feet, possibly also taking a jump. Thus, the third Young's modulus Y₁₀₀May be, for example, at most 15MPa or at most 5 MPa. Further, the third Young's modulus Y₁₀₀May be, for example, at least 0.05MPa or at least 0.2 MPa. A large strain (caused by a small young's modulus) may cause the material of the elastically deformable layer 100 to creep in use. In the long term, this may deteriorate the measurement. In addition, small strains (caused by large young's modulus) are difficult to measure.

Thickness t of the elastically deformable layer 100₁₀₀It is not important. The stress applies strain (i.e., proportional deformation) to layer 100, and the strain affects a change in the capacitance of the electrode. In some applications, such as insoles, the thickness of the elastically deformable layer 100 may be, for example, from 1mm to 5mm in order to have a comfortable sensor that fits conventional footwear.

In an embodiment, the elastically deformable layer 100 includes at least one of: polyurethanes, polyethylenes, poly (ethylene-vinyl acetate), polyvinyl chloride, polyboronated polydimethylsiloxanes, polystyrene, acrylonitrile-butadiene-styrene, styrene-butadiene styrene, ethylene propylene rubber, neoprene, cork, latex, natural rubber, silicone, and thermoplastic elastomeric gels.

Some of these materials are marketed under the following trade names: plastazote, Evazote, Zotek, Poron, Pe-Lite (middle) armor, Spenco and Sorboothane ® armor.

The force sensor includes a stretchable layer 200. The layer 200 is stretchable so that it is in useIn use, to the shape of the object comprising the sensor. For example, if the mitt or insole includes a sensor, in use, the stretchable layer 200 may stretch to conform to the dynamic shape of the mitt or insole. In this way, stretchability improves the comfort of the sensor. However, for moderately simple stretching, the stretchable layer 200 (i.e., the material of the stretchable layer) has a relatively small first young's modulus Y₂₀₀. In an embodiment, the first Young's modulus Y₂₀₀Young's modulus Y less than 500 of the flex foil₅₀₀. However, in order to concentrate the deformation within the sensor primarily in the elastically deformable layer 100, in an embodiment, the third Young's modulus Y₁₀₀Less than the first Young's modulus Y₂₀₀. This improves the measurement accuracy, since the location of the compression is better controlled.

With respect to stretchability, the stretchable layer 200 (i.e., the material of the stretchable layer 200) has a moderately large first yield strain ε_y,200. In an embodiment, the first yield strain ε_y,200Is at least 10 percent. It has been found that this value is high enough for a force sensor that is comfortable in many applications. It has been found that this value is also sufficiently high from the viewpoint of mechanical reliability of the stretchable layer 200, since typical deformations are smaller than this value. In the alternative, the first yield strain ε_y,200May be at least 20 percent or at least 30 percent. Further, the stretchable layer 200 (i.e., the material of the stretchable layer) is electrically insulating. Throughout this description, an electrically insulating material refers to a material having a resistivity (i.e., resistivity) greater than 100 Ω m at a temperature of 20 ℃.

The stretchable layer 200 may be made of a suitable polymer film. The stretchable layer 200 may be made of a suitable fabric. In an embodiment, the stretchable layer 200 comprises a polymer film, such as a film of Thermoplastic Polyurethane (TPU). The TPU may include polyester-based TPU and/or polyether-based TPU. In an embodiment, the stretchable layer comprises a fabric, for example, a polyamide (such as nylon) or a polyester. The stretchable layer 200 may include a fabric and a film.

The force sensor includes attachment to the stretchable layer 200 or toAt least one first stretchable electrode 301 and a second stretchable electrode 302 of the elastic and stretchable layer 050. The individual stretchable electrodes are designated by reference numerals 301, 302, 303 …; and the stretchable electrode is generally referred to by reference numeral 300. The stretchable electrode 300 is made of a conductive material. Throughout this description, a conductive material refers to a material having a resistivity (i.e., resistivity) less than 1 Ω m at a temperature of 20 ℃. In order to electrically insulate the stretchable electrodes 300 from each other, the first stretchable electrode 301 is disposed at a distance d from the second stretchable electrode 302₁Here (see fig. 1 b). With respect to stretchability of the stretchable electrode 300, the stretchable electrode 300 has a second yield strain ∈_y,300In an embodiment, the second yield strain is at least 10 percent. It has been found that this value is sufficiently high for a force sensor that is conformable in many applications. Conformable sensors are comfortable to wear and mechanically reliable under variable loads. It has been found that this value is also sufficiently high from the mechanical reliability point of view of the stretchable electrode 300, since typical deformations are smaller than this value. In the alternative, the second yield strain ε_y,300May be at least 20 percent or at least 30 percent. Typically, the second yield strain ε_y,300Less than the first yield strain epsilon_y,200. Conventionally, the distance d between the first and second electrodes₁And the distance d between the electrodes i and j_1,i,jRefers to the distance between the closest points of the two electrodes, i.e., the minimum distance between the two electrodes.

In an embodiment, the stretchable electrodes (301, 302) or all stretchable electrodes 300 are made of conductive ink. In an embodiment, the stretchable electrodes (301, 302) or all stretchable electrodes are made of a conductive fabric or fiber. In an embodiment, the stretchable layer 200 comprises TPU, and the stretchable electrode 300 is made of conductive ink. In an embodiment, the stretchable layer 200 comprises a non-conductive fabric between the stretchable electrodes 300, and the stretchable electrodes 300, or at least some thereof, may have been made using a conductive fabric, such as polyamide or polyester coated with a metal such as silver. In the alternative or in addition, conductive ink may be used in conjunction with the fabric to form the stretchable electrode 300 or at least some of the stretchable electrodes.

The conductive ink and the fabric typically include conductive particles, such as flakes or nanoparticles, attached to each other. Thus, in an embodiment, the first stretchable electrode 301 comprises conductive particles, such as flakes or nanoparticles, attached to each other in a conductive manner. In a preferred embodiment, the conductive particles comprise at least one of carbon, copper, silver and gold.

