A carbon nanotube-based device (40) includes a substrate (10), a number of alloyed, nano-sized catalytic particles (26) formed on the substrate, and an array of aligned carbon nanotubes (15) extending from the alloyed, nano-sized catalytic particles. The nanotube array bends in an arcuate configuation. A method for making the carbon nanotube-based device includes the steps of: providing a substrate; depositing a catalyst layer on the substrate; depositing two different layers of catalyst-doped materials on different areas of the catalyst layer for accelerating or decelerating the rate of synthesis of the aligned carbon nanotube array; annealing the catalyst and the catalyst-doped materials in an oxygen-containing gas at a low temperature; introducing a carbon source gas; and forming an array of aligned carbon nanotubes extending from the alloyed, nano-sized catalytic particles using a chemical vapor deposition method.