Method for shaping a nanotube and a nanotube shaped thereby

Abstract

The invention relates to a method for shaping small three-dimensional articles such as nanotube exhibiting a layered structure through material removal such that the article is controllably shaped to exhibit a desired contour. Typically, material removal does not require use of a chemical etchant and is carried out while the article and a shaping electrode are positioned in contact material removal relationship with under a potential difference. The invention also relates to nanotubes and small three-dimensional articles exhibiting a layered structure having a controllably shaped contour.

We claim:  
     
         1 . A nanotube having a controllably shaped contour and a varying cross-sectional dimension along the longitudinal axis.  
     
     
         2 . The nanotube of  claim 1 , wherein the nanotube is comprised of a material having a layered structure.  
     
     
         3 . The nanotube of  claim 2 , wherein the material is selected from the group consisting of carbon, boron nitride, boron carbide, carbon nitride, boron carbon nitride and transition metal chalcogenides.  
     
     
         4 . The nanotube of  claim 3 , wherein the material is carbon.  
     
     
         5 . The nanotube of  claim 2 , wherein at least a portion of the nanatube comprises 1 to about 1000 layers.  
     
     
         6 . The nanotube of  claim 5 , wherein at least a portion of the nanotube comprises 1 to about 100 layers.  
     
     
         7 . The nanotube of  claim 6 , wherein at least a portion of the nanotube comprises about 2 to about 50 layers.  
     
     
         8 . The nanotube of  claim 1 , wherein the controllably shaped contour is tapered.  
     
     
         9 . The nanotube of  claim 1 , wherein cross-sectional dimension of the nanotube along the longitudinal axis varies by up to about 100-fold.  
     
     
         10 . The nanotube of  claim 9 , wherein the cross-sectional dimension of the nanotube along longitudinal axis varies by about 2-fold to about 10-fold.  
     
     
         11 . The nanotube of  claim 1 , wherein the nanotube is substantially symmetric about the longitudinal axis.  
     
     
         12 . The nanotube of  claim 1 , wherein the nanotube is substantially asymmetric about the longitudinal axis.  
     
     
         13 . The nanotube of  claim 1 , wherein the nanotube exhibits substantially no exfoliation.  
     
     
         14 . A catalyst comprising the nanotube of  claim 1 .  
     
     
         15 . An electrode comprising the nanotube of  claim 1 .  
     
     
         16 . The electrode of  claim 15 , wherein the electrode is a biological cell electrode.  
     
     
         17 . An electronic system comprising the nanotube of  claim 1 .  
     
     
         18 . A mechanical system comprising the nanotube of  claim 1 .  
     
     
         19 . An emission tip comprising the nanotube of  claim 1 .  
     
     
         20 . The emission tip of  claim 19 , wherein the emission tip is an electron field emission tip.  
     
     
         21 . The emission tip of  claim 19 , wherein the emission tip is a scanned probe microscope emission tip.  
     
     
         22 . A probe for biological insertion comprising the nanotube of  claim 1 .  
     
     
         23 . A three-dimensional object comprising a material having a layered structure and having a controllably shaped exterior contour, wherein at least one dimension of the solid article does not exceed about 100 nm in length.