Three-axis sensor, distribution measurement system, distribution measurement program, recording medium, and method for manufacturing three-axis sensor

Abstract

Provided are, inter alia, a distribution measurement system with which it is possible, when measuring pressure or the like at measurement points that are distributed two-dimensionally, to reduce the thickness of the entire distribution measurement system and to precisely measure pressure or the like in a low range, without employing a complicated circuit configuration.　In a measurement element (10) of a three-axis sensor, a stress-sensitive layer (4) is formed so as to straddle a lower electrode (6) on one end side (6r) of the lower electrode (6). An upper electrode (2) is formed on the stress-sensitive layer (4), and the electrodes and the stress-sensitive layer (4) are stacked in close contact with each other. The lower electrode (6) and the upper electrode (2) have regions that overlap in the vertical direction on a plane at the one end side (6r) of the lower electrode (6). The three-axis sensor M is manufactured through a lithography technique. In the three-axis sensor, measurement elements for measuring shear stress in the direction of one axis of the plane and contact stress in the direction of an axis perpendicular to the plane are arranged in the form of a matrix on the plane. The contact pressure (Pc) and / or the shear stress (S) are detected on the basis of a change in electrical resistance of a pair of measurement elements adjacent to each other in the direction of the one axis.

Description

Three-axis sensor, distribution measurement system, distribution measurement program, recording medium, and three-axis sensor manufacturing method

[0001] The present invention relates to a three-axis sensor and a distribution measurement system using a three-axis sensor, and in particular to a three-axis sensor in which measurement elements that measure shear stress in one axis direction of a plane (X-axis or Y-axis direction) and contact stress in an axis direction perpendicular to the plane (Z-axis) are arranged in a matrix on the plane.

[0002] Conventional pressure-sensitive or tactile sensors have a structure in which two electrodes are opposed to each other and a conductive or resin layer is sandwiched between them. These pressure-sensitive sensors detect a physical quantity (e.g., the electrical resistance between the electrodes) that changes when the conductive or resin layer is deformed by an applied force, as pressure or shear stress. Therefore, it is necessary for the force-sensing layer, such as the conductive or resin layer between the opposed electrodes, to have sufficient room to deform in the direction of the force. In other words, the greater the deformation before and after the application of stress, the better the stress can be detected, so it is better for the sensing layer to be easily deformed. To achieve this with the same material, the sensing layer must be thicker. However, this poses a problem in that it hinders the realization of thinner pressure-sensitive sensors.

[0003] Patent Document 1 discloses a tactile sensor that can reduce the thickness of pressure-sensitive sensors. The tactile sensor disclosed in Patent Document 1 is capable of measuring a single measurement point. However, in order to measure two-dimensionally distributed measurement points, it is necessary to route electrodes to each stress measurement area for each measurement point, and a bridge circuit must be constructed for each measurement point. This poses a problem of cumbersome and difficult measurement of two-dimensionally distributed measurement points. Patent Document 2 discloses a distributed measurement system in which sensor units for measuring pressure and the like are arranged two-dimensionally. The distributed measurement system disclosed in Patent Document 2 uses a copper-clad polyimide film, with upper and lower electrodes formed by wet etching, and a pressure-sensitive layer sandwiched between the two electrodes. Therefore, the overall thickness of the distributed measurement system increases, and the adhesion between the electrodes and the pressure-sensitive layer is insufficient, making it difficult to accurately measure low-range pressures and the like.

[0004] International Publication No. 2021 / 039600 International Publication No. 2018 / 084284

[0005] Therefore, the object of the present invention is to solve the above problems and to provide a distribution measurement system etc. that enables precise measurement of low-range pressure etc. when measuring pressure etc. at each measurement point distributed two-dimensionally without using a complicated circuit configuration and by making the entire distribution measurement system thin.

[0006] The three-axis sensor of the present invention is a three-axis sensor in which measurement elements for measuring shear stress in one axis direction of a plane (X-axis or Y-axis direction) and contact stress in an axis direction (Z-axis) perpendicular to the plane are arranged in a matrix on the plane, and the measurement elements for the XZ axes for measuring shear stress in the X-axis direction and contact stress in the Z-axis direction are arranged in every other row of the matrix, and in every other column in each row, and the measurement elements for the YZ axes for measuring shear stress in the Y-axis direction and contact stress in the Z-axis direction are arranged in rows of the matrix where no measurement elements for the XZ axes are arranged, and in columns of each row where no measurement elements for the XZ axes are arranged, and the measurement elements comprise a pair of lower electrodes, a stress-sensitive layer formed across each end side of the pair of lower electrodes, The measurement element has a laminated structure in which an upper electrode formed on the stress-sensitive layer and an upper electrode formed on the stress-sensitive layer are stacked, and at one end of each of the pair of lower electrodes, the lower electrode and the upper electrode have a vertical overlapping area on a two-dimensional plane. When contact pressure is applied to the measurement element in the Z-axis direction, the stress-sensitive layer is compressed, and the electrical resistance between both electrodes (the upper electrode and the lower electrode) decreases. When shear stress is applied to the measurement element in the horizontal direction on the plane, the electrical resistance between both electrodes increases in the direction in which the overlapping area decreases, and decreases in the direction in which the overlapping area increases. Each of the measurement elements is characterized in that one side of the pair of lower electrodes is connected in common in the Y-axis direction by a respective connecting line, and the other side is connected in common in the X-axis direction by a respective connecting line. When contact pressure is applied to the measurement element in the Z-axis direction, the stress-sensitive layer is compressed, increasing the capacitance between the two electrodes (the upper electrode and the lower electrode), and when shear stress is applied to the measurement element in a horizontal direction on the plane, the capacitance between the two electrodes decreases in the direction in which the overlapping area decreases, and the capacitance between the two electrodes increases in the direction in which the overlapping area increases.

[0007] In the triaxial sensor of the present invention, when a contact pressure is applied in the Z-axis direction and / or a shear stress is applied in the horizontal direction, the contact pressure and / or the shear stress can be detected based on a change in the electrical resistance of a pair of measurement elements adjacent to each other in one axis direction in the matrix. Alternatively, the contact pressure and / or the shear stress can be detected based on a change in the electrostatic capacitance of a pair of measurement elements adjacent to each other in the one axis direction in the matrix.

[0008] Here, in the three-axis sensor of the present invention, an inverting amplifier circuit can be further connected to the output end side of the connecting wire in the X-axis direction, in which the resistance between the two lower electrodes of the measuring element connected to the connecting wire is used as the input resistance, and the resistance between the two lower electrodes when no contact pressure or shear stress is applied is used as the feedback resistance.

[0009] Here, in the three-axis sensor of the present invention, when contact pressure and / or shear stress is applied to the measurement element and another measurement element adjacent to the measurement element as a pair, the resistance change between the two lower electrodes of the measurement element and the resistance change between the two lower electrodes of the other measurement element due to contact pressure alone are obtained based on the output voltage of the inverting amplifier circuit for the measurement element and the output voltage of the inverting amplifier circuit for the other measurement element, and based on a relationship between a known contact pressure that has been created in advance and the resistance change between the two lower electrodes of the measurement element in response to that contact pressure obtained by the above principle, when an arbitrary contact pressure and / or shear stress is applied to the measurement element and another measurement element, the arbitrary contact pressure can be obtained using the resistance change between the two lower electrodes of the measurement element obtained based on the above principle and the above relationship.

[0010] Here, in the three-axis sensor of the present invention, when contact pressure and / or shear stress is applied to the measurement element and another measurement element adjacent to the measurement element as a pair, the resistance change between the two lower electrodes of the measurement element and the resistance change between the two lower electrodes of the other measurement element due to shear stress alone are obtained based on the output voltage of the inverting amplifier circuit for the measurement element and the output voltage of the inverting amplifier circuit for the other measurement element, and based on a relationship between a known shear stress and the resistance change between the two lower electrodes of the measurement element obtained in advance using the above principle, when arbitrary contact pressure and / or shear stress is applied to the measurement element and another measurement element, the arbitrary shear stress can be obtained using the resistance change between the two lower electrodes of the measurement element obtained based on the above principle and the above relationship.

[0011] a relay unit configured to select each of the column-wise connecting lines of the matrix in the triaxial sensor based on an input selection signal; an inverting amplifier circuit unit configured of inverting amplifier circuits connected to the output terminals of the row-wise connecting lines of the matrix in the triaxial sensor; a multiplexer unit in which a switch corresponding to each row is connected to the output terminal of each inverting amplifier circuit of the inverting amplifier circuit unit; an A / D converter unit whose input terminal is connected to the multiplexer unit; and a computer connected to the multiplexer unit, the A / D converter unit, and the relay unit; wherein when the computer selects a measurement element corresponding to a row and a column of the matrix, the computer outputs a column selection signal to the relay unit to select a column, and the relay unit selects the connection line corresponding to the column based on the column selection signal, thereby selecting one of a pair of lower electrodes of the measurement element connected to the connection line; A switch selection signal for selecting a switch corresponding to a row is output from the computer to the multiplexer unit, the corresponding switch is selected in the multiplexer unit based on the switch selection signal, and a connection line connected to an inverting amplifier circuit corresponding to the switch is selected, thereby selecting the other side of the pair of lower electrodes in the measurement element connected to the connection line, and the measurement element having both of the pair of lower electrodes selected is selected as the measurement element corresponding to the row and column, and output voltages based on the contact pressure, shear stress in the X-axis direction, and shear stress in the Y-axis direction applied to the selected measurement element are output to the computer via the inverting amplifier circuit unit, multiplexer unit, and A / D conversion unit, and the computer processes the voltages based on the contact pressure, X-axis shear stress, and Y-axis shear stress from the measurement element corresponding to the row and column, and repeatedly outputs a column selection signal and a switch selection signal for selecting the measurement element corresponding to the next row and column.

[0012] In the distribution measurement system of the present invention, the computer comprises: column selection signal control means for outputting to the relay unit a column selection signal that selects a column of the matrix; switch selection signal control means for outputting to the multiplexer unit a switch selection signal that selects a switch corresponding to a row of the matrix; output voltage data recording means for recording output voltage data based on the contact pressure, shear stress in the X-axis direction, and shear stress in the Y-axis direction applied to measurement elements corresponding to the column selected by the column selection signal control means and the row selected by the switch selection signal control means, the output voltage data being output to the computer via the inverting amplifier circuit unit, multiplexer unit, and A / D conversion unit, in a contact pressure recording area, an x-axis shear stress recording area, and a y-axis shear stress recording area; and output voltage data recording means for recording, in the contact pressure recording area, an x-axis shear stress recording area, and a y-axis shear stress recording area, output voltage data of the inverting amplifier circuit for the measurement element recorded in the contact pressure recording area by the output voltage data recording means, and output voltage data of the inverting amplifier circuit for another measurement element adjacent to the measurement element as a pair, a resistance change between the two lower electrodes of the measurement element due only to contact pressure and a resistance change between the two lower electrodes of another measurement element a contact pressure conversion means for obtaining the contact pressure applied to the measurement element and another measurement element based on a predetermined principle of obtaining a change in resistance between the two lower electrodes of the measurement element due to shear stress alone and a change in resistance between the two lower electrodes of another measurement element based on the output voltage data of the inverting amplifier circuit for the measurement element recorded in the contact pressure recording area by the output voltage data recording means and the output voltage data of the inverting amplifier circuit for the other measurement element adjacent to the measurement element as a pair, and based on the predetermined relationship between the known shear stress and the change in resistance between the two lower electrodes of the measurement element due to the shear stress alone; a display means for displaying the contact pressure applied to each measurement element converted by the contact pressure conversion means and the shear stress converted by the shear stress conversion means in a predetermined display format on an output display unit of the computer;and repeating means for repeating each process from the column selection signal control means.

[0013] In the distribution measurement system of the present invention, the predetermined principle in the contact pressure conversion means is to calculate the input voltage (E) to the triaxial sensor, the feedback resistance (R ｆ ), the input resistance (R ０ ), the change in resistance due to contact pressure at the measuring element (1) and at the other measuring element (2) (ΔR Ｘ１ｐ , ΔR Ｘ２ｐ ), the output voltages (V １ , V ２ ), then, as shown in the following equation 8,

[0014] Each output voltage of the inverting amplifier circuit (V １ , V ２ ) to calculate the resistance change (ΔR Ｘ１ｐ ) and the resistance change between the two lower electrodes of another measuring element (ΔR Ｘ２ｐ ) can be obtained.

[0015] In the distribution measurement system of the present invention, the predetermined principle in the shear stress conversion means is to calculate the input voltage (E) to the triaxial sensor, the feedback resistance (R ｆ ), the input resistance (R ０ ), the change in shear stress resistance (ΔR Ｘ１τ , ΔR Ｘ２τ ), the output voltages (V １ , V ２ ) then, as shown in the following equation 2,

[0016] The output voltage of the inverting amplifier circuit (V １ , V ２ ) to calculate the resistance change (ΔR Ｘ１τ ) and the resistance change between the two lower electrodes of another measuring element (ΔR Ｘ２τ ) can be obtained.

[0017] Here, in the distribution measurement system of the present invention, the predetermined display format in the display means arranges the display of the measurement elements in correspondence with the matrix, and for each measurement element, the magnitude of the contact pressure is indicated by a predetermined color, and the shear stress obtained by combining the x-axis shear stress and the y-axis shear stress can be indicated as a vector.

