JP2007262623A - Electrode for contact sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the linearity of a load-resistance change, since a conventional contact sensor using a material obtained by laminating a metal thin plate, metal mesh or metal foil on a synthetic resin plate or synthetic resin film has no problem in contact sensing for a machine, apparatus, etc., but in the case of detecting or sensing by direct contact with a human body or an animal, touch feeling, incompatible feeling on a long time contact, flexibility, etc., become problems. <P>SOLUTION: This material produced by weaving an electroconductive fiber plated with a thin electroconductive metal on the surface of a synthetic resin fiber, which is excellent in suppleness and flexibility, and an insulation fiber at a fixed interval into a cloth form, or an electroconductive non-woven fabric obtained by mixing and bonding the metal-plated electroconductive fiber with the insulation synthetic resin fiber are used as the electrodes of the contact sensor so as to improve suppleness, flexibility, touch, incompatibility, the linearity of the load-resistance change, etc. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a sensor for contact detection using an elastomer-based pressure-sensitive conductive sheet as a sensor sheet. The contact with a human body or an animal is soft, and there is little discomfort even for a long-time contact. -It relates to an electrode of a contact sensor having good resistance change linearity.

  As the elastomer-based pressure-sensitive conductive sheet, a conductive rubber obtained by mixing conductive fine particles, graphite fine particles, carbon black, metal fine particles, etc. in a non-conductive elastomer is previously crosslinked, and then the conductive The conductive fine particles inside the conductive rubber are processed to be evenly or suitably dispersed at a minute interval by absorbing a non-volatile oil compatible with the conductive rubber (disclosed example, Sho 59) -11343, Hei 6-192485), conductive carbon fine particles are blended in a non-conductive elastomer at a ratio of 45 to 55% by volume with respect to the total volume of the composition, and the conductive fine particles are incorporated into the rubber. Electrical resistance is improved by pressurizing and deforming a cross-linked product (disclosed example, Hei 2-196936, Hei 4-253109) uniformly or suitably dispersed at minute intervals. There are those that change appropriately and continuously.

  In recent years, with the aging population declining in Japan, nursing care, medical care, and rehabilitation equipment corresponding to the aging have been developed. In addition, a monitoring device for elderly people is also required, and a contact sensor that is in direct contact with the human body and has a sense of incongruity in contact with the human body that is detected for a long time, is soft in touch, has a good feel, and has a good load-resistance change linearity. It is desired.

  There is a growing need for detection of contact with animals for the purpose of protection and monitoring when animals such as cats and dogs are kept indoors as pets or in the car.

  Wearable electronic devices that can be worn on the human body by reducing the size, thickness, and weight of personal computers, music, video equipment, etc. have been developed, and contact sensors that are worn on the human body are also desired to have soft, flexible, and uncomfortable feelings. ing.

  There is a demand for an electrode that is used for these contact sensors and has good feel, flexibility, deformation, flexibility, and excellent linearity of load-resistance change that hardly causes permanent deformation.

JP 59-11343 A JP 2-19636 A Japanese Patent Laid-Open No. 4-253109 JP-A-6-192485

  In the conventional contact sensor, the electrode member is made of a material such as a thin metal plate, a metal mesh, or a printed circuit board in which a copper foil having a thickness of 35 to 18 microns is attached to a synthetic resin plate or film. It feels uncomfortable because it feels hard and cold when it comes into contact with the human body or animals.It is difficult to use for a long time, especially when it is used for a long time. As a result, there are problems such as generation of noise when there is no load, and steep changes in resistance to the load. In addition, a contact sensor in which an electrode is printed on a thin polyester film with a silver paste and a pressure-sensitive resin is printed thereon can be manufactured thinly, but there is a problem that it is easily damaged by an acute angle deformation.

  A conductive metal such as gold, silver, copper, nickel, tin, indium, chromium, zinc is deposited on the surface of synthetic resin fibers such as polyimide, polyamide, polyester, acrylic, and polyurethane by vacuum deposition, sputtering, etc. Metal plated conductive fibers that are thin and electrolessly plated in micron to 0.2 microns and are electrolessly plated are woven together with insulating synthetic resin fibers in a cloth shape.

