CN213748875U - Capacitive pressure sensing device and electronic equipment - Google Patents

Abstract

The embodiment of the application provides a capacitive pressure sensing device and electronic equipment, wherein the capacitive pressure sensing device comprises a first elastic part, a second elastic part, a connecting part, a first electrode plate, a second electrode plate, a first medium and a second medium, wherein the connecting part, the first elastic part and the second elastic part enclose to form a sealed cavity, and the sealed cavity is provided with a first direction and a second direction which are perpendicular to each other; the first electrode plate and the second electrode plate are oppositely arranged on the connecting part along the first direction, and the relative positions are kept fixed; the first medium and the second medium are distributed in the sealed cavity along the second direction, and the proportion of the first medium and the second medium between the first electrode plate and the second electrode plate changes along with the elastic deformation of the first elastic part or the second elastic part. The capacitive pressure sensing device provided by the embodiment of the application can realize pressure sensing when the relative position of the first electrode plate and the second electrode plate is kept fixed, and can avoid the problem that the service life is shortened due to deformation and abrasion of the electrode plates.

Description

Capacitive pressure sensing device and electronic equipment

Technical Field

The utility model relates to a sensor technical field, concretely relates to capacitanc pressure sensing device and electronic equipment.

Background

A capacitive pressure sensor is a pressure sensor that uses a capacitance as a sensing element to convert a measured pressure into a change in capacitance. At present, a circular metal film or a metal-plated film is generally adopted as two electrodes of a capacitor in a capacitive pressure sensor on the market, when the electrodes sense pressure and change the distance between the two electrodes, capacitance formed between the two electrodes changes, and an electric signal which has a certain relation with the capacitance can be output through a measuring circuit. However, the capacitive pressure sensor requires that the electrode material can deform and recover, the manufacturing cost is high, and the electrode deformation can be worn to shorten the life cycle of the sensor.

SUMMERY OF THE UTILITY MODEL

An object of the present application is to provide a capacitive pressure sensing device and an electronic apparatus, so as to solve the above problems. The present application achieves the above object by the following technical solutions.

In a first aspect, an embodiment of the present application provides a capacitive pressure sensing device, which includes a first elastic portion, a second elastic portion, a connecting portion, a first electrode plate, a second electrode plate, a first medium, and a second medium, where the connecting portion is disposed between the first elastic portion and the second elastic portion, the first elastic portion, the second elastic portion, and the connecting portion enclose to form a sealed cavity, and the sealed cavity has a first direction and a second direction that are perpendicular to each other; the first electrode plate and the second electrode plate are oppositely arranged on the connecting part along the first direction, and the relative position between the first electrode plate and the second electrode plate is kept fixed; the first medium and the second medium are distributed in the sealed cavity along the second direction, the dielectric constant of the first medium is different from that of the second medium, the first medium and the second medium are not mutually soluble, and the proportion of the first medium and the second medium between the first electrode plate and the second electrode plate is changed along with the elastic deformation of the first elastic part or the second elastic part.

In a second aspect, an embodiment of the present application provides an electronic device, which includes a housing and the capacitive pressure sensing device of the first aspect, where the capacitive pressure sensing device is disposed in the housing.

Compared with the prior art, the capacitive pressure sensing device provided by the embodiment of the application comprises the first elastic part and the second elastic part, the first elastic part and the second elastic part can deform under the action of external pressure, the proportion of the first medium and the second medium between the first electrode plate and the second electrode plate changes along with the deformation of the first elastic part or the second elastic part, and further the capacitance value between the first electrode plate and the second electrode plate changes, the pressure acting on the first elastic part or the second elastic part can be sensed by detecting the capacitance value between the first electrode plate and the second electrode plate, and the pressure sensing function is realized. Because the relative position between first electrode board and the second electrode board keeps fixed, need not to take place deformation, consequently can not take place first electrode board and second electrode board and warp the problem that wearing and tearing lead to sensing device life-span to shorten.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a cross-sectional view of a capacitive pressure sensing device provided by an embodiment of the present application.

Fig. 2 is a cross-sectional view of a capacitive pressure sensing device provided by an embodiment of the present application when under pressure.