Referring to fig. 4a, the first stretchable electrode 301 may be made of conductive ink, whereby the first stretchable electrode 301 is moderately uniform. Such stretchable electrodes are configured to detect changes in capacitance in approximately the same area as the area of the electrode. Thus, the active area A from which such stretchable electrode is configured to measure pressure₃₀₁(see fig. 1b and 4 a) is equal to the area of the stretchable electrode 301 itself. Herein, area refers to the area of a cross-section of the stretchable electrode onto a plane having a surface normal parallel to the direction of thickness of the sensor 900.

However, referring to figure 4b, the first stretchable electrode 301 may for example be stitched to an otherwise non-conductive layer 200, e.g. a textile layer. Thus, the stretchable electrode 301 may be made as a mesh of conductive yarns, such as metal coated polyamide or polyester. It should also be noted that such stretchable electrodes are configured to detect a change in capacitance in approximately the same area as the area bounded by the outer edge of the stretchable electrode (limit). Thus, the stretchable electrode is configured to have an effective area A from which a pressure is measured₃₀₁(FIG. 4 b) is equal to the area defined by the outer edge of the stretchable electrode 301; even though the area of the conductive yarn may be smaller. As an alternative to stitching, electrodes having the shape of a mesh can be printed with conductive ink. As is apparent, in both types of electrodes, the active area of the stretchable electrode is equal to the area defined by the outer edge of the stretchable electrode 301.

As known to those skilled in the art, the force (i.e., the total force) is the integral of the pressure over the surface on which the force acts. Therefore, in order to be able to measure exceptForces other than pressure (i.e., local pressure) (i.e., total force), preferably substantially the entire measurement area, should be covered with the stretchable electrode 300. Thus, the aforementioned distance d₁Should be small. On the other hand, if the distance d₁Too small, adjacent electrodes 300 may capacitively couple to each other, which may hamper the measurement.

Referring to fig. 3a, in an embodiment, each stretchable electrode i (301, 302, 303, …, 315, 316) is positioned at a distance d from each other stretchable electrode j (316, 301, 302, 303, …, 315)_1,i,jTo (3). In fig. 3a, only the distance d is shown_1,301,302And d_1,301,311. In an embodiment, the distance d_1,i,jIs at least 1mm, preferably at least 2 mm. Such a minimum distance improves the separation of the stretchable electrodes, resulting in less capacitive coupling between the electrodes. Thus, the interference caused by capacitive coupling during measurement will be reduced.

An alternative or additional way of characterizing the preferred configuration is that the distance between the electrode 300 and the other electrode closest to it should be reasonably small. This ensures that a large portion of the stretchable layer 200 is covered by the electrodes, which improves the accuracy for measuring the force. Which can utilize the distance d_1,i,jTo indicate. Given electrode i, electrode jm (i) is selected such that it is closest to electrode i. That is, for a given electrode i, jm (i) is the distance d that results for the given electrode i_1,i,jElectrode j of the minimum value of (3). As an example, in fig. 3a, electrode 302 is closest to electrode 301. Thus, jm (301) is equal to 302, and d_1,301,302Is equal to d_{1,301,jm(301)}. In a preferred electrode configuration, each two nearest electrodes are reasonably close to each other. More specifically, in the embodiment, d_1,i,jm(i)Is at most 15 mm, preferably at most 10 mm, or at most 5 mm. The maximum can be found by considering each electrode i in succession.

In an embodiment, the force sensor 900 includes at least fifteen stretchable electrodes 300 attached to the stretchable layer 200 (or layer 050). Further, each of the stretchable electrodes 300 is arranged to be in contact with the stretchable electrode300 are at a distance d from all other stretchable electrodes_1,i,j. Through said distance d_1,i,jThe number of stretchable electrodes electrically insulated from each other is related to the spatial accuracy of the sensor. The more electrodes 300 that are used, the better the spatial accuracy. In a preferred embodiment, for example, in the embodiment of fig. 6c, the number of stretchable electrodes is at least twenty, such as twenty-three.

Considering the area of the stretchable electrode 300 and referring to FIG. 1b, in an embodiment, the total effective cross-sectional area A of the stretchable electrode 300₃₀₀Is the total cross-sectional area A of the stretchable layer 200₂₀₀At least 50%, at least 70%, or at least 80%. Herein, the total effective cross-sectional area A of the stretchable electrode 300₃₀₀Refers to the sum of the active areas of the stretchable electrodes; for example, in fig. 1b, the sum of the active areas of the first stretchable electrode 301 and the second stretchable electrode 302. For the effective area, see above. As is apparent, the cross-sectional area is defined on a cross-sectional plane having a surface normal parallel to the direction of thickness of the sensor 900.

Referring to fig. 1a, in an embodiment, the stretchable layer 200 is disposed between the first stretchable electrode 301 and the elastically deformable layer 100. In typical applications, the sensor is more comfortable to use in cases where the elastically deformable layer 100 is in direct contact with the stretchable layer 200, i.e., the stretchable electrode 300 is not disposed between the elastically deformable layer 100 and the stretchable layer 200.

As indicated in fig. 1e, in an embodiment, the elastic and stretchable layer 050 is used for both stretchable layer 200 and elastic layer 100 purposes. Those already described with respect to the stretchable layer 200 with respect to the stretchable electrode 300 also apply to the stretchable electrode 300 with respect to the elastic and stretchable layer 050. Further, the stretchability of the stretchable layer 200 (particularly its first yield strain ∈ has been referred to_y,200) Those described are also applicable to the elastic and stretchable layer 050. In addition, those already mentioned in relation to the electrical conductivity of the stretchable layer 200 also apply to the elastic and stretchable layer 050. Still further, those already described with respect to the elasticity of the elastically deformable layer 100 (particularly its Young's modulus) also apply to the elasticity and mayStretched layer 050. Thus, the Young's modulus Y of the elastic and stretchable layer 050₀₅₀May be within the limitations discussed above for layer 100. Still further, reference has been made to the thickness t of the elastically deformable layer 100₁₀₀Direction or thickness t of₁₀₀Those described (or those which will be described) apply to the thickness t of the elastically stretchable layer 050₀₅₀And a thickness t₀₅₀In the direction of (a).

Referring to fig. 1a and 1c, the force sensor 900 further comprises a sensor having a second young's modulus Y₅₀₀The flexible foil 500; and conductive traces 400 attached to the flex foil 500. First Young's modulus Y (of stretchable layer 200)₂₀₀Less than the second Young's modulus Y₅₀₀. In this way, the flexible foil 500 is more resistant to deformation than the stretchable layer 200.

