Physical sensor

• US 7,059,203 B2
• Filed: 11/16/2004
• Issued: 06/13/2006
• Est. Priority Date: 11/19/2003
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Inventors: Asai, Mitsuru, Takatori, Kazumasa, Homma, Takahiko, Sugiyama, Jun, Makino, Hiroaki
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US10/988,642
• Publication Number:
  US 20050103124A1
• Time in Patent Office: 574 Days
• Field of Search: 73862041-862045, 738/620.46
• US Class Current: 73/862.046
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress

Abstract

A physical sensor having a pressure sensing layer having such property that electrical resistance is changed by application of a stress, and electrical insulating layers which are integrally formed on opposite two surfaces of the pressure sensing layer, respectively, wherein the pressure sensing layer has a matrix comprising glass, and an electrically conductive particle having electrical conductivity and dispersed in the matrix and preferably, the electrically conductive particle includes RuO₂, and a thickness of the pressure sensing layer is 1 μm to 200 μm, and it is preferable that one pair of electrodes are disposed on the pressure sensing layer.

Claims

1. A physical sensor comprising:

a pressure sensing layer whose electrical resistance is changed by application of a stress; and

electrical insulating layers which are integrally formed on opposite two surfaces of the pressure sensing layer, respectively,

wherein the pressure sensing layer comprises

a matrix comprising glass, and

electrically conductive particles having electrical conductivity and dispersed in the matrix.

2. The physical sensor according to claim 1, wherein the electrically conductive particles comprise ruthenium oxide (RuO₂) and/or lead ruthenate.

3. The physical sensor according to claim 1, wherein a thickness of the pressure sensing layer is 1 μ

m to 200 μ

m.

4. The physical sensor according to claim 1, wherein one pair of electrodes are disposed on the pressure sensing layer.

5. The physical sensor according to claim 1, wherein generally spherical pores are formed in the pressure sensing layer.

6. The physical sensor according to claim 1, wherein the glass is a lead borosilicate glass.

7. The physical sensor according to claim 1, wherein the electrically conductive particles are dispersed at a ratio of 10 to 50 parts by weight relative to 100 parts by weight of the matrix.

8. The physical sensor according to claim 1, wherein the electrical insulating layers comprise ZrO₂, Al₂O₃, MgAl₂O₄, SiO₂, 3Al₂O₃.2SiO₂, Y₂O₃, CeO₂, La₂O₃ or Si₃N₄.

9. The physical sensor according to claim 1, wherein said electrical insulating layers cover the surface of a metal.

10. The physical sensor according to claim 5, wherein the pores have a diameter that is 90% or smaller of the thickness of the pressure sensing layer.

11. The physical sensor according to claim 10, wherein the pores occupy a volume that is 50 volume % or smaller of the pressure sensing layer.