Smart yarn and method for manufacturing a yarn containing an electronic device

1. A method for producing a smart yarn, the method comprising:

aligning a set of sensing elements offset along a lateral axis in a magazine, each sensing element in the set of sensing elements comprising:

a sensor;

a first conductive lead extending from a first side of the sensor along a longitudinal axis perpendicular to the lateral axis; and

a second conductive lead extending from a second side of the sensor opposite the first side and along the longitudinal axis;

wrapping a set of fibers into a yarn within a wrapping field;

feeding a leading end of a first sensing element, in the set of sensing elements, from the magazine into the wrapping field;

releasing the first sensing element from the magazine into the wrapping field;

encasing the first sensing element between the set of fibers within the yarn;

in response to a trailing end of the first sensing element passing through the wrapping field following release of the first sensing element from the magazine into the wrapping field, feeding a leading end of a second sensing element, in the set of sensing elements, from the magazine into the wrapping field;

releasing the second sensing element from the magazine into the wrapping field; and

encasing the second sensing element between the set of fibers and longitudinally offset behind the first sensing element within the yarn.

2. The method of claim 1 :

further comprising

etching a serpentine trace onto a flexible substrate, the serpentine trace defining:

a first set of linear sections extending parallel to the longitudinal axis, offset along the lateral axis, and defining conductive leads;

a first set of curvilinear sections coupling adjacent ends of linear sections in the first set of linear sections; and

a component site coincident each linear section in the first set of linear sections;

for each component site:

installing a sensor on the trace at the component site; and

applying sealant over the sensor and the flexible substrate; and

separating the serpentine trace from regions of the flexible substrate beyond the serpentine trace to form a first flexible serpentine circuit board defining the set of sensing elements offset along the lateral axis; and

loading the first flexible serpentine circuit board into the magazine; and

wherein feeding the leading end of the first sensing element into the wrapping field comprises feeding a start end of the first flexible serpentine circuit board into the wrapping field.

3. The method of claim 2 :

further comprising loading a second flexible serpentine circuit board into the magazine, the second flexible serpentine circuit board defining a second set of sensing elements offset along the lateral axis;

further comprising sequentially deforming curvilinear sections in the first set of curvilinear sections to axially align each curvilinear section to the longitudinal axis as the first flexible serpentine circuit board is fed from the magazine into the wrapping field;

wherein releasing the first sensing element from the magazine into the wrapping field comprises releasing tension on a section of the first flexible serpentine circuit board remaining in the magazine in response to the leading end of the second flexible serpentine circuit board passing the wrapping field; and

wherein feeding the leading end of the second sensing element from the magazine into the wrapping field comprises feeding a start end of the second flexible serpentine circuit board into the wrapping field in response to the first flexible serpentine circuit board fully exiting the magazine.

4. The method of claim 2 , wherein separating the serpentine trace from regions of the flexible substrate beyond the flexible substrate comprises:

perforating the flexible substrate between the serpentine trace and regions of the flexible substrate beyond the serpentine trace; and

tearing the flexible serpentine circuit board from perforations in the flexible substrate, loaded into the magazine, as the first flexible serpentine circuit board is fed from the magazine into the wrapping field.

5. The method of claim 1 :

further comprising

etching a set of traces onto a flexible substrate, the set of traces parallel and offset along the lateral axis, each trace in the set of traces defining a component site;

for each trace in the set of traces:

installing a sensor at a component site defined by the trace; and

coating the trace and the electrical component in an insulative material;

dicing the flexible substrate parallel to and between traces in the set of traces to form the set of sensing elements; and

stacking the set of sensing elements in the magazine; and

wherein feeding the leading end of the first sensing element, in the set of sensing elements, from the magazine into the wrapping field and releasing the first sensing element from the magazine into the wrapping field comprise dispensing the first sensing element into the wrapping field in a direction substantially parallel to the set of fibers in the wrapping field.