Fig. 3 is another cross-sectional view of a capacitive pressure sensing device provided by an embodiment of the present application when under pressure.

FIG. 4 is a cross-sectional view of a capacitive pressure sensing device according to another embodiment of the present application.

FIG. 5 is a cross-sectional view of the capacitive pressure sensing device provided in the embodiment of FIG. 4 when under pressure.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1, a capacitive pressure sensing device 100 according to an embodiment of the present disclosure includes a first elastic portion 111, a second elastic portion 112, and a connecting portion 113, where the connecting portion 113 is disposed between the first elastic portion 111 and the second elastic portion 112, the first elastic portion 111, the second elastic portion 112, and the connecting portion 113 enclose a sealed cavity 114, and the sealed cavity 114 has a first direction Y and a second direction X that are perpendicular to each other.

The capacitive pressure sensing device 100 further includes a first electrode plate 121 and a second electrode plate 122, the first electrode plate 121 and the second electrode plate 122 are oppositely disposed on the connection portion 113 along the first direction Y, and a relative position between the first electrode plate 121 and the second electrode plate 122 is kept fixed, so that a distance between the first electrode plate 121 and the second electrode plate 122 is kept unchanged.

The capacitive pressure sensing device 100 further includes a first medium 131 and a second medium 132, the first medium 131 and the second medium 132 are distributed in the sealed cavity 114 along the second direction X, the dielectric constant of the first medium 131 is different from the dielectric constant of the second medium 132, the first medium 131 and the second medium 132 are immiscible with each other, and the ratio of the first medium 131 to the second medium 132 between the first electrode plate 121 and the second electrode plate 122 changes along with the elastic deformation of the first elastic part 111 or the second elastic part 112.

Exemplarily, as shown in fig. 1, fig. 2 and fig. 3, when the first elastic part 111 and the second elastic part 112 are not subjected to the external pressure, the first dielectric 131 and the second dielectric 132 are in the initial position, only the second dielectric 132 is between the first electrode plate 121 and the second electrode plate 122, and the ratio of the first dielectric 131 to the second dielectric 132 between the first electrode plate 121 and the second electrode plate 122 is 0: 1.

when the first elastic part 111 is subjected to the external pressure, the first elastic part 111 and the second elastic part 112 are elastically deformed, and then the first medium 131 and the second medium 132 are pressed to move, so that the first medium 131 partially moves between the first electrode plate 121 and the second electrode plate 122, and the ratio of the first medium 131 to the second medium 132 between the first electrode plate 121 and the second electrode plate 122 may be 1: 9.

when the pressure acting on the first elastic part 111 is increased, the first medium 131 may press the second medium 132 out of the first electrode plate 121 and the second electrode plate 122, and a ratio of the first medium 131 to the second medium 132 between the first electrode plate 121 and the second electrode plate 122 is 1: 0. therefore, the ratio of the first dielectric 131 to the second dielectric 132 between the first electrode plate 121 and the second electrode plate 122 may be changed according to the elastic deformation of the first elastic part 111 or the second elastic part 112, and is related to the external pressure to which the first elastic part 111 or the second elastic part 112 is subjected.

In this embodiment, the first dielectric 131 and the second dielectric 132 are both insulating dielectrics, and the first electrode plate 121, the second electrode plate 122, and the first dielectric 131 and/or the second dielectric 132 between the first electrode plate 121 and the second electrode plate 122 constitute a capacitor. According to a capacitance calculation formula: c ═ es/d, where C is capacitance, S is an overlapping area between the first electrode plate 121 and the second electrode plate 122, d is a distance between the first electrode plate 121 and the second electrode plate 122, and e is a dielectric constant of the dielectric layer between the first electrode plate 121 and the second electrode plate 122. When the first elastic part 111 or the second elastic part 112 is subjected to the external pressure, the ratio of the first medium 131 to the second medium 132 between the first electrode plate 121 and the second electrode plate 122 changes, and the average dielectric constant of the medium between the first electrode plate 121 and the second electrode plate 122 changes, that is, the dielectric constant ∈ changes due to the difference in dielectric constants of the first medium 131 and the second medium 132, and finally the capacitance value C changes. After the external pressure disappears, the first elastic part 111 and the second elastic part 112 are restored to their original states by the elastic restoring force, and the first medium 131 and the second medium 132 may be restored to their original positions.