Regarding the difference between the first Young's modulus and the second Young's modulus, the first Young's modulus Y₂₀₀May for example be lower than the second Young's modulus Y₅₀₀At least 25%, at least 50%, or at least 75% less.

The difference between the young's moduli has the effect that, in use, the tensile strain in the flexible foil 500 is small, whereby the wire 400 attached to the flexible foil 500 need not be stretchable. This has the further effect that the lines 400 can be made much narrower than if the lines 400 were stretchable. For example, in an embodiment, electrically conductive trace 400 includes a width W of at most 200 μm or at most 150 μm₄₀₀The lines (401, 402). More preferably, the conductive line 400 comprises such lines (401, 402): at least 50% or at least 60% of the lines (401, 402) have a width W of at most 200 [ mu ] m or at most 150 [ mu ] m₄₀₀. In this context, the ratio with a given width is given along the length direction. Thus, for example, in case the total length of the wires is 1000 mm, for example, at least 500 mm of the wires may have a width of at most 200 μm.

As known to those skilled in the art, the flexibility of a foil is inversely proportional to the third power of the thickness of the foil. Therefore, the flexible foil should be thin enough to ensure its flexibility in use. In an embodiment, the thickness t of the flexible foil 500₅₀₀Is at most 0.5 mm. Thickness t of the flexible foil 500₅₀₀May be for example less than 0.4 mm. In an embodiment, the flexible foil comprises at least one of polyester, polyimide, polyethylene naphthalate (polyethylene naphthalate), and polyetheretherketone.

Furthermore, in order to have a comfortable sensor 900, it is preferred that a majority of the sensor 900 is stretchable or at least feels stretchable. Conversely, the flexible foil 500, which may be a non-stretchable foil 500 in the aforementioned sense (sense), may be small compared to the stretchable layer 200. Thus, in an embodiment, the cross-sectional area of the flexible foil 500 is at most half the cross-sectional area of the stretchable layer 200. Herein, the cross-sectional area refers to the area of the cross-section on a plane having a surface normal parallel to the direction of the thickness of the sensor 900. In some of these embodiments, the cross-sectional area of the flexible foil 500 is at most one third or at most one quarter of the cross-sectional area of the stretchable layer 200. Such embodiments are depicted, for example, in fig. 1d, 3d and 6 d.

In the force sensor 900, at least a portion of the conductive trace 400 is conductively coupled to the first stretchable electrode 301; and at least a portion of conductive trace 400 is conductively coupled to second stretchable electrode 302. In this manner, the sensor 900 includes a connection 490 between the wire 400 and the stretchable electrode 300. The connection is electrically conductive. The connection portion 490 may be made such that the resistivity of the connection portion is at most 10 Ω. Additionally or alternatively, in the foregoing sense, the material of the connection portion 490 may be electrically conductive.

In an embodiment, the connection portion 490 is made of a conductive adhesive, i.e., includes a cured conductive adhesive. Such adhesives include isotropic conductive adhesives and anisotropic conductive adhesives. The connection portion 490 may be formed using a conductive tape such as an anisotropic conductive adhesive. The conductive adhesive typically includes nickel, graphite, or silver particles mixed in a matrix material. The matrix material may be a cured polymer formed by polymerization of the resin of the binder during curing thereof. The resin may be an epoxy resin. Examples of such adhesives are known under the names LOCTITE adhesive CA3150 and Hysol ecobond CA 3150. Additionally, the connection 490 may be plated, whereby the connection may include some solder, wherein the solder may include tin. Commonly available solders include tin-lead, tin-copper-silver, and tin-zinc-copper solder alloys.

As indicated in fig. 3c and 4c, the line 400 comprises lines 401, 402, 403, …, 416. The wires 401, 402, 403, …, 416 are electrically insulated from each other. Further, for each stretchable electrode, at least one wire is conductively coupled thereto. For example, in an embodiment, at least a portion of the conductive trace 400, such as the line 401, is coupled to the first stretchable electrode 301 with a conductive connection 490. In an embodiment, at least a portion of the conductive trace 400, such as line 402, is coupled to the second stretchable electrode 302 with a conductive connection 490.

In addition, typically, the wire is conductively coupled to only one stretchable electrode. This serves to improve the spatial resolution of the sensor, i.e. each stretchable electrode can be used to measure a force or pressure substantially only at the location of the stretchable electrode.

The wire connected to the electrode overlaps (overlap) the stretchable electrode to which it is connected. In this context, the term "overlap" means that the area defined by the boundary of the stretchable electrode comprises at least one protrusion of a wire that protrudes onto the area in the direction of the thickness of the sensor 900. Furthermore, preferably, each line overlaps only one electrode. This ensures that measurements using the first stretchable electrode 301 do not interfere with measurements using the second stretchable electrode 302.

Additionally or alternatively, in embodiments, at least some of the lines 400 are arranged so as not to overlap any stretchable electrodes 300. For example, in an embodiment, up to 25% (percentage measured in the length direction, see above) of the line 400 is arranged to overlap (in the sense described above) the stretchable electrode 300. Accordingly, electrode-free spaces 210 (see fig. 1 b) are left on the stretchable layer 200 outside all such stretchable electrodes (300, 301, 302, 303, 304, 305, 306) attached to the stretchable layer 200. In an embodiment, at least some of the electrically conductive traces 400 are arranged to overlap the electrode-free spaces 210. Thus, the electrode-free space 210 includes at least some of the protrusions of the line 400, which protrude onto the electrode-free space 210 in the direction of the thickness of the sensor 900. In other words, at least some of the conductive lines 400 are disposed on or under the electrode-free spaces 210. As indicated above, in an embodiment, at least 75% of the electrically conductive line 400 is arranged to overlap the electrode-free space 210. This also reduces the hindrance of the measurement using the first stretchable electrode 301 to the measurement using the second stretchable electrode 302.