[0018] The distribution measurement program of the present invention is a distribution measurement program that operates the computer in the distribution measurement system of the present invention, and includes a column selection signal control step of causing the computer to output to the relay unit a column selection signal that selects a column of the matrix; a switch selection signal control step of causing the computer to output to the multiplexer unit a switch selection signal that selects a switch corresponding to a row of the matrix; an output voltage data recording step of recording output voltage data based on contact pressure, shear stress in the X-axis direction, and shear stress in the Y-axis direction applied to measurement elements corresponding to the column selected in the column selection signal control step and the row selected in the switch selection signal control step, the output voltage data being output to the computer via the inverting amplifier circuit unit, multiplexer unit, and A / D converter, in a contact pressure recording area, an x-axis shear stress recording area, and a y-axis shear stress recording area for each measurement element; a contact pressure conversion step of obtaining the contact pressure applied to the measurement element and another measurement element based on a predetermined principle of obtaining a resistance change between the two lower electrodes of the measurement element and a resistance change between the two lower electrodes of another measurement element due to contact pressure alone, based on output voltage data from a circuit, and a previously created relationship between a known contact pressure and a resistance change between the two lower electrodes of the measurement element for that contact pressure, obtained by the aforementioned principle; a shear stress conversion step of obtaining the shear stress applied to the measurement element and another measurement element based on a predetermined principle of obtaining a resistance change between the two lower electrodes of the measurement element and a resistance change between the two lower electrodes of another measurement element due to shear stress alone, based on output voltage data from an inverting amplifier circuit for the measurement element recorded in the contact pressure recording area in the output voltage data recording step and output voltage data from an inverting amplifier circuit for another measurement element adjacent to the measurement element as a pair, and a previously created relationship between a known shear stress and a resistance change between the two lower electrodes of the measurement element for that shear stress, obtained by the aforementioned principle; and the contact pressure applied to each measurement element converted in the contact pressure conversion step.The distribution measurement program includes a display step of displaying the shear stress converted in the shear stress conversion step on the output display unit of the computer in a predetermined display format, and a repeat step of specifying measurement elements corresponding to the next row and column and repeating each process from the column selection signal control means.

[0019] The recording medium of the present invention is a computer-readable recording medium on which the distribution measurement program of the present invention is recorded.

[0020] The three-axis sensor manufacturing method of the present invention is a three-axis sensor manufacturing method for manufacturing the three-axis sensor of the present invention, and is characterized by comprising: a first lower electrode layer forming step of printing a first lower electrode layer on a polyimide film substrate using a first pattern that forms the columns of the matrix; an insulating layer forming step of applying photoresist to the first lower electrode layer formed in the first lower electrode layer forming step and exposing the photoresist using a predetermined mask to form an insulating layer that insulates the intersections of the X-axis and Y-axis connection lines; a second lower electrode layer forming step of printing a second lower electrode layer on the first lower electrode layer on which the insulating layer has been formed in the insulating layer forming step using a second pattern that forms the rows of the matrix; a stress-sensitive layer forming step of forming the stress-sensitive layer by screen printing that applies conductive ink using a predetermined mask on the first lower electrode layer and second lower electrode layer after the second lower electrode layer forming step; and an upper electrode layer forming step of forming the upper electrode on the stress-sensitive layer formed in the stress-sensitive layer forming step.The three-axis sensor of the present invention is a three-axis sensor in which measurement points for measuring shear stress in one axis direction of a plane (X-axis or Y-axis direction) and contact stress in an axis direction (Z-axis) perpendicular to the plane are arranged in a matrix on the plane, and the measurement points include two XZ-axis measurement elements arranged side by side in the X-axis direction to measure shear stress in the X-axis direction and contact stress in the Z-axis direction, and two YZ-axis measurement elements arranged side by side in the Y-axis direction to measure shear stress in the Y-axis direction and contact stress in the Z-axis direction, and the measurement elements for the XZ axes and the YZ axes are arranged without overlapping between each measurement point, and the measurement elements include a pair of lower electrodes, a stress-sensitive layer formed across each end side of the pair of lower electrodes, and an upper electrode formed on the stress-sensitive layer. and a pair of lower electrodes, each of which has a laminated structure, and at one end of each of the pair of lower electrodes, the lower electrode and the upper electrode have a vertical overlapping area on a two-dimensional plane; when contact pressure is applied to the measurement element in the Z-axis direction, the stress-sensitive layer is compressed, and the electrical resistance between both electrodes (the upper electrode and the lower electrode) decreases; and when shear stress is applied to the measurement element in the horizontal direction on the plane, the electrical resistance between both electrodes increases in the direction in which the overlapping area decreases, and decreases in the direction in which the overlapping area increases; and each of the measurement elements is characterized in that one side of the pair of lower electrodes is connected in common in the Y-axis direction by a respective connecting line, and the other side is connected in common in the X-axis direction by a respective connecting line.

[0021] The triaxial sensor of the present invention can be configured to have measurement elements arranged in a matrix on a plane, each measuring a shear stress in one axis (X-axis or Y-axis) of the plane and a contact stress in an axis (Z-axis) perpendicular to the plane. When a contact pressure is applied to the triaxial sensor in the Z-axis direction and / or a shear stress is applied horizontally, the contact pressure and / or shear stress can be detected based on a change in the electrical resistance of a pair of measurement elements adjacent to each other in the one axis (X-axis or Y-axis) in the matrix. In other words, the triaxial sensor M of the present invention has the advantage of providing a distribution measurement system or the like that enables measurement of contact pressure and / or shear stress at each measurement point distributed two-dimensionally without requiring a complex circuit configuration.

[0022] The principle of contact pressure measurement in the triaxial sensor of the present invention is as follows. When contact pressure and / or shear stress are applied to a measurement element and another measurement element adjacent to the measurement element, the resistance change between the two lower electrodes of the measurement element due to contact pressure alone and the resistance change between the two lower electrodes of the other measurement element can be obtained based on the output voltage of the inverting amplifier circuit for the measurement element and the output voltage of the inverting amplifier circuit for the other measurement element. A relationship between a known contact pressure and the resistance change between the two lower electrodes of the measurement element obtained using the above principle for that contact pressure is created in advance. When an arbitrary contact pressure and / or shear stress is applied to the measurement element and the other measurement element, an arbitrary contact pressure can be obtained using the resistance change between the two lower electrodes of the measurement element obtained based on the above principle and the above relationship.

[0023] The principle of shear stress measurement in the triaxial sensor of the present invention is as follows: When contact pressure and / or shear stress is applied to a measurement element and another adjacent measurement element X as a pair of measurement elements, the resistance change between the two lower electrodes of the measurement element X due to shear stress alone and the resistance change between the two lower electrodes of the other measurement element can be obtained based on the output voltage of the inverting amplifier circuit for the measurement element and the output voltage of the inverting amplifier circuit for the other measurement element. A relationship between a known shear stress and the resistance change between the two lower electrodes of the measurement element obtained based on the above principle for that shear stress is previously created. When an arbitrary contact pressure and / or shear stress is applied to the measurement element and the other measurement element, an arbitrary shear stress S can be obtained using the resistance change between the two lower electrodes of the measurement element obtained based on the above principle and the above relationship.

[0024] The distribution measurement system of the present invention can be configured to include a relay unit configured to select each column-wise connection line of the matrix in the triaxial sensor based on an input selection signal, a measurement unit consisting of the triaxial sensor, an inverting amplifier circuit unit composed of inverting amplifier circuits connected to the output ends of the row-wise connection lines of the matrix in the triaxial sensor, a multiplexer unit in which a switch corresponding to each row is connected to the output side of each inverting amplifier circuit of the inverting amplifier circuit unit, an A / D converter whose input side is connected to the multiplexer unit, and a computer connected to the multiplexer unit, the A / D converter, and the relay unit. This has the advantage that each process in the distribution measurement sensor system can be performed by software using a computer.

[0025] According to the method for manufacturing a three-axis sensor of the present invention, the three-axis sensor can be manufactured using lithography technology used in semiconductor manufacturing. Therefore, compared to Patent Document 2 and the like, it is possible to achieve a thinner three-axis sensor by stacking the layers more closely together. As a result, compared to Patent Document 2 and the like, it is possible to more accurately and stably measure lower range contact pressures and shear stresses.

[0026] 5 is a diagram showing the conductive ink used as the material of the stress-sensitive layer for measuring contact pressure and shear stress in the triaxial sensor of the present invention; FIG. 6 is a diagram showing the principle of contact pressure measurement in the measuring element 10 of the triaxial sensor of the present invention; FIG. 7 is a diagram showing the principle of shear stress measurement in the measuring element 10 of the triaxial sensor of the present invention; FIG. 8 is a diagram showing the cross-sectional structure, perspective view, and pair of measuring elements of the measuring element 10 of the triaxial sensor of the present invention; FIG. 9 is a diagram showing the triaxial sensor M of the present invention in which the measuring elements 10 and the like are arranged in a matrix; FIG. 10 is an enlarged view of the measuring point Mp shown surrounded by a chain line in FIG. 5; ｉ An inverting amplifier circuit Ca connected to the ｉ1 is a diagram showing a distribution measurement system 20 of the present invention. It is a photograph showing photographs of devices, etc. actually used in the distribution measurement system 20. It is a diagram showing an inverting amplifier circuit used in explaining the present principle. It is a diagram showing a functional block 30 showing functions, etc. of the computer PC 26. It is a flowchart showing the processing flow of a distribution measurement program that operates the computer PC 26 in the distribution measurement system 20 of the present invention. It is a block diagram showing the internal circuit 50 of the computer PC 26 that executes the distribution measurement program of the present invention. It is a diagram showing a pattern (first pattern) of the lower electrode 6-1 formed using an inkjet printer. It is a photograph of the state in which the lower electrode 6-1 is heated at approximately 423 K by a sheet heater using an inkjet printer. It is a photograph showing the pattern of the lower electrode 6-1 printed on a substrate. It is a diagram showing a predetermined mask (insulating pattern). It is a diagram showing a pattern (second pattern) of the lower electrode 6-2 formed using an inkjet printer. It is a diagram showing the printed lower electrode 6-2. It is a diagram showing a CAD pattern of a mask for screen printing. It is a diagram showing the state in which it is coated with conductive ink. It is a diagram showing the pattern of the upper electrode 2 that has been formed. It is a diagram showing the printed upper electrode 2. It is a photograph showing a manufactured three-axis sensor. 1 is a diagram showing a material testing device 80 used for calibrating contact pressure; FIG. 2 is a diagram showing a calibration system 90 used for calibrating shear stress; FIG. 3 is a graph showing the results of a calibration test for contact pressure; FIG. 4 is a graph showing the results of a calibration test for shear stress in the X-axis direction; FIG. 5 is a graph showing the results of a calibration test for shear stress in the Y-axis direction; FIG. 6 is a diagram showing an example of display on the display 28 by the display unit 36 ​​when contact pressure and shear stress are applied; FIG. 7 is a diagram showing an example of display on the display 28 by the display unit 36 ​​when different contact pressure and shear stress are applied; ｉｊ 10 is a diagram showing an example of the arrangement of measurement elements E in a three-axis sensor G in Example 8. ｉｊ FIG. 10 is a diagram illustrating an example of the arrangement of the

[0027] The objective of the triaxial sensor, distributed measurement system, etc. of the present invention is to provide a distributed measurement system, etc., that enables precise measurement of pressures, etc. in a low range (low pressure measurement range) without requiring a complicated circuit configuration and by reducing the overall thickness of the distributed measurement system when applying the tactile sensor, etc., of Patent Document 1 to the distributed measurement system of Patent Document 2. Therefore, first, we will briefly explain the main differences between the background art and the present invention. In the distributed measurement system of Patent Document 2, the upper electrodes of the sensor units are "upper electrodes commonly used for measuring shear stress and contact pressure," and "each upper electrode of each sensor unit is commonly connected in the column direction." In contrast, in the triaxial sensor of the present invention, the upper electrodes are formed independently for each measurement element and are not commonly connected with other upper electrodes. In each measurement element of the triaxial sensor of the present invention, one side of a pair of lower electrodes is commonly connected in the Y-axis direction by respective connecting lines, and the other side is commonly connected in the X-axis direction by respective connecting lines. Furthermore, in the distributed measurement system of Patent Document 2, "the upper electrodes and the lower electrodes are made of copper-clad polyimide film." In other words, a copper-clad polyimide film + lower electrode + pressure-sensitive layer and a pressure-sensitive layer + upper electrode + copper-clad polyimide film were prepared and then stacked so that both pressure-sensitive layers were in contact, resulting in a configuration in which substrates were installed on both ends. In contrast, the triaxial sensor of the present invention uses a manufacturing method in which an electrode layer is printed on a polyimide film substrate using lithography. Therefore, the configuration is such that a substrate is installed on only one side, i.e., polyimide film substrate + lower electrode + pressure-sensitive layer + upper electrode. Therefore, the overall thickness is significantly thinner than the distribution measurement system of Patent Document 2. Each embodiment will be described in detail below with reference to the drawings.

[0028] First, we will explain the measurement element of the triaxial sensor of the present invention, and then we will explain the triaxial sensor in which the measurement element is arranged. Figure 1 shows the conductive ink 1 (Henkel®, LOCTITE® ECI 7004HR E&C) used as the material of the stress-sensitive layer that measures contact pressure and shear stress in the triaxial sensor of the present invention. The conductive ink uses carbon particles as a conductive filler that imparts conductivity to the resin. When contact pressure is applied, the carbon particles come into contact with each other, forming a conductive path, reducing electrical resistance.

[0029] 2(A) and 2(B) show the principle of contact pressure measurement in the measurement element 10 of the triaxial sensor of the present invention. In FIGS. 2(A) and 2(B), reference numeral 2 denotes the upper electrode of the measurement element 10, 4 denotes the conductive ink layer (stress-sensitive layer), 6 denotes the lower electrode, and r denotes the distance in the thickness direction between the upper electrode 2 and the lower electrode 6 in the stress-sensitive layer 4. When contact pressure Pc acts on the measurement element 10 in the Z-axis direction (the thickness direction), deformation in the Z-axis direction occurs in the stress-sensitive layer 4, as shown in FIG. 2(B). As a result, in the stress-sensitive layer 4, the distance in the thickness direction between the upper electrode 2 and the lower electrode 6 becomes r', which is shorter than the original distance r, and the electrical resistance of the measurement element 10 decreases.

