JPH0192603A - Strain and stress detection sensor element - Google Patents

Abstract

PURPOSE:To detect even large deformation without placing any load on a body to be detected by connecting >=1 elastic bodies in parallel or in series to a drawn conductive sheet which decreases in electric resistance owing to deformation. CONSTITUTION:A strain and stress detection sensor is constituted by connecting the elastic bodies to the drawn conductive element in series. Namely, an electrode 3a and one-end sides of the elastic bodies are fitted to one end of the drawn conductive sheet 1 by using a hook having a snap button 5a, and a lead wire 4a is connected to the electrode 3a. An electrode 3b is fitted to the other end of the drawn conductive sheet 1 by using a hook with a snap button 5b and a lead wire 4b is connected to the electrode 3b. Thus, the elastic bodies with desired elasticity are connected to the drawn conductive element in series and then even when large deformation which exceeds the permissible deformation quantity of the drawn conductive element itself is applied to the sensor element, the elastic bodies deform, so the drawn conductive element is prevented from breaking and changing in characteristics.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to strain and stress sensing sensor elements.

[Conventional technology]

There are cases where it is necessary to electrically detect deformations such as large extensions, bends, compressions, twists, etc. (hereinafter referred to as "deformations such as extensions") such as in bent portions of elbows and knees of the human body. For such detection, it is conceivable to adopt either a method using a material whose electrical resistance value decreases due to deformation such as elongation, or a method using a material whose electrical resistance value increases when deformed such as elongation.

An example of the material whose electrical resistance value increases due to deformation such as elongation is a strain gauge. However, the deformation rate of the metal wires used in strain gauges is extremely small (1% or less), and therefore cannot be used to detect deformations such as large elongations, such as those at bent parts of the human body, such as elbows and knees.

On the other hand, sheets are known whose electrical resistance value decreases due to deformation such as elongation, and which can be used to detect deformation such as large elongation. For example, by the same applicant as the present invention, by putting a conductive filler in the shape of a flake into an insulating polymer elastomer, when the filler is stretched in a direction parallel to the plane of the filler, the conductivity in the stretching direction is increased. A sheet with improved performance has been proposed (see Japanese Unexamined Patent Publication No. 80708/1983). In addition, by the same applicant as the present invention, the intertwined parts of the threads constituting the sheet-like product and the electrical conductivity or electrical insulation between the intertwined parts are formed so as to satisfy the following conditions, so that the threads can be stretched in any direction. A deformed electrically sensitive knitted fabric whose electrical resistance value changes when subjected to such deformations has been proposed (see Japanese Patent Laid-Open No. 61/201045).

■ Among all intertwined parts in a given area of knitted fabric,
When the number of electrically insulated intertwined parts is β and the number of electrically conductive interlaced parts is 12, the value of the ratio 1r/Ilz is 1 in the measured value per square inch.
/9 or more; ■ Between a plurality of adjacent intertwined parts in a constant length in the longitudinal direction of each yarn constituting the knitted fabric, the number of intertwined parts that are electrically insulated is m
, and the number of intertwined parts that are electrically conductive is m2
In this case, the value of the ratio m1/m2 shall be 1/9 or more as measured value per inch.

As mentioned above, a sheet-like material whose electrical resistance value decreases when deformed such as elongation is applied is referred to as an elongated conductive sheet. Further, in order to detect deformation behavior such as elongation of a subject using such an elongated conductive sheet, an element in which electrodes are attached to arbitrary two points of the elongated conductive sheet is referred to as an elongated conductive element.

The same applicant as the present inventor has also proposed an element (hereinafter referred to as sensor element) that incorporates the elongated conductive element and has means for adhesively fixing it to the subject, converting the movement of the subject into an electrical signal. (See Japanese Unexamined Patent Publication No. 61-259103).

In this way, the electrical resistance value of the stretchable conductive sheet decreases when it is deformed such as stretching, and it can handle large extensions, so a sensor element made using this stretchable conductive sheet can be used on the elbows and knees of the human body. Deformations such as large elongations such as bends can be electrically detected.

[Problem to be solved by the invention]

However, when using a sensor element using an elongated conductive element made of these elongated conductive sheets as a runaway prevention switch for a robot or when detecting the bending of a human joint such as an elbow or knee, However, there is a problem in that a large deformation exceeding the allowable amount of deformation or stress is applied to the elongated conductive sheet, resulting in changes in the properties of the elongated conductive sheet or even destruction of the elongated conductive element.

