JP2008304390A - Sensor module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suitable sensor module that allows use in a wide field and operates stably, as a sensor using a flexible element. <P>SOLUTION: The sensor module 10 includes a flexible element 13 where a plurality of metal electrode layers are separated in electrical insulation and formed on a surface of ion-exchange resin, a case having the flexible element 13 inside, and a connector section for transmitting the electric energy generated by deformation of the flexible element 13 to the outside of the case. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sensor module using a flexible element in which a plurality of metal electrode layers are electrically isolated from each other on the surface of an ion exchange resin.

As a flexible element that converts mechanical energy into electrical energy, a configuration of a prior application by the present applicant is known (Patent Document 1). The flexible element having this configuration is a flexible element that is an ion exchange resin composite in which an electrode layer is formed on an ion exchange resin layer, and a plurality of the electrode layers are formed on the ion exchange resin layer. The deformation of the element can be converted into electric energy. And as an application of this flexible element, the application to various sensors is described.
JP 2005-39995 A

  As a sensor using the flexible element described in Patent Document 1, use in a wide range of fields is desired. In addition, when a flexible element is used as a sensor, it is necessary to reduce the influence of the external environment and eliminate problems caused by contact with foreign matter or the like for stable operation.

  Accordingly, an object of the present invention is to provide a suitable sensor module that can be used in a wide range of fields as a sensor using a flexible element and that operates stably.

In order to solve the above problems, the sensor module of the present invention is:
A flexible element formed by electrically insulating a plurality of metal electrode layers from each other on the surface of an ion exchange resin;
A housing in which the flexible element is provided;
And a connector portion that transmits electric energy generated by deformation of the flexible element to the outside of the housing.

  According to this configuration, the electrical energy generated by the deformation of the flexible element inside the housing can be suitably taken out of the housing by the connector portion. In addition, since a flexible element is provided inside the housing, the influence of the external environment on the flexible element is reduced, no direct mechanical shock is applied, and the sensor can operate stably. it can. In addition, the modularization of the housing shape makes it a general-purpose component that can be easily incorporated into other devices and can be used for a wide range of applications.

  In the present invention, it is preferable that the casing has a columnar shape or a prismatic shape, and is configured to allow deformation of the flexible element.

  When functioning as a sensor, it is necessary to deform the flexible element, and in order to detect the orientation, it is possible to restrict the orientation depending on the orientation, and to provide a spatial restriction. It can also be configured so as not to exist. Moreover, a plurality of directions can be detected by providing a plurality of pairs of metal electrodes. Further, by installing a plurality of flexible elements inside the housing, multi-axis orientation detection can also be performed. The shape of the housing is preferably a shape that can be easily incorporated into other devices when modularized. From this viewpoint, a cylindrical shape and a prismatic shape are preferable. The prismatic shape is not particularly limited, and examples thereof include a quadrangular column, a hexagonal column, and an octagonal column.

  The present invention is further characterized by further comprising an amplifying unit for amplifying the electric energy.

  According to this configuration, the electric energy due to the deformation of the flexible element can be amplified, and can be amplified depending on the amount of electric energy required by the application of the sensor module. can do.

(Flexible element)
The flexible element used in the present invention is formed by separating a plurality of metal electrode layers on the surface of an ion exchange resin so as to be electrically insulated from each other. This flexible element generates electrical energy due to its deformation. Utilizing this property, it can be applied to various sensors. In particular, in this embodiment, applications as an acceleration sensor and an impact detection sensor will be described. First, the flexible element will be described.
(Flexible element)

  The ion exchange resin complex can be obtained by a known method. For example, the ion exchange resin composite can be obtained by forming a metal layer by electroless plating on an ion exchange resin and using the metal layer as a metal electrode layer.

  As the electroless plating, for example, after performing a roughening treatment, the ion exchange resin is adsorbed to adsorb a metal complex such as a platinum complex or a gold complex in a state where the ion exchange resin is swollen by being immersed in water. An electroless plating method can be suitably used in which a step is performed, a reduction step is performed in which the adsorbed metal complex is reduced with a reducing agent to deposit a metal, and a cleaning step is performed to remove the reducing agent as desired. In this electroless plating, the adsorption process, the reduction process, and the cleaning process can be repeated in order to make the electrode layer, which is an electrode, thick enough to energize or bend. In the ion exchange resin composite thus obtained, an electrode layer grows in the inner direction of the ion exchange resin to form an electrode, and the cross section of the electrode layer is fractal at the interface between the ion exchange resin and the electrode layer. Therefore, it is possible to have a large electric double layer at the interface between the electrode layer and the ion exchange resin layer. Furthermore, since the electrode layer forms a fractal structure in the inner direction of the ion exchange resin layer, the anchor effect works, so that the ion exchange resin composite has durability even when it is repeatedly bent.