[0030] 3A and 3B show the principle of measuring shear stress in the measuring element 10 of the three-axis sensor of the present invention. In FIGS. 3A and 3B, the same reference numerals as in FIG. 2 indicate the same elements, and therefore their explanations will be omitted. In FIGS. 3A and 3B, the reference numeral Ao indicates the overlapping region where the upper electrode 2 and the lower electrode 6 overlap in the Z-axis direction. Here, when shear stress Sx acts on the measuring element 10 in the X-axis direction, as shown in the right diagram of FIG. 3B, if the shear stress Sx is on the positive side in the X-axis direction, the overlapping region Ao decreases, and the electrical resistance of the measuring element 10 increases. On the other hand, as shown in the left diagram of FIG. 3B, when shear stress Sx acts on the measuring element 10 ... Ｘ When the voltage V is on the negative side of the X-axis direction, the overlap area Ao increases, and therefore the electrical resistance in the measurement element 10 decreases.

[0031] FIG. 4A shows the cross-sectional structure of the measuring element 10 of the triaxial sensor of the present invention. In FIG. 4A, the same reference numerals as in FIG. 2 indicate the same elements, and therefore their explanations are omitted. As shown in FIG. 4A, the stress-sensitive layer 4 is formed on one end side 6r of the lower electrode 6 (to the right of the lower electrode 6 in FIG. 4A) so as to straddle the lower electrode 6. The upper electrode 2 is formed on the stress-sensitive layer 4. As shown in FIG. 4A, the lower electrode 6 and the stress-sensitive layer 4, and the stress-sensitive layer 4 and the upper electrode 2 are closely stacked together. On the one end side 6r of the lower electrode 6, the lower electrode 6 and the upper electrode 2 have a vertically overlapping region (overlap region Ao, which is approximately rectangular in plan view) (via the stress-sensitive layer 4) on a plane. When a voltage is applied to the measuring element 10, the current path is as shown in FIG. 4A, i.e., the current I in the lower electrode 6. Ｌ The current I passing through the stress-sensitive layer 4 from Ｃ and the current I Ｕ (Strictly speaking, it is in the depth direction of the drawing).

[0032] 4(B) shows a perspective view of the measuring element 10. In FIG. 4(B), the same reference numerals as in FIG. 4(A) indicate the same elements, and therefore the description thereof will be omitted. As shown in FIG. 4(B), the lower electrode 6 of the measuring element 10 is composed of a pair of lower electrodes 6-1 and 6-2. This is because the electrical resistance value R of the measuring element 10 is determined by the following formula: Ｘ１ The stress-sensitive layer 4 is provided to measure the stress. The stress-sensitive layer 4 is formed across (bridges) one end 6r-1 of the pair of lower electrodes 6-1 and one end 6r-2 of the lower electrode 6-2. However, on the one end 6r-1, similar to the one end 6r shown in FIG. 4A, the lower electrode 6-1 and the upper electrode 2 have a vertically overlapping region (an overlapping region similar to the overlapping region Ao shown in FIG. 4A) on a plane, where the stress-sensitive layer 4 is interposed between the lower electrode 6-1 and the upper electrode 2. Similarly, on the other end 6r-2, the lower electrode 6-2 and the upper electrode 2 have a vertically overlapping region (an overlapping region similar to the overlapping region Ao shown in FIG. 4A) on a plane, where the stress-sensitive layer 4 is interposed between the lower electrode 6-2 and the upper electrode 2. Therefore, as shown in FIG. 4B, the current path is such that the current I Ｌ２ , a current (not shown) flowing from the lower electrode 6-2 to the stress-sensitive layer 4, and a current I flowing through the upper electrode 2.Ｕ , a current (not shown) flowing from the stress-sensitive layer 4 to the lower electrode 6-1, and a current I flowing through the lower electrode 6-1. Ｌ１ This becomes:

[0033] Referring to FIG. 4B, a shear stress S Ｒ When a force (from left to right in the figure) is applied, the overlapping area Ao increases and the electrical resistance R between the upper electrode 2 and the lower electrodes 6-1 and 6-2 increases. Ｘ１ On the other hand, the shear stress S Ｌ When a force (direction from right to left in the figure) is applied, the overlapping area Ao decreases and the electrical resistance R between the upper electrode 2 and the lower electrodes 6-1 and 6-2 decreases. Ｘ１ Therefore, the shear stress acting on the measuring element 10 can be measured based on the relationship between the change in the electrical resistance value and the shear stress.

[0034] FIG. 4(C) shows a pair of measurement elements, two of the above-mentioned measurement elements 10 (measurement elements 10 and 10'), arranged on one axis (X axis) on the XY plane. In FIG. 4(C), the same reference numerals as in FIG. 4(B) indicate the same elements, and therefore their explanations will be omitted. Elements on the measurement element 10' side are indicated by adding a dash (') to the corresponding elements on the measurement element 10 side. As shown in FIG. 4(C), the pair of measurement elements are arranged symmetrically on the left and right along one axis (X axis) on the plane, with the pair of lower electrodes 6-1 and 6-2 of the measurement element 10 and the pair of lower electrodes 6-1' and 6-2' of the measurement element 10' facing each other. The electrical resistance value between the lower electrodes 6-1 and 6-2 is represented by R Ｘ１ , the electrical resistance between the lower electrodes 6-1′ and 6-2′ is R Ｘ２ It was decided.

[0035] As described above, the shear stress S is applied to the measurement element 10 in the horizontal direction (X-axis direction). Ｘ When the voltage V is applied, the overlap area Ao decreases or increases depending on the horizontal direction, and the electrical resistance R between the upper electrode 2 and the lower electrode 6-1, etc. Ｘ１ The same applies to the case of the measuring element 10 shown in FIG. 4C, where a shear stress S ＲWhen the electric field (from left to right in the figure) is applied, the overlapping area Ao increases and the electrical resistance R between the upper electrode 2 and the lower electrode 6-1 etc. Ｘ１ On the other hand, in the case of the measuring element 10′, the same shear stress S Ｒ When the voltage V is applied, the overlapping area Ao' decreases and the electrical resistance R between the upper electrode 2' and the lower electrode 6-1', etc. Ｘ２ Similarly, in the reverse direction, the shear stress S Ｌ When a force (from left to right in the figure) is applied, the overlapping area Ao decreases and the electrical resistance R between the upper electrode 2 and the lower electrode 6-1, etc. Ｘ１ On the other hand, in the case of the measuring element 10′, the same shear stress S Ｌ When the voltage V is applied, the overlapping area Ao' increases and the electrical resistance R between the upper electrode 2' and the lower electrode 6-1' etc. Ｘ２ Therefore, the electrical resistance R of each of the pair of measuring elements 10 and 10′ decreases. Ｘ１ Changes in and R Ｘ２ By subtracting the change in the shear stress S Ｒ , S Ｌ can be detected.

[0036] Next, a three-axis sensor of the present invention using the above-mentioned measuring elements 10 and the like will be described. Fig. 5 shows a three-axis sensor M of the present invention in which the measuring elements 10 and the like are arranged in a matrix. As shown in Fig. 5, the horizontal direction is the X axis and the vertical direction is the Y axis. The Z axis is not shown, but is perpendicular to the paper surface and faces towards the viewer. The measuring elements 10 and the like are arranged in a matrix with the upper left corner of the drawing as the origin, and the E ｉｊ , i=1 to 9, j=1 to 9. For example, the measurement element 10 in the first row and second column of the three-axis sensor M is the measurement element E １２ The same applies below. However, 9 rows x 9 columns is an example, and the number of rows and columns of the three-axis sensor M of the present invention is not limited to this. As shown in Figure 5, the three-axis sensor M of the present invention has a measuring element E that measures shear stress in one axis direction (X-axis or Y-axis direction) of a plane and contact stress in the axis direction (Z-axis) perpendicular to the plane. ｉｊAs described above with reference to FIG. 4C, the shear stress in the X-axis direction is measured by two measurement elements (for example, E ２１ and E ２３ and ), and the shear stress in the Y direction is measured by the measuring element in the Y (column) direction (e.g., E １２ and E ３２ That is, in the three-axis sensor M, the measuring element E for the XZ axis measures the shear stress in the X-axis direction and the contact stress in the Z-axis direction. ｉｊ are arranged in every other row (second row, fourth row, ...) of the matrix M, and in each row, are arranged in every other column (first column, third column, ...). On the other hand, the measurement elements E for the YZ axes, which measure the shear stress in the Y-axis direction and the contact stress in the Z-axis direction, ｉｊ is the matrix M plus the measurement element E for the X and Z axes. ｉｊ are arranged in rows where they are not arranged (first row, third row, ...), and in each row where they are arranged, the measuring element E for the X and Z axes ｉｊ The measurement elements E are arranged in rows where the measurement elements E are not arranged (the second row, the fourth row, ...). ｉｊ The layout configuration is easier to understand if you imagine a go board. Measurement elements for the X and Z axes are placed in each row of the grid, not at the intersections of the vertical and horizontal lines of the go board. However, one square is left open in each row. This is repeated, leaving one square open row by row. Measurement elements for the Y and Z axes are placed in rows of the go board where measurement elements for the X and Z axes are not placed (rows that were previously opened). However, in each row, measurement elements for the X and Z axes are placed in columns of the go board where measurement elements for the X and Z axes are not placed (columns of squares that were previously opened). Note that even though it is a go board, the size of the grid is not limited to squares, and the grid can be flexibly deformed, and the size of each grid can also be different.

[0037] Measurement element E ｉｊAs described above with reference to FIGS. 4A and 4B, the measurement element E has a laminated structure including a pair of lower electrodes 6-1 and 6-2, a stress-sensitive layer 4 formed across the ends 6r-1 etc. of the pair of lower electrodes 6-1 etc., and an upper electrode 2 formed on the stress-sensitive layer 4. On the ends 6r-1 etc. of the pair of lower electrodes 6-1 etc., the lower electrodes 6-1 etc. and the upper electrode 2 have an overlapping area Ao in the vertical direction (Z-axis direction) on a two-dimensional plane. As described above with reference to FIGS. 2 and 4C, the measurement element E ｉｊ When a contact pressure Pc is applied to the stress-sensitive layer 4 in the Z-axis direction, the stress-sensitive layer 4 is compressed, and the electrical resistance R between the two electrodes (the upper electrode 2 and the lower electrode 6-1, etc.) ｘ１ As described above with reference to FIGS. 3 and 4C, the measurement element E ｉｊ Shear stress S in the horizontal direction on the plane Ｒ When the voltage is applied, the electric resistance R between the two electrodes decreases in the direction of the overlap area Ao. ｘ１ When the overlapping area Ao increases, the electrical resistance R ｘ１ etc. will decrease.

[0038] As shown in FIG. 5, measuring element E ｉｊ Each of the pair of lower electrodes has one side (6-1 side, shown in red in the original drawing) commonly connected to each connection line (for example, connection line Lf １ ), and the other side (6-2 side, shown in blue in the original drawing) is connected in common in the X-axis direction by each connection line (for example, connection line Ls １ ) are connected.

[0039] FIG. 6 shows an enlarged view of the measurement point Mp shown in FIG. 5 surrounded by a chain line. ｉｊ The lower electrodes 6-1 and 6-2 are E ｉｊ (6-1), E ｉｊ (6-2), and the upper electrode 2 is E ｉｊ (2). For example, the measurement element E １８ The lower electrodes 6-1 and 6-2 are E １８ (6-1), E １８ (6-2), and the upper electrode 2 (green line in the original drawing) is E １８ (2) is represented by the symbol R １８ is the measurement element E １８Both lower electrodes E １８ (6-1) Electrical resistance between equal parts, R ３８ is the measurement element E ３８ Both lower electrodes E ３８ (6-1) Electrical resistance between equal parts, R ２７ is the measurement element E ２７ Both lower electrodes E ２７ (6-1) Interval electrical resistance, R ２９ is the measurement element E ２９ Both lower electrodes E ２９ (6-1) is the electrical resistance between the upper electrode E ｉｊ (2) is the measurement element E ｉｊ Each upper electrode E is formed independently. ｒｓ As in the case described with reference to FIG. 4C, the shear stress S Ｘ is the measurement element E ２７ and the measurement element E adjacent thereto in the X-axis direction ２９ and the shear stress S in the Y-axis direction Ｙ is the measurement element E １８ and the measurement element E adjacent thereto in the Y-axis direction ３８ That is, when a contact pressure Pc is applied to the three-axis sensor M in the Z-axis direction and / or a shear stress S Ｘ When the above-mentioned voltages are applied, a pair of adjacent measurement elements E in one axis (X-axis or Y-axis) direction in the matrix is ｉｊ Electrical resistance R ｉｊ Based on the changes in the contact pressure Pc and / or shear stress S Ｘ As shown in FIG. 6, for example, the lower electrode E １８ The left end of (6-1) and the lower electrode E １８ The width in the X-axis direction between the right end of (6-2) and the bottom electrode E ３８ The width of the lower electrode (6-1) in the X-axis direction is 0.75 mm, and the width in the Y-axis direction is 0.5 mm. ｉｊ The same applies to the upper electrode E. ３８ The width of the other upper electrode E (2) in the X-axis direction is 2.0 mm and the width in the Y-axis direction is 0.5 mm. ｉｊ The same applies to (2). The above sizes are just examples.ｉｊ The sizes of are not limited to these. In this specification, "A and / or B" means A, B, or A and B. The same applies in the claims.

[0040] As described above, according to the first embodiment of the present invention, the three-axis sensor M detects the shear stress S in one axis direction (X-axis or Y-axis direction) on the plane. Ｘ and a measuring element E for measuring the contact stress Pc in the direction of the axis (Z axis) perpendicular to the plane. ｉｊ The three-axis sensor M is arranged in a matrix on the plane. The shear stress S in the X-axis direction Ｘ and the Z-axis contact stress Pc. ｉｊ are arranged in every other row (2nd row, 4th row, ...) of the matrix M, and in each row, are arranged in every other column (1st column, 3rd column, ...). On the other hand, the shear stress S in the Y-axis direction Ｙ and the contact stress Pc in the Z-axis direction. ｉｊ is the matrix M plus the measurement element E for the X and Z axes. ｉｊ are arranged in rows where they are not arranged (first row, third row, ...), and in each row where they are arranged, the measuring element E for the X and Z axes ｉｊ are arranged in columns where no measurement element is arranged (second column, fourth column, ...). ｉｊ Each of the pair of lower electrodes has one side (6-1 side, shown in red in the original drawing) commonly connected to each connection line (for example, connection line Lf １ ), and the other side (6-2 side, shown in blue in the original drawing) is connected in common in the X-axis direction by each connection line (for example, connection line Ls １ ) are connected to the upper electrode E ｉｊ (2) is the measurement element E ｉｊ Each upper electrode E is formed independently. ｒｓ When a contact pressure Pc is applied to the three-axis sensor M in the Z-axis direction and / or a shear stress S Ｘ When the above-mentioned voltages are applied, a pair of adjacent measurement elements E in one axis (X-axis or Y-axis) direction in the matrix is ｉｊ Electrical resistance R Ｘ１Based on the changes in the contact pressure Pc and / or shear stress S Ｒ As described above, the three-axis sensor M of the present invention can provide a distribution measurement system or the like that can measure contact pressure and / or shear stress at each of two-dimensionally distributed measurement points without requiring a complicated circuit configuration.