Further, in an embodiment, at least some of the lines 400 are arranged at a central region of the sensor 900. Preferably, a majority of the line 400 is disposed at a central region of the sensor 900. This has two effects. First, it has been found that in typical use, the boundaries of the sensor are exposed to the highest mechanical strain, particularly in a direction other than thickness. Accordingly, such strain is lower at the center. Applying the foil 500 and the lines to the central area improves the mechanical reliability of the sensor 900, since the flexible foil 500 is hardly stretchable. Second, in this manner, the sensor 900 can be cut to shape (cut to shape). In particular, the boundaries of the sensor 900 can be cut without affecting the functionality of the sensor 900. In this manner, a similar sensor 900 can be produced and can be cut to shape as desired. For example, one-size (i.e., large) insoles of the same size can be created and can be cut to fit the user's footwear. Thus, in an embodiment, at least 90% of the conductive traces 400 are disposed a second distance d from the boundary of the stretchable layer 200₂(see FIG. 1 d). In an embodiment, the second distance d₂Is the length L of the stretchable layer 200₂₀₀And width W₂₀₀At least 5% of the smaller. In an embodiment, the second distance d₂Is at least 5 mm. In an embodiment, at least 95% of the conductive traces 400 are disposed a second distance d from a boundary of the stretchable layer 200₂。

An alternative way of describing the preferred arrangement of the lines is to consider the configuration of the stretchable electrode 300. Referring to fig. 4a and 4b, all stretchable electrodes 300 are arranged within a convex region of a plane having a surface normal parallel to the direction of the thickness of the sensor 900. In fig. 4a and 4b, the smallest of such convex regions including all stretchable electrodes 300 is denoted by reference numeral 390. In the figure, only the boundaries of such regions are shown. Conventionally, the term "convex region" refers to a portion of a plane where a line segment connecting any two points of the portion of the plane is completely contained within the portion of the plane. In some embodiments, such a minimum convex region is included by the stretchable layer 200. However, if the shape of the stretchable layer 200 is not convex, it is possible that the minimum convex region is not included by the stretchable layer 200. This is the case, for example, in fig. 6 c. In an embodiment, at least 90% or at least 95% of the traces 400 overlap the smallest convex region 390 that includes all of the stretchable electrodes 300.

In FIG. 1b, p is₄₀₁Indicating the location to which the line 401 is attached. Such a location may be referred to as a contact location. In a corresponding manner, from p₄₀₂Indicating the location to which line 402 is attached. The line 400 may comprise a pad arranged to be connected to the contact location p₄₀₁、p₄₀₂. A similar situation is also shown in fig. 2 and 3 a. Contact position p₄₀₁、p₄₀₂The location of … is optimized so that the length of the line 400 will be minimized. In this way, the resistance of the line 400 is also small. As indicated in fig. 1d, the wire 401 is attached to the contact position p₄₀₁And wire 402 is attached to contact location p₄₀₂。

In the force sensor 900, the stretchable layer 200, the first and second stretchable electrodes 301, 302, the flexible foil 500 and the electrically conductive line 400 are left on the same side of the elastically deformable layer 100. This facilitates manufacturability of the force sensor.

Referring to fig. 1c, 1d and 4c, an embodiment of a force sensor 900 includes at least one integrated circuit 700 that is conductively attached to a conductive trace 400. With respect to fig. 1d and 4c, it should be noted that in these figures the lines 400 and the circuitry 700 are left underneath the flex foil 500. However, for purposes of clarity, the circuit 400 and the circuit 700 are shown in the figure. In fig. 1b and 1c, the views (top or bottom) are chosen such that the conductive substances (400, 300) are on top of the respective substrates (500, 200, respectively).

Further, embodiments of force sensor 900 include a battery configured to supply power to integrated circuit 700. Preferably, the battery is rechargeable. The integrated circuit 700 is configured to measure a capacitance of at least one of the stretchable electrodes 300. Preferably, the integrated circuit 700 is configured to measure the capacitance of each of the stretchable electrodes 300 individually. In an embodiment, the integrated circuit 700 is configured to send the measurement results to an external control unit. In an embodiment, the integrated circuit 700 is configured to wirelessly send the measurement results to an external control unit. This allows the measurement data to be analyzed in real time. In an embodiment, the integrated circuit 700 is configured to store the measurement results to a memory of the force sensor 900, such as a memory of the integrated circuit 700. This allows the measurement data to be analyzed at least after the measurement.

In an embodiment, integrated circuit 700 is configured to receive data from another force sensor. Further, in an embodiment, the integrated circuit 700 is configured to transmit (i.e., transceive) such data to another external control unit. In this way, a plurality of force sensors can send measurement data to the external control unit via the other sensors.

With the sensor structure as discussed above, it is possible to measure the capacitance of the stretchable electrode 300 with respect to something. The capacitance can be measured relative to the other stretchable electrode 300. For example, all other stretchable electrodes 300 may form a common ground against which capacitance may be measured. Thus, subsequently, the capacitance of all stretchable electrodes 300 can be measured. However, this reduces the sampling rate. It is also possible to measure the capacitance with respect to the environment. However, this does not give accurate results.

Thus, referring to fig. 5a, a preferred embodiment of sensor 900 includes a first conductive layer 600 (or 600 a). An elastic and stretchable layer 050 is arranged between the electrode 300 and the first conductive layer 600. When the elastic and stretchable layer 050 includes the elastically deformable layer 100 and the stretchable layer 200, the elastically deformable layer 100 is disposed between the first conductive layer 600 and the stretchable layer 200. In this manner, the first conductive layer 600 may serve as a ground electrode against which the capacitance of each of the stretchable electrodes 300 is measured. In this configuration, compression of the elastically deformable layer 100 affects the distance between the two electrodes (i.e., the first conductive layer 600 and the stretchable electrode 300, such as the first stretchable electrode 301). As known to those skilled in the art, the capacitance of such a capacitor formed by the two electrodes is inversely proportional to the distance between the electrodes. By measuring the capacitance, the distance between the electrodes can be calculated. From this distance, the strain within the elastically deformable layer 100 can be determined. Because the material of the layer 100 is known, strain defines the stress (i.e., pressure) within the deformable layer 100. In this manner, the pressure at each stretchable electrode can be determined. Furthermore, since the effective area of the stretchable electrode is known, the force acting at the stretchable electrode can be determined. Finally, the total force can be measured with the electrodes covering substantially the entire cross-sectional area of the sensor.

With respect to the material of the first conductive layer 600 (or 600a), the first conductive layer 600 may include at least one of:

-a conductive material made of a conductive ink,

-an electrically conductive fabric, and

-a conductive polymer.