The allowable stress here refers to the maximum stress within a range in which the properties of the elongated conductive element, that is, the elongated conductive sheet do not change. FIG. 2 shows a conceptual diagram of the relationship between stress and electrical resistance of an elongated conductive element. As shown in FIG. 2, as the stress applied to the elongated conductive element increases, the electrical resistance value decreases, but when the stress exceeds a certain level, the resistance value begins to increase. The stress at which this change in resistance changes from decreasing to increasing is defined as the allowable stress. Further, the amount of deformation at this time is defined as the allowable amount of deformation.

If stress or deformation exceeding the allowable stress or allowable deformation amount is applied to the elongated conductive element, there is a high possibility that the characteristics of the elongated conductive element will change or it will break.

Therefore, the same applicant as the present invention is
No. 2 proposes an elongated conductive element of an action elongation setting type that is provided with an elongation suppressing member that can set the elongation of the elongated conductive element to a predetermined elongation or less.

In this way, when an elongation suppressing member is installed, it is possible to prevent the elongated conductive element from being deformed more than the allowable amount of deformation or to apply stress more than the allowable stress to the elongated conductive element. You can prevent it from happening. However, with such an elongated conductive element, it is not only difficult to detect the amount of deformation such as elongation ranging from small deformation to large deformation, but also because the elongation suppressing member is stretched when viewed from the subject's side. This has the disadvantage that free movement of the body is obstructed, causing a feeling of pressure and pain, especially when the subject is a human or animal.

The present invention solves the problems in use of the elongated conductive element previously proposed by the applicant of the present invention, and enables the elongated conductive element to be subjected to large deformations exceeding its own allowable deformation or allowable stress. The object of the present invention is to provide a strain/stress detection sensor element that can detect strain and stress without imposing a burden on the subject.

[Means to solve the problem]

The object of the present invention is to form an elongated conductive element in which at least two electrodes are provided at intervals on an elongated conductive sheet whose electrical resistance value decreases when deformed, and one electrode is connected in series and/or in parallel to the elongated conductive element.
This is achieved by a strain/stress sensing sensor element characterized by connecting two or more elastic bodies.

As the elastic body, any material can be used as long as it has a strong tendency to return to its original state when subjected to strain. For example, rubber-like materials (silicone rubber, urethane rubber, EPR rubber, etc.), springs, knitted fabrics with good elasticity (knitted fabrics with urethane thread mixed in, or the above-mentioned rubber-like materials bonded or embedded), etc. Can be used.

As a method of connecting the elongated conductive element and the elastic body, a method of connecting in series with respect to the direction of deformation such as elongation, a method of connecting in parallel, and a method of using both series and parallel connections can be used. .

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings showing embodiments of strain and stress detection sensor elements according to the present invention.

1, 4, 6a, 6b, 7, 9, 10, and 11 show embodiments of strain and stress detection sensors according to the present invention.

In the sensor element shown in FIG. 1, an elastic body is connected in series to an elongated conductive element. That is, stretched conductive sheet 1
An electrode 3a and one end of the elastic body 2 are attached to one end of the electrode 3a using a hook having a snap button 5a, and a lead wire 4a is connected to the electrode 3a. Stretched conductive sheet 1
An electrode 3b is attached to the other end using a hook having a snap button 5b, and a lead wire 4b is connected to the electrode 3b. In this way, a strain/stress detection sensor according to the present invention including an elastic body is formed.

In the figure, 8a and 8b are surgical tapes and 7a.

7b indicates adhesive. As in this example, when an elongated conductive element and an elastic body having a desired elasticity are connected in series, even if a large deformation exceeding the allowable deformation amount of the elongated conductive element itself is applied to the sensor element, the elastic body will Since the elongated conductive element is deformed, it is possible to prevent the elongated conductive element from breaking or changing its properties without actually exceeding the permissible deformation amount. Furthermore, since the movement of the subject is applied to both the elongated conductive element and the elastic body, the sensitivity of the sensor element in terms of the amount of deformation can be adjusted by selecting the type and shape of the elastic body.

Furthermore, by selecting the type and shape of the elastic body, it is possible to greatly deform the sensor element with a small stress that does not inhibit the movement of the subject.

