Method for thermally drawing nanocomposite-enabled multifunctional fibers

Abstract

A method of thermally drawing fibers containing continuous crystalline metal nanowires therein includes forming a preform comprising an inner core and an outer cladding, wherein at least one of the core and cladding has nanoelements dispersed therein. The preform is drawn through a heated zone to form a reduced size fiber. A second preform is then created from a plurality of fibers created from the reduced size fiber. The second preform is then drawn through the heated zone to form an elongated fiber containing continuous crystalline metallic nanowires therein having a maximum cross-sectional dimension of less than 100 nm. Optionally, a third or additional preforms are created from fibers made from the previous thermal drawing operation that are then drawn through the heated zone to form a fiber containing even smaller crystalline metal continuous nanowires therein. In some embodiments, only a single pass through the heated zone may be needed.

1 . A method of thermally drawing fibers containing continuous crystalline metal nanowires therein comprising:
 a) forming a preform comprising an inner core comprising the crystalline metal and an outer cladding, wherein at least one of the core and cladding having nanoelements dispersed therein;   b) drawing the preform through a heated zone to form a reduced size fiber;   c) forming a second preform created from a plurality of fibers from the reduced size fiber of (b); and   d) drawing the second preform of (c) through the heated zone to form another reduced sized fiber having a continuous length exceeding one meter and containing crystalline metal nanowires therein having a diameter less than 100 nm.   
     
     
         2 . The method of  claim 1 , wherein the nanoelements comprise nanoparticles, nanowires, nanoplates, nanoflakes, or nanowhiskers. 
     
     
         3 . The method of  claim 1 , further comprising forming a third preform created from a plurality of fibers of (d) and drawing the third preform through the heated zone to form another reduced sized fiber having a continuous length exceeding 1 meter and containing crystalline metal nanowires therein having a diameter less than 100 nm. 
     
     
         4 . The method of  claim 3 , further comprising forming one or more additional preforms created from a plurality of fibers formed by the third preform and drawing the one or more additional preforms through the heated zone to form another reduced sized fiber having a continuous length exceeding 1 meter and containing crystalline metal nanowires therein having a diameter less than 100 nm. 
     
     
         5 . The method of  claim 1 , wherein the nanoelements have a diameter or major cross-sectional dimension within the range of 1 to 100 nm. 
     
     
         6 . The method of  claim 1 , wherein the nanoelements comprises a metal or ceramic. 
     
     
         7 . (canceled) 
     
     
         8 . The method of  claim 1 , wherein the core comprises one of gold, platinum, or silver. 
     
     
         9 . The method of  claim 1 , wherein the cladding comprises a polymer or glass. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 1 , further comprising sintering the reduced sized fiber having metal nanowires therein. 
     
     
         12 . The method of  claim 1 , further comprising cutting the fiber, wherein the cut fiber has a distal end and a proximal end and the diameter of the distal end is << the diameter of the proximal end. 
     
     
         13 . A method of thermally drawing a fiber containing crystalline metal nanowires therein comprising:
 forming a preform comprising an inner core having a plurality of individual metal wires surrounded by an outer cladding, wherein at least one of the inner core and cladding comprise nanoelements dispersed therein; and   drawing the preform through a heated zone to form a reduced size fiber having a length of at least one meter and containing a plurality of continuous crystalline metal nanowires therein having a maximum cross-sectional dimension less than 100 nm.   
     
     
         14 . The method of  claim 13 , wherein the nanoelements comprise one or more of nanoparticles, nanowires, nanoplates, nanoflakes, or nanowhiskers. 
     
     
         15 . The method of  claim 13 , wherein the nanoelements have a diameter or major cross-sectional dimension within the range of 1 to 100 nm. 
     
     
         16 . The method of  claim 13 , wherein the nanoelements comprises a metal or ceramic. 
     
     
         17 . (canceled) 
     
     
         18 . The method of  claim 13 , wherein the core comprises one of gold, platinum, or silver. 
     
     
         19 . The method of  claim 13 , wherein the cladding comprises a polymer or glass. 
     
     
         20 . (canceled) 
     
     
         21 . A nanoelectrode array comprising:
 a fiber having a distal end and a proximal end, the fiber having a plurality of crystalline metal nanowires each with a maximum cross-sectional dimension less than 100 nm embedded therein and terminating at a plurality of exposed electrodes at the distal end of the fiber, wherein the distal end of the fiber has a diameter that is << than a diameter of the proximal end of the fiber.   
     
     
         22 . The nanoelectrode array of  claim 21 , further comprising a circuit interface device coupled to the proximal end of the fiber. 
     
     
         23 . The nanoelectrode array of  claim 21 , wherein the distal end of the fiber is disposed in a well, channel, or reservoir of a microfluidic device. 
     
     
         24 . The nanoelectrode array of  claim 21 , wherein the composition of the metal nanowires changes along the length thereof with the exposed electrodes comprising a first metal and a proximal portion that is located proximally with respect to the exposed electrodes comprises a second, different metal. 
     
     
         25 . (canceled)