[0041] In Example 2, an outline of the distribution measurement system 20 of the present invention and the measurement principle of contact pressure and shear stress in the three-axis sensor M will be described. The three-axis sensor M is connected to the connection line Ls in the X-axis direction in FIG. １ An inverting amplifier circuit is further connected to the output terminal side (right side in FIG. 5) of the connecting line Ls ｉ An inverting amplifier circuit Ca connected to the ｉ In FIG. 7, the symbol R １ is the input resistance, and the connection line Ls １ measuring element E connected to ｉｊ Both lower electrodes E ｉｊ (6-1) Resistance R between equal distances ｉｊ Symbol R ２ is the feedback resistance, and the contact pressure Pc and shear stress S Ｘ When no voltage is applied to the lower electrodes E ｉｊ (6-1) is the resistance between the two. The symbol E is the applied voltage, and V is the inverting amplifier circuit Ca. ｉ The output voltage is the resistance R ｉｊ The change in the inverting amplifier circuit Ca ｉ Therefore, the change in the contact pressure Pc or shear stress S Ｘ etc. can be detected by measuring the output voltage V.

[0042] 8 shows a distribution measurement system 20 of the present invention. The operation of the distribution measurement system 20 will be described in detail in Example 3, so only a general configuration will be described here. In FIG. 8, reference numeral 22 denotes a measurement unit consisting of a triaxial sensor M, 21 denotes a relay unit that selects a column j of the triaxial sensor M in the measurement unit 22, and 23 denotes a connection line Ls for each row i of the triaxial sensor M in the measurement unit 22. ｉ Each inverting amplifier circuit C connected to ａｉ2, an inverting amplifier circuit section 23 is configured with a multiplexer 24 that selects the output from the inverting amplifier circuit section 23, an A / D converter 25 that A / D converts the output selected by the multiplexer 24, and a computer such as a PC connected to the A / D converter 25 and the relay section 21. The relay section 21 and the inverting amplifier circuit section 23 form a drive circuit for the three-axis sensor M. The A / D converter 25 used was AI-1664LAX-USB, CONTEC (registered trademark). However, this product is not limited to this. A voltage E is applied to the column j selected by the relay section 21, and the other column k is grounded. When row i is selected by the multiplexer 24, the measurement element E ｉｊ is selected, and the measurement element E ｉｊ Resistance R ｉｊ Inverting amplifier circuit C based on pressure-induced changes ａｉ Output voltage V ｉｊ The measurement result is converted by an A / D converter 25, and then sent to a computer 26 where it is recorded.

[0043] Figure 9 shows a photograph of the devices actually used in the distribution measurement system 20. In Figure 9, the same reference numerals as in Figure 8 indicate the same elements, and therefore their explanation will be omitted. In Figure 9, reference numeral 27 denotes a power supply, and the parts designated by 21 and 23 are drive circuits.

[0044] Next, the principle of measuring contact pressure and shear stress in the three-axis sensor M will be explained. As can be seen from the enlarged view shown in FIG. 6, the measurement point Mp is divided into four measurement elements E ｉｊ Each measurement element E ｉｊ For the sake of convenience, let us read E ２７ X １ , E ２９ X ２ , E １８ Y １ , E ３８ Y ２ Furthermore, the electrical resistance R between the two lower electrodes ｉｊ For convenience of explanation, let us reinterpret this as electrical resistance R ２７ R Ｘ１ , R ２９ R Ｘ２ , R １８ R Ｙ１ , R３８ R Ｙ２ It is called.

[0045] First, let us take the X axis as an example. Each measurement element X １ Electrical resistance R Ｘ１ The change in electrical resistance due to contact pressure alone is ΔR. Ｐ The change in electrical resistance due to shear stress alone is defined as ΔR τ ΔR can be expressed by the following equation 1.

[0046]

[0047] The change in electrical resistance between a pair of adjacent measuring elements can be expressed as in Equations 2 and 3.

[0048]

[0049] Here, ΔR Ｘ１ｐ , ΔR Ｘ２ｐ is the change in electrical resistance due to contact pressure, ΔR Ｘ１Τ , ΔR Ｘ２Τ is the change in electrical resistance due to shear stress in the X-axis direction. As shown in Figure 6, a pair of adjacent measuring elements are installed in opposite directions in the X-axis direction, so when shear stress is applied, the electrical resistance of the pair of adjacent measuring elements changes in opposite directions. Therefore, from Equations 1 to 3, the change in electrical resistance of the pair of adjacent measuring elements ΔR Ｘ１ , ΔR Ｘ２ are expressed as the following equations 4 and 5.

[0050]

[0051] Therefore, Equation 5 expresses the change in electrical resistance due to contact pressure alone as the change in electrical resistance ΔR between a pair of adjacent measurement elements. Ｘ１ , ΔR Ｘ２ can be used to determine using

[0052] As mentioned above, an inverting amplifier circuit is used to determine the change in electrical resistance of each measurement element. Figure 10 shows the inverting amplifier circuit used in the explanation of this principle. In Figure 10, symbol E represents the input voltage to the three-axis sensor M, R ｓ is the resistance of the measurement element (input resistance), R ｆis the feedback resistor. The symbol V is the output voltage, which is given as follows, and Equation 6 can be obtained:

[0053]

[0054] The resistance of the measuring element when no pressure is applied is R ０ and the change in electrical resistance of the three-axis sensor M is ΔR, the following equation 7 can be obtained from equation 6.

[0055]

[0056] Substituting Equation 7 into Equation 5, we obtain Equation 8 below.

[0057]

[0058] Here, V １ , V ２ is the change in electrical resistance between the two measurement elements ΔR Ｘ１ , ΔR Ｘ２ The output voltage of the inverting amplifier circuit reflects the change in electrical resistance due to contact pressure alone. From the output voltages of the two measurement elements, the change in electrical resistance due to contact pressure alone can be obtained. In summary, the principle of measurement of contact pressure Pc in the three-axis sensor M is as follows: １ and measurement element X １ Another measurement element X adjacent to the ２ Contact pressure Pc and / or shear stress S Ｘ Measurement element X when １ The output voltage V of the inverting amplifier circuit １ and another measurement element X ２ The output voltage V of the inverting amplifier circuit ２ Based on this, the resistance change amount ΔR between the two lower electrodes of the constant element X1 due only to the contact pressure Pc is Ｘ１ｐ , and another measurement element X ２ The resistance change ΔR between the two lower electrodes Ｘ２ｐ Similarly, in the case of the Y axis, an equation similar to equation 8 can be obtained, and the same measurement principle is followed.

[0059] Here, the known contact pressure Pm and the measurement element X obtained by the above principle for the contact pressure Pm １ The resistance change amount ΔR between the two lower electrodes Ｘ１ｐThe relationship is created in advance as follows: Since an inverting amplifier circuit is used, R ｓ <R ｆ =R ０ Therefore, |V|>E. When the contact pressure Pm increases, the upper electrode X １ (2) and the lower electrode X １ (6-1), X １ Resistance R between (6-2) Ｘ１ As a result, the lower electrode X １ (6-1), X １ Resistance R between (6-2) Ｘ１ Therefore, the output voltage V on the right side of Equation 8 also decreases. １ , V ２ The absolute value of each negative value |V １ |, |V ２ | further increases from E. Therefore, ΔR on the left side of Equation 8 Ｘ１Ｐ , ΔR Ｘ２Ｐ The resistance change ΔR Ｘ１ｐ If the vertical axis is taken as the feedback resistance R ｆ is R ０ Therefore, when the contact pressure Pm is 0, the line passes through the origin.

[0060] Measurement element X １ and another measuring element X ２ When an arbitrary contact pressure Pc and / or shear stress S is applied to the measuring element X obtained based on the above principle, １ The resistance change amount ΔR between the two lower electrodes Ｘ１ｐ and the above relationship (a straight line sloping downward to the right passing through the origin), any contact pressure Pc can be obtained.

[0061] Next, the principle of measuring shear stress in the three-axis sensor M will be explained. Ｘ１ , ΔR Ｘ２ The difference is expressed as the following equation 9, and equation 10 can be obtained.

[0062]

[0063] Therefore, Equation 10 expresses the change in electrical resistance due to shear stress alone as the change in electrical resistance ΔR between a pair of adjacent measuring elements. Ｘ１ , ΔR Ｘ２ Substituting Equation 7 into Equation 10, we obtain Equation 11 below.

[0064]

[0065] As a result, the change in electrical resistance due to shear stress alone can be obtained from the output voltages of the two measuring elements. To summarize, the principle of measurement of shear stress S in the three-axis sensor M is as follows: Measuring element X １ and measurement element X １ Another measurement element X adjacent to the ２ Contact pressure Pc and / or shear stress S Ｘ Measurement element X when １ The output voltage V of the inverting amplifier circuit １ and another measurement element X ２ The output voltage V of the inverting amplifier circuit ２ Based on this, the shear stress S Ｘ Measurement element X by only １ The resistance change amount ΔR between the two lower electrodes Ｘ１τ and another measuring element X ２ The resistance change ΔR between the two lower electrodes Ｘ２τ In the case of the Y axis, an equation similar to equation 1 can be obtained in the same way, and the same measurement principle is followed.

[0066] Here, the known shear stress Sm and the measurement element X obtained by the above principle for the shear stress Sm are １ The resistance change amount ΔR between the two lower electrodes Ｘ１τ The relationship between the output voltage V and the shear stress Sm is created in advance. The relationship is as follows: When the shear stress Sm increases, the output voltage V １ decreases, and V ２ increases (or the output voltage V １ increases, and V ２ Therefore, the above relationship is expressed as follows: the horizontal axis is the shear stress Pm, and the horizontal axis is the resistance change ΔR Ｘ１τ If the vertical axis is the feedback resistance R, it will be a straight line sloping downward to the right with the origin as the center.ｆ is R ０ Therefore, when the shear stress Sm is 0, the line passes through the origin.

[0067] Measurement element X １ and another measuring element X ２ When an arbitrary contact pressure Pm and / or shear stress Sm is applied to the measuring element X obtained based on the above principle, １ The resistance change amount ΔR between the two lower electrodes Ｘ１τ Using the above relationship (a straight line sloping downward to the right with the origin as the center), any shear stress S can be obtained.

[0068] As described above, according to the second embodiment of the present invention, the principle of measurement of the contact pressure Pc in the three-axis sensor M is as follows: １ and measurement element X １ Another measurement element X adjacent to the ２ Contact pressure Pc and / or shear stress S Ｘ Measurement element X when １ The output voltage V of the inverting amplifier circuit １ and another measurement element X ２ The output voltage V of the inverting amplifier circuit ２ Based on this, the constant element X due to the contact pressure Pc alone １ The resistance change amount ΔR between the two lower electrodes Ｘ１ｐ , and another measurement element X ２ The resistance change ΔR between the two lower electrodes Ｘ２ｐ In the case of the Y axis, an equation similar to equation 8 can be obtained in the same way, and the measurement principle is the same. Here, the known contact pressure Pm and the measurement element X obtained by the above principle for the contact pressure Pm can be calculated. １ The resistance change amount ΔR between the two lower electrodes Ｘ１ｐ The relationship between the measurement element X and the measurement element X is created in advance. １ and another measuring element X ２ Any contact pressure Pc and / or shear stress S Ｘ When the above-mentioned voltages are applied, the measurement element X obtained based on the above principle is １ The resistance change amount ΔR between the two lower electrodes Ｘ１ｐand the above relationship (a straight line sloping downward to the right passing through the origin), any contact pressure Pc can be obtained.

[0069] Measurement element X １ and measurement element X １ Another measurement element X adjacent to the ２ Contact pressure Pc and / or shear stress S Ｘ Measurement element X when １ The output voltage V of the inverting amplifier circuit １ and another measurement element X ２ The output voltage V of the inverting amplifier circuit ２ Based on this, the shear stress S Ｘ Measurement element X by only １ The resistance change amount ΔR between the two lower electrodes Ｘ１τ and another measuring element X ２ The resistance change ΔR between the two lower electrodes Ｘ２τ In the case of the Y axis, an equation similar to Equation 11 can be obtained in the same way, and the measurement principle is the same. Here, the known shear stress Sm and the measurement element X obtained by the above principle for the shear stress Sm are １ The resistance change amount ΔR between the two lower electrodes Ｘ１τ The relationship between the measurement element X and the measurement element X is created in advance. １ and another measuring element X ２ Any contact pressure Pc and / or shear stress S ｘ When the above-mentioned voltages are applied, the measurement element X obtained based on the above principle is １ The resistance change amount ΔR between the two lower electrodes Ｘ１τ Using the above relationship (a straight line sloping downward to the right with the origin as the center), any shear stress S can be obtained.

