An Analysis of Scale Dependent and Quantum Effects on Electrical Contact Resistance between Rough Surfaces

The objective of this work is to evaluate the effect of scale dependent mechanical and electrical properties on electrical contact resistance (ECR) between rough surfaces. This work attempts to build on existing ECR models that neglect potentially important quantum- and size-dependent contact and electrical conduction mechanisms of the asperity sizes present on typical surfaces. The electrical conductance at small scales can quantize or show a stepping trend as the contact area is varied in the range of the free electron Fermi wavelength squared. This work then evaluates if these effects remain important for the interface between rough surfaces which may include many small scale contacts of varying sizes. The results suggest that these effects may not always be significant in some cases and macro-scale and continuum mechanics based models may be sufficient.