6. The method of claim 1 , further comprising:

for each sensing element in the set of sensing elements:

soldering a first insulated wire of a first color onto a first side of a temperature sensor, the first insulated wire defining the first conductive lead; and

soldering a second insulated wire of a second color onto a second side of the temperature sensor, the second insulated wire defining the second conductive lead; and

loading the set of sensing elements into the magazine with longitudinal axes of the set of sensing elements arranged parallel and offset along the lateral axis.

7. The method of claim 6 , further comprising, for each sensing element in the set of sensing elements:

soldering a third insulated wire of a third color onto a first side of a light element adjacent the temperature sensor;

soldering a fourth insulated wire of a fourth color onto a second side of the light element;

twisting the first insulated wire and the third insulated wire along the longitudinal axis to form the first conductive lead; and

twisting the second insulated wire and the fourth insulated wire along the longitudinal axis to form the second conductive lead.

8. The method of claim 7 , further comprising:

knitting a segment of the yarn comprising the first sensing element into a garment;

supplying power via a third insulated wire and a fourth insulated wire of the first sensing element to illuminate a first light element in the first sensing element; and

confirming a location of a first temperature sensor of the first sensing element in the garment based on a location of the first light element when illuminated.

9. The method of claim 1 :

wherein wrapping the set of fibers into the yarn comprises:

drawing the set of fibers into the wrapping field as discrete fibers in a first direction;

joining the set of fibers at a wrapping site within the wrapping field; and

drawing the yarn out of the wrapping field along the first direction;

wherein feeding the leading end of the first sensing element from the magazine into the wrapping field comprises feeding the leading end of the first sensing element into the wrapping field ahead of the wrapping site and with the longitudinal axis of the first sensing element substantially parallel to the first direction; and

wherein encasing the first sensing element between the set of fibers within the yarn comprises wrapping the set of fibers along a length of the first sensing element from the leading end of the first sensing element to the trailing end of the first sensing element as the first sensing element passes through the wrapping site.

10. The method of claim 9 :

wherein feeding the leading end of the first sensing element from the magazine into the wrapping field comprises dispensing the first sensing element from an outlet of the magazine coaxial the wrapping site along the first direction; and

wherein wrapping the set of fibers into the yarn comprises drawing the set of fibers through fiber guides rotating about the outlet of the magazine ahead of the wrapping site.

11. The method of claim 1 , wherein encasing the first sensing element between the set of fibers within the yarn comprises:

arranging packing fibers along a first conductive lead, a sensor, and a second conductive lead of the first sensing element; and

wrapping the set of fibers radially about the packing fibers and the first sensing element to form the yarn.

12. The method of claim 1 :

wherein feeding the leading end of the second sensing element from the magazine into the wrapping field comprises feeding the leading end of the second sensing element from the magazine into the wrapping field in response to fully encasing the first sensing element in the yarn, the leading end of the second sensing element offset behind and electrically isolated from a second conductive lead of the first sensing element;

further comprising:

in response to fully encasing the second sensing element in the yarn, feeding a leading end of a third sensing element, in the set of sensing elements, from the magazine into the wrapping field, the leading end of the third sensing element offset behind and electrically isolated from a second conductive lead of the second sensing element;

releasing the third sensing element from the magazine into the wrapping field; and

encasing the third sensing element between the set of fibers and longitudinally offset behind the second sensing element within the yarn.

13. The method of claim 1 , further comprising winding a length of the yarn exiting the wrapping field onto a bobbin, the length of the yarn comprising sensing elements, in the set of sensing elements, aligned and offset along the longitudinal axis.

14. The method of claim 13 , further comprising:

loading the bobbin into a garment knitting apparatus;

loading a second bobbin into the garment knitting apparatus, the second bobbin containing a second length of a second yarn excluding sensing elements;

at the garment knitting apparatus:

knitting the second yarn from the second bobbin into a garment; and

interweaving a first segment of the yarn into the garment, the first segment of the yarn comprising the first sensing element;

trimming the first segment of the yarn along a first conductive lead of the first sensing element and along a second conductive lead of the first sensing element.

