Patent ID: 8343451

Claim:
A method for making a carbon nanotube film, the method comprising: (a) providing a circular substrate having a surface, wherein material of the substrate is glass, quartz, silicon, or aluminum oxide; (b) forming a catalyst layer on the surface of the circular substrate, and the catalyst layer having two substantially parallel sides, wherein the catalyst layer is away from a border of the surface, wherein step (b) is executed by the steps of: forming a growing surface on the surface of the circular substrate by forming two substantially parallel slits on the surface of the circular substrate, wherein the two substantially parallel slits extend into the substrate from the surface of the substrate, the growing surface is defined by the two substantially parallel slits and located between the two substantially parallel slits; and forming the catalyst layer on the growing surface; (c) annealing the catalyst layer in air at a high temperature; (d) heating the annealed catalyst layer up to a predetermined reaction temperature in a furnace with a protective gas therein, and supplying a carbonaceous gas into the furnace to grow a carbon nanotube array from the circular substrate, the carbon nanotube array having two substantially parallel side faces; and (e) drawing a carbon nanotube film from the carbon nanotube array along a drawing direction substantially parallel to the two substantially parallel side faces of the carbon nanotubc array.