Sensor and a method of making the same

{
  "publication_number": "US9745436B2",
  "country": "US",
  "kind": "B2",
  "title": "Sensor and a method of making the same",
  "abstract": "The present invention provides a sensor having an improved sensitivity and precision, which is lighter and more flexible than conventional sensors, and a method of making the sensor. The present invention relates to a sensor comprising a resin foam containing a magnetic filler, and a magnetic sensor that detects a magnetic change caused by a deformation of the resin foam, wherein the resin foam is a polyurethane resin foam that comprises a polyisocyanate component, an active hydrogen component, a catalyst and a foam stabilizer, and wherein the resin foam has a hardness change (H 1 -H 60) of 0 to 10 between a JIS-C hardness (H 1) in one second after contact with a pressure surface of a hardness tester and a JIS-C hardness (H 60) in 60 seconds after the contact.",
  "claims": [
    "1. A sensor comprising: a resin foam containing a plurality of bubbles and a magnetic filler, and a magnetic sensor that detects a change in magnetic field caused by a deformation of the resin foam, wherein the resin foam is a polyurethane resin foam that comprises a polyisocyanate component, an active hydrogen component, a catalyst and a foam stabilizer, and wherein the resin foam has a hardness change (H 1 -H 60) of 0 to 10 between a JIS-C hardness (H 1) in one second after contact with a pressure surface of a hardness tester and a JIS-C hardness (H 60) in 60 seconds after the contact.",
    "2. The sensor according to claim 1, wherein the resin foam has a specific gravity of 0.3 to 1.0 and an average cell diameter of 50 to 500 μm.",
    "3. The sensor according to claim 1, wherein an amount of the foam stabilizer is within the range of 1 to 10 parts by mass per 100 parts by mass of the resin foam.",
    "4. A method of making a sensor comprising a polyurethane resin foam containing a plurality of bubbles and a magnetic filler and a magnetic sensor, the method comprises the steps of: (I) forming the polyurethane resin foam containing the plurality of bubbles and the magnetic filler comprising the steps of; (i) forming an isocyanate group-containing urethane prepolymer from a polyisocyanate component and an active hydrogen component, (ii) preliminary stirring an active hydrogen component, a catalyst and a magnetic filler to form a magnetic filler dispersion, (iii) adding a foam stabilizer to the isocyanate group-containing urethane prepolymer to vigorously stir it under a non-reactive gas atmosphere such that it incorporates bubbles therein as a primary stirring step, (iv) further adding the magnetic filler dispersion thereto and stirring it as a secondary stirring step to prepare a bubble dispersed urethane composition containing the magnetic filler, (v) molding the bubble dispersed urethane composition into a desired shape and then curing it to prepare an urethane resin foam containing the magnetic filler, and (vi) magnetizing the urethane resin foam to form a magnetic urethane resin foam, and (II) placing the polyurethane resin foam containing the plurality of bubbles and the magnetic filler on a surface of the magnetic sensor.",
    "5. The sensor according to claim 1, wherein the sensor is a tactile sensor or a bending sensor.",
    "6. The sensor according to claim 1, wherein the magnetic filler is a metal powder or metal oxide powder which can have a magnetic force by magnetization.",
    "7. The sensor according to claim 1, wherein the magnetic sensor is selected from the group consisting of a semiconductor compound magnetoresistive element, an anisotropic magnetoresistive element, giant magnetoresistive element, a tunnel magnetoresistive element, a Hall element, an inductor, MI element, and a flux gate sensor.",
    "8. The method of making a sensor according to claim 4, wherein the sensor is a tactile sensor or a bending sensor.",
    "9. The method of making a sensor according to claim 4, wherein the magnetic filler is a metal powder or metal oxide powder which can have a magnetic force by magnetization.",
    "10. The method of making a sensor according to claim 4, wherein the desired shape is selected from the group consisting of a spherical shape, a flat shape, a needle shape and a columnar shape.",
    "11. The method of making a sensor according to claim 4, wherein the magnetic sensor is selected from the group consisting of a semiconductor compound magnetoresistive element, an anisotropic magnetoresistive element, giant magnetoresistive element, a tunnel magnetoresistive element, a Hall element, an inductor, MI element, and a flux gate sensor."
  ],
  "description_excerpt": "The present invention relates to a sensor such as a tactile sensor and a bending sensor, that detects deformation caused by a contact with a magnetic foam which is a resin foam containing magnetic fillers; and a method of making the sensor.\n\nA sensor that detects a deformation caused by a contact of an object with another object includes a tactile sensor, a bending sensor and the like, and is widely used in various fields. The tactile sensor detects intensity, a position, a direction and the like of the contact and the bending sensor detects a bending deformation. The sensors are applied to, for example, a hand and a skin of a robot, and information such as the intensity, position, direction and the like of the contact obtained from the sensors is utilized as information to determine next action of the robot when controlling a motion of the robot and corresponding to an external pressure. There are various proposals with respect to the sensor and a method of making the sensor (in Patent Documents 1 to 3).\n\nPatent Document 1 discloses a pressure detection device comprising: a buffer member deformable by pressurizing and depressurizing including a magnet, and a sensor assembly for detecting a change in a magnetic field caused by deformation of a buffer portion with a magnetic sensor. The magnet present in the buffer member may be one large magnet (FIG. 1 of Patent Document 1) or small magnets uniformly dispersed (FIG. 7 and the like of Patent Document 1).",
  "cpc": [
    "C08J 9/0014",
    "B29C 44/02",
    "C08G 18/10",
    "C08G 2101/00",
    "C08J 2201/022",
    "C08J 2205/06",
    "C08J 2207/00",
    "C08J 2375/08",
    "C08J 9/0061",
    "C08J 9/0066",
    "C08J 9/0095",
    "C08J 9/30",
    "G01D 5/12",
    "G01L 1/12",
    "G01L 1/122"
  ],
  "ipc": [
    "B29C 44/02",
    "G01D 5/12",
    "G01L 1/12",
    "C08G 18/10",
    "C08J 9/00",
    "C08J 9/30"
  ],
  "assignees": [
    "Toyo Tire and Rubber Co Ltd"
  ],
  "inventors": [
    "Junichi Shigeto",
    "Takeshi Fukuda",
    "Hiroyuki Anzai",
    "Zhiwei Luo"
  ],
  "filing_date": "2013-11-27",
  "publication_date": "2017-08-29",
  "grant_date": "2017-08-29",
  "priority_date": "2013-01-15",
  "application_number": "US-201314653117-A",
  "family_id": "51209326",
  "cited_by_count": 2,
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}