The conductive polymer may be a film made of a polymer. In some embodiments, the first conductive layer 600 includes conductive particles, such as flakes or nanoparticles, that are conductively attached to each other. In some of these embodiments, the conductive particles comprise at least one of carbon, copper, silver, and gold.

It has also been found that humidity (or water) may affect the measurement results. Moderately common (accessible common), wearable sensors are used in such a way that sweat introduces moisture to the sensor 900. In particular, when moisture is near the electrode 300, the moisture may significantly affect the measurement.

Referring to fig. 5b, to prevent problems associated with excessive moisture, embodiments of the force sensor 900 include an additional elastically deformable layer 100b and a second conductive layer 600 b. The additional elastically deformable layer 100b is disposed between the second conductive layer 600b and the stretchable layer 200. Further, at least a portion of the stretchable layer 200 is disposed between the elastically deformable layer 100 and the additional elastically deformable layer 100 b. Thus, at least a portion of the stretchable layer 200 is disposed between the first conductive layer 600a and the second conductive layer 600 b. In an embodiment, at least the first stretchable electrode 301 is disposed between the first conductive layer 600a and the second conductive layer 600 b. In an embodiment, all stretchable electrodes 300 are disposed between the first conductive layer 600a and the second conductive layer 600 b.

Those already described with respect to the material of the first conductive layer (600, 600a) apply to the material of the second conductive layer 600 b. Those already mentioned in relation to the material of the elastically deformable layers 100, 100a apply to the additional elastically deformable layer 100 b.

A problem associated with such sensors is the choice of materials for the elastically deformable layers 100, 100a and/or the additional elastically deformable layer 100 b. As indicated above, the young's modulus of the layer should be reasonably small. However, many materials that are soft and/or have a small young's modulus are known to creep. On the other hand, creep is not preferred, as permanent compression of the elastically deformable layer 100, 100a, 100b will affect the measurement results.

Referring to fig. 7a to 7c, to address this problem, in an embodiment the elastically deformable layer 100, 100a defines an aperture 110, the aperture 110 being along a thickness t of the elastically deformable layer 100₁₀₀Extend in the direction of (a). Such holes 110 actually make the material softer. Thus, by having the apertures 110, it is possible to use stiffer materials and/or materials with higher Young's modulus. Such materials generally creep significantly less than softer materials. The effect of the apertures 110 is simply to reduce the area of the portion of the elastically deformable layer 100 that includes the deformable solid material. Similar forces generate higher stresses as the area decreases. Even if not explicitly shown, in the alternative or in addition, an additional elastically deformableThe layer 100b may define a corresponding aperture.

Preferably, the total cross-sectional area A of the apertures 110₁₁₀Cross-sectional area A of the elastically deformable layer 100₁₀₀At least 5% or at least 10%. Herein, a cross section refers to a cross section on a plane having a surface normal parallel to the direction of thickness. Further, the total cross-sectional area A of the holes 110₁₁₀Refers to the sum of the cross-sectional areas of the individual holes 110. Further, the cross-sectional area A of the elastically deformable layer 100₁₀₀Refers to the area of the cross-section defined by the outer boundaries of the elastically deformable layer 100. Thus, the cross-sectional area A of the elastically deformable layer 100₁₀₀From the total cross-sectional area A of the hole 110₁₁₀And the area of the portion of the elastically deformable layer 100 that includes the deformable solid-state material of the deformable layer 100. However, it is possible that only a small portion of the elastically deformable layer 100 defines an aperture, whereby the total cross-sectional area A of the aperture 110₁₁₀May be small.

In an embodiment, at least some of the apertures 110 extend through the elastically deformable layer 100, 100a from the first side 102, 102a (see fig. 5a and 5 b) of the elastically deformable layer 100, 100a to the second side 104, 104a of the elastically deformable layer 100. In addition to softening, such through-holes may improve ventilation of the sensor 900. In case the sensor 900 comprises an additional elastically deformable layer 100b, in an embodiment at least some of the apertures extend from the first side 102b (see fig. 5 b) of the additional elastically deformable layer 100b, through the additional elastically deformable layer 100b to the second side 104b of the additional elastically deformable layer 100 b.

Referring to fig. 7 a-7 c, and in particular fig. 7b and 7c, the apertures 110 can be used to manipulate the local effective stiffness of the elastically deformable layer 100. By using apertures, one zone can be made softer than the other zone, even if the same material is used in both zones. Accordingly, in areas where the load (force or pressure) is known to be small, a large number of holes can be made to significantly soften the material. A large number of holes refers to the total cross-sectional area of the holes being proportional to the respective zones of the deformable layer 100 (in contribution to). By increasing the size and/or number of holes, the material can be made softer. Fig. 7b indicates stiffer and softer zones formed by the holes 110, wherein the holes are of the same size but differ in number density. Fig. 7b indicates stiffer and softer zones formed by the holes 110, wherein the size of the holes and their number density differ. Naturally, it will be possible to influence only the size of the holes.

In FIGS. 7B and 7c, the elastically deformable layer 100 includes a first floor belt 100A and a second floor belt 100B. The second zone 100B does not include portions of the first zone 100A. The first zone 100A defines a thickness t along the elastically deformable layer 100₁₀₀A first hole 110A extending in the direction of (a). Total cross-sectional area A of the first hole_110ACross-sectional area A of the first land 100A_100AFirst part (part) (A)_110A/A_100A). Furthermore, the second floor strip 100B defines a thickness t along the elastically deformable layer 100₁₀₀In the direction of (a) and (B). Total cross-sectional area A of the second hole_110BA cross-sectional area A constituting the second floor area 100B_100BSecond part (A) of_110B/A_100B). In order to have the aforementioned effect of softening the material differently at different points, the first portion (A)_110A/A_100A) Different from the second part (A)_110B/A_100B). For example, in part (A)_110A/A_100A) And (A)_110B/A_100B) The difference between may be at least 25 percentage points.