Therefore, the pressure acting on the first elastic part 111 or the second elastic part 112 will cause the capacitance value between the first electrode plate 121 and the second electrode plate 122 to change, and the capacitive pressure sensing device 100 can sense the pressure acting on the first elastic part 111 or the second elastic part 112 by detecting the capacitance value between the first electrode plate 121 and the second electrode plate 122, thereby implementing the pressure sensing function. Since the relative position between the first electrode plate 121 and the second electrode plate 122 is kept fixed, deformation is not required, and therefore the problem that the service life of the sensing device is shortened due to deformation and abrasion of the first electrode plate 121 and the second electrode plate 122 is avoided.

The capacitive pressure sensing apparatus 100 further includes a capacitance detection circuit (not shown) electrically connected to the first electrode plate 121 and the second electrode plate 122. The capacitance detection capacitor is used for detecting capacitance value changes of the first electrode plate 121 and the second electrode plate 122 and outputting a detection result. In this embodiment, the capacitance detection circuit may establish electrical connection with the first electrode plate 121 and the second electrode plate 122 through the connection portion 113 by a connection wire.

In some embodiments, the capacitive pressure sensing apparatus 100 may further include a third medium (not shown), the first medium 131, the second medium 132, and the third medium are distributed in the sealed cavity 114 along the second direction X, a dielectric constant of the third medium, a dielectric constant of the first medium 131, and a dielectric constant of the second medium 132 are different from each other, and the third medium, the first medium 131, and the second medium 132 are mutually insoluble from each other, and a ratio of the first medium 131, the second medium 132, and the third medium between the first electrode plate 121 and the second electrode plate 122 changes along with the elastic deformation of the first elastic part 111 or the second elastic part 112, which can be referred to the above description. When the number of the mediums arranged in the second direction X in the sealed cavity 114 is different, the capacitance change amplitude between the first electrode plate 121 and the second electrode plate 122 is different, and a person skilled in the art can set the number of the mediums arranged in the second direction X in the sealed cavity 114 according to actual requirements, which is not specifically limited herein.

At least one of the first medium 131 and the second medium 132 may be an elastic medium, such as rubber or elastic plastic, such as Polyethylene (PE), thermoplastic elastomer (TPE), etc. When the first medium 131 is an elastic medium, the second medium 132 may be any gaseous medium (e.g., air, carbon dioxide, or sulfur hexafluoride), liquid medium (e.g., natural mineral oil, silicone oil, or trichlorobiphenyl), or elastic medium (e.g., rubber, PE, or TPE). Likewise, when the second medium 132 is an elastic medium, the first medium 131 may be any of a gas medium, a liquid medium, or an elastic medium. Of course, both the first medium 131 and the second medium 132 may be elastic media.

By setting at least one of the first medium 131 and the second medium 132 as an elastic medium, the first medium 131 and the second medium 132 can be limited from moving within an elastic deformation range of the elastic medium, so as to avoid flowing in any direction, and after the external pressure disappears, the first medium 131 and the second medium 132 can be accurately restored to the initial positions by using the elastic restoring force of the elastic medium, thereby improving the structural stability of the capacitive pressure sensing device 100.

An interface 133 between the first dielectric 131 and the second dielectric 132 may be located between the first electrode plate 121 and the second electrode plate 122 when the first elastic part 111 or the second elastic part 112 is not deformed, so that when the first elastic part 111 or the second elastic part 112 is deformed under the action of an external pressure, the ratio of the first dielectric 131 to the second dielectric 132 between the first electrode plate 121 and the second electrode plate 122 is immediately changed, and the pressure sensing sensitivity of the capacitive pressure sensing device 100 may be further improved.