15. The method of claim 13 :

wherein knitting the second yarn from the second bobbin into the garment comprises knitting the second yarn from the second bobbin into the garment comprising a sock;

wherein interweaving the first segment of the yarn into the garment comprises interweaving into the garment the first segment of the yarn containing the first sensing element comprising a first temperature sensor;

further comprising:

interweaving into the garment a second segment of the yarn containing a second sensing element comprising a second temperature sensor, the second temperature sensor offset from the first temperature sensor in a sole of the sock;

trimming the second segment of the yarn along a first conductive lead of the second sensing element and along a second conductive lead of the second sensing element, the first conductive lead of the second sensing element and the second conductive lead of the second sensing element terminating proximal the first conductive lead of the first sensing element and the second conductive lead of the first sensing element;

electrically coupling the first conductive lead of the first sensing element, the second conductive lead of the first sensing element, the first conductive lead of the second sensing element, and the second conductive lead of the second sensing element to a controller arranged proximal an opening of the sock.

16. The method of claim 13 , further comprising:

tensioning the yarn between the wrapping field and the bobbin to elongate the set of fibers around sensing elements, in the set of sensing elements, within the yarn;

monitoring a tension on the yarn; and

maintaining the tension in the yarn, between the wrapping field and the bobbin, below a preset break stress of the set of sensing elements.

17. The method of claim 1 , wherein wrapping the set of fibers into the yarn within the wrapping field comprises wrapping the set of fibers comprising a continuous polymeric filament and a spun yarn of natural staple fibers.

18. A method comprising:

storing, in a dispenser, a set of sensing elements offset along a lateral axis, each sensing element in the set of sensing elements comprising:

a sensor;

a first conductive lead extending from a first side of the sensor along a longitudinal axis perpendicular to the lateral axis; and

a second conductive lead extending from a second side of the sensor opposite the first side and along the longitudinal axis;

feeding a leading end of a first sensing element, in the set of sensing elements, from the dispenser toward a wrapping site;

at the wrapping site, wrapping a set of fibers around the first sensing element to form a yarn;

in response to a trailing end of the first sensing element passing the wrapping site, feeding a leading end of a second sensing element, in the set of sensing elements, from the dispenser toward the wrapping site; and

at the wrapping site, wrapping the set of fibers around the second sensing element to continue the yarn, the leading end of the second sensing element longitudinally offset behind the trailing end of the first sensing element within the yarn.

19. The method of claim 18 , further comprising:

feeding the yarn, comprising a sensing element in the set of sensing elements, into a garment knitting apparatus;

feeding a second yarn excluding sensing elements into the garment knitting apparatus;

at the garment knitting apparatus:

knitting the second yarn into a garment; and

interweaving a first segment of the yarn into the garment, the first segment of the yarn comprising the first sensing element;

trimming the first segment of the yarn along a first conductive lead of the first sensing element and along a second conductive lead of the first sensing element; and

electrically coupling the first conductive lead of the first sensing element and the second conductive lead of the first sensing element to a controller arranged on the garment.

20. The method of claim 19 :

wherein interweaving the first segment of the yarn into the garment comprises knitting the first segment of the yarn into the garment comprising a sock, the first sensing element containing a first temperature sensor arranged proximal a first target location in a sole of the sock; and

further comprising:

at the garment knitting apparatus, knitting a second segment of the yarn into the sock, the second segment of the yarn comprising the second sensing element containing a second temperature sensor arranged proximal a second target location in the sole of the sock, the second target location offset from the first target location in the sole of the sock;

trimming the second segment of the yarn along a first conductive lead of the second sensing element and along a second conductive lead of the second sensing element; and

electrically coupling the first conductive lead of the second sensing element and the second conductive lead of the second sensing element to the controller arranged proximal an opening of the sock.