TACTILE SENSOR UTILIZING MICROCOILS WITH SPIRAL SHAPE

• US 20090045820A1
• Filed: 08/16/2007
• Published: 02/19/2009
• Est. Priority Date: 08/16/2007
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: SHIMAZAWA, Koji
• Granted Patent: US 7,868,628 B2
• Time in Patent Office: Days
• US Class Current: 324/652
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 21/04 by relative movement of turns or parts of windings
• CPC Class Codes: H01F 21/08 by varying the permeability of the core, e.g. by varying magnetic bias
• CPC Class Codes: H01F 41/0266 Moulding; Pressing H01F41/0273 takes precedence; hard magnetic particles H01F1/06, H01F1/11
• CPC Class Codes: H01F 41/0273 Imparting anisotropy methods and devices for magnetising permanent magnets H01F13/003
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01F 7/0294 Detection, inspection, magnetic treatment
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

Provided is a material for tactile sensor, which is easy to be formed, and in which the shape, size and orientation of coils dispersed in the medium are sufficiently controlled. The tactile-sensitive material comprises a medium and a plurality of micro coils dispersed in the medium and constituting a LCR resonance circuit, and wherein each of the plurality of micro coils comprises at least one spiral coil portion, and coil axes of the plurality of micro coils are aligned along at least one direction and/or directed in at least one plane. When a tactile stress is applied to the tactile-sensitive material, the C component is varied significantly, which contributes to the improvement in sensitivity of the tactile sensor. Further, by providing a core at the coil center, the sensitivity is more improved.

Claims

1. A tactile-sensitive material comprising a medium and a plurality of micro coils dispersed in said medium and constituting a LCR resonance circuit,

each of said plurality of micro coils comprising at least one spiral coil portion, and

coil axes of said plurality of micro coils, being aligned along at least one direction and/or directed in at least one plane.

2. The tactile-sensitive material as claimed in claim 1, wherein each of said plurality of micro coils comprises a core formed of a soft-magnetic material at the central position of the spiral coil portion.

3. The tactile-sensitive material as claimed in claim 1, wherein all the coil axes of said plurality of micro coils are aligned along one direction.

4. The tactile-sensitive material as claimed in claim 1, wherein the coil axes of said plurality of micro coils are aligned along one direction and directed in one plane perpendicular to said one direction, with a controlled ratio of aligned axes and directed axes.

5. The tactile-sensitive material as claimed in claim 1, wherein the coil axes of said plurality of micro coils are aligned along three directions orthogonal with one another, with a controlled ratio.

6. The tactile-sensitive material as claimed in claim 1, wherein at least a part of each of said plurality of micro coils is formed of a hard-magnetic material, and is magnetized in a predetermined direction in each of said plurality of micro coils.

7. The tactile-sensitive material as claimed in claim 6, wherein all the magnetizations of said plurality of micro coils are aligned along one direction.

8. The tactile-sensitive material as claimed in claim 6, wherein each of said plurality of micro coils has a double-layered structure of a coil base layer formed of a non-magnetic conductive material and a coil magnetization layer formed of a hard-magnetic material.

9. The tactile-sensitive material as claimed in claim 1, wherein each of said plurality of micro coils comprises a plurality of spiral coil portions parallel with one another and sandwiching a dielectric layer therebetween.

10. A tactile sensor comprising:

a tactile-sense part formed of a tactile-sensitive material; and

at least a pair of electrodes provided so as to sandwich said tactile-sense part therebetween and electrically connected with said tactile-sense part,

said tactile-sensitive material comprising a medium and a plurality of micro coils dispersed in said medium and constituting a LCR resonance circuit,

each of said plurality of micro coils comprising at least one spiral coil portion, and

coil axes of said plurality of micro coils, being aligned along at least one direction and/or directed in at least one plane.

11. The tactile sensor as claimed in claim 10, wherein each of said plurality of micro coils comprises a core formed of a soft-magnetic material at the central position of the spiral coil portion.

12. The tactile sensor as claimed in claim 10, wherein all the coil axes of said plurality of micro coils are aligned along one direction.

13. The tactile sensor as claimed in claim 10, wherein the coil axes of said plurality of micro coils are aligned along one direction and directed in one plane perpendicular to said one direction, with a controlled ratio of aligned axes and directed axes.

14. The tactile sensor as claimed in claim 10, wherein the coil axes of said plurality of micro coils are aligned along three directions orthogonal with one another, with a controlled ratio.

15. The tactile sensor as claimed in claim 10, wherein at least a part of each of said plurality of micro coils is formed of a hard-magnetic material, and is magnetized in a predetermined direction in each of said plurality of micro coils.

16. The tactile sensor as claimed in claim 15, wherein all the magnetizations of said plurality of micro coils are aligned along one direction.

17. The tactile sensor as claimed in claim 15, wherein each of said plurality of micro coils has a double-layered structure of a coil base layer formed of a non-magnetic conductive material and a coil magnetization layer formed of a hard-magnetic material.

18. The tactile sensor as claimed in claim 10, wherein each of said plurality of micro coils comprises a plurality of spiral coil portions parallel with one another and sandwiching a dielectric layer therebetween.

19. The tactile sensor as claimed in claim 10, wherein two pairs of electrodes are provided so as to sandwich said tactile-sense part therebetween in respective directions orthogonal with each other.

20. The tactile sensor as claimed in claim 10, wherein three pairs of electrodes are provided so as to sandwich said tactile-sense part therebetween in respective directions orthogonal with one another.

21. A manufacturing method of a tactile-sensitive material comprising the steps of:

forming a plurality of micro coils, the micro coil having at least one spiral coil portion, and at least a part of the micro coil being formed of a hard-magnetic material;

magnetizing each of said plurality of micro coils in a predetermined direction;

adding and dispersing said plurality of micro coils in a medium;

applying a predetermined direct-current magnetic field to said medium with the dispersed micro coils to align coil axes of the micro coils along one direction and/or to direct coil axes of the micro coils in one plane; and

hardening said medium.

22. The manufacturing method as claimed in claim 21, wherein multiple kinds of the micro coils in which a relation between a direction of magnetization and a direction of coil axis is different among them are added in said medium with a predetermined ratio.

23. The manufacturing method as claimed in claim 21, wherein the coil axes of said plurality of micro coils are aligned along one direction.

24. The manufacturing method as claimed in claim 21, wherein the coil axes of said plurality of micro coils are aligned along one direction and directed in one plane perpendicular to said one direction, with a predetermined ratio of aligned axes and directed axes.

25. The manufacturing method as claimed in claim 21, wherein the coil axes of said plurality of micro coils are aligned along three directions orthogonal with one another, with a predetermined ratio.

26. The manufacturing method as claimed in claim 21, wherein a coil base film made of a non-magnetic conductive material and a coil magnetization film made of a hard-magnetic material are deposited on a substrate;

then, a plurality of micro coils each of which comprises at least one spiral coil portion is formed by etching;

then, each of said plurality of micro coils is magnetized in a predetermined direction; and

then, said plurality of micro coils is brought out from said substrate.

27. The manufacturing method as claimed in claim 21, wherein formed is a plurality of micro coils, each of said plurality of micro coils comprising a plurality of spiral coil portions parallel with one another and sandwiching a dielectric layer therebetween.