In some embodiments, the interface 133 between the first dielectric 131 and the second dielectric 132 may be located outside the first electrode plate 121 and the second electrode plate 122 when the first elastic part 111 or the second elastic part 112 is not deformed, or may be away from the first electrode plate 121 and the second electrode plate 122, so that only when the first elastic part 111 or the second elastic part 112 is subjected to a sufficiently large external pressure, the ratio of the first dielectric 131 to the second dielectric 132 between the first electrode plate 121 and the second electrode plate 122 may be changed, and the occurrence of a false touch condition may be reduced.

An interface 133 between the first medium 131 and the second medium 132 may be perpendicular to the second direction X, where the interface 133 may be a plane, and the interface 133 between the first medium 131 and the second medium 132 being perpendicular to the second direction X may mean that the interface 133 between the first medium 131 and the second medium 132 is always perpendicular to the second direction X, so that a ratio between the first medium 131 and the second medium 132 between the first electrode plate 121 and the second electrode plate 122 may exhibit regular changes, and further a capacitance value between the first electrode plate 121 and the second electrode plate 122 exhibits regular changes, and a corresponding relationship between the capacitance value and the pressure value may be established, so that the capacitive pressure sensing device 100 can detect the magnitude of the pressure value.

In some embodiments, the interface 133 may not be perpendicular to the second direction X. For example, the boundary surface 133 may have a regular shape such as a plane or a curved surface that is not perpendicular to the second direction X, or may have an irregular shape such as a concave-convex surface.

Referring to fig. 4 and 5, the number of the first electrode plates 121 and the second electrode plates 122 may include a plurality. The "plurality" means two or more. The plurality of first electrode plates 121 and the plurality of second electrode plates 122 are arranged along the second direction X, the first electrode plates 121 and the second electrode plates 122 are arranged in a one-to-one manner, and a capacitor is formed between the oppositely arranged first electrode plates 121 and the second electrode plates 122.

For example, the number of the first electrode plates 121 and the second electrode plates 122 may each include five, and five first electrode plates 121 and five second electrode plates 122 are arranged in a one-to-one correspondence to form five capacitors. When the first and second elastic parts 111 and 112 are not subjected to the external pressure, only the second medium 132 may be interposed between the five first electrode plates 121 and the five second electrode plates 122. When the first elastic part 111 or the second elastic part 112 is subjected to the external pressure, the interface 133 between the first medium 131 and the second medium 132 may sequentially penetrate through each of the first electrode plate 121 and the second electrode plate 122, so that the capacitance value between the electrode plates changes, and the more capacitors the capacitance value changes with the increasing of the external pressure. Therefore, the magnitude of the pressure value can be determined by detecting the number and the positions of the capacitors with the changed capacitance values.

Certainly, in the embodiment of the present application, the number of the first electrode plate 121 and the second electrode plate 122 is not particularly limited, and as the number of the first electrode plate 121 and the second electrode plate 122 increases, the capacitive pressure sensing apparatus 100 can sense the magnitude of the pressure value more accurately, and a person skilled in the art can set the magnitude according to actual requirements.

Still referring to fig. 1, the first elastic portion 111 has a first receiving cavity 115, the second elastic portion 112 has a second receiving cavity 116, the connecting portion 113 has a communicating cavity 117, the first receiving cavity 115, the communicating cavity 117 and the second receiving cavity 116 are communicated with each other to form a sealed cavity 114, the first medium 131 is at least partially received in the first receiving cavity 115, and the second medium 132 is at least partially received in the second receiving cavity 116.

When the first elastic part 111 deforms under the action of the external pressure, the shape of the first medium 131 in the first accommodating cavity 115 changes synchronously, so that the ratio of the first medium 131 to the second medium 132 between the first electrode plate 121 and the second electrode plate 122 changes. When the second elastic part 112 deforms under the action of the external pressure, the shape of the second medium 132 in the second receiving cavity 116 changes synchronously, and the ratio of the first medium 131 to the second medium 132 between the first electrode plate 121 and the second electrode plate 122 can also change. Therefore, the capacitive pressure sensing device 100 can sense not only the external pressure acting on the first elastic portion 111 but also the external pressure acting on the second elastic portion 112, thereby increasing the area of the region where the pressure can be sensed.

