UCLA

Electrostatic interactions are shown to exert a significant effect on the buckling instability of a rod. In particular, the threshold value of the compressional force needed to induce buckling is found to be independent of rod length for long charged rods. In the case of rods of intermediate length, the critical buckling force crosses over from the classic inverse-square length dependence to asymptotic length-independent form with increasing rod length. It is suggested that this effect leads to the possibility of electromechanical stiffening of nanotubes, which would allow relatively long segments of them to be used as atomic force probes. (C) 2004 American Institute of Physics.