FIG. 3a shows an example of the relationship between the amount of deformation and the stress of a sensor element in which an elongated conductive element and an elastic body are connected in series as shown in FIG. Curve a is for the elongated conductive element, curve a is for the elastic body,
Curve C shows the relationship between the amount of deformation and stress of a sensor element in which an elongated conductive element and an elastic body are connected in series. In a sensor element in which an elongated conductive element and an elastic body are connected in series, when a stress F is applied, a stress of magnitude F is applied to both ends of the elongated conductive element and the elastic body. (Figure 3b) In other words, the amount of deformation xc of the sensor element when stress F is applied to the sensor element is the amount of deformation xa of the elongated conductive element when stress F is applied and the amount of deformation xa of the elastic body when stress F is applied. Deformation amount x
The result is (xc-xa+xb) obtained by integrating b. Therefore, the permissible deformation amounts x, , X, c of the sensor element become larger than the permissible deformation amount xmix,a of the elongated conductive element.

Next, an example of a sensor element in which an elongated conductive element and an elastic body are connected in parallel is shown in FIG. 4, and an example of the relationship between the amount of deformation and stress in that case is shown in FIG. 5a. In FIG. 4, the elastic body 2b is connected in parallel to the elongated conductive element. In the figure, 6a, 6b
is a flexible printed circuit, 8a and 8b are surgical tapes, and 7a.

7b is an adhesive.

As in this example, when an elongated conductive element and an elastic body having a desired elasticity are connected in parallel, the allowable stress of the sensor element can be made larger than the allowable stress of the elongated conductive element itself.

In Fig. 4, the elongated conductive element and the elastic body are bonded only at both ends, but the entire back surface of the elongated conductive element may be bonded, or both ends and a part of the center may be bonded. It may be glued.

Further, the length of the elastic body 2b does not necessarily have to be the same as the length of the elongated conductive element, and may be made longer or longer depending on the case.
By shortening the length, it is possible to improve the fit between the sensor element and the subject and to adjust the detection sensitivity.

In FIG. 5a, curve a shows the relationship between deformation and stress of the elongated conductive element, the curve C shows the relationship between the deformation amount and the stress of the sensor element in which the elongated conductive element and the elastic body are connected in parallel. If the lengths of the elongated conductive element and the elastic body 2b are the same, the amount of deformation of the elongated conductive element and the amount of deformation of the elastic body 2b are the same. Furthermore, the internal stress Fa+b of the sensor element in which the elongated conductive element and the elastic body are connected in parallel (equal to the external stress FC applied to the sensor element) is the internal stress Fa of the elongated conductive element and the elastic body Fb.
It is the sum of . Therefore, compared to the allowable stress F max,a of the elongated conductive element, the allowable stress F of the sensor element
max'c becomes larger.

Further, when the elongated conductive element and the elastic body are connected in parallel, as a modification, the elongated conductive element may be spirally wound around the elastic body. FIG. 11a and FIG. 11b show schematic diagrams of the present invention having S-type spiral winding and Z-type spiral winding, respectively.

In the figure, 1 represents an elongated conductive element, 2e represents an elastic body (for example, a rubber tube), and 5a and 6b represent lead wires. In this way, when the sensor element is extended in the length direction, the amount of deformation of the elongated conductive element itself becomes smaller than the amount of deformation of the sensor element due to geometric effects. Therefore, the allowable deformation amount and allowable stress of the sensor element are larger than the allowable deformation amount and allowable stress of the elongated conductive element itself. In other words, large deformations can be detected. In addition, by changing the number of windings, the spacing, the type and shape of the elastic body when winding the elongated conductive element around the elastic body, it is possible to determine the relationship between the amount of deformation of the sensor element and the electrical resistance value, or the stress applied to the sensor element and the electrical resistance value. The relationship can be adjusted as desired. Therefore, by making these characteristic curves gentler, it is possible to widen the range of deformation amounts and the range of stress that can be detected accurately in an analog manner. Although the elongated conductive element is spirally wound around an elastic body, another important feature is that it is also possible to detect torsional deformation that does not involve elongation in the length direction of the sensor element.

Of course, it goes without saying that torsional deformation accompanied by elongation can also be detected.

That is, as shown in FIG.
By combining spiral windings and detecting the voltage output with the bridge circuit shown in Figure 8a, it is possible to accurately detect the direction and magnitude of twist without being affected by the elongation deformation in the length direction of the sensor element. can.

In Fig. 7, 1a is an S-shaped spiral winding, 1b is a Z-shaped spiral winding elongated conductive element, 2e is an elastic body (rubber tube), and 6
a, 6b, 6c, and 6d indicate lead wires.

′ Regarding torsional deformation, when an elongated conductive element is wound in an S-shaped spiral around an elastic body, the electric resistance value of the sensor element decreases when a clockwise twist is applied, but the electric resistance value decreases when a counterclockwise twist is applied. does not change. Conversely, if the elongated conductive element is wound in a Z-shaped spiral, the electric resistance value of the sensor element will decrease when a counterclockwise twist is applied, but the electric resistance value will change when a clockwise twist is applied. do not. This is useful in detecting the direction and magnitude of twist.