At least one of the first elastic part 111 and the second elastic part 112 is provided with a pressure receiving surface 118, for example, only the first elastic part 111 or the second elastic part 112 is provided with the pressure receiving surface 118, or both the first elastic part 111 and the second elastic part 112 are provided with the pressure receiving surface 118. The pressing surface 118 may be any surface of the first elastic part 111 or the second elastic part 112, and is used for providing an acting point for the external pressure, so as to facilitate the pressing of the first elastic part 111 or the second elastic part 112. Illustratively, the compression surface 118 may be planar to facilitate compression. In some embodiments, the compression surface 118 may have other shapes such as a curved surface or a wavy surface.

In this embodiment, only the first elastic portion 111 may be provided with the pressure receiving surface 118, and the first elastic portion 111 is configured to receive the external pressure. The dielectric constant of the first dielectric 131 may be greater than that of the second dielectric 132, and when the first elastic part 111 is not subjected to the external pressure, the first dielectric 131 is located outside the first electrode plate 121 and the second electrode plate 122, and the capacitance between the first electrode plate 121 and the second electrode plate 122 is at a minimum value. When the first elastic portion 111 is deformed under the action of the external pressure, one end of the first medium 131 can move between the first electrode plate 121 and the second electrode plate 122, and at this time, the capacitance between the first electrode plate 121 and the second electrode plate 122 is gradually increased, so that the capacitance between the first electrode plate 121 and the second electrode plate 122 is in a direct proportional relationship with the pressure value of the external pressure, and pressure sensing can be performed more intuitively.

In the present embodiment, the cross-sectional shapes of the first receiving cavity 115, the communication cavity 117, and the second receiving cavity 116 in the direction perpendicular to the second direction X may be uniform, for example, the cross-sectional shapes of the first receiving cavity 115, the communication cavity 117, and the second receiving cavity 116 are all circular, elliptical, or rectangular, and the like. The first electrode plate 121 and the second electrode plate 122 may be embedded in an inner wall of the connection portion 113, and the first electrode plate 121 and the second electrode plate 122 are flush with the inner wall of the connection portion 113, so that a sealed cavity 114 with smooth transition inner walls may be formed, and blocking of the first medium 131 and the second medium 132 during movement in the sealed cavity 114 may be avoided. In other embodiments, the first electrode plate 121 and the second electrode plate 122 may also be directly adhered to the inner wall of the connection portion 113, so as to facilitate assembly.

The cross-sectional shapes of the first receiving cavity 115, the communicating cavity 117, and the second receiving cavity 116 in the direction perpendicular to the second direction X may also be different, for example, the cross-sectional area of the first receiving cavity 115 and the second receiving cavity 116 in the direction perpendicular to the second direction X is larger than the cross-sectional area of the communicating cavity 117 in the direction perpendicular to the second direction X, so that the moving distance of the interface 133 when the first elastic part 111 or the second elastic part 112 is deformed can be increased, and the variation amplitude of the capacitance value between the first electrode plate 121 and the second electrode plate 122 can be further increased.

The shape of the connecting portion 113 may be fixed, that is, the shape of the communication chamber 117 is fixed, and an interface 133 between the first medium 131 and the second medium 132 is located in the communication chamber 117. By limiting the movement of the interface 133 in the communication cavity 117 with a fixed shape, the shape of the interface 133 can be kept relatively stable, for example, the interface 133 can be always a plane in the moving process, and the situation that the first medium 131 and the second medium 132 cannot return to the initial positions due to the fact that the interface 133 moves into the first receiving cavity 115 or the second receiving cavity 116 is avoided.

In the present embodiment, the first elastic part 111 and the second elastic part 112 may be an elastic housing made of a rubber material, such as styrene-butadiene rubber, isoprene rubber, or the like. The connecting portion 113 may be a hard shell made of thermosetting plastic, such as phenolic plastic, polyurethane plastic, or epoxy plastic, and the like. Thus, the first elastic portion 111, the second elastic portion 112, and the connection portion 113 may also function as insulation. In some embodiments, the first elastic portion 111, the second elastic portion 112 and the connecting portion 113 may be hermetically connected by bonding, welding or the like.

Still referring to fig. 1, an electronic device according to an embodiment of the present disclosure includes a housing (not shown) and a capacitive pressure sensing device 100, where the capacitive pressure sensing device 100 is disposed in the housing.

The electronic device may be any electronic device with a touch function. For example, the electronic device may be a smartphone, a tablet, a wearable device, an e-reader, an in-vehicle device, and so on.

In this embodiment, the housing can be attached to the first elastic portion 111 or the second elastic portion 112, so that the pressure applied to the housing can cause the first elastic portion 111 and the second elastic portion 112 to deform, and further cause the capacitance between the first electrode plate 121 and the second electrode plate 122 to change, and the capacitive pressure sensing device 100 can sense the pressure applied to the housing by detecting the capacitance between the first electrode plate 121 and the second electrode plate 122, thereby implementing pressure sensing. Since the relative position between the first electrode plate 121 and the second electrode plate 122 is kept fixed, deformation is not required, and therefore, the problem that the service life of the sensing device is shortened due to abrasion of the first electrode plate 121 and the second electrode plate 122 does not occur.

In some embodiments, the first elastic part 111 or the second elastic part 112 may also be exposed outside the housing of the electronic device, so that the first elastic part 111 or the second elastic part 112 may be directly deformed by an external pressure.

For detailed structural features of the capacitive pressure sensing apparatus 100, refer to the related description of the above embodiments. Since the electronic device includes the capacitive pressure sensing apparatus 100 in the above embodiments, all the advantages of the capacitive pressure sensing apparatus 100 are provided, and are not described herein again.

Although the present application has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A capacitive pressure sensing device, comprising:

the connecting part is arranged between the first elastic part and the second elastic part, the first elastic part, the second elastic part and the connecting part are enclosed to form a sealed cavity, and the sealed cavity is provided with a first direction and a second direction which are perpendicular to each other;

the first electrode plate and the second electrode plate are oppositely arranged on the connecting part along the first direction, and the relative position between the first electrode plate and the second electrode plate is kept fixed; and

the first medium and the second medium are distributed in the sealed cavity along the second direction, the dielectric constant of the first medium is different from that of the second medium, the first medium and the second medium are insoluble with each other, and the proportion of the first medium to the second medium between the first electrode plate and the second electrode plate is changed along with the elastic deformation of the first elastic part or the second elastic part.

2. The capacitive pressure sensing apparatus of claim 1, wherein at least one of the first medium and the second medium is an elastic medium.

3. The capacitive pressure sensing device of claim 1, wherein an interface between the first media and the second media is between the first electrode plate and the second electrode plate when the first spring or the second spring is undeformed.

4. The capacitive pressure sensing device of claim 1, wherein an interface between the first medium and the second medium is perpendicular to the second direction.

5. The capacitive pressure sensing device according to claim 1, wherein the number of the first electrode plates and the second electrode plates each includes a plurality, the plurality of first electrode plates and the plurality of second electrode plates are respectively arranged along the second direction, and the first electrode plates and the second electrode plates are arranged in a one-to-one manner.

6. The capacitive pressure sensing device according to claim 1, wherein the first elastic portion has a first receiving cavity, the second elastic portion has a second receiving cavity, the connecting portion has a communicating cavity, the first receiving cavity, the communicating cavity and the second receiving cavity are communicated with each other to form the sealed cavity, the first medium is at least partially received in the first receiving cavity, and the second medium is at least partially received in the second receiving cavity.

7. Capacitive pressure sensing device according to claim 6, wherein the shape of the connection is fixed and the interface between the first medium and the second medium is located in the communication cavity.

8. The capacitive pressure sensing apparatus according to claim 1, wherein at least one of the first resilient portion and the second resilient portion is provided with a pressure surface.

9. The capacitive pressure sensing device according to any of claims 1-8, further comprising a capacitance detection circuit electrically connected to the first electrode plate and the second electrode plate.

10. An electronic device comprising a housing and the capacitive pressure sensing device of any one of claims 1-9, the capacitive pressure sensing device disposed on the housing.

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