Furthermore, the stiffness of the layer 100 may be manipulated, in particular at the locations where the stretchable electrodes are arranged. Thus, in an embodiment, the area surrounded by the outer edge of the stretchable electrode 300 comprises at least a portion of the protrusion (projection) of the aperture 110, wherein the protrusion of the aperture 110 protrudes onto the area in the direction of the thickness of the sensor 900. In an embodiment, the area surrounded by the outer edge of the stretchable electrode 300 comprises a protrusion of the aperture 110. In an embodiment, the area surrounded by the outer edge of the stretchable electrode 300 comprises a protrusion of the plurality of holes 110. In an embodiment, the zones 100A, 100B, 100C include at least portions of the stretchable electrode 300. Further, preferably, the zones 100A, 100B, 100C comprise stretchable electrodes 300.

It should also be noted that the manipulation of softness may be more effective when the number of first apertures 110A and second apertures 110B is significant (significant). For example, the number of first apertures 110A in the first zone 100A may be at least ten or at least fifty. For example, the number of second apertures 110B in the second zone 100B may be at least ten or at least fifty. In addition, the first zone 100A or the second zone 100B is not arbitrarily large. In an embodiment, the first zone 100A is the smallest convex area surrounding all the first apertures 110A. In an embodiment, the second zone 100B is the smallest convex area surrounding all of the second apertures 110B. In an embodiment, the first and second zones 100A and 100B constitute the elastically deformable layer 100.

However, as indicated in fig. 7B and 7C, the elastically deformable layer 100 may comprise the third zone 100C such that the third zone 100C does not comprise a portion of the second zone 100B or a portion of the first zone 100A. The third zone 100C defines a thickness t along the elastically deformable layer 100₁₀₀A third hole 110C extending in the direction of (a). Total cross-sectional area A of the third bore_110CCross-sectional area A constituting third zone 100C_100CFirst part (A) of_110C/A_100C). Furthermore, the third part (A)_110C/A_100C) With the first part (A)_110A/A_100A) And a second part (A)_110B/A_100B) Different. In an embodiment, the first, second and third belts 100A, 100B, 100C constitute the elastically deformable layer 100.

Referring to fig. 7d to 7f, in addition to or instead of the apertures 110, the material of the deformable, elastically deformable layer 100, 100a can be softened by applying a layer of softer material 160 as part of the elastically deformable layer 100, 100 a. The softer layer 160 may be arranged, for example, between two harder layers 150, as indicated in fig. 7 d. Furthermore, as indicated in fig. 7e and 7f, the harder material 150 may comprise holes 110, which holes 110 have been filled with the softer material 160. As indicated above, the holes 110 do not need to be filled.

Even if not shown in the figures, it is possible, in addition or alternatively, to soften the additional elastically deformable layer 100b in a similar manner.

Further, referring to fig. 1e, in an embodiment, the elastic and stretchable layer 050 comprises layers of only one material. Those already mentioned in relation to manipulating the stiffness of the elastically deformable layer 100 are also applicable to the elastic and stretchable layer 050. The apertures 110 may extend in the direction of the thickness of the elastic and stretchable layer 050. Apertures 110 may extend in a direction of a thickness of elastic and stretchable layer 050 from one side of elastic and stretchable layer 050 to an opposite side of elastic and stretchable layer 050.

In addition to measurement, embodiments of the sensor may also be used to support a user. Such support may also improve comfort. Referring to fig. 8 a-8 b, an embodiment of a sensor 900 includes a support layer 650. Such supports are generally comfortable if they have been shaped to follow the body part in use. However, the shape of the body part may vary from one user to another.

To shape the support layer 650 as desired, the support layer 650 comprises a thermoplastic material. Above the deflection temperature (deflectiontemperature), the thermoplastic material becomes deformable and recovers its stiffness upon cooling. In this way, the support layer may be heated above the deflection temperature. When heated, the support layer 650 may deform into a shape, e.g., deform into a shape that conforms to a body part of a user, such as a shape that conforms to a foot. Upon cooling, the support layer 650 regains its stiffness and may serve as a support for the user. In this way, the support can be personalized.

The deflection temperature of the thermoplastic material of the support layer 650 should not be too low in order to have a supporting effect also when in use; particularly when in use, has a supporting effect when in contact with a body part. Furthermore, the deflection temperature of the thermoplastic material of the support layer 650 should not be too high, since the sensor 900 comprises electrical contacts, which are vulnerable to heat. Preferably, the deflection temperature is from 60 ℃ to 120 ℃. Further, in order to have a moderately supportive layer 650, the thickness of the support layer 650 should be at least 0.2 mm, such as from 0.2 mm to 2 mm. Here, the thickness refers to an average thickness.

In an embodiment, the support layer 650 includes at least one of polycarbonate, polyvinyl chloride, acrylic resin (e.g., styrene-acrylonitrile copolymer, acrylonitrile styrene acrylate), polymethylmethacrylate, polyethylene terephthalate, and glycol-modified polyethylene terephthalate. The support layer 650 may also include reinforcing fibers from the group including carbon fibers, glass fibers, and aramid fibers.

The support layer 650 may be arranged such that, in use, the resiliently deformable layer (100, 100 a) or the additional resiliently deformable layer 100b is arranged to be left between the point at which the sensed force acts and the support layer 650. For example, the sensors of fig. 8a to 8c are configured to be used: such that the sensed force acts at a point on top of the first conductive layer 600 or 600 a. Thus, the elastic layer 100, 100a is left between the support 650 and such a point.

As indicated above, the force sensor 900 may be included in a wearable article, such as apparel. Accordingly, an embodiment of the present invention is a wearable article comprising the force sensor 900 as disclosed above.

Examples of wearable articles include:

an item to be worn on the foot, such as footwear, an insole, or a sock,

-an article worn on a hand, such as a glove, mitt or mitt; in particular sports apparel such as boxing gloves, golf gloves or the like; and

trousers (troussers) and trousers (pans).

Furthermore, sensors may be used in smart furniture such as:

-a vehicle seat having a seat body,

-a seat, a sofa,

-sheet, blanket, mattress, and

-floor mats (rug) and carpets.

However, because of the stretchable layer 200, the sensor 900 is best suited for such applications: wherein the sensor deforms in use.

The sensor is particularly suitable for use in an insole 910 suitable for footwear. In such a case, the shape of the insole 910 is adapted to the shape of the footwear. In addition, the insole 910 includes the force sensor 900 as discussed above.