[0070] In the third embodiment, the distribution measurement system 20 of the present invention, which was briefly mentioned in the second embodiment, will be described in detail with reference to Fig. 8. The distribution measurement system 20 uses the three-axis sensor M described in the first and second embodiments. In Fig. 8, reference numeral 21 denotes each connection line Lf in the column direction of the matrix in the three-axis sensor M. ｊ The input selection signal SEL ｊ22 is a measurement unit consisting of a three-axis sensor M; 23 is a row-direction connection line L of the matrix in the three-axis sensor M; Ｓｊ Each inverting amplifier circuit Ca connected to the output terminal side of ｉ 24 is an inverting amplifier circuit of the inverting amplifier circuit section 23. ｉ On the output side of the switch 24SW corresponding to each row ｉ is connected to a multiplexer unit, 25 is an A / D converter (A / D conversion unit) whose input side is connected to the multiplexer unit 24, and 26 is a computer PC connected to the multiplexer unit 24, the A / D converter 25, and the relay unit 21.

[0071] The relay unit 21 includes power supply terminals (or relay contacts) L1E to L9E connected to the power supply voltage E side and ground terminals L1G to L9G connected to the ground side. ４ When the connection line Lf ４ is connected to the power supply side terminal L4E, and the other connection line Lf ｊ is connected to the ground terminal LjG). ｊ etc., measurement element E ｉｊ The lower electrode E ｉｊ 8 shows nine relay contacts, but this is just an example and the number is not limited to nine. The inverting amplifier circuit 23 is connected to the row-direction connection line Ls of the matrix in the three-axis sensor M. ｉ An inverting amplifier circuit Ca connected to the ｉ The connecting line Ls ｉ etc., measurement element E ｉｊ The lower electrode E ｉｊ (6-2) is connected. In FIG. ｉ Although five switches 24SW are shown, this is an example and the number is not limited to five. The input side of the A / D converter 25 is connected to the switches 24SW constituting the multiplexer unit 24. ｉ (i=1 to 5) to the inverting amplifier circuit Ca of the inverting amplifier circuit unit 23. ｉ is connected to.

[0072] The computer PC 26 calculates the measurement element E corresponding to row i and column j of the matrix. ｉｊ When selecting column j, the operation is as follows: First, the computer PC 26 sends a column selection signal SEL to the relay unit 21 to select column j. ｊ is output, and the column selection signal SEL ｊ The connection line Lf corresponding to the column j based on ｊ is selected, the connection line Lf ｊ measuring element E connected to ｉｊ One side E of the pair of lower electrodes in ｉｊ The switch 24 SWR corresponding to row i is connected from the computer PC 26 to the multiplexer unit 23. ｉ Switch selection signal SEL ｉ is outputted, and the multiplexer unit 24 outputs the switch selection signal SEL ｉ The corresponding switch 24SW ｉ is selected. ｉ Inverting amplifier circuit Ca according to ｉ The connection line Ls connected to ｉ By selecting ｉ measuring element E connected to ｉｊ The other side E of the pair of lower electrodes in ｉｊ (6-2) is selected. As a result, the measurement element E ｉｊ is the measurement element E corresponding to row i and column j ｉｊ is selected as.

[0073] Selected measurement element E ｉｊ The contact pressure Pc applied to the ｘ , shear stress S in the Y-axis direction ｙ Output voltage V based on １ etc. are output to the computer PC 26 via the inverting amplifier circuit section 23, the multiplexer section 24 and the A / D converter section 25. As a result, the computer PC 26 receives the measurement element E corresponding to the row i and the column j. ｉｊ Contact pressure Pc from the X-axis shear stress S ｘ , Y-axis shear stress S ｙ Voltage V based on ｉetc., and selects the measurement element corresponding to the next row i+1 and column j. ｊ , switch selection signal SEL ｉ＋１ Repeatedly outputting

[0074] 11 is a diagram showing a function block 30 showing the functions of the computer PC 26. In the function block 30, reference numeral 40 indicates a recording area for data, etc. As shown in FIG. 11, the computer PC 26 outputs a column selection signal SEL ｊ to the relay unit 21, and a switch selection signal SEL ｉ and a switch selection signal control section (switch selection signal control means) 32 that outputs the signal to the multiplexer section 24.

[0075] The output voltage data recording unit (output voltage data recording means) 33 records the measurement element E corresponding to the column j selected by the column selection signal control unit 31 and the row i selected by the switch selection signal control unit 32. ｉｊ The contact pressure Pc applied to the ｘ , shear stress S in the Y-axis direction ｙ Output voltage V based on １ The output voltage data V is output to the computer PC 26 via the inverting amplifier circuit 23, the multiplexer 24, and the A / D converter 25. １ These are recorded in a contact pressure recording area (contact pressure recording region) 41, an X-axis shear stress recording area (X-axis shear stress recording region) 42, and a Y-axis shear stress recording area (Y-axis shear stress recording region) 43 for each measurement element.

[0076] The contact pressure conversion unit (contact pressure conversion means) 34 converts the measurement element E recorded in the contact pressure recording area 41 by the output voltage data recording unit 33. ｉｊ Inverting amplifier circuit Ca ｉ Output voltage data V １ etc., and measurement element R ｉｊ Another measuring element E adjacent to ｉ、ｊ＋２ Inverting amplifier circuit Ca for ｉ Output voltage data V２ Based on the above, the measurement element E is determined by the contact pressure Pc alone. ｉｊ The resistance change ΔR between the two lower electrodes ｉｊｐ and another measuring element E ｉ、ｊ＋２ The resistance change ΔR between the two lower electrodes ｉ、ｊ＋２　ｐ and a predetermined principle of obtaining a known contact pressure Cm and a measurement element E obtained by the above principle for the contact pressure Cm. ｉｊ The resistance change ΔR between the two lower electrodes ｉｐ Based on the relationship between the measurement element E ｉｊ and another measuring element E ｉ、ｊ＋２ The above explanation is for a pair of adjacent measurement elements in the X-axis direction. In the case of a pair of adjacent measurement elements in the Y-axis direction, the contact pressure Cp applied to the measurement elements R ｉｊ and another adjacent measuring element E ｉ＋２、ｊ etc.

[0077] The shear stress conversion unit (shear stress conversion means) 35 converts the measured element E recorded in the contact pressure recording area 41 by the output voltage data recording unit 33 into the shear stress. ｉｊ Inverting amplifier circuit Ca ｉ Output voltage data V １ etc. and measurement element E ｉｊ Another measuring element E adjacent to ｉ、ｊ＋２ Inverting amplifier circuit Ca for ｉ Output voltage data V １ Based on the above, the shear stress S Ｘ Measurement element E by only ｉｊ The resistance change ΔR between the two lower electrodes ｉｊτ and another measuring element E ｉ、＋２ｊ The resistance change ΔR between the two lower electrodes ｉ、ｊ＋２　τ A predetermined principle is to obtain a known shear stress Sm and a measurement element E obtained by the above principle for the shear stress Sm. ｉｊ The resistance change ΔR between the two lower electrodes ｉτ Based on the relationship between the measurement element E ｉｊ and another measuring element E ｉ、ｊ＋２ The shear stress S applied to ＸThe above explanation is for a pair of measurement elements adjacent in the X-axis direction, and for a pair of measurement elements adjacent in the Y-axis direction, measurement element R ｉｊ and another adjacent measuring element E ｉ＋２、ｊ etc.

[0078] The display unit (display means) 36 displays the measured values ​​E converted by the contact pressure conversion unit 34. ｉｊ and the shear stress S converted by the shear stress conversion unit 35. Ｘ The repeating unit (repeating means) 37 displays the measurement element E corresponding to the next column j+1 and row i in a predetermined display format. ｉ，ｊ＋１ The above is repeated until all the columns and rows are reached. ｉｊ The contact pressure and shear stress can be displayed as a two-dimensional distribution. Reference numeral 29 denotes an input device such as a keyboard or a mouse.

[0079] The predetermined principle of the contact pressure conversion unit is to convert the input voltage (E) to the three-axis sensor M, the feedback resistance (R ｆ ), the input resistance (R ０ ), measurement element (X １ ) and another measurement element (X ２ ) the change in resistance (ΔR Ｘ１ｐ , ΔR Ｘ２ｐ ), the output voltages (V １ , V ２ ), then, as shown in the above-mentioned equation 8, each output voltage (V １ , V ２ ) to calculate the resistance change (ΔR Ｘ１ｐ ) and the resistance change between the two lower electrodes of another measuring element (ΔR Ｘ２ｐ ) can be obtained.

[0080] The predetermined principle of the shear stress conversion unit 35 is to calculate the input voltage (E) to the three-axis sensor M, the feedback resistance (R ｆ ), the input resistance (R ０ ), measurement element (X １ ) and another measurement element (X ２ ) change in shear stress resistance (ΔR Ｘ１τ , ΔR Ｘ２τ ), the output voltages (V １ , V ２ ), then, as shown in the above-mentioned equation 11, the output voltage (V １ , V ２ ) to calculate the resistance change (ΔR Ｘ１τ ) and the resistance change between the two lower electrodes of another measuring element (ΔR Ｘ２τ ) can be obtained.

[0081] The predetermined display format in the display unit 36 ​​is a matrix of measurement elements E ｉｊ and the measurement element E ｉｊ For each test, the magnitude of the contact pressure Pc is indicated by a predetermined color, and the X-axis shear stress S ｘ and Y-axis shear stress S ｙ The shear stress S obtained by combining the above is displayed as a vector. A specific example will be described in Example 6.

[0082] 12 is a flowchart showing the processing flow of the distribution measurement program that operates the computer PC 26 in the distribution measurement system 20 of the present invention. As shown in FIG. 12, first, the number of rows of the matrix is ​​set to m, the number of columns is set to n, and row i is set to 1 (step S10). Next, column j is set to 1 (step S12). A column selection signal SEL that selects column j of the matrix is ｊ to the relay unit 21 (column selection signal control step, step S14). ｉ Switch selection signal SEL ｉto the multiplexer unit 24 (switch selection signal control step, step S16). The measurement element E corresponding to the column j selected in the column selection signal control step (step S14) and the row i selected in the switch selection signal control step (step S16) is ｉｊ The contact pressure Pc applied to the ｘ , shear stress S in the Y-axis direction ｙ Output voltage V based on １ The output voltage data V is output to the computer PC 26 via the inverting amplifier circuit 23, the multiplexer 24, and the A / D converter 25. １ etc., for each measurement element E ｉｊ The output voltage data is recorded in the contact pressure recording area 41, the X-axis shear stress recording area 42, and the Y-axis shear stress recording area 43 (output voltage data recording step, step S18).

[0083] Measurement element E recorded in the contact pressure recording area 41 in the output voltage data recording step (step S18) ｉｊ Inverting amplifier circuit Ca ｉ Output voltage data V １ etc., and measurement element E ｉｊ Another measuring element E adjacent to ｉ＋２，ｊ Inverting amplifier circuit Ca ｉ＋２ Output voltage data V ２ Based on the above, the measurement element E is determined by the contact pressure Pc alone. ｉｊ The resistance change ΔR between the two lower electrodes ｉｐ and another measuring element E ｉ＋２、ｊ The resistance change ΔR between the two lower electrodes ｉ＋２、ｐ and a predetermined principle of obtaining a known contact pressure Pm and a measurement element E obtained by the above principle for the contact pressure Pm. ｉｊ The resistance change ΔR between the two lower electrodes ｉｐ Based on the relationship between the measurement element E ｉｊ and another measuring element E ｉ＋２、ｊ The contact pressure Cp applied to the contact points is calculated (contact pressure conversion step, step S20).

[0084] Measurement element E recorded in the contact pressure recording area 41 in the output voltage data recording step (step S18) ｉｊInverting amplifier circuit Ca ｉ Output voltage data V １ etc. and measurement element E ｉｊ Another measuring element E adjacent to ｉ＋２，ｊ Inverting amplifier circuit Ca ｉ＋２ Output voltage data V ２ Based on the above, the shear stress S Ｒ Measurement element E by only ｉｊ The resistance change ΔR between the two lower electrodes ｉτ and another measuring element E ｉ＋２，ｊ The resistance change ΔR between the two lower electrodes ｉ＋２τ A predetermined principle is to obtain a known shear stress Sm and a measurement element E obtained by the above principle for the shear stress Sm. ｉｊ The resistance change ΔR between the two lower electrodes ｉτ Based on the relationship between the measurement element E ｉｊ and another measuring element E ｉ＋２，ｊ The shear stress S applied to Ｒ etc. are obtained (shear stress conversion step, step S22).

[0085] Each measurement element E converted in the contact pressure conversion step (step S20) ｉｊ and the shear stress S converted in the shear stress conversion step (step S22). Ｒ etc. are displayed in a predetermined display format on the display 28 of the computer PC 26 (display step, step S24). ｉ，ｊ＋１ is specified, and each process from the column selection signal control step (step S14) is repeated (repeated step, step S26). When the number of columns exceeds the number of columns n, row i+1 is set and the process is repeated from step S12 (step S30). When the number of rows exceeds the number of rows m, one scan of the measurement surface is completed. Although not shown in FIG. 12 due to limitations of the drawing, the measurement surface is continuously scanned. For example, the process may be returned to step S10, and scanning may be terminated by an instruction from the input device 29. Alternatively, the number of scans may be set in advance and scanning may be repeated the number of times specified.

[0086] As described above, according to the third embodiment of the present invention, the distribution measurement system 20 uses the three-axis sensor M described in the first and second embodiments. ｊ The relay unit 21 is configured to be selectable based on the input column selection signal SELj, the measurement unit 22 is configured of a three-axis sensor M, and the row-direction connection line L of the matrix in the three-axis sensor M is Ｓｊ Each inverting amplifier circuit Ca connected to the output terminal side of ｉ The inverting amplifier circuit section 23 is configured by the inverting amplifier circuit Ca of the inverting amplifier circuit section 23. ｉ On the output side of the switch 24SW corresponding to each row ｉ 11 is connected to a multiplexer unit 24, an A / D converter (A / D conversion unit) 25 whose input side is connected to the multiplexer unit 24, and a computer PC 26 connected to the multiplexer unit 24, the A / D converter 25, and the relay unit 21. Each process in the distribution measurement sensor system 20 can be performed by software using the computer PC 26. However, some of the functions (programs, software functions) of the computer PC 26 shown in the function block 30 in FIG. 11 can also be realized by hardware.

