Strain sensor

• US 9,476,782 B2
• Filed: 05/09/2014
• Issued: 10/25/2016
• Est. Priority Date: 05/10/2013
• Status: Active Grant

• Current Assignee: National University Corporation Shizuoka University, Yamaha Corporation
• Original Assignee: National University Corporation Shizuoka University, Yamaha Corporation
• Inventors: Suzuki, Katsunori, Sakakibara, Shingo, Yataka, Koji, Okumiya, Yasuro, Sugiura, Masahiro, Inoue, Yoku
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): COTEY, PHILIP L
• Application Number:
  US14/274,305
• Publication Number:
  US 20140331793A1
• Time in Patent Office: 900 Days
• Field of Search: 738/626.29, 156/299, 156/280
• US Class Current: 1/1
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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
• CPC Class Codes: G01L 1/2287 constructional details of the strain gauges adjustable resistors H01C10/00
• CPC Class Codes: Y10T 156/1092 All laminae planar and face to face

Abstract

A strain sensor provided with a substrate that has flexibility; a carbon nanotube (CNT) film that is provided on the surface of the substrate and that has a plurality of CNT fibers oriented in one direction; and a pair of electrodes that are arranged at both ends in the orientation direction of the CNT fibers in the CNT film; in which the CNT film has a plurality of CNT fiber bundles that consist of the plurality of CNT fibers, and a resin layer that covers the peripheral surface of the plurality of the CNT fiber bundles and joins with the surface of the substrate.

Claims

1. A strain sensor comprising:

a substrate that has flexibility;

a carbon nanotube (CNT) film that is provided on the surface of the substrate and that has a plurality of CNT fibers oriented in one direction; and

a pair of electrodes that are arranged at both ends of the CNT film in the orientation direction of the CNT fibers;

wherein the CNT film has a plurality of CNT fiber bundles that consist of the plurality of CNT fibers, and a resin layer that covers the peripheral surface of the plurality of the CNT fiber bundles and joins with the surface of the substrate, and wherein the plurality of CNT fiber bundles have break places in a longitudinal direction, and wherein the break places have lengths between 5 μ

m and 50 μ

m in a stationary state.

2. The strain sensor according to claim 1, wherein the resin layer is not impregnated within the CNT fiber bundles.

3. The strain sensor according to claim 2, wherein the resin layer is formed from an aqueous emulsion.

4. The strain sensor according to claim 1, wherein the CNT fiber bundles have connecting portions at which the CNT fibers connect in the longitudinal direction.

5. The strain sensor according to claim 1, wherein the CNT film has an average thickness of between 0.1 μ

m and 50 μ

m.

6. The strain sensor according to claim 1, wherein the CNT fiber bundles include an impregnated portion which is impregnated with the resin layer and a non-impregnated portion which is wrapped with the impregnated portion and not impregnated with the resin layer.

7. The strain sensor according to claim 1, wherein surfaces of the CNT fiber bundles are partly impregnated with resin forming the resin layer.

8. The strain sensor according to claim 1, wherein a gradation change is generated as a distribution of the CNT fibers in a longitudinal direction of the CNT fiber bundles.