In Figure 8a, R1 and R2 are resistors, E is a power source, ■ is a voltmeter, S, and S2 are electrode terminals connected to the lead wires attached to both ends of the S-shaped spirally wound elongated conductive element. Zl and Z2 are electrode terminals connected to lead wires attached to both ends of the Z-shaped spirally wound elongated conductive element.

FIG. 8b shows the S
An example is shown in which a torsion detection waveform is detected by the sensor element of the present invention, which is a combination of type spiral winding and Z-type spiral winding. In Figure 8b, the curve AB is 180 degrees from the clockwise ratio O degrees.
Curve BC when twisted from 180 degrees to 0 degrees, and curve CD when twisted counterclockwise from 0 degrees to 18 degrees.
When twisted to 0 degrees, curve DE is the output waveform when twisted from 180 degrees to 0 degrees.

Furthermore, when an elongated conductive element is spirally wound around an elastic body, if the entire elongated conductive element is fixed to the elastic body, even if bending deformation is applied to the sensor element, the entire elongated conductive element will be bent and deformed. Stress and deformation are transmitted, and the electrical resistance value decreases depending on the degree of bending, so the existence and magnitude of bending deformation can also be recognized.

Furthermore, if a tube-shaped object is used as an elastic body and a fluid such as water or oil is poured into the hollow space, when pressure is applied to one part of the tube, the other part of the tube expands, increasing the electrical resistance of the elongated conductive element. decreases, so compressive deformation can be detected.

The cross section of the elastic body used in the spirally wound sensor element described above is preferably circular, but is not particularly critical, and may be, for example, hexagonal or quadrangular. Alternatively, it may be a hollow object or a composite of a plurality of elastic bodies.

Next, FIG. 9 shows an example of a sensor element in which an elongated conductive element and an elastic body are connected in series and parallel, and FIG. 12a shows an example of the relationship between the amount of deformation and stress in that case.

In the case of FIG. 9, the elastic body 2a is connected in series with the elongated conductive element, and the elastic body 2b is connected in parallel with the elongated conductive element. In the figure, 6a, 6b are flexible printed circuits, 8a, 8b are surgical tapes, 7a, 7b,
7c is an adhesive. The elastic bodies 2a and 2b may be formed as an integral elastic body 2C as shown in FIG. 10, or may be connected to the elongated conductive element on its entire surface facing the elongated conductive element.

In FIG. 12a, curve a is the curve b of the elongated conductive element.
ib is the elastic body 2b, the song "gAbz- is the elastic body 2a,
Curve C shows the relationship between the amount of deformation and stress of a sensor element in which an elongated conductive element and an elastic body are connected in series and in parallel. If the lengths of the elongated conductive element and the elastic body 2b are the same, the amount of deformation x8 of the elongated conductive element and the amount of deformation xbzb of the elastic body 2b are the same. The amount of deformation xc of the entire sensor element is the sum of the amount of deformation xa of the elongated conductive element and the amount of deformation Xb2a of the elastic body 2a (x (-x @ + x b2a). Note that the external stress FC applied to the sensor element And, the internal stress Fi+bzb of the entire structure in which the elongated conductive element and the elastic body 2b are connected in parallel is equal (FC-Fa+bzb), and F a+b2b is the internal stress F3 of the elongated conductive element and the internal stress F bzb of the elastic body 2b. The integrated value (F,,
b□, -Fa+Fbzb). That is, the amount of deformation xc of the sensor element and the internal stress F a+b2b (external stress F
Comparing the amount of deformation x3 of the elongated conductive element and the internal stress Fa', xc>xR,Fa, z,>F
a (However, Xb2a> o, l Fbzb>
(in case of O). Therefore, when the elongated conductive element and the elastic body are connected in series and parallel, the permissible deformation of the sensor element XH
aX+(, allowable stress F maXic are both allowable deformation amount xmBx-s of the elongated conductive element itself, allowable stress F.8
It is larger than 8.3.

Also, patent application No. 89207/1989 filed by the same applicant as the present invention.
An elastic body may be connected in series and/or in parallel to a structure in which an elongated conductive element and a leaf spring-like material are bonded together as proposed in Publication No. G. It is preferable that a plate spring-like object is present because bending deformation is concentrated on the elongated conductive element and detection can be performed with higher sensitivity. An example thereof is shown in FIG. In this case, it is preferable to use a soft rubber-like elastic body 2d because it can prevent the leaf spring-like object 9 from injuring the subject. This is especially good when the subject is a person, animal, or soft object.