The following examples outline some embodiments:

example 1. a sensor (900), the sensor comprising:

-an elastic and stretchable layer (050, 100, 200) comprising a layer (200) or an inclusion layer (050), said layer (200) or said layer (050) having a first young's modulus (Y)₂₀₀) And first yield strain (. epsilon.)_y,200），

-at least a first stretchable electrode (301) and a second stretchable electrode (302) attached to the elastic and stretchable layer (050, 100, 200) and arranged at a first distance (d) from each other₁、d_1,301,302），

-has a second Young's modulus (Y)₅₀₀) A flexible foil (500), and

-a conductive line (400) attached to the flexible foil (500),

wherein the content of the first and second substances,

-at least a portion of the conductive line (400) is conductively coupled to the first stretchable electrode (301),

-at least a portion of the conductive line (400) is conductively coupled to the second stretchable electrode (302),

-said first yield strain (ε)_y,200) Is at least 10 percent of the total weight of the composition,

-said first Young's modulus (Y)₂₀₀) Less than said second Young's modulus (Y)₅₀₀），

-a thickness (t) of the flexible foil (500)₅₀₀) Is at most 0.5mm, and

-the total effective cross-sectional area (A) of the stretchable electrode₃₀₀) Is said elastic and stretchableOf the layers (050, 100, 200) is characterized by a total cross-sectional area (A)₂₀₀) At least 50% of the total weight of the composition.

Example 2. the sensor (900) of example 1, wherein,

-the elastic and stretchable layer (050) comprises an elastically deformable layer (100) and a stretchable layer (200) in the following manner:

such that the stretchable layer (200), the first and second stretchable electrodes (301, 302), the flexible foil (500) and the electrically conductive line (400) are left on the same side of the elastically deformable layer (100).

Example 3. the sensor (900) of example 2, wherein,

-the stretchable layer (200) is arranged between the first stretchable electrode (301) and the elastically deformable layer (100).

Example 4. the sensor (900) of example 2 or 3, wherein,

-said elastically deformable layer (100) having a Young's modulus (Y)₁₀₀) Less than the first Young's modulus (Y)₂₀₀）。

Example 5. the sensor (900) of any of examples 2 to 4, wherein,

-the stretchable layer (200) comprises one of a Thermoplastic Polyurethane (TPU), a polyamide and a polyester.

Example 6. the sensor (900) of any of examples 1 to 5, wherein,

-the elastic and stretchable layer (050, 100, 200), such as an elastic and deformable layer (100) of the elastic and stretchable layer, comprising at least one of: polyurethanes, polyethylenes, poly (ethylene-vinyl acetate), polyvinyl chloride, boronated polydimethylsiloxanes, polystyrene, acrylonitrile-butadiene-styrene, styrene-butadiene styrene, ethylene propylene rubber, neoprene, cork, latex, natural rubber, silicone, and thermoplastic elastomeric gels.

Example 7. the sensor (900) of any of examples 1 to 6, wherein,

-leaving an electrode-free space (210) on the elastic and stretchable layer (050, 100, 200), the electrode-free space being outside all stretchable electrodes (300, 301, 302, 303, 304, 305, 306) attached to the elastic and stretchable layer (050, 100, 200), and

-at least some of the electrically conductive lines (400) are arranged on the electrode-free space (210) or below the electrode-free space (210);

preferably, the first and second electrodes are formed of a metal,

-at least 75% of the electrically conductive line (400) is arranged on the electrode-free space (210) or below the electrode-free space (210).

Example 8 the sensor (900) of any of examples 1 to 7, wherein,

-the electrically conductive line (400) comprises a width (W) of at most 200 [ mu ] m₄₀₀) The lines (401, 402);

preferably, the first and second electrodes are formed of a metal,

-the conductive line (400) comprises such lines (401, 402): at least 50% of the wire has a width (W) of at most 200 [ mu ] m₄₀₀）。

Example 9. the sensor (900) of any of examples 1 to 8, wherein,

-the first stretchable electrode (301) comprises conductive particles, such as flakes or nanoparticles, attached to each other in a conductive manner;

preferably, the first and second electrodes are formed of a metal,

-the electrically conductive particles comprise at least one of carbon, copper, silver and gold.

Example 10 the sensor (900) of any of examples 1 to 9, wherein,

-the flexible foil (500) comprises at least one of polyester, polyimide, polyethylene naphthalate and polyetheretherketone.

Example 11 the sensor (900) of any of examples 1 to 10, wherein,

-the total effective cross-sectional area (A) of the stretchable electrode₃₀₀) Is the stretchable layer(200) Total cross-sectional area (A)₂₀₀) At least 50% of the total weight of the composition.

Example 12. the sensor (900) of any of examples 1 to 11, comprising:

-at least one integrated circuit (700) attached to the electrically conductive line (400) in an electrically conductive manner, wherein,

-the integrated circuit (700) is configured to measure the capacitance of at least the first stretchable electrode (301).

Example 13. the sensor (900) of any of examples 1 to 12, wherein,

-at least 90% of the conductive tracks (400) are arranged on top of a minimum convex area (390) comprising all the stretchable electrodes (300) or below the minimum convex area (390).

Example 14. the sensor (900) of any of examples 1 to 13, wherein,

-at least 90% of the conductive line (400) is arranged at a second distance (d) from the boundaries of the elastic and stretchable layer (050, 100, 200)₂) In the process, wherein,

-said second distance (d)₂) Is the length (L) of the elastic and stretchable layer (050, 100, 200)₂₀₀) And width (W)₂₀₀) At least 5% of the smaller.

Example 15. the sensor (900) of any of examples 1 to 14, comprising:

-a plurality of stretchable electrodes (300) attached to the elastic and stretchable layer (050, 100, 200) such that

-each of the stretchable electrodes (300) is arranged at a distance (d) from all other of the stretchable electrodes (300)_1,i,j）；

Preferably

-said distance (d)_1,i,j) Is at least 1 mm.

Example 16. the sensor (900) of any of examples 1 to 15, comprising:

a connection portion (490) electrically connecting the stretchable electrode (300) to the line (400), wherein,

-at least one of said connections (490) comprises an electrically conductive adhesive or solder.

