An electrical brush having at least one conductive element and at least one conditioning material coated on the at least one conductive element wherein the conditioning material has a composition and thickness on the conductive element such that, as deposited on a moving contact surface in the course of brush operation, the conditioning material can have an average film thickness S<.about.1 .mu.m so that current can be conducted by means of electron tunneling through a film thickness of the deposited conditioning material of S.sub.i.ltoreq.12 nm thickness over a fractional area f.sub.C, greater than 0.01 of a foot print of the conductive element in a current conductive area.