The elongated conductive element and the elastic body can be connected by bonding using an adhesive or heat-sealing film, or by using the adhesive properties of the elastic body itself during the formation process (for example, using a silicone rubber film). (drying during the production process, bonding before curing, etc.), methods that use spring clamping such as snap buttons, wa-locrisop, magnets, pressure differences, tying with woven zipper thread, and sewing methods. It will be done. However, methods other than these may be used as long as they have a clamping force that can withstand deformation of the sensor element.

The strain/stress detection sensor element of the present invention configured as described above can respond to large deformations of the subject, so it is useful for the following applications that cannot be used with conventional detection sensor elements. It can be used for.

For example, a breathing band breathing monitoring device that detects the cycle and number of breathing, a pulmonary function testing device [respiratory management for neonatal apnea, especially premature infants, or recording respiratory waveforms, etc.]
It can be used as a medical sensor to measure lung function from vital capacity and flow velocity (calculated from the slope of the waveform to test peripheral lung function). In addition, sensors that can be attached to the elbow or knee as a pedometer or incorporated into shoes to detect the number of steps taken, as well as various training devices (involving bending and stretching) for the purpose of strengthening muscle strength and shaping the body, as well as the number of times and degrees of flexion. It can be used in sports training sensors that detect levels such as

Furthermore, finger switches that directly respond to finger movements by applying them directly to the hand or arm or attaching them to gloves, etc.
That is, it can be used as a joystick for games with a sense of realism, a sign language voice conversion device combined with a computer, and an input device that can remotely control robot hands for dangerous or precision work.

It is also used in rehabilitation equipment that detects the degree of elongation and flexion for the purpose of restoring the functions of joints of the human body.

Furthermore, by detecting elongation stress or strain, it can be used as a strain meter, load meter, accelerometer, or vibration meter.

If the shape and spacing of the connecting ends of the sensor element are selected appropriately, minute movements on the surface can be detected with high sensitivity. It can also be used as a strain gauge to detect minute deformations such as.

In addition, by fixing both ends of the sensor element and changing its extension by pressing the center part, we can create tactile sensors for robots, non-contact switches for keyboards and handwriting input, and seating detection sensors that can be used in seats to confirm seating. It can be used for crime prevention and danger prediction sensors installed on window frames and handrails for crime prevention and safety (pressure sensors such as touch sensors, danger prediction sensors for power windows of cars, etc.). Next, as an industrial sensor, it can be attached to the rotating or bending part of an industrial robot.
Sensors for detecting the direction of robot hands, position control sensors for position control, limit switches and microswitches, safety switches installed around the robot to prevent it from running out of control, and sheet-shaped sensors installed in dangerous areas. By laying a (mat-like) sensor element, it can be used as a safety switch that detects the intrusion of a worker and stops the robot in an emergency. In addition, diaphragms, pressure gauges, sensors for detecting the expansion rate of expansion bodies, pulse meters, blood pressure monitors, and various current meters (for fluids such as liquids and gases)
It can be used as

It is clear that the uses of the sensor element of the present invention are not limited to the above-mentioned uses.

〔Example〕

Hereinafter, a more detailed explanation will be given using examples, but it is clear that the strain and stress detection sensor element according to the present invention is not limited to only those examples and those shown in the drawings.

Taffeta made of polyester fiber yarn manufactured by Asahi Kasei Corporation (warp 50d/24f, weft 75d/36f)
Thorium hydroxide solution (80g/l, 100"C
(liquid volume ratio 20%), SnCβ2:hydrochloric acid is 3
: After sensitization in a bath with a weight ratio of 10, washing with water and dehydration, Pd
(J2: Hydrochloric acid is activated in a bath with a weight ratio of 1:15, and after washing with water and dehydrating, NiC#2.6 H2O, NaHPOz, sodium citrate, NH, C1, and aqueous ammonia are mixed in a 1:1 ratio.
:3:' Treated for 2 minutes at 90°C in a bath with a weight ratio of 2:2,
Ni-metsuki ester taffeta was produced. This is 10cm
A double cylindrical laminar flow generator (the inner cylinder rotates at high speed, the outer cylinder has an inner diameter of 25 cm)
, an inner cylinder with an outer diameter of 10 cm) together with water, and treated at an inner cylinder rotation speed of 20 rpm for 300 minutes to obtain an elongated conductive fabric.

