Mechanical properties of sharpened carbon nanotube tips

We investigate the mechanical properties of sharpened nanotube tips for use in scanning probe microscopy in terms of tip bending under a force acting on the side of the tip. The sharpened nanotube probe fabricated by means of a modified electrical breakdown process effectively acts as a probe with high lateral resolution not only in the topographic measurement but also in the potential distribution measurement. Based on molecular mechanics calculations for a sharpened triple-walled nanotube probe, although the interlayer van-der-Waals interaction weakens the probe stiffness expected on the basis of the continuum model, the stiffness of the tapered nanotube is confirmed to be 10 times higher than that for a single-walled nanotube with the same tip radius and the same length.