Stitched stretch sensor

• US 9,322,121 B2
• Filed: 02/28/2014
• Issued: 04/26/2016
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Dunne, Lucy E., Gioberto, Guido
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Jenkins, Jermaine
• Application Number:
  US14/193,892
• Publication Number:
  US 20140238151A1
• Time in Patent Office: 788 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: D05B 93/00 Stitches; Stitch seams
• CPC Class Codes: D05B 97/08 using special threads or wires
• CPC Class Codes: D05B 97/12 for attaching patches or like small pieces of fabric
• CPC Class Codes: G01B 7/18 using change in resistance
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G01L 1/2287 constructional details of the strain gauges adjustable resistors H01C10/00

Abstract

A stitched sensor including a plurality of threads stitched to a textile in a stitch geometry is described. The plurality of threads includes a conductive thread, and the stitch geometry is configured such that an electrical property of the stitched sensor changes based on at least one of stretching, relaxation, or bending of the textile. Methods for forming a stitched sensor are also described.

Claims

1. A system comprising:

a stitched sensor comprising a plurality of threads stitched to a textile in a stitch geometry, the plurality of threads comprising a conductive thread defining a plurality of loops in the stitch geometry, wherein the stitch geometry is configured such that an electrical property of the stitched sensor changes based on at least one of stretching or relaxation of the textile that causes at least two loops of the plurality of loops to change between a first configuration in which the at least two loops contact each other and a second configuration in which the at least two loops are separated from each other and do not overlap each other.

2. The system of claim 1, wherein the plurality of loops are configured to become farther apart upon stretching of the textile and closer together upon relaxation of the textile.

3. The system of claim 1, wherein the plurality of loops are configured to become closer together upon stretching of the textile and farther apart upon relaxation of the textile.

4. The system of claim 1, wherein the electrical property of the stitched sensor is a resistance of the stitched sensor.

5. The system of claim 4, wherein the stitched sensor is configured such that resistance of the stitched sensor increases in response to stretching of the textile.

6. The system of claim 4, wherein the stitched sensor is configured such that resistance of the stitched sensor decreases in response to stretching of the textile.

7. The system of claim 1, wherein the electrical property of the stitched sensor is a resonant frequency of the stitched sensor.

8. The system of claim 1, wherein the plurality of threads comprises the conductive thread and at least one non-conductive thread.

9. The system of claim 1, wherein the stitch geometry comprises at least one of a coverstitch geometry, an overlock stitch geometry, and a lockstitch geometry.

10. The system of claim 1, further comprising the textile.

11. The system of claim 1, further comprising a sensing unit coupled to the conductive thread and configured to sense the change in the electrical property of the stitched sensor.

12. The system of claim 1, wherein:

the plurality of loops of the conductive thread comprise a first plurality of loops,

the at least one non-conductive thread defines a second plurality of loops in the stitch geometry, and

the first plurality of loops has an orientation perpendicular to the second plurality of loops to form at least a portion of the stitch geometry.

13. A method comprising:

forming a stitched sensor by at least stitching a plurality of threads to a textile in a stitch geometry configured such that an electrical property of the stitched sensor changes based on at least one of stretching or relaxation of the textile, wherein the plurality of threads comprise a conductive thread defining a plurality of loops in the stitch geometry, and wherein the at least one of stretching or relaxation of the textile causes at least two loops of the plurality of loops to change between a first configuration in which the at least two loops contact each other and a second configuration in which the at least two loops are separated from each other and do not overlap each other.

14. The method of claim 13, wherein stitching the plurality of threads to the textile in the stitch geometry comprises stitching the conductive thread such that the conductive thread defines a plurality of loops in the stitch geometry, and wherein the plurality of threads comprises the conductive thread and at least one non-conductive thread.

15. The method of claim 14, wherein stitching the plurality of threads to the garment in the stitch geometry comprises stitching the conductive thread such that the plurality of loops are configured to become farther apart upon stretching of the textile and closer together upon relaxation of the textile.

16. The method of claim 14, wherein stitching the plurality of threads to the garment in the stitch geometry comprises stitching the conductive thread such that the plurality of loops are configured to become closer together upon stretching of the textile and farther apart upon relaxation of the textile.

17. The method of claim 13, wherein the electrical property of the stitched stretch sensor comprises a resistance of the stitched sensor, and wherein the resistance of the stitched sensor increases in response to stretching of the textile.

18. The method of claim 13, wherein the electrical property of the stitched sensor comprises a resistance of the stitched sensor, and wherein the resistance of the stitched sensor decreases in response to stretching of the textile.

19. The method of claim 13, wherein stitching the plurality of threads to the textile in the stitch geometry comprises stitching the plurality of threads in at least one of a coverstitch geometry, an overlock stitch geometry, and a lockstitch geometry.

20. The method of claim 13, further comprising attaching a sensing unit to the stitched sensor and the textile, the sensing unit configured to sense the change in the electrical property of the stitched sensor.

21. A system comprising:

a plurality of threads stitched to a textile in a stitch geometry, the plurality of threads comprising a conductive thread defining a first plurality of loops in the stitch geometry and one or more non-conductive threads defining a second plurality of loops in the stitch geometry, wherein the stitch geometry is configured such that an electrical property of the conductive thread changes based on at least one of stretching or relaxation of the textile that causes at least two loops of the first plurality of loops to change between a first configuration in which the at least two loops contact each other and a second configuration in which the at least two loops are separated from each other and do not overlap each other; and

a sensing unit electrically coupled to the conductive thread in the stitch geometry and configured to sense the change in the electrical property of the conductive thread.