Next, commercially available urethane elastomer resin (solvent DMF,
Solid content 10wt/%) 90ttm, 300Jr
100℃ after coating on release paper with m gauge
After drying for 3 min and in a half-dry state, thermal adhesive transfer was applied to both sides of this sheet-shaped elongated conductive fabric at 110°C with a pressure of 4 kg/cJ, and dried at 100°C for 30 minutes to obtain an elongated conductive sheet. .

Next, this stretched conductive sheet was cut in the bias direction to 1 cm width x 5 cm length, and a 1 cm length from both ends was sandwiched between copper plates and stretched by 20%.The electrical resistance value was measured. The resistance value changed from 4.5×10Ω to 60Ω before and after stretching.

Using this stretched conductive sheet, eight types of sensor elements as comparative examples corresponding to the following eight types of sensor elements according to the present invention were made.

(2) A carbon-based conductive resin was applied to a distance of 1 cm from both ends of the stretched conductive sheet 1. Next, an elastic body 2 made of a ribbon (1 cm wide x 10 cm long) knitted from urethane thread, an elongated conductive sheet 1, and a lead wire 4. A and 4b are stacked in the order shown in FIG. 1, pressed with brass snap buttons 5a and 5b, and surgical tapes 8a and 8b are bonded with adhesive to form a strain/stress detection sensor element of the present invention in the form shown in FIG. 1. , Sample N[Ll was prepared.

■ Carbon-based conductive resin is applied 1 cm from both ends of the stretched conductive sheet 1, and lead wires 6a are placed on top of it.

As 6b, a commercially available flexible printed circuit (polyester base film 35 μm thick, Ag-based conductive layer, surface heat-sealable polymer lamination) was cut into 1 cm x 6 cm length and adhered. Furthermore, a silicone rubber sheet (thickness 300 feet) was cut into a length of 1 cm x 5 am.
Conductive sheet 1 stretched l cm from both ends as elastic body 2b
It was attached with silicone adhesive. Further, the surgical tapes 8a and 8b were adhered to a silicone rubber sheet using an epoxy adhesive to prepare a sample floor 2 of the present invention shown in FIG. 4.

■ Cut the stretched conductive sheet to 511 width x 12 CIIl length, apply silver-based conductive resin to 5mm from both ends, and place a commercially available flexible printed circuit on it to 5n width x 5CIl length.
The canted pieces were glued together. Next, cut the silicone tube (outer diameter: 5 fins) to a length of 9 cm, and wrap the stretched conductive sheet on top of it in an S-shaped spiral (pitch distance: 1 cm).
The entire back surface of the elongated conductive sheet was adhered to a silicone tube using a silicone adhesive to prepare a sample 3 of the present invention shown in FIG. 6a.

(2) Sample 4 of the present invention shown in FIG. 6b was prepared from the same materials and configuration as sample 11h3 except that the stretched conductive sheet was wound in a Z-shaped spiral around a silicon tube.

■ Cut the stretched conductive sheet into 2 pieces 5 cm wide x 12 cm long, apply silver-based conductive resin to 5 mm from both ends of each, and place 5 commercially available flexible printed circuits on top of it.
A piece measuring 1 width x 5 am width was glued together. Next, cut a silicone tube (diameter 5 mm) to a length of 9 cm, and wrap one stretched conductive sheet on top of it in an S-shape spiral (pinch distance 1 (, m4 multiplicity 7), starting from both ends of the stretched conductive sheet. A silicone adhesive was applied to the back side of the 1 cm section and it was adhered to the silicone tube. On top of that, another stretched conductive sheet was wound in a Z-shape (with a pitch distance of 1 cm).
am, the number of turns is 7), and l from both ends of the stretched conductive sheet.
A silicone adhesive was applied to the back surface of the cm portion and adhered to a silicone tube to prepare a sample 5 of the present invention shown in FIG. 7.

■ Carbon-based conductive resin is applied 1 cm from both ends of the stretched conductive sheet 1, and lead wires 6a are placed on top of it.

As 6b, a commercially available flexible printed circuit (polyester base film 35μ+4, Ag-based conductive layer, surface heat-sealable polymer laminate) cut into a 1 am width x 6 cm length was adhered. Furthermore, a silicone rubber sheet (thickness: 300 squares) was cut into a piece 1 cm wide by 5 cm long, and 1 cm from both ends was adhered to the stretched conductive sheet 1 using a silicone adhesive as an elastic body 2b.

