Co-extrusion printing of filaments for superconducting wire

Abstract

A structure has a substrate, and stripes of superconducting material on the metal substrate, wherein each stripe is separated from adjacent stripes by a gap. A method of manufacturing a superconducting tape includes forming a slurry of superconducting material, forming a slurry of sacrificial material, extruding the slurries of superconducting and sacrificial materials as interdigitated stripes onto a substrate, and removing the sacrificial material to form superconducting filaments.

What is claimed is: 
     
         1 . A structure, comprising:
 a substrate; and   stripes of superconducting material on the substrate, wherein each stripe is separated from adjacent stripes by a gap.   
     
     
         2 . The structure of  claim 1 , wherein the superconducting material comprises magnesium diboride. 
     
     
         3 . The structure of  claim 1 , wherein the substrate comprises one of metal, metal foil, silicon-carbide, alumina or sapphire, carbon or graphene. 
     
     
         4 . The structure of  claim 1 , wherein each stripe has a width of 50 micrometers or less. 
     
     
         5 . The structure of  claim 1 , further comprising a buffer layer on the substrate between the substrate and the stripes of superconducting material. 
     
     
         6 . The structure of  claim 5 , wherein the buffer layer further comprises a material selected to provide one of a chemical barrier, an electrical insulator, or to match coefficients of thermal expansion of one of the substrate or the superconducting material. 
     
     
         7 . The structure of  claim 1 , further comprising a top layer on top of the stripes of superconducting material. 
     
     
         8 . The structure of  claim 7 , wherein the top layer comprises one of a metal, an electrical insulator, or combination of a metal and an electrical insulator. 
     
     
         9 . A method of manufacturing a superconducting metal tape, comprising:
 forming a slurry of superconducting material;   forming a slurry of sacrificial material;   extruding the slurries of superconducting and sacrificial materials as interdigitated stripes onto a metal substrate; and   removing the sacrificial material to form superconducting filaments.   
     
     
         10 . The method of  claim 9 , further comprising forming the metal tape into a rotor for a synchronous machine. 
     
     
         11 . The method of  claim 9 , wherein forming a first slurry of superconducting material comprises wherein mixing a superconductive powder into an organic solvent with a binder. 
     
     
         12 . The method of  claim 11 , wherein mixing a superconducting powder into an organic solvent comprises mixing magnesium diboride powder into butyl carbitol. 
     
     
         13 . The method of  claim 11 , wherein mixing a superconducting powder into an organic solvent comprises mixing magnesium diboride powder and chemical dopants into butyl carbitol 
     
     
         14 . The method of  claim 9 , wherein forming a second slurry of sacrificial material comprises mixing a binder into a solvent. 
     
     
         15 . The method of  claim 14 , wherein mixing a binder into a solvent comprises dissolving a cellulose binder into an organic solvent. 
     
     
         16 . The method of  claim 9 , wherein removing the sacrificial material comprises heating the substrate and slurries to a temperature in the range of 700-800° C. 
     
     
         17 . The method of  claim 9 , further comprising removing excess liquid from the first slurry separately from removing the sacrificial material. 
     
     
         18 . The method of  claim 9 , wherein forming a slurry of superconducting material comprises forming two slurries of superconducting material and extruding the slurries of superconducting and sacrificial material comprises extruding the two slurries of superconducting material as adjacent stripes. 
     
     
         19 . The method of  claim 18 , further comprising allowing the two slurries of superconducting material to react and form a superconducting compound. 
     
     
         20 . The method of  claim 9 , wherein forming a slurry of superconducting material comprises mixing powders of two different materials to form the slurry, and removing the sacrificial material comprises sintering the slurries, which causes the powders to form a superconducting compound. 
     
     
         21 . The method of  claim 9 , further comprising coating the substrate with a buffer layer prior to extruding the slurries. 
     
     
         22 . The method of  claim 9 , further comprising coating the stripes of superconducting material with a top layer.