[0087] FIG. 13 is a block diagram showing the internal circuit 50 of the computer PC 26 that executes the distribution measurement program of the present invention. As shown in FIG. 13, a CPU 51, a ROM 52, a RAM 53, an image control unit 54, a controller 55, an input control unit 56, and an external I / F unit 57 are connected to a bus 60. In FIG. 13, the distribution measurement program of the present invention is recorded in the ROM 52, a recording area 62 such as a disk, or a recording medium 63 (including a removable recording medium) such as a DVD. The disk 62 can store the contact pressure recording area 41, the X-axis shear stress recording area 42, the Y-axis shear stress recording area 43, and the like. The distribution measurement program is loaded from the ROM 52 via the bus 60, or from the disk 62 or the recording medium 63 such as a DVD via the controller 55 and the bus 60 into the RAM 51. The image control unit 54 sends data of various images (such as images shown in FIGS. 30 and 31, which will be described later) to be displayed on the display 28 to the VRAM 61. The display 28 displays the data sent from the VRAM 61. The VRAM 61 is an image memory having a capacity equivalent to the data capacity of one screen of the display 28. The input device 29 is an input device such as a mouse or keyboard for inputting data to the computer PC 26, and the input control unit 56 is connected to the input device 29 and controls the input. The external I / F unit 657 has an interface function for connecting to the outside of the computer PC 26 (CPU 51) (relay unit 21, multiplexer 24, etc.).

[0088] As described above, the object of the present invention can be achieved by having the computer PC 26 (CPU 51) execute the distribution measurement program of the present invention. As described above, the distribution measurement program can be supplied to the computer PC 26 (CPU 51) in the form of a recording medium 63 such as a DVD, and a recording medium 63 such as a DVD on which the distribution measurement program is recorded also constitutes the present invention. In addition to the recording media described above, the recording medium 63 on which the distribution measurement program is recorded can also be, for example, an optical disc (DVD-RW, BD-RE, etc.), a flash memory (USB, SD card, etc.), an external hard disk, etc.

[0089] In Example 5, a method for manufacturing a three-axis sensor according to the present invention will be described. The three-axis sensor manufacturing method uses inkjet and screen printing techniques, as well as photolithography, to manufacture the three-axis sensors described in Examples 1 to 4. The three-axis sensor is composed of three electrode layers (lower electrodes 6-1 and 6-2, upper electrode 2), one insulating layer, and one conductive ink layer (stress-sensitive layer 4). The lower electrode 6-1 and other layers were printed using an inkjet printer (Deskviwer, CLUSTER TECHNOLOGY) and metal ink. A suitable metal ink is, for example, silver ink (Ag ink, NPS-J, HARIMA Chemical Group). While silver ink is used as an example below, the metal ink is not limited to silver ink. A 100 μm-thick polyimide film (HJA-A4-100 μm, SONE) was used as the substrate. The thickness of the lower electrode 6-1 etc. is approximately 1 μm or less, the stress-sensitive layer 4 is several μm thick, and the upper electrode 2 is approximately 1 μm or less, so the total thickness of the triaxial sensor including the substrate is approximately 110 μm. For practical purposes, the surface is coated with a 7.5 μm thick polyurethane film. The method for manufacturing the triaxial sensor will be explained below with reference to the drawings.

[0090] 14 shows a pattern (first pattern) of the lower electrode 6-1 formed using an inkjet printer. ｉｊ L1 is the measurement element E ｉｊ The lower electrode 6-1 of I ｊ is the connecting line Lf ｊThe input terminals are shown. The X axis is the downward direction in the drawing, and the Y axis is the horizontal direction to the right of the drawing. The crosses PY1, PY2, PX1, and PX2 are marks used for aligning with other patterns, as described below. To prevent the silver ink from spreading during printing, printing was performed while heating (approximately 423 K) using a hot plate (sheet heater). Figure 15 shows a photograph of the lower electrode 6-1 being printed using an inkjet printer while being heated at approximately 423 K by a sheet heater. In Figure 15, reference numeral 71 denotes the inkjet printer nozzle, and reference numeral 72 denotes the sheet heater. After printing the lower electrode 6-1, it was annealed in an electric furnace at 393 K for 60 minutes. The lower electrode 6-1 shown in Figure 14 was inkjet printed under the following conditions: voltage 8 V, print speed 15 mm / s, and discharge voltage period 1000 Hz. Marks PY1 and PY2 were also printed. Figure 16 is a photograph showing the pattern of the lower electrode 6-1 printed on the substrate. In Figure 16, the same reference numerals as in Figure 14 indicate the same elements, and therefore their explanation will be omitted. Electrical continuity (electrical conductivity) was confirmed. As described above, a layer of lower electrode 6-1 (first lower electrode layer) was printed on the polyimide film substrate using the pattern of lower electrode 6-1 that forms column j of the matrix (first lower electrode layer formation process).

[0091] As shown in FIG. 5 described in the first embodiment, the connection line Lf of the lower electrode 6-1 ｊ and the connection line Ls of the lower electrode 6-2 ｉ Since the X-axis and Y-axis connecting lines Lf intersect, these intersections must be insulated. Photoresist (OFPR-800LB, TOKYO OHKA KOGYO) was used as the insulating layer. The photoresist was applied onto the layer of the lower electrode 6-1 (first lower electrode layer) formed in the first lower electrode layer forming process, and exposed to light using a predetermined mask, thereby forming the X-axis and Y-axis connecting lines Lf. １ An insulating layer was formed to insulate the intersections of the lines, etc. (insulating layer forming step). Figure 17 shows a predetermined mask (insulating pattern). In Figure 17, the same reference numerals as in Figure 14 indicate the same elements, and therefore their explanations will be omitted. Cross marks PY1, etc. on the mask were used for alignment with the cross marks PY1, etc. in Figure 16.

[0092] Next, the lower electrode 6-2 was formed in the same manner as the lower electrode 6-1 described above. Fig. 18 shows the pattern (second pattern) of the lower electrode 6-2 formed using an inkjet printer. In Fig. 18, the symbol E ｉｊ L2 is the measurement element E ｉｊ Oi indicates the lower electrode 6-2 of the connecting line Ls ｉ 18 shows the output terminal of the lower electrode 6-2. The same reference numerals in FIG. 14 indicate the same elements, and therefore their descriptions are omitted. The lower electrode 6-2 was aligned so that the cross mark PX1 and other marks on the substrate on which the lower electrode 6-1 in FIG. 14 was printed overlapped with the cross mark in FIG. 18. Specifically, a drop of silver ink was dropped onto the center of the cross mark PX1 and other marks, and the alignment was performed while observing the flight and landing conditions of the silver ink with a camera. After printing the lower electrode 6-2, it was annealed in an electric furnace at 393 K for 60 minutes. FIG. 19 shows the printed lower electrode 6-2. The same reference numerals in FIG. 19 indicate the same elements, and therefore their descriptions are omitted. It was confirmed that the lower electrode 6-2 printed with silver ink was placed on the insulating layer on the crossing described above, and electrical continuity was also confirmed. As described above, on the layer of lower electrode 6-1 (first lower electrode layer) on which the insulating layer was formed in the insulating layer forming process, the layer of lower electrode 6-2 (second lower electrode layer) was printed with the pattern of lower electrode 6-2 (second pattern) forming row i of the matrix (second lower electrode layer forming process).

[0093] Next, the formation of the stress-sensitive layer 4 will be described. The stress-sensitive layer 4 was formed on the layers of the lower electrodes 6-1 and 6-2 by screen printing, and annealed in an electric furnace at 393K for 20 minutes. FIG. 20 shows a CAD pattern of a mask for screen printing. FIG. 21 shows the state after being coated with conductive ink. In FIG. 21, the same reference numerals as in FIG. 19 indicate the same elements, and therefore their explanations will be omitted. In FIG. 21, the reference numeral E ｉｊ C is the measurement element E ｉｊAs described above, the stress-sensitive layer 4 was formed by screen printing, which involved applying a conductive ink using a predetermined mask (the CAD pattern shown in FIG. 20 ), onto the layer of the lower electrode 6-1 (first lower electrode layer) and the layer of the lower electrode 6-2 (second lower electrode layer) after the second lower electrode layer formation step (stress-sensitive layer formation step).

[0094] Next, the formation of the upper electrode 2 will be described. The upper electrode 2 was formed on the stress-sensitive layer 4 using an inkjet printer. The upper electrode 2 was printed while being heated, similar to the lower electrode 6-1, etc. Figure 22 shows the pattern of the formed upper electrode 2. In Figure 22, parts with the same reference numerals as in Figure 21 indicate the same elements, and therefore their explanations will be omitted. As with the printing of the lower electrode 6-2, the upper electrode 2 was aligned so that the cross mark PX1, etc. on the substrate on which the lower electrode 6-1 in Figure 14 was printed overlapped with the cross mark in Figure 22. Specifically, a drop of silver ink was dropped onto the center of the cross mark PY1, etc., and the alignment was performed while observing the flight and landing state of the silver ink with a camera. After printing the upper electrode 2, it was annealed in an electric furnace at 393 K for 60 minutes. Figure 23 shows the printed upper electrode 2. In Figure 23, parts with the same reference numerals as in Figure 21 indicate the same elements, and therefore their explanations will be omitted. It was confirmed that the upper electrode 2 printed with silver ink was printed without spreading on the surface of the stress-sensitive layer 4 described above, and electrical continuity was also confirmed. The electrical resistance between the upper electrode 2 and the lower electrode 6-1, etc. was measured to be approximately 150 Ω. As described above, the upper electrode 2 was formed by printing the upper electrode 2 on the stress-sensitive layer 4 formed in the stress-sensitive layer forming step (upper electrode layer forming step).

[0095] Finally, the lead wires were connected to the substrate using conductive adhesive (TKpaste CR-2800, Kaken-tech). The surface of the triaxial sensor was coated with polyurethane film for electrical insulation and protection. Figure 24 is a photograph showing the manufactured triaxial sensor. In Figure 24, the same symbols as in Figure 21 indicate the same elements, so their explanations will be omitted. In Figure 24, the symbol W (I ｊ ) is the input terminal I ｊ indicates the lead wire connected to W(O ｊ) is the output terminal O ｊ The lead wires connected to the

[0096] As described above, according to the fifth embodiment of the present invention, a layer of the lower electrode 6-1 (first lower electrode layer) was printed on a polyimide film substrate according to the pattern of the lower electrode 6-1 that forms the column j of the matrix (first lower electrode layer forming step). A photoresist was applied to the layer of the lower electrode 6-1 (first lower electrode layer) formed in the first lower electrode layer forming step, and exposed to light using a predetermined mask, thereby forming the connecting lines Lf of the X-axis and Y-axis. １ An insulating layer was formed to insulate the intersections of the lower electrodes 6-1 and 6-2 (insulating layer formation process). A lower electrode 6-2 layer (second lower electrode layer) was printed on the lower electrode 6-1 layer (first lower electrode layer) on which the insulating layer was formed in the insulating layer formation process, using a pattern (second pattern) of the lower electrode 6-2 that forms row i of the matrix (second lower electrode layer formation process). A stress-sensitive layer 4 was formed by screen printing, in which a conductive ink was applied using a predetermined mask (CAD pattern shown in FIG. 20 ) on the lower electrode 6-1 layer (first lower electrode layer) and the lower electrode 6-2 layer (second lower electrode layer) after the second lower electrode layer formation process (stress-sensitive layer formation process). An upper electrode 2 was printed on the stress-sensitive layer 4 formed in the stress-sensitive layer formation process to form the upper electrode 2 (upper electrode layer formation process).

[0097] According to the triaxial sensor manufacturing method of the present invention, the insulating layer of the triaxial sensors of Examples 1 to 4 was manufactured using photolithography technology used in semiconductor manufacturing, and the lower electrode 6-1, etc., upper electrode 2, and stress-sensitive layer 4 were manufactured using inkjet and screen printing technologies. Therefore, compared to Patent Document 2 and the like, it was possible to manufacture a thinner triaxial sensor by stacking the layers more closely and tightly adhering them. As a result, compared to Patent Document 2 and the like, it is possible to more accurately and stably measure contact pressure and shear stress in a lower range (low pressure measurement range). When manufacturing the lower electrode 6-1, etc., the upper electrode 2, and stress-sensitive layer 4, it is also possible to form the films using photolithography technology instead of the inkjet and printing technology. When all components are manufactured using photolithography, integration on the order of micrometers is also possible.

[0098] Example 6 describes a calibration test of the distribution measurement system described above. Figure 25 shows a material testing machine 80 (INSTRON 4464, INSTRON (registered trademark)) used to calibrate the contact pressure. Sixteen measurement points were used in this test. Figure 25(A) is a photograph of the material testing machine 80, and Figure 25(B) is a schematic diagram. As shown in Figure 25, a 6-axis load cell 83 is placed on a base 84, and a 3-axis sensor M is placed on the 6-axis load cell 83. An acrylic plate 81 is placed on the 3-axis sensor M via a sponge rubber sheet 82 (22 mm x 22 mm x 3 mm). A contact pressure Cp is applied from above the acrylic plate 81, and the contact pressure Cp is measured using the 6-axis load cell 83. The range of the contact pressure Cp was set to 0 to 10 kPa.

[0099] Figure 26 shows the calibration system 90 used to calibrate shear stress. In Figure 26, the same reference numerals as in Figure 25 indicate the same elements, and therefore their explanations are omitted. As shown in Figure 26, a triaxial sensor M is mounted on a base 84. An acrylic plate 81 is placed on the triaxial sensor M via a sponge rubber sheet 82. A weight 91 for applying contact pressure is placed on the acrylic plate 81. A piezoelectric actuator 94 is used to generate horizontal displacement for shear stress. A load cell (USM-5N, UNIPULSE®) 93 is attached to the tip of the piezoelectric actuator 94, and the load cell 93 and the acrylic plate 81 are connected by a wire 92. The wire 92 is pulled while the applied voltage to the piezoelectric actuator 94 is varied from 0 to 2.5 V. A contact pressure (weight 91) of 5 kPa is applied, and a shear stress of -1 to 1 kPa is applied. The shear stress was measured in the X-axis and Y-axis directions using a load cell 93 .

