Time-Dependent Electrical Contact Resistance at the Nanoscale

Conductive-atomic force microscopy (C-AFM) and molecular dynamics (MD) simulations are used to investigate time-dependent electrical contact resistance (ECR) at the nanoscale. ECR is shown to decrease over time as measured using C-AFM and estimated using two approaches from MD simulations, although the experiments and simulations explore different time scales. The simulations show that time dependence of ECR is attributable to an increase in real contact area due to atoms diffusing into the contact. This diffusion-based aging is found to be a thermally activated process that depends on the local contact pressure. The results demonstrate that contact aging, previously identified as an important mechanism for friction, can significantly affect electrical conduction at the nanoscale.

Automated summary

The study using C-AFM and MD simulations found that the electrical contact resistance at the nanoscale decreases over time due to the increase in real contact area caused by atoms diffusing into the contact. This diffusion-based aging is a thermally activated process dependent on the local contact pressure.