Furthermore, 1 cm of silicone rubber sheet (100 feet thick)
The elastic body 2a was made into a width x 3cm length, one end of which was glued to one end of the stretched conductive sheet 1 with epoxy resin, and the other end of the silicone rubber sheet was glued to the surgical tape 8a with an adhesive. Sample 6 was prepared.

■ In order to use it as the elastic body 2C of the sensor element shown in Fig. 10, a commercially available urethane elastomer resin (solvent toluene, solid content 20 wt%) was coated on a release paper using a 500 inch gauge, and then dried at 100°C x 3 ml to form a film. In a half-dried state, as shown in Fig. 10, it was thermally adhesively transferred to one side of the stretched conductive sheet 1 at 110°C with a pressure of 4 kg/cut, and then 110°C x 30 m1.
n dried. Cant this into a length of 1 cm x 10 cm, and add carbon-based conductive resin 7a and 7b from both ends to a length of 1 cm.
was applied, and flexible printed circuits 6a and 6b were adhered in the same manner as samples No. 2. Furthermore, surgical tapes 8a and 8b were adhered to both ends to produce a sample tooth 7 of the present invention.

■ As shown in FIG. 11, the stretched conductive sheet 1 is attached to a polycarbonate film 9 (thickness 80 side, l
It was heat-sealed to a sheet (cm width x 7 mark length). Further, in the same manner as Sample No. 4, a urethane elastomer resin film (length 10 cm) was bonded as the elastic body 2d with both sides left open as shown in FIG. Also, Q, 7 cm from both ends of the polycarbonate film.
A copper plate of 10 (thickness: 35 porcelain) was glued to the. Further, a silver-based conductive resin 3C is applied to a portion 1 cm from both ends of the elongated conductive sheet 1- and on the copper plate, and the lead wire 4. a, 4
Sample No. 8 of the present invention was soldered to a copper plate, and surgical tapes 8a and 8b were attached using adhesives 7a and 7b.
was created.

Next, these distortion and stress detection sensor element sample No.
As comparative examples for samples 1 to 8, strain and stress detection sensor elements made of the same material and structure as samples Nos. 1 to 8, without connecting the elastic body, and samples 1' to 1' to 8' was produced. (Comparative examples of samples No. 1 to Magnetic 8 are ml', N12', N[L3',
Floor 4', Arashi 5', N1116', Floor 7' and Yang 8'. ) Next, the critical deformation amount and critical stress of sample teeth 1 to 7 and floors 1' to 7' were measured, and the results shown in Table 1 were obtained. That is, due to the connection of the elastic body, an increase in the critical deformation amount was observed in Sample Tooth 1, an increase in critical stress in Sample Tooth 2, and an increase in the critical deformation amount and critical stress in Samples N113 to No. 7.

In addition, when we fixed both ends of samples 11kL8 and 8' to the second joint of the middle finger of a person's right hand with surgical tape and measured the degree of flexion of the joint, we found that in sample N114', the skin was stretched and the flexion of the finger was hindered. In addition, after about 2 hours of measurement, the skin became red, but on floor 4, the fingers could be freely flexed, and there was no change in the skin even after 24 hours of continuous measurement.

Next, an elastic body 2 (silicon rubber sheet thickness: 500 m) was cut into the shape shown in Fig. 13a, and an elongated conductive element was attached to a polycarbonate film (thickness: 80 m) using the same method as sample No. 8. A sample tooth 9 of the present invention was produced by adhering to this elastic body with an epoxy adhesive. In the figure, 11 is a double-sided adhesive tape.

In addition, a commercially available medical bag with rubber elasticity is available in No. 13b.
Sample N of the present invention was cut out as shown in the figure to form an elastic body 2, and an elongated conductive element was attached in the same manner as in Figure 13a.
o, 10 was prepared.

Samples No. 9 and No. 10 were attached to the finger joints as shown in Fig. 13c, and the number of bends was measured.
It has been found that the sensor can detect the number of times the finger joint is flexed, which has an appropriate fit and allows the finger to be flexed without discomfort. For example, this sensor can be used not only for rehabilitation purposes, but also as a diagnostic sensor for detecting the number of scratches for atopic dermatitis, pruritus, and other conditions.

Next, grasp both ends of the sample 111o, 3 and stretch and deform it (
20%), only clockwise (180 degrees) torsional deformation, counterclockwise (180 degrees) only torsional deformation, elongation deformation (20%) and clockwise (180 degrees) The changes in electrical resistance were measured in each of the cases in which both an elongated deformation (20%) and a counterclockwise (180 degree) torsional deformation were applied. Next, both ends of the sample tooth 4 were grasped, and the electrical resistance value was measured in the same manner as for patient 3. The results are shown in Table-2.

