Carbon Nanotube Sharpening Using an Induced Electrical Current

We developed a well-controlled method for sharpening an isolated carbon nanotube (CNT) by inducing an electrical current. Conical CNT tips were produced by increasing the electrical current abruptly in isolated suspended CNTs to achieve sublimation temperature. Because of the parabolic temperature distribution along the CNT axis from the one-dimensional equation of heat conduction, the amount of sublimation from the CNT center region is greater than that from the region near the electrodes. Consequently, two conical tips were formed at the cutting section. The sharpening process mechanism was examined quantitatively through comparison with different sharpening methods reported by Yuzvinsky et al. [Nano Lett. 6 (2006) 2718]. ©2010