  For the electrode, a metal-plated conductive fiber is woven into a cloth by weaving warp and / or weft at regular intervals.

  Alternatively, a metal-plated conductive fiber and insulating synthetic fiber are mixed and heat-welded, or a non-woven fabric having conductivity by bonding with an adhesive is also used as the electrode.

By adopting the above electrode, the contact with the elastomer pressure-sensitive conductive sheet is loosened, the resistance change with respect to the load is moderated, and the characteristics of the load-resistance change are prevented from becoming steep.

  The linearity of the load-resistance change is improved by adjusting the number and interval of the metal plating fibers to be woven in the vertical and horizontal directions to moderate the change in the contact area with the elastomeric pressure-sensitive conductive sheet.

  A contact sensor that uses an elastomer-based pressure-sensitive conductive sheet for the sensor sheet has excellent flexibility, soft contact with the human body and animals, and less discomfort even when used for long periods of time. It is possible to provide a contact sensor electrode with improved linearity.

  The surface of the polyester resin fiber having a thickness of 20 to 30 denier synthetic resin fibers is electrolessly plated with silver to a thickness of 0.1 to 0.2 microns to impart conductivity. 1 to 12 fibers combined with 40 to 50 denier insulating polyester fiber into one yarn, every three warp yarns and every other weft yarn, processed into a plain weave fabric The conductive cloth having a thickness of 0.1 to 0.2 mm is formed, and 20 to 36 insulating polyester fibers of 50 to 75 denier are used as a single thread for the middle and used for warp and weft. The material made into a cloth-like fabric is used for the electrode.

  Twelve silver-plated conductive fibers that are electrolessly plated with 0.1 micron thick silver on the surface of a polyester resin fiber having a thickness of 30 denier and having a thickness of 50 denier. A combination of 24 insulating polyester fibers was made into one thread.

  Each of the above-mentioned yarns is used for every three warp yarns and every two weft yarns to form a plain cloth with a thickness of 0.15 mm. The middle part is composed of 36 75-denier insulating polyester fibers. A conductive cloth (M20048, manufactured by Mitsufuji Textile Industry Co., Ltd.) made into a woven fabric using warp and weft as a single thread is cut into dimensions of 80 mm in length and 80 mm in width. Adopted.

  One side of an Irax HF electric wire (UL3302 AWG32 manufactured by Sumitomo Electric Co., Ltd.) having a length of 5 mm stripped at both ends is brought into contact with the conductive cloth electrode, and a conductive paste (Fujikura Kasei Co., Ltd., Dortite D) is formed thereon. -362) was applied and dried to connect and fix the lead wire and the conductive cloth electrode.

  This conductive cloth-like electrode is not in contact with the upper and lower sides, and a conductive rubber obtained by mixing conductive carbon black in silicone rubber is previously cross-linked, and then non-volatile that is compatible with the conductive rubber. An elastomer-based pressure-sensitive conductive sheet obtained by absorbing oil was disposed at the center of the top and bottom of 90 mm in length, 90 mm in width, and 0.5 mm in thickness.

  In addition, a cloth of 100mm length, 100mm width and 0.15mm thickness plain weave of 50 denier polyester synthetic resin fibers is placed at the top and bottom as an insulating surface protection sheet, and the outer periphery is overlocked. A contact sensor was manufactured by sewing and fixing.

  FIG. 6A shows the result of placing the contact sensor horizontally on a phenol resin plate having a thickness of 10 mm and applying a load from above to measure the load-resistance change. As a comparative example 1, the load (horizontal axis—equal interval scale) —resistance (vertical axis—logarithmic scale) change characteristic when a stainless steel mesh having an opening size of 1.0 mm and a thickness of 0.1 mm is used for the upper and lower electrodes is shown in FIG. Shown in Table 1 shows changes in the bending radius and resistance, and Table 2 shows whether the electrode is permanently deformed. One end is fixed with no load applied to the contact sensor and the other end is bent with left and right alarms. .

  Silver is plated on the surface of a nylon fiber having a thickness of 30 denier to a thickness of 0.1 micron to impart conductivity, and one conductive fiber is insulated polyester having a thickness of 40 denier. One twisted resin fiber and four 70 denier polyester resin fibers were combined into a warp.