That is, it can be said that the S-shaped spiral wound sample tooth 3 detects clockwise torsional deformation, and the Z-shaped spiral wound sample No. 4 detects counterclockwise torsional deformation.

Next, the sample tooth 5 having both the S-type spiral winding and the Z-type spiral winding was connected to a bridge circuit shown in FIG. 8a. In the bridge circuit, the two resistors R1 and R2 are both 10
[kΩ], the power supply E uses a 3 [V] battery, and the voltmeter ■
A commercially available digital multimeter was used. That is, S
31. Electrode of a spirally wound stretched conductive sheet. In S2,
Electrodes of a Z-shaped spirally wound stretched conductive sheet were connected to Zl and Z2. Next, both ends of the sample tooth 5 were grasped, and the sample tooth 5 was twisted clockwise and counterclockwise to examine the output voltage.

The results are shown in Figure 8b. That is, a sensor element using both an S-type spiral winding and a Z-type spiral winding can detect the direction and magnitude of torsional deformation.

Table 1 Limit deformation amount and limit stress of each sample Table 2 [Effects of the invention] Since the strain and stress detection sensor element according to the present invention is configured as described above, it is possible to detect the strain and stress that cannot be detected using conventionally known sensor elements. Large deformation can be detected without placing any burden on the subject. Therefore, as detailed above, the movements of the human body (bending of joints such as fingers and toes, wrists, elbows, shoulders, neck, hips, knees, etc., expansion and contraction of the chest and abdomen due to breathing, muscle contraction due to exercise, etc.) It can be used to detect tension, relaxation, etc.

[Brief explanation of the drawing]

1, 4, 6a, 6b, 7, 9, 10, and 11 are front views showing various embodiments of the strain/stress detection sensor element according to the present invention, respectively. FIG. 2 is a graph showing the relationship between stress and electrical resistance of an elongated conductive element, and FIG. FIG. 3b is a graph showing an example of the relationship between the amount of deformation and stress, and FIG. 3b is a conceptual diagram showing how force is applied to the elongated conductive element and the elastic body when external force is applied to the sensor element. Figure 5a is a graph showing an example of the relationship between strain and stress detection sensor element deformation amount and stress when an elongated conductive element and an elastic body are connected in parallel, and Figure 5b is a graph showing an example of the relationship between the amount of deformation and stress of the sensor element when an elongated conductive element and an elastic body are connected in parallel. FIG. 8a is an example of a circuit diagram connected to the strain/stress detection sensor according to the present invention shown in FIG. 7; Figure 8b is a graph showing the output waveform when torsional deformation is applied to the strain/stress detection sensor shown in Figure 7, and Figure 12a is a graph when the elongated conductive element and the elastic body are connected in series and parallel. distortion,
12b is a graph showing an example of the relationship between the amount of deformation of the stress detection sensor element and the stress, and FIG. 12b is a conceptual diagram showing how force is applied to the elongated conductive element and the elastic body when external force is applied to the sensor element. FIG. 13a to FIG. 13C are diagrams showing an example in which the strain/stress detection sensor element according to the present invention is used as a sensor for detecting the number of finger joint flexions, and FIG. 13a is a plan view, and FIG. 13b is a diagram. Perspective view, No. 13C
The figure is a front view. 1.12. Ib...stretched conductive sheet, 2.2a, 2b
, 2c, 2d, 2e--elastic body, 3.3a, 3b, 3
c, ](L...electrode, 4a, 4b...lead wire, 5a, 5b...snap button, 6a, 6b, 6c, 6d...flexible printed circuit, 7a, 1b, 7cm--adhesive , 3a, 3b...Surgical tape, 9...Resin film, 11...Double-sided tape, R,, R2・
...Resistance, E...Power supply, ■...Voltmeter, sl, Sz, Zl, Z2...Electrode terminal, A~B...
Process of adding clockwise torsional deformation (0-180 degrees), B-C... Process of undoing torsional deformation (180-0 degrees), C-D... Counterclockwise torsional deformation ( 0-180 degrees)
The process of adding , D to E... Returning the torsional deformation < (180-0 degrees)
process.

Claims (1)

[Claims] 1. One or more elastic bodies are connected in series and/or in parallel to an elongated conductive element comprising at least two electrodes spaced apart from each other on an elongated conductive sheet whose electrical resistance value decreases when deformed. A strain and stress detection sensor element characterized by: