Electrical contact resistance of silver with different coatings

The contact resistance between silver rods is measured when different contact load is applied. The relation of tunnel resistivity and contact pressure is found based on the contact area calculation from Hertzian solution. The tunnel resistivity of clean silver rods, and silver rods with different coatings, such as stearic acid, adipic acid, malonic acid, oxalic acid, terephthalic acid, un-cured and cured epoxy, are measured. The tunnel resistivity - contact pressure curves of silver with difference coatings are plotted. The measured tunnel resistivity of silver can be used to calculate the contact resistance between silver contacts in electrically conductive adhesives.