  The ion exchange resin is not particularly limited. The ion exchange resin is not particularly limited, and known ion exchange resins can be used, and those obtained by introducing hydrophilic functional groups such as sulfonic acid groups and carboxyl groups into polyethylene, polystyrene, fluororesin and the like. Can be used. Examples of such a resin include perfluorosulfonic acid resin (trade name “Nafion”, manufactured by DuPont), perfluorocarboxylic acid resin (trade name “Flemion”, manufactured by Asahi Glass Co., Ltd.), ACIPLEX (manufactured by Asahi Kasei Kogyo Co., Ltd.), NEOSEPTA (manufactured by Tokuyama Corporation) can be used.

  The metal complex solution used in the electroless plating adsorption step is not particularly limited as long as the metal layer formed by reduction contains a metal complex that can function as an electrode layer. . The metal complex is preferably a metal complex such as a gold complex, a platinum complex, a palladium complex, a rhodium complex, or a ruthenium complex because a metal with a small ionization tendency is electrochemically stable. As such, a metal complex composed of a noble metal having good electrical conductivity and high electrochemical stability is preferable, and a gold complex containing gold that is relatively difficult to undergo electrolysis is preferable. In the metal salt solution, the solvent is not particularly limited. However, since the metal salt is easy to dissolve and easy to handle, the solvent is preferably based on water. A metal salt aqueous solution is preferred. Therefore, the metal complex solution is preferably a metal complex aqueous solution, particularly preferably a gold complex aqueous solution or a platinum complex aqueous solution, and more preferably a gold complex aqueous solution.

  As the reducing agent used in the reducing agent step of electroless plating, it can be used by appropriately selecting the type according to the type of metal complex used in the metal complex solution adsorbed on the ion exchange resin, for example, Sodium sulfite, hydrazine, sodium borohydride and the like can be used. In addition, when reducing a metal complex, you may add an acid or an alkali as needed. The concentration of the reducing agent solution is not particularly limited as long as it contains a sufficient amount of reducing agent to obtain the amount of metal to be deposited by reduction of the metal complex. It is also possible to use a concentration equivalent to the metal salt solution used when forming the electrode by plating. Further, the reducing agent solution can contain a good solvent for the ion exchange resin.

  The method for forming a plurality of electrode layers on the ion exchange resin layer obtained by electroless plating is not particularly limited. For example, a laser is applied to the electrode layer formed on the ion exchange resin layer. The metal layer may be partially excised using irradiation or a sharp blade to form metal layers insulated from each other.

The flexible element is in a state where the ion exchange resin is swollen by a solution containing ions. The ions function as charge carriers and are not particularly limited. When the resin component of the ion exchange resin is a cation exchange resin, (C ₂ H ₅ ) ₄ N ⁺ , (C ₂ H ₅ ) _{3 is used} as a cation contained in the solvent containing the ions. Tetraalkylammonium ions having an alkyl group having 1 to 4 carbon atoms such as (CH ₃ ) N ⁺ and (CH ₃ ) ₄ N ^+, and tetraalkylphosphoniums such as (C ₂ H ₅ ) ₄ P ⁺ Ions, monovalent ions such as H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Fr ⁺ , Cu ²⁺ , Ni ²⁺ , Co ²⁺ , Fe ²⁺ , Fe ³⁺ , Al ²⁺ , Al ³⁺ , Zn Divalent or trivalent ions such as ²⁺ , Pb ²⁺ , Sn ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Cr ³⁺ can be used.

When the solution for swelling the ion exchange resin of the flexible element of the present invention is a solution containing an anion, BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , Ts ⁻ , SO ₄ are used as the anion. ^{_{2-, NO 3 -, Cl -}} , Br -, I -, CF 3 SO 4 -, C 4 F 9 SO 4 -, (CF 3 SO 2) 2 N -, BCH 3 (C 2 H 5) 3 - B (C ₂ H ₅ ) ₄ ⁻ , B (C ₄ H ₉ ) ₄ ⁻ , AsF ⁻ , SbF ₆ ^{− and the} like can be used. Similarly to the above, when an anion exchange resin is used as the ion exchange resin, the ions in the solution contained in the ion exchange resin are preferably ions having an ion radius. The solvent used for the solution containing ions contained in the ion exchange resin is a polar solvent that can dissolve ions regardless of whether the ion exchange resin is a cation exchange resin or an anion exchange resin. If it is, it will not specifically limit.
(Shape of flexible element)

  The shape of the flexible element is not particularly limited, and may be a membrane ion exchange resin composite by electroless plating on a membrane (or plate) ion exchange resin. In addition, a plurality of electrode layers that can form electrode pairs on the inner side surface and / or outer side surface of the cylindrical ion exchange resin and provide insulating grooves by laser irradiation or the like to form mutually insulated electrode pairs An ion exchange resin composite provided with the above may be used as the flexible element. The flexible element has a sufficient flexibility so that the membrane ion-exchange resin composite is formed into a cylindrical shape, a box shape, a short diameter, a flat plate shape, a cylindrical shape, a prismatic shape, a coil shape, a hollow shape, and the like. Can be easily formed into a desired shape such as a cylindrical shape. Therefore, the flexible element is excellent in moldability.

  In the case where the shape of the flexible element is a cylindrical shape, a flexible structure in which two or more electrode layers are arranged on the same surface of the cylindrical ion exchange resin layer in an insulated state. Element. The flexible element having a columnar shape is more preferably a flexible element in which three or more electrode layers are arranged in order to facilitate sensing from each direction of 360 °. Since this flexible element has two or more electrode layers on the same surface of a cylindrical ion exchange resin layer, it can be detected from which direction by detecting which electrode layer the charge is moving from. It is possible to easily detect whether a force is applied to the outer periphery of the cylindrical element or a deformed portion. The cylindrical shape may be hollow inside. FIG. 1A shows a cylindrical flexible element. Four metal electrodes are formed, that is, it is possible to detect deformation from four directions of up, down, left and right. FIG. 1C shows a hollow cylindrical flexible element.

  Further, when the shape of the flexible element is a flat plate shape, it is possible to detect deformation from two directions by providing metal electrodes on the two planes. FIG. 1B shows a flat flexible element.

  When the shape of the flexible element is a quadrangular prism, deformation from four directions can be detected by providing metal electrodes on the four planes. FIG. 1D shows a quadrangular prism-like flexible element.

The thickness of the ion exchange resin composite constituting the flexible element is not particularly limited, but it needs to be a thickness that can easily exhibit flexibility, for example, a prismatic or plate-like body. In this case, it is preferably 0.05 mm or more, and more preferably in the range of 0.05 mm to 5 mm. In the case of a cylindrical shape, the diameter is preferably 0.5 mm or more. Further, the ratio of the area of the ion exchange resin composite to the thickness of the ion exchange resin composite is preferably 10 (mm ² / mm), more preferably 20 (mm ² / mm).

  Next, generation of electrical energy due to deformation of the flexible element will be briefly described. FIG. 2 is a cross-sectional view of an embodiment of a flexible element that converts element deformation into electric energy when the electrode layers 2 and 2 ′ are provided so that the ion exchange resin layer 3 is sandwiched therebetween. When an external force is applied to the ion exchange resin composite from one direction, the flexible element 1 is deformed from a stationary state shown in FIG. 1 (a) as shown in FIG. 1 (b). Become. In the state of FIG. 1B, at least one electrode layer 2 of the two or more electrodes formed on the ion exchange resin layer expands, and the other electrode layer 2 'contracts. When the resin component of the ion exchange resin layer is a cation exchange resin, the electrode layer 2 is a negative electrode and the electrode layer 2 'is a positive electrode. When the resin component of the ion exchange resin layer is an anion exchange resin, the positive electrode and the negative electrode are reversed.

  Although the detailed mechanism by which electric energy is generated by the deformation is not clear, when a cation exchange resin is used, in this deformation, the water molecules in the ion exchange resin layer are the electrode layer 2 on the side extended by the deformation. Water molecules and counter ions are likely to be unevenly distributed near the side due to the volume expansion of the ion exchange resin. Further, in the vicinity of the contracted electrode layer 2 ′ side, water molecules and counter ions tend to be sparse due to the volume contraction of the ion exchange resin. Such uneven distribution is considered to be due to the occurrence of charge unevenness inside the ion exchange resin. Due to this bias of charge, the electrode layer 2 ′ becomes a positive electrode, the electrode layer 2 becomes a negative electrode, and the charge moves from the negative electrode to the positive electrode. The current flows from the electrode layer 2 ′ to the electrode layer 2. That is, the flexible element is different from a normal piezoelectric element in order to obtain electric energy by electrochemical ion behavior.

  The flexible element is not particularly limited as long as it is formed of an ion exchange resin composite in which an electrode layer is formed on an ion exchange resin layer. The flexible element may be the ion exchange resin composite itself, or the outside of the ion exchange resin composite may be partially or entirely covered with a coating layer.

(Casing)
The size, shape, material, etc. of the housing are not particularly limited, and can be set according to the application. In particular, considering that it is widely incorporated into the apparatus, for example, a cylindrical shape or a prismatic shape is more preferable. The inside of the housing is preferably free space so as to allow deformation of the flexible element. Moreover, you may provide the wall part which partitions off space so that a change direction may be restrict | limited. Moreover, as a housing | casing, it is more preferable to use glass and a transparent resin material so that the flexible element installed in the inside can be visually recognized. Further, the casing preferably has a sealed configuration so as to reduce adverse effects on the flexible element (for example, environmental temperature, humidity, contact with foreign matter, etc.). Moreover, it is preferable to make the inside of a housing | casing into a pressure reduction state, a vacuum state, and an inert gas filling state according to the specification and application of a flexible element. Further, the housing is provided with a fixing portion for fixing one end portion of the flexible element. The configuration of the fixing portion is not particularly limited, but a configuration in which the fixing portion is fixed so as to sandwich the outer periphery of the end portion of the flexible element via a connector portion described later is preferable. Further, the housing is provided with a holder part that facilitates connection to an external device, and an output terminal (described later) is provided on the holder part. The holder part is preferably made of a material having excellent sealing properties, strength, and temperature characteristics.

(Connector part)
The connector portion is provided so as to correspond to each of the metal electrode layers of the flexible element. The electrical energy generated by the deformation of the flexible element is transmitted to the outside of the housing by the connector portion, and is configured to be detectable. For example, one end of the connector portion is in contact with the metal electrode layer, and the other end is provided outside the housing and functions as an output terminal. The connector part is not particularly limited as long as it is an electrically conductive member, but the same material as the metal electrode layer is more preferable.

(Amplification part)
The amplification unit is an amplification circuit, a chip, or the like that amplifies electric energy. When the electric energy generated by the deformation of the flexible element is several mV, it can be amplified to a desired value (for example, several hundred to several thousand mV) by this amplification unit, and can be set according to the application. The amplifying unit can be provided inside the casing or can be provided outside the casing.
(Sensor module)
FIG. 3 shows an embodiment of the sensor module. FIG. 3A shows an example of a cylindrical sensor module 10, and FIG. 3B shows an example of a rectangular parallelepiped sensor module 20. In the columnar sensor module 10 of FIG. 3A, the column body is a glass tube 11 and both end portions are metal holder portions 12. A flexible element 13 shown in FIG. 1A is fixed inside, and four metal electrodes 13 a, 13 b, 13 c, and 13 d are formed on the surface of the flexible element 13. Connector portions 14a, 14b, 14c, and 14d are in contact with the four metal electrodes 13a, 13b, 13c, and 13d so as to correspond to the respective electrodes.

  In addition, the rectangular parallelepiped sensor module 20 in FIG. 3B has a glass top plate 21 at the center of the upper surface, and the other face material 22 is made of metal. Two prismatic flexible elements 23a and 23b are fixed inside. The flexible element 23a is fixed vertically upward from the bottom surface in the drawing, the flexible element 23b is fixed horizontally from the side surface in the drawing, and the longitudinal directions of the flexible elements 23a and 23b are orthogonal to each other. It is installed to do. By installing in this way, biaxial sensing is possible. Metal electrode layers are respectively formed on the four planes of the prismatic flexible elements 23a and 23b, and connector portions (not shown) are in contact with the respective metal electrode layers.

