Nanostructure sorting

Abstract

Apparatus, methods, and systems for sorting nanostructures, such as nanodots or nanotubes, are described. Sorting the nanostructures removes remnants of the nanotube fabrication from a mixture or bundle of material. The sorting activity may include suspending the mixture in a plasma to separate nanostructures and remnant material. A motive force, such as gas flow or laser, can be applied to the suspended nanostructures and remnants to move larger material out of the plasma, leaving smaller material trapped in the plasma. Additional embodiments are disclosed.

1 . A method comprising:
 suspending bulk nanostructures in a plasma such that the nanostructures substantially evenly distribute in the plasma, providing plasma-suspended nanostructures;   separating nanostructure remnants from the plasma-suspended nanostructures using a motive force to form plasma-suspended, separated nanostructures;   positioning the plasma-suspended, separated nanostructures over a workpiece; and   releasing the plasma-suspended, separated nanostructures onto the workpiece such that the plasma-suspended, separated nanostructures are positioned according to a predetermined pattern on the workpiece.   
     
     
         2 . The method of  claim 1 , wherein suspending the bulk nanostructures includes suspending single walled carbon nanotubes. 
     
     
         3 . The method of  claim 1 , wherein releasing the plasma-suspended, separated nanostructures includes substantially evenly distributing the plasma-suspended, separated nanostructures on the workpiece. 
     
     
         4 . The method of  claim 3 , wherein substantially evenly distributing the plasma-suspended, separated nanostructures includes improving the structural strength of the workpiece by the placement of the nanotubes. 
     
     
         5 . The method of  claim 1 , wherein suspending the bulk nanostructures in a plasma includes creating a plasma around a bundle of nanotubes that includes nanotubes and remnant material from fabrication of the nanotubes. 
     
     
         6 . The method of  claim 5 , wherein creating the plasma includes creating a dirty plasma that separates the nanotubes from each other and other remnant material. 
     
     
         7 . The method of  claim 5 , wherein the remnant material includes a carbonaceous particulate. 
     
     
         8 . The method of  claim 1 , wherein separating the nanostructure remnants from the plasma-suspended nanostructures includes sorting the plasma-suspended nanostructures by size. 
     
     
         9 . The method of  claim 8 , wherein sorting the plasma-suspended nanostructures includes applying a gas flow to the plasma-suspended nanostructures. 
     
     
         10 . The method of  claim 8 , wherein sorting the plasma-suspended nanostructures includes lazing the plasma-suspended nanostructures. 
     
     
         11 . The method of  claim 8 , wherein sorting the plasma-suspended nanostructures includes sorting the plasma-suspended nanostructures into groups that have essentially the same length. 
     
     
         12 . The method of  claim 1 , further comprises providing the nanostructures. 
     
     
         13 . The method of  claim 12 , wherein providing the nanostructures includes subjecting the nanostructures to filtration, chromatography, and centrifugation of sonicated solutions of raw fabrication material of the nanostructures. 
     
     
         14 . A method, comprising:
 fabricating a bundle of nanotubes using an electric arc technique;   suspending the nanotubes in a plasma to provided plasma-suspended nanotubes;   sorting the plasma-suspended nanotubes according to size and separating the plasma-suspended nanotubes from remnant material resulting from the fabricating;   positioning the plasma-suspended, separated nanotubes over a workpiece; and   releasing the plasma-suspended, separated nanotubes onto the workpiece such that the plasma-suspended, separated nanostructures are positioned according to a predetermined pattern on the workpiece.   
     
     
         15 . The method of  claim 14 , wherein releasing the plasma-suspended, separated nanotubes includes substantially evenly distributing the plasma-suspended, separated nanotubes on the workpiece. 
     
     
         16 . The method of  claim 15 , wherein substantially evenly distributing the plasma-suspended, separated nanostructures includes improving the structural strength of the workpiece by the placement of the nanotubes. 
     
     
         17 . The method of  claim 14 , wherein sorting the plasma-suspended nanotubes according to size includes sorting the plasma-suspended nanotubes according to size using a motive force. 
     
     
         18 . The method of  claim 17 , wherein sorting the plasma-suspended nanotubes using a motive force includes applying a gas flow to the plasma-suspended nanotubes. 
     
     
         19 . The method of  claim 17 , wherein sorting the plasma-suspended nanotubes using a motive force includes lazing the plasma-suspended nanotubes. 
     
     
         20 . The method of  claim 17 , wherein fabricating a bundle of nanotubes includes creating a dirty plasma that separates the nanotubes from each other and other remnant material.