Insulated Conductive Strands With Polymer Cores

Abstract

An item may include fabric or other materials formed from intertwined strands of material. The item may include circuitry that produces signals. The strands of material may include non-conductive strands and conductive strands. The non-conductive strands and conductive strands may be close in size. The conductive strands may carry the signals produced by the circuitry. Each conductive strand may have a strand core, a conductive coating on the strand core, and an insulating coating on the conductive coating. The strand cores may be strands formed from polymer. The conductive coating may be formed from metal. The insulating coating may have a relatively thin thickness and may be formed from a polymer.

What is claimed is: 
     
         1 . Intertwined strands of material, comprising:
 non-conductive strands; and   conductive strands that are intertwined with the non-conductive strands, wherein each conductive strand has a strand core, a conductive coating on the strand core, and an insulating coating on the conductive core.   
     
     
         2 . The intertwined strands of material defined in  claim 1  wherein the strand core of each conductive strand comprises a dielectric material. 
     
     
         3 . The intertwined strands of material defined in  claim 2  wherein the strand core of each conductive strand comprises a polymer. 
     
     
         4 . The intertwined strands of material defined in  claim 3  wherein the polymer is selected from the group consisting of: polyamide, aromatic polyamide, polyimide, polyester, polyolefin, acrylic, aromatic polyesters, polyethylene, cellulosic polymer, and polyurethane. 
     
     
         5 . The intertwined strands of material defined in  claim 3  wherein the polymer is a para-aramid. 
     
     
         6 . The intertwined strands of material defined in  claim 3  wherein the polymer is an aromatic polyester. 
     
     
         7 . The intertwined strands of material defined in  claim 1  wherein the conductive coating comprises metal and wherein the strand core has a linear mass density of less than 100 denier. 
     
     
         8 . The intertwined strands of material defined in  claim 7  wherein the conductive coating comprises silver. 
     
     
         9 . The intertwined strands of material defined in  claim 8  wherein the insulating coating comprises a polymer coating having a thickness of less than 5 microns. 
     
     
         10 . The intertwined strands of material defined in  claim 1  wherein the insulating coating comprises a polymer material selected from the group consisting of: polyvinyl formal, polyester-polyimide, polyamide-polyimide, polyamide, polyimide, polyester, polytetrafluoroethylene, and polyurethane. 
     
     
         11 . The intertwined strands of material defined in  claim 10  wherein the conductive coating is a metal coating. 
     
     
         12 . The intertwined strands of material defined in  claim 11  wherein the strand core comprises a material selected from the group consisting of: para-aramid and polyester. 
     
     
         13 . The intertwined strands of material defined in  claim 12  wherein the insulating coating has a thickness of less than 5 microns. 
     
     
         14 . The intertwined strands of material defined in  claim 13  wherein the metal coating comprises silver. 
     
     
         15 . The intertwined strands of material defined in  claim 14  wherein the non-conductive strands have a first diameter, wherein the conductive strands have a second diameter, and wherein the second diameter is within 30% of the first diameter. 
     
     
         16 . The intertwined strands of material defined in  claim 1  wherein the non-conductive strands have a first diameter, wherein the conductive strands have a second diameter, and wherein the second diameter is within 50% of the first diameter. 
     
     
         17 . The intertwined strands of material defined in  claim 16  wherein the strand core of each conductive strand is a polymer strand, wherein the conductive coating of each conductive strand is a metal coating, and wherein the insulating coating of each conductive strand has a thickness of less than 3 microns. 
     
     
         18 . A fabric-based item, comprising:
 circuitry; and   intertwined strands of material including conductive strands that carry signals for the circuitry and non-conductive strands, wherein the conductive strands each have a polymer strand core, a metal coating on the polymer strand core, and an insulating coating on the metal coating.   
     
     
         19 . The fabric-based item defined in  claim 18  wherein the insulating coating has a thickness of less than 5 microns. 
     
     
         20 . The fabric-based item defined in  claim 19  wherein the insulating coating comprises a material selected from the group consisting of: polyvinyl formal, polyester-polyimide, polyamide-polyimide, polyamide, polyimide, polyester, polytetrafluoroethylene, and polyurethane. 
     
     
         21 . The fabric-based item defined in  claim 20  wherein the conductive coating comprises metal and wherein the strand core has a linear mass density of less than 100 denier. 
     
     
         22 . A fabric-based item, comprising:
 electrical components that produce signals; and   fabric that includes non-conductive strands and conductive strands, wherein the conductive strands carry the signals and wherein each conductive strand has a polymer strand core with a linear mass density of less than 100 denier, a metal coating on the polymer strand core, and an insulating coating with a thickness of less than 5 microns on the metal coating.