Example 17 the sensor (900) of any of examples 1 to 16, wherein,

-the elastic and stretchable layer (050, 100, 200) defining an aperture (110), the aperture (110) being along a thickness (t) of the elastic and stretchable layer (050, 100, 200)₀₅₀、t₁₀₀) Extend in the direction of (a);

preferably, the first and second electrodes are formed of a metal,

-the total cross-sectional area (A) of the holes (110)₁₁₀) A cross-sectional area (A) constituting the elastic and stretchable layer (050, 100, 200)₁₀₀) At least 5% of, and/or

-at least some of the apertures (110) extend through the elastic and stretchable layer (050, 100, 200) from a first side of the elastic and stretchable layer (050, 100, 200) to a second side of the elastic and stretchable layer (050, 100, 200), and/or

-the elastic and stretchable layer (050, 100, 200) comprises an elastically deformable layer (100), and

-at least some of the apertures (110) extend through the elastically deformable layer (100) from a first side (102) of the elastically deformable layer (100) to a second side (104) of the elastically deformable layer (100).

Example 18. the sensor (900) of example 17, wherein,

-the elastic and stretchable layer (050, 100, 200) comprises a first zone (100A) and a second zone (100B), the second zone (100B) not comprising a portion of the first zone (100A),

-the first zone (100A) delimits a first hole (110A), the first hole (110A) being along the elastically deformable layer(100) Thickness (t) of₀₅₀、t₁₀₀) Such that the total cross-sectional area (A) of said first holes_110A) A cross-sectional area (A) constituting the first zone (100A)_100A) First part (A) of_110A/A_100A) And is and

-the second floor strip (100B) defining a second aperture (110B), the second aperture (110B) being along a thickness (t) of the elastically deformable layer (100)₀₅₀、t₁₀₀) Such that the total cross-sectional area (A) of said second holes_110B) A cross-sectional area (A) constituting the second zone (100B)_100B) Second part (A) of_110B/A_100B) Wherein, in the step (A),

-said first portion (A)_110A/A_100A) And the second part (A)_110B/A_100B) Different.

Example 19. the sensor (900) of examples 1 to 18, comprising:

-an additional elastically deformable layer (100 b) such that,

-the first stretchable electrode (301) and the second stretchable electrode (302) are arranged between the elastic and stretchable layer (050, 100, 200) and the additional elastically deformable layer (100 b).

Example 20. the sensor (900) of example 19, wherein,

-the elastic and stretchable layer (050) comprises an elastically deformable layer (100) and a stretchable layer (200) in the following manner:

such that the first stretchable electrode (301) and the second stretchable electrode (302) are arranged between the elastically deformable layer (100) and the additional elastically deformable layer (100 b).

Example 21. the sensor (900) of any of examples 1 to 20, comprising:

-a first electrically conductive layer (600, 600a) such that

-the elastic and stretchable layer (100) is arranged between the first electrically conductive layer (600, 600a) and the first stretchable electrode (301) in the direction of the thickness of the sensor (900).

Example 22. the sensor (900) of example 21, comprising:

-an additional elastically deformable layer (100 b), and

-a second electrically conductive layer (600 b) such that

-the first conductive layer (600, 600a) and the second conductive layer (600 b) are left on opposite sides of the first stretchable electrode (301), and

-the additional elastically deformable layer (100 b) is arranged between the second conductive layer (600 b) and the first stretchable electrode (301) in the direction of the thickness of the sensor (900).

Example 23. the sensor (900) according to example 21 or 22, wherein,

-at least a portion of said first and/or said second conductive layer (600, 600a, 600 b) is made of a conductive ink, and/or

-said first and/or said second conductive layer (600, 600a, 600 b) comprises a conductive fabric, and/or

-said first and/or said second conductive layer (600, 600a, 600 b) comprises a conductive polymer.

Example 24. the sensor (900) of examples 1-23, comprising:

-a support layer (650) such that

-the first stretchable electrode (301) and the second stretchable electrode (302) are arranged between the elastic and stretchable layer (050, 100, 200) and the support layer (650).

Example 25. the sensor of any of examples 1-24, comprising:

-a support layer (650) comprising a thermoplastic material having a deflection temperature of from 60 ℃ to 120 ℃, wherein,

-the support layer (650) has a thickness of at least 0.2 mm.

Example 26. the sensor of example 25, wherein,

-the support layer (650) is arranged such that, in use, at least one of the following is arranged to be left between [ i ] a point at which a force can be sensed and [ ii ] the support layer (650):

the elastic and stretchable layer (050);

the elastically deformable layer (100, 100 a); and

an elastically deformable layer (100 b) is added.

Example 27. the sensor according to example 25 or 26, wherein,

-the support layer (650) comprises at least one of: polycarbonates, polyvinyl chlorides, acrylic resins (e.g., styrene-acrylonitrile copolymer, acrylonitrile styrene acrylate), polymethyl methacrylates, polyethylene terephthalates, and ethylene glycol-modified polyethylene terephthalates;

alternatively,

-the support layer (650) further comprises reinforcing fibers from the group comprising carbon fibers, glass fibers and aramid fibers.

Example 28. the sensor of any of examples 1-27, wherein,

-the cross-sectional area of the flexible foil (500) is at most half of the cross-sectional area of the elastic and stretchable layer (050, 100, 200).

Example 29 the sensor of any one of examples 1 to 28, wherein,

-each stretchable electrode (300, i) is positioned at a distance (d) from the stretchable electrode (300, jm (i)) closest to the preceding stretchable electrode (300, i)_1,i,jm(i)) And, thus,

-the configuration of the stretchable electrodes (300, i) each stretchable electrode (300, i) defining a minimum distance (d) from the other stretchable electrodes (300)_1,i,jm(i)) At least some of the minimum distances may be equal, an

-said minimum distance (d)_1,i,jm(i)) Is the maximum value ofAt most 15 mm, such as at most 10 mm or at most 5 mm.

Example 30 a wearable article, such as a garment, comprising a sensor (900) according to any of examples 1 to 29.

Example 31 the wearable article of example 30, the article being one of:

-shoes, insoles or socks, or

Gloves or mitts, such as boxing gloves.

Example 32. an insole (910) suitable for footwear, wherein,

-the shape of the insole (910) is adapted to the shape of the footwear, and

-the insole (910) comprises a sensor (900) according to any of examples 1 to 29.