  The weft is composed of 90% polyester resin fiber with a thickness of 40 denier and 10% silver-plated nylon fiber to form a plain-woven cloth with a thickness of 0.15 mm (Kanebo Fibers Co., Ltd.) X-Age AG-01, manufactured by company, cut to 30 mm length and 100 mm width and used for the upper and lower electrodes.

  One side of an Irax HF electric wire (UL3302 AWG30, manufactured by Sumitomo Electric Co., Ltd.) having a length of 5 mm stripped at both ends is brought into contact with the conductive cloth electrode, and a conductive paste (Dotite D, manufactured by Fujikura Kasei Co., Ltd.) is formed thereon. -362) was applied and dried to connect and fix the lead wire and the conductive cloth electrode.

  Elastomer-based pressure sensitivity obtained by blending conductive carbon fine particles with silicone rubber at a ratio of 45 to 55% by volume with respect to the total volume of the composition so that the upper and lower sides of the conductive cloth electrode are not in contact with each other. A conductive sheet, 40 mm long, 110 mm wide, and 0.5 mm thick was placed up and down.

  Furthermore, a 50 mm long, 120 mm wide, 0.15 mm thick cloth with a polyester synthetic resin fiber having a thickness of 50 denier is placed on the top and bottom as an insulating surface protection sheet, and the outer periphery is sewn with overlock. A contact sensor fixed by sewing was manufactured.

  This contact sensor is placed horizontally on a phenol resin plate with a thickness of 10 mm, and the load (horizontal axis-equally spaced scale)-resistance (vertical axis-logarithmic scale) change is measured by applying a load from above. This is shown in FIG. One end is fixed in a state where no load is applied to the contact sensor, and the other end is bent by attaching an alarm to the left and right. Changes in the bending radius and the resistance value are shown in Example 2 of Table 1, and the presence or absence of permanent deformation of the electrode is shown. 2 of Example 2. As Comparative Example 2, a flexible printed circuit board in which a 35-micron-thick copper foil was bonded to one side of a 25-micron-thick polyimide film was used as a grid-like electrode having a conductive pattern width of 0.5 mm and a repeating pitch of 1.0 mm. The results are shown in FIG. 6D, Table 1 and Table 2.

It is a perspective view of the sensor which uses the electrode of the contact sensor of Example 1 of this invention. It is a perspective view of the electrode of the contact sensor of Example 1. It is an enlarged view of the electrode of Example 1. It is an expansion perspective view of the metal plating fiber used for the electrode of the Example 1. It is a schematic diagram of the AA cross section of the sensor using the electrode of Example 1. It is a figure which shows the change of the load-resistance of the Example 1, Example 2, the comparative example 1, and the comparative example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Contact sensor 2 Lead wire 3 Electrode 4 Conductive paste 5 Metal plating conductive fiber 6 Synthetic resin fiber 7 Elementary fiber of synthetic resin fiber 8 Metal plating film 9 Cloth-like surface protection sheet woven with synthetic resin fiber 10 With lead wire 11 Electrode 11 Sensor sheet 12 Sewing process fixing part of the surface protection sheet

Claims (4)

Conductive metal is plated on the surface of synthetic resin fiber to form conductive fiber with excellent flexibility and flexibility, and this metal-plated conductive fiber is separated into a cloth-like woven fabric made of insulating fibers at regular intervals. An electrode for a contact sensor, characterized in that it is woven into a cloth shape having conductivity, and a metal-plated conductive fiber and an insulating fiber are mixed and bonded to form a nonwoven fabric.
The electrode for a contact sensor according to claim 1, wherein the synthetic resin fiber is polyimide, polyamide, polyester, acrylic, or polyurethane.
2. The conductive metal according to claim 1, wherein the conductive metal forms a multi-layer thin film or an alloy thin film of a single or a plurality of gold, silver, copper, nickel, chromium, zinc, tin, indium, and aluminum. Contact sensor electrode.
2. The electrode for a contact sensor according to claim 1, wherein the metal-plated conductive fiber is woven into one or both of warp and weft.

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