Hereinafter, examples in which the sensor module according to the present invention is used as an impact sensor will be described. Note that the present invention is not limited to this.
(Example 1) An ion exchange resin membrane (fluororesin-based ion exchange resin: perfluorocarboxylic acid resin, manufactured by Asahi Glass Co., Ltd., Flemion, film thickness when dried: 0.2 mm, ion exchange capacity: 1.4 meq / g) The following steps (1) to (3) were repeated for 6 cycles to obtain an ion exchange resin composite including a pair of metal electrodes formed with the ion exchange resin interposed therebetween.
(1) Adsorption step: The dichlorophenanthroline gold complex was immersed in an aqueous solution of dichlorophenphenanthroline gold chloride for 12 hours to adsorb the dichlorophenanthroline gold complex in the ion exchange resin complex.
(2) Reduction step: The adsorbed dichlorophenanthroline gold complex is reduced in an aqueous solution containing sodium sulfite and ethylmethylimidazole (5% by weight), and a gold electrode is formed on the membrane polymer electrolyte (ion exchange resin complex). Formed. At this time, the temperature of the aqueous solution was set to 60 to 80 ° C., and the dichlorophenanthrine gold complex was subjected to reduction treatment for 6 hours while gradually adding sodium sulfite.
(3) Washing step: The membranous polymer electrolyte (ion exchange resin composite) having a gold electrode formed on the surface was taken out and washed with water at 70 ° C. for 1 hour.
(4) Cutting step: The ion exchange resin composite in which a pair of metal electrodes was formed by electroless plating was cut into a size of length (L): 3 mm and width (W): 5 mm.
(5) Immersion step: The ion exchange resin composite was immersed in a water mixed solution (1) (67% by weight) of glycerin carbonate. Next, the ion exchange resin composite was immersed in the mixed solution (1) containing 0.01 mol / l LiTFSI (trifluoromethanesulfonimide) salt, and immersed for 3 hours so that the degree of swelling was about 25%.

  The ion exchange resin composite obtained above constitutes a flexible element. The shape is a plate shape, thickness (t): about 0.2 mm, length (L): 3 mm, width (W): 5 mm. This was incorporated into a cylindrical casing to constitute a sensor module. The sensor module has a diameter of 8 mm and a height of 25 mm.

  This sensor module was fixed and installed inside an iron ball having a mass of 462 g and a diameter of 40 mm. The output terminal of the connector portion of the sensor module is connected to a voltmeter by extending electrical wiring to the outside of the iron ball (not shown). As shown in FIG. 4, this iron ball was allowed to freely drop (drop from 50, 75, and 100 cm in height) onto the lower iron plate, and the electromotive force due to the impact at this time was measured. The results are shown in Table 1.

  As can be seen from the results in Table 1, the sensor module inside the iron ball senses an impact and generates an electromotive force. Further, the electromotive force value increases in proportion to the drop distance (in proportion to the strength of the impact force). That is, the sensor module functions as an impact sensor, and furthermore, the electromotive force value increases in proportion to the impact force, so that the strength of the impact force can also be detected.

  As described above, the sensor module according to the present invention effectively functions as an acceleration sensor and an impact sensor, and has a configuration (shape and size) that can be easily incorporated into the apparatus, so that it can be used in a wide range of applications. For example, it can be incorporated into a personal computer, does not require power supply, functions as a drop impact sensor, and can be used, for example, to predict battery damage. When used as an acceleration sensor, it can be used as an operating device, for example, an operating device for a game machine or an operating device for a mobile phone.

The figure for demonstrating the example of a shape of a flexible element The figure for demonstrating generation | occurrence | production of the electrical energy by deformation | transformation of a flexible element The figure for demonstrating the example of a sensor module The figure for demonstrating the Example of an impact sensor

Explanation of symbols

10, 20 Sensor module 11 Glass tube 12 Holder part 13, 23a, 23b Flexible element 14a, 14b, 14c, 14d Connector part

Claims (3)

A flexible element formed by electrically insulating a plurality of metal electrode layers from each other on the surface of an ion exchange resin;
A housing in which the flexible element is provided;
A connector portion that transmits electrical energy generated by deformation of the flexible element to the outside of the housing;
A sensor module comprising:   The sensor module according to claim 1, wherein the casing has a columnar shape or a prismatic shape, and is configured to allow deformation of the flexible element. The sensor module according to claim 1, further comprising an amplifying unit that amplifies the electric energy.

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