[0100] Figure 27 shows the results of the contact pressure calibration test in a graph. In Figure 27, the horizontal axis represents contact pressure (kPa) and the vertical axis represents the change in electrical resistance (ΔR Ｘ１ｐ ) (Ω). As explained in Example 1, the relationship between the contact pressure and the change in electrical resistance (ΔR Ｘ１ｐ) is a straight line sloping downward to the right and passing through the origin. Therefore, it was found that Equation 8 is correct. Therefore, by using the slope of the line in Figure 27, the contact pressure can be calculated as the change in electrical resistance (ΔR Ｘ１ｐ ) can be determined from

[0101] Figure 28 shows the results of the calibration test for shear stress in the X-axis direction in a graph. In Figure 28, the horizontal axis represents shear stress (kPa) and the vertical axis represents the change in electrical resistance (ΔR Ｘ１τ ) (Ω). As explained in Example 1, the shear stress in the X-axis direction and the change in electrical resistance (ΔR Ｘ１τ ) is a straight line sloping downward to the right and passing through the origin. Therefore, it was found that Equation 11 is correct. Therefore, the shear stress in the X-axis direction can be calculated by using the slope of the straight line in Figure 28 to obtain the change in electrical resistance (ΔR Ｘ１τ ) can be determined from the shear stress in the Y-axis direction. Figure 29 shows the results of the calibration test of the shear stress in the Y-axis direction in a graph. In Figure 29, the horizontal axis represents the shear stress in the Y-axis direction (kPa), and the vertical axis represents the change in electrical resistance due to the shear stress in the Y-axis direction (ΔR Ｙ１τ ) (Ω). As explained in Example 1, the shear stress in the Y-axis direction and the change in electrical resistance (ΔR Ｙ１τ ) is a straight line sloping downward to the right and passing through the origin. Therefore, it was found that Equation 11 is correct. Therefore, the shear stress in the Y-axis direction can be calculated by using the slope of the straight line in Figure 29 to calculate the change in electrical resistance (ΔR Ｙ１τ ) can be determined from

[0102] Figure 30 shows an example of what is displayed on the display 28 by the display unit 36 ​​when contact pressure and shear stress are applied. Figure 30(A) is a photograph of a measurement element in the three-axis sensor M being pressed with a human finger. Figure 30(B) shows the color coding indicating the degree of contact pressure Cp (0 to 10; in the original figure, 0 is blue and 10 is red) and the shear stress S Ｘ 30(C) shows the degree of contact pressure Cp in each measurement element of the three-axis sensor M by color coding, and the shear stress S ＸAs shown in Fig. 30(C), the points corresponding to the measurement elements pressed by the human finger in Fig. 30(A) are color-coded and shown by vectors (predetermined display format). Fig. 31 shows the relationship between the contact pressure Cp and the shear stress S Ｘ Another example of the display is shown when a force such as the above is applied. In Fig. 31(A), a person's finger is pressing two points on the three-axis sensor. Fig. 31(B) is the same as Fig. 30(B). As shown in Fig. 31(C), the points corresponding to the two measurement elements pressed by the person's finger in Fig. 31(A) are displayed in different colors and with vectors. 8

[0103] In the above-described examples, attention was focused on the fact that when contact pressure Pc is applied to the measurement element 10 in the Z-axis direction, the stress-sensitive layer 4 is compressed, the distance r decreases, and the electrical resistance between the upper electrode 2 and the lower electrode 6 decreases. In other words, the contact pressure Pc was detected based on the change in electrical resistance due to the change in distance r. Meanwhile, as the distance r changes, the capacitance between the two electrodes (the upper electrode 2 and the lower electrode 6) also changes. If the capacitance is C, the area of ​​the two electrodes (the upper electrode 2 and the lower electrode 6) is S, and the dielectric constant is ε, then the relationship C = εS / r holds. Therefore, when the distance r decreases due to the application of contact pressure Pc, the capacitance C increases. Therefore, like a capacitance-type pressure sensor, it is also possible to measure the contact pressure Pc by measuring the increase in capacitance (ΔC) and converting it appropriately.

[0104] The above conversion can be performed in the same manner as in the above-described embodiments. For example, a relationship between a known contact pressure Pm and the change ΔC in capacitance between both electrodes of the measurement element 10 measured with respect to the contact pressure Pm is prepared in advance using a graph or the like. When an arbitrary contact pressure Pc is applied to the measurement element 10, the arbitrary contact pressure Pc can be obtained using the graph.

[0105] In the above-described examples, we focused on the fact that when shear stress Sx is applied to the measurement element 10 in the X-axis direction, the overlap area Ao decreases or increases depending on the direction, thereby increasing or decreasing the electrical resistance between the upper electrode 2 and the lower electrode 6. In other words, the shear stress Sx was detected based on the change in electrical resistance due to the change in the overlap area Ao. Meanwhile, if the overlap area Ao changes, the capacitance between the two electrodes (upper electrode 2 and lower electrode 6) also changes. If the overlap area Ao is S in the above relationship C = εS / r, the capacitance C changes when the overlap area S changes due to the application of shear stress Sx. Therefore, it is also possible to measure shear stress Sx and other parameters by appropriately converting the change in capacitance between a pair of measurement elements adjacent in one axis direction in the above-described matrix M.

[0106] The above conversion can be performed in the same manner as in the above-described embodiments. For example, a relationship between a known shear stress Sm and the change ΔC in capacitance between both electrodes of the measuring element 10 measured in response to the shear stress Sm is prepared in advance using a graph or the like. When an arbitrary shear stress Sx is applied to the measuring element 10, the arbitrary shear stress Sx can be obtained using the graph.

[0107] In each of the above-described embodiments, in the measurement by the three-axis sensor M, the measurement element E ｉｊ The measurement element E in the three-axis sensor M is used in duplicate except for the peripheral portion. ｉｊ 32 shows an example of the arrangement of measurement elements E. In FIG. 32, the same reference numerals as in FIG. 5 indicate the same elements, and therefore the explanation thereof will be omitted. The connections between the measurement elements are the same as in FIG. 5, and therefore will be omitted. As shown in FIG. 32, measurement elements E ２３ , E ３２ , E ３４ and E ４３ (shown in green in the original diagram) are used redundantly in measuring shear stress in the X-axis and Y-axis directions. For example, in measuring shear stress in the X-axis direction, the adjacent measurement element E ２１ and E ２３ and is measured using measuring element E ２３ and E ２５と Therefore, the measurement element E ２３はSimilarly, in the measurement of shear stress in the Y direction, the adjacent measurement element E １２ and E ３２ and is measured using measuring element E ３２ and E ５２ Therefore, the measurement element E ３２ are used in duplicate in the measurements.

[0108] FIG. 33 shows the measurement element E in the three-axis sensor G in Example 8 of the present application. ｉｊ 33 shows an example of the arrangement of the same elements as in FIG. 5. In FIG. 33, the same reference numerals as in FIG. 5 indicate the same elements, and therefore the explanation will be omitted. The connections between the same measurement elements as in FIG. 5 are the same as in FIG. 5, and therefore will be omitted. １１ , G １２ , G ２１ , G ２２ 5. Unlike the measurement points Mp in FIG. 5, the measurement elements E ｉｊ For example, measurement point G １１ The measuring element E for the XZ axis measures the shear stress in the X-axis direction and the contact stress in the Z-axis direction. ２１ and E ２３ Two measurement points are arranged side by side in the X-axis direction. １２ Then, the measuring element E for the X and Z axes ２３ ' and E ２５ Two measuring elements E are arranged side by side in the X-axis direction. ２３ The structure of the measurement element E ２３ and the structure of the measuring element E ２３ The lower electrode E ２３ (6-1), E ２３ (6-2), and the upper electrode E ２３ As in (2), the lower electrode E ２３ '(6-1), E ２３ '(6-2), and the upper electrode E ２３ '(2) is placed at measurement point G. １２ When shear stress is applied in the horizontal direction (X-axis direction) at ２３ The overlap area of ​​the upper electrode E ２３ '(2) and the lower electrode E ２３The electrical resistance between the measurement element E and the measurement element E' (6-1) increases or decreases. ２５ The decrease or increase in the overlap area of ​​the measurement area E ２３ The increase or decrease in the electrical resistance is also the opposite of that in the measurement area E ２３ This is the same as the case of the measurement point Mp in the three-axis sensor M described above. １１ and G １２ Between the measurement element E ２３ and E ２３ ' and are placed without overlapping.

[0109] The same applies to the Y-axis direction. ｉｊ For example, measurement point G １１ The YZ axis measuring element E measures the shear stress in the Y axis direction and the contact stress in the Z axis direction. １２ and E ３２ Two measurement points are arranged side by side in the Y-axis direction. ２１ Then, the measuring element E for the Y and Z axes ３２ ' and E ５２ Two measuring elements E are arranged side by side in the Y-axis direction. ３２ The structure of the measurement element E ３２ and the structure of the measuring element E ３２ The lower electrode E ３２ (6-1), E ３２ (6-2), and the upper electrode E ３２ As in (2), the lower electrode E ３２ '(6-1), E ３２ '(6-2), and the upper electrode E ３２ '(2) is placed at measurement point G. ２１ When a shear stress is applied in the horizontal direction (Y-axis direction) at ３２ '(2) and the lower electrode E ３２ The electrical resistance between the measurement element E and the measurement element E' (6-1) increases or decreases. ５ The decrease or increase in the overlapping area of ​​2 is the measurement area E ３２ The increase or decrease in the electrical resistance is also the opposite of that in the measurement area E ３２This is the same as the case of the measurement point Mp in the three-axis sensor M described above. １１ and G ２１ Between the measurement element E ３２ and E ３２ ' and are placed without overlapping.

[0110] As described above, the three-axis sensor G in Example 8 measures the shear stress in one axis direction (X-axis or Y-axis direction) of the plane and the contact stress in the axis direction (Z-axis) perpendicular to the plane at the measurement point G. ｉｊ The three-axis sensor is arranged in a matrix on the plane. ２３ ', E ３２ ', E ３４ ' etc. are the electrodes on one side E of a pair of lower electrodes ２３ '(6-1) and the like are commonly connected in the Y-axis direction by respective connection lines Ls1 and the like, and the other side E ２３ '(6-2), etc. are commonly connected in the X-axis direction by the respective connection lines Lf1, etc. Therefore, when a contact pressure Pc is applied to the three-axis sensor G in the Z-axis direction and / or a shear stress S Ｘ When the above-mentioned voltages are applied, a pair of measurement elements E adjacent in one axis (X-axis or Y-axis) direction at the measurement point Gnm of the matrix in FIG. 33 is ｉｊ Electrical resistance R Ｘ１ Based on the changes in the contact pressure Pc and / or shear stress S as in the above-mentioned Example 1, etc. Ｒ etc. can be detected.

[0111] One application of the present invention is to measure contact pressure and shear stress acting on the interface between a living body and an object, particularly to measure the distribution of tactile sensations with high spatial resolution. If the three-axis sensor is manufactured entirely using photolithography technology, which is used in semiconductor manufacturing, it can be made even finer and more highly integrated. As a result, it is possible to develop a three-axis sensor with high spatial resolution, arranging tens of thousands of measuring elements, each measuring a few microns in size, at the semiconductor level.

[0112] 1 Conductive ink, 2, 2' Upper electrode, 4 Conductive ink layer (stress sensitive layer), 6, 6-1, 6-2, 6-1', 6-2' Lower electrode, 6r, 6r-1, 6r-2 One end side of lower electrode 6, 10, 10' Measuring element, 20 Distribution measurement system, 21 Relay section, 22 Measuring section, 223 Inverting amplifier circuit section, 24 Multiplexer, 24SW ｉ Switch, 25 A / D converter, 26 Computer PC, 27 Power supply, 28 Display, 29 Input device, 30 Function block, 31 Column selection signal control section, 32 Switch selection signal control section, 33 Output voltage data recording section, 34 Contact pressure conversion section, 36 Display section, 37 Repeating section, 40 Recording area, 41 Contact pressure recording area, 42 X-axis shear stress recording area, 43 Y-axis shear stress recording area, 50 Internal circuit, 51 CPU, 52 ROM, 53 RAM, 54 Image control section, 55 Controller, 56 Input control section, 57 External I / F section, 60 Bus, 61 VRAM, 62 Disk, 63 Recording medium, 71 Nozzle, 72 Sheet heater, 80 Material testing device, 81 Acrylic plate 82 sponge rubber sheet, 83 six-axis load cell, 84 base, 90 calibration device, 91 weight, 92 wire, 94 piezo actuator.

[0113] Ao, Ao' overlap region, Ca ｉ　 Inverting amplifier circuit, E Applied voltage, E ｉｊ , X １ , X ２ , Y １ , Y ２ Measuring element, E ｉｊ (2) Upper electrode, E ｉｊ (6-1), E ｉｊ (6-2) Lower electrode, IC Current through stress sensitive layer 4, IL, IL1, IL2 Current in lower electrode 6, IU Current through upper electrode 2, Lf, Lf ｊ , Ls, Ls ｉConnecting wire, L1E to L9E power supply side terminal, L1G to L9G installation side terminal, M 3-axis sensor, Mp measurement point, Pc contact pressure, PY1, PY2, PX1, PX2 cross marks, R １、 R ｓ Input resistance, R ２、　 R ｆ　 Feedback resistor, R Ｘ１ , R Ｘ２　、 R いｊ　 Electrical resistance value, S, S Ｌ , S Ｒ , S Ｘ Shear stress, ΔR, ΔR Ｐ , ΔR Ｘ１ｐ , ΔR Ｘ２ｐ , ΔR τ、 ΔR Ｘ１Τ , ΔR Ｘ２Τ　　 Amount of change in electrical resistance, SEL, SEL ｊ (Column) select signal, SEL ｉ Switch selection signal, V, V １ , V ２ Output voltage.

Claims

1. A three-axis sensor in which measurement elements for measuring shear stress in one axis direction of a plane (X-axis or Y-axis direction) and contact stress in an axis direction (Z-axis) perpendicular to the plane are arranged in a matrix on the plane, wherein the measurement elements for the XZ axes, which measure shear stress in the X-axis direction and contact stress in the Z-axis direction, are arranged in every other row of the matrix, and in every other column in each row; the measurement elements for the YZ axes, which measure shear stress in the Y-axis direction and contact stress in the Z-axis direction, are arranged in rows of the matrix where no measurement elements for the XZ axes are arranged, and in columns of each row where no measurement elements for the XZ axes are arranged; the measurement elements each have a laminated structure comprising a pair of lower electrodes, a stress-sensitive layer formed across each end side of the pair of lower electrodes, and an upper electrode formed on the stress-sensitive layer, and each end side of the pair of lower electrodes has an area where the lower electrode and the upper electrode vertically overlap on the two-dimensional plane, When contact pressure is applied to the measurement element in the Z-axis direction, the stress-sensitive layer is compressed and the electrical resistance between the two electrodes (the upper electrode and the lower electrode) decreases; when shear stress is applied to the measurement element in a horizontal direction on a plane, the electrical resistance between the two electrodes increases in the direction in which the overlapping area decreases, and decreases in the direction in which the overlapping area increases; and each of the measurement elements is a three-axis sensor characterized in that one side of a pair of lower electrodes is connected in common in the Y-axis direction by each connecting line, and the other side is connected in common in the X-axis direction by each connecting line.

2. A three-axis sensor according to claim 1, characterized in that when contact pressure is applied to the three-axis sensor in the Z-axis direction and / or shear stress is applied in the horizontal direction, the three-axis sensor detects the contact pressure and / or shear stress based on the change in electrical resistance of a pair of measuring elements adjacent in one axis direction in the matrix.

3. A three-axis sensor according to claim 2, further characterized in that an inverting amplifier circuit is connected to the output end of the connecting wire in the X-axis direction, with the resistance between the two lower electrodes of the measuring element connected to the connecting wire as the input resistance, and the resistance between the two lower electrodes when no contact pressure or shear stress is applied as the feedback resistance.

4. A triaxial sensor according to claim 3, characterized in that, when contact pressure and / or shear stress is applied to the measuring element and another measuring element adjacent to the measuring element as a pair, a change in resistance between the two lower electrodes of the measuring element and a change in resistance between the two lower electrodes of the other measuring element due to contact pressure alone are obtained based on the output voltage of the inverting amplifier circuit for the measuring element and the output voltage of the inverting amplifier circuit for the other measuring element, and based on a relationship between a known contact pressure and the resistance change between the two lower electrodes of the measuring element obtained in advance using the principle in response to that contact pressure, when any contact pressure and / or shear stress is applied to the measuring element and another measuring element, the any contact pressure is obtained using the resistance change between the two lower electrodes of the measuring element obtained in accordance with the principle and the relationship.

5. A triaxial sensor according to claim 3, characterized in that, when contact pressure and / or shear stress is applied to the measuring element and another measuring element adjacent to the measuring element as a pair, the change in resistance between the two lower electrodes of the measuring element and the change in resistance between the two lower electrodes of the other measuring element due to shear stress alone are obtained based on the output voltage of the inverting amplifier circuit for the measuring element and the output voltage of the inverting amplifier circuit for the other measuring element, and based on a previously created relationship between a known shear stress and the resistance change between the two lower electrodes of the measuring element in response to that shear stress obtained using the above principle, when any contact pressure and / or shear stress is applied to the measuring element and the other measuring element, the any shear stress is obtained using the resistance change between the two lower electrodes of the measuring element obtained based on the above principle.

6. A distribution measurement system using a triaxial sensor as defined in claims 4 and 5, comprising: a relay section configured to be able to select each column-direction connection line of the matrix in the triaxial sensor based on an input selection signal; an inverting amplifier circuit section consisting of inverting amplifier circuits connected to the output terminal side of the row-direction connection line of the matrix in the triaxial sensor; a multiplexer section in which a switch corresponding to each row is connected to the output side of each inverting amplifier circuit of the inverting amplifier circuit section; an A / D converter section whose input side is connected to the multiplexer section; and a computer connected to the multiplexer section, the A / D converter section, and the relay section, wherein when the computer selects measurement elements corresponding to the rows and columns of the matrix, a column selection signal for selecting a column is output from the computer to the relay unit, and the relay unit selects a connection line corresponding to the column based on the column selection signal, thereby selecting one of a pair of lower electrodes in the measurement element connected to the connection line; a switch selection signal for selecting a switch corresponding to a row is output from the computer to the multiplexer unit, and the multiplexer unit selects a corresponding switch based on the switch selection signal and selects a connection line connected to an inverting amplifier circuit corresponding to the switch, thereby selecting the other of the pair of lower electrodes in the measurement element connected to the connection line; and a measurement element for which both of the pair of lower electrodes are selected is selected as the measurement element corresponding to the row and column; output voltages based on the contact pressure, shear stress in the X-axis direction, and shear stress in the Y-axis direction applied to the selected measurement element are output to the computer via the inverting amplifier circuit unit, multiplexer unit, and A / D conversion unit, and the computer processes voltages based on the contact pressure, X-axis shear stress, and Y-axis shear stress from the measurement element corresponding to the row and column, and repeats the steps of outputting a column selection signal and a switch selection signal for selecting a measurement element corresponding to the next row and column.

7. A distribution measurement system according to claim 6, wherein the computer comprises: column selection signal control means for outputting to the relay section a column selection signal that selects a column of the matrix; switch selection signal control means for outputting to the multiplexer section a switch selection signal that selects a switch corresponding to a row of the matrix; and output voltage data recording means for recording output voltage data based on the contact pressure, shear stress in the X-axis direction, and shear stress in the Y-axis direction applied to measurement elements corresponding to the column selected by the column selection signal control means and the row selected by the switch selection signal control means, which output voltage data is output to the computer via the inverting amplifier circuit section, multiplexer section, and A / D conversion section in a contact pressure recording area, an x-axis shear stress recording area, and a y-axis shear stress recording area for each measurement element. contact pressure conversion means for obtaining the contact pressure applied to the measurement element and the other measurement element based on a predetermined principle of obtaining a resistance change between the two lower electrodes of the measurement element and a resistance change between the two lower electrodes of the other measurement element due to contact pressure alone, based on output voltage data of the inverting amplifier circuit for the measurement element recorded in the contact pressure recording area by the output voltage data recording means and output voltage data of the inverting amplifier circuit for another measurement element adjacent to the measurement element as a pair, and based on a previously created relationship between known contact pressures and the resistance change between the two lower electrodes of the measurement element in response to the contact pressure obtained by the principle; a shear stress conversion means for obtaining the shear stress applied to the measurement element and the other measurement element based on a predetermined principle of obtaining the resistance change between the two lower electrodes of the measurement element and the resistance change between the two lower electrodes of the other measurement element due to shear stress alone, based on the output voltage data of the inverting amplifier circuit for the measurement element recorded in the contact pressure recording area by the output voltage data recording means and the output voltage data of the inverting amplifier circuit for another measurement element adjacent to the measurement element as a pair, and based on a previously created relationship between known shear stresses and the resistance change between the two lower electrodes of the measurement element in response to the shear stress obtained by the above-mentioned principle; and a display means for displaying the contact pressure applied to each measurement element converted by the contact pressure conversion means and the shear stress converted by the shear stress conversion means on an output display unit of the computer in a predetermined display format.and repeating means for specifying a measurement element corresponding to the next row and column, and repeating each process from said column selection signal control means.

8. In the distribution measurement system of claim 7, the predetermined principle in the contact pressure conversion means is to use the input voltage (E) to the triaxial sensor, the feedback resistance (R) of the inverting amplifier circuit, ｆ ), the input resistance (R ０ ), the change in resistance due to contact pressure at the measuring element (1) and at the other measuring element (2) (ΔR Ｘ１ｐ , ΔR Ｘ２ｐ ), the output voltages (V １ , V ２ ) then, as shown in the following equation 1, Each output voltage of the inverting amplifier circuit (V １ , V ２ ) to calculate the resistance change (ΔR Ｘ１ｐ ) and the resistance change between the two lower electrodes of another measuring element (ΔR Ｘ２ｐ A distribution measurement system characterized by the principle that it is possible to obtain a distribution.

9. In the distribution measurement system according to claim 7, the predetermined principle in the shear stress conversion means is to use the input voltage (E) to the triaxial sensor, the feedback resistance (R) of the inverting amplifier circuit, ｆ ), the input resistance (R ０ ), the change in shear stress resistance (ΔR Ｘ１τ , ΔR Ｘ２τ ), the output voltages (V １ , V ２ ) then, as shown in the following equation 2, The output voltage of the inverting amplifier circuit (V １ , V ２ ) to calculate the resistance change (ΔR Ｘ１τ ) and the resistance change between the two lower electrodes of another measuring element (ΔR Ｘ２τ A distribution measurement system characterized by the principle that it is possible to obtain a distribution.

10. A distribution measurement system according to any one of claims 7 to 9, characterized in that the predetermined display format of the display means arranges the display of the measurement elements in correspondence with the matrix, indicates the magnitude of contact pressure for each measurement element using a predetermined color, and displays the shear stress obtained by combining the x-axis shear stress and the y-axis shear stress as a vector.

11. A distribution measurement program for operating the computer in the distribution measurement system according to any one of claims 6 to 9, comprising: a column selection signal control step for causing the computer to output to the relay section a column selection signal for selecting a column of the matrix; a switch selection signal control step for outputting to the multiplexer section a switch selection signal for selecting a switch corresponding to a row of the matrix; and an output voltage data recording step for recording output voltage data based on contact pressure, shear stress in the X-axis direction, and shear stress in the Y-axis direction applied to measurement elements corresponding to the column selected in the column selection signal control step and the row selected in the switch selection signal control step, which output voltage data has been output to the computer via the inverting amplifier circuit section, multiplexer section, and A / D conversion section in a contact pressure recording area, an x-axis shear stress recording area, and a y-axis shear stress recording area for each measurement element. a contact pressure conversion step of obtaining the contact pressures applied to the measurement element and the other measurement element based on a predetermined principle of obtaining the resistance change between the two lower electrodes of the measurement element and the resistance change between the two lower electrodes of the other measurement element due to contact pressure alone, based on the output voltage data of the inverting amplifier circuit for the measurement element recorded in the contact pressure recording area in the output voltage data recording step and the output voltage data of the inverting amplifier circuit for another measurement element adjacent to the measurement element as a pair, and based on a previously created relationship between known contact pressures and the resistance change between the two lower electrodes of the measurement element obtained by the principle in response to the contact pressure; a shear stress conversion step of obtaining the shear stress applied to the measurement element and the other measurement element based on a predetermined principle of obtaining the resistance change between the two lower electrodes of the measurement element and the resistance change between the two lower electrodes of the other measurement element due to shear stress alone, based on the output voltage data of the inverting amplifier circuit for the measurement element recorded in the contact pressure recording area in the output voltage data recording step and the output voltage data of the inverting amplifier circuit for another measurement element adjacent to the measurement element as a pair, and based on a previously created relationship between known shear stresses and the resistance change between the two lower electrodes of the measurement element in response to the shear stress obtained by the principle;a display step of displaying the contact pressure applied to each measurement element converted in the contact pressure conversion step and the shear stress converted in the shear stress conversion step on the output display unit of the computer in a predetermined display format; and a distribution measurement program for executing a repeat step of specifying a measurement element corresponding to the next row and column and repeating each process from the column selection signal control means.

12. A computer-readable recording medium on which is recorded a distribution measurement program for operating the computer in the distribution measurement system according to any one of claims 6 to 9.

13. A method for manufacturing a three-axis sensor as defined in claim 1, comprising: a first lower electrode layer forming step of printing a first lower electrode layer on a polyimide film substrate using a first pattern that forms the columns of the matrix; an insulating layer forming step of applying photoresist to the first lower electrode layer formed in the first lower electrode layer forming step and exposing the photoresist using a predetermined mask to form an insulating layer that insulates the intersections of the X-axis and Y-axis connection lines; a second lower electrode layer forming step of printing a second lower electrode layer on the first lower electrode layer on which the insulating layer has been formed in the insulating layer forming step using a second pattern that forms the rows of the matrix; a stress-sensitive layer forming step of forming the stress-sensitive layer by screen printing that applies conductive ink using a predetermined mask on the first lower electrode layer and second lower electrode layer after the second lower electrode layer forming step; and an upper electrode layer forming step of forming the upper electrode by printing the upper electrode on the stress-sensitive layer formed in the stress-sensitive layer forming step.

14. A three-axis sensor in which measurement points for measuring shear stress in one axis direction of a plane (X-axis or Y-axis direction) and contact stress in an axis direction (Z-axis) perpendicular to the plane are arranged in a matrix on the plane, wherein the measurement points are: two XZ-axis measurement elements for measuring shear stress in the X-axis direction and contact stress in the Z-axis direction, arranged side by side in the X-axis direction; two YZ-axis measurement elements for measuring shear stress in the Y-axis direction and contact stress in the Z-axis direction, arranged side by side in the Y-axis direction; and the XZ-axis measurement elements and the YZ-axis measurement elements are arranged without overlapping between each measurement point; the measurement elements each have a laminated structure comprising a pair of lower electrodes, a stress-sensitive layer formed across each end side of the pair of lower electrodes, and an upper electrode formed on the stress-sensitive layer, and each end side of the pair of lower electrodes has an area where the lower electrode and the upper electrode vertically overlap on the two-dimensional plane; When contact pressure is applied to the measurement element in the Z-axis direction, the stress-sensitive layer is compressed and the electrical resistance between the two electrodes (the upper electrode and the lower electrode) decreases; when shear stress is applied to the measurement element in a horizontal direction on a plane, the electrical resistance between the two electrodes increases in the direction in which the overlapping area decreases, and decreases in the direction in which the overlapping area increases; and each of the measurement elements is a three-axis sensor characterized in that one side of a pair of lower electrodes is connected in common in the Y-axis direction by each connecting line, and the other side is connected in common